Manual of Surgery/Chapter XIV

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CHAPTER XIV

THE BLOOD VESSELS


Anatomy--INJURIES OF ARTERIES: _Varieties_--INJURIES OF

   VEINS: _Air Embolism_--Repair of blood vessels and natural
   arrest of haemorrhage--HAEMORRHAGE: _Varieties_;
   _Prevention_; _Arrest_--Constitutional effects of
   haemorrhage--Haemophilia--DISEASES OF BLOOD VESSELS:
   Thrombosis; Embolism--Arteritis: _Varieties_;
   Arterio-sclerosis--Thrombo-phlebitis--Phlebitis:
   _Varieties_--VARIX--ANGIOMATA--Naevus: _Varieties_;
   _Electrolysis_--Cirsoid aneurysm--ANEURYSM: _Varieties_;
   _Methods of treatment_--ANEURYSMS OF INDIVIDUAL ARTERIES.
  1. Surgical Anatomy.#--An _artery_ has three coats: an internal coat--the

_tunica intima_--made up of a single layer of endothelial cells lining the lumen; outside of this a layer of delicate connective tissue; and still farther out a dense tissue composed of longitudinally arranged elastic fibres--the internal elastic lamina. The tunica intima is easily ruptured. The middle coat, or _tunica media_, consists of non-striped muscular fibres, arranged for the most part concentrically round the vessel. In this coat also there is a considerable proportion of elastic tissue, especially in the larger vessels. The thickness of the vessel wall depends chiefly on the development of the muscular coat. The external coat, or _tunica externa_, is composed of fibrous tissue, containing, especially in vessels of medium calibre, some yellow elastic fibres in its deeper layers.

In most parts of the body the arteries lie in a sheath of connective tissue, from which fine fibrous processes pass to the tunica externa. The connection, however, is not a close one, and the artery when divided transversely is capable of retracting for a considerable distance within its sheath. In some of the larger arteries the sheath assumes the form of a definite membrane.

The arteries are nourished by small vessels--the _vasa vasorum_--which ramify chiefly in the outer coat. They are also well supplied with nerves, which regulate the size of the lumen by inducing contraction or relaxation of the muscular coat.

The _veins_ are constructed on the same general plan as the arteries, the individual coats, however, being thinner. The inner coat is less easily ruptured, and the middle coat contains a smaller proportion of muscular tissue. In one important point veins differ structurally from arteries--namely, in being provided with valves which prevent reflux of the blood. These valves are composed of semilunar folds of the tunica intima strengthened by an addition of connective tissue. Each valve usually consists of two semilunar flaps attached to opposite sides of the vessel wall, each flap having a small sinus on its cardiac side. The distension of these sinuses with blood closes the valve and prevents regurgitation. Valves are absent from the superior and inferior venae cavae, the portal vein and its tributaries, the hepatic, renal, uterine, and spermatic veins, and from the veins in the lower part of the rectum. They are ill-developed or absent also in the iliac and common femoral veins--a fact which has an important bearing on the production of varix in the veins of the lower extremity.

The wall of _capillaries_ consists of a single layer of endothelial cells.


HAEMORRHAGE

Various terms are employed in relation to haemorrhage, according to its seat, its origin, the time at which it occurs, and other circumstances.

The term _external haemorrhage_ is employed when the blood escapes on the surface; when the bleeding takes place into the tissues or into a cavity it is spoken of as _internal_. The blood may infiltrate the connective tissue, constituting an _extravasation_ of blood; or it may collect in a space or cavity and form a _haematoma_.

The coughing up of blood from the lungs is known as _haemoptysis_; vomiting of blood from the stomach, as _haematemesis_; the passage of black-coloured stools due to the presence of blood altered by digestion, as _melaena_; and the passage of bloody urine, as _haematuria_.

Haemorrhage is known as arterial, venous, or capillary, according to the nature of the vessel from which it takes place.

In _arterial_ haemorrhage the blood is bright red in colour, and escapes from the cardiac end of the divided vessel in pulsating jets synchronously with the systole of the heart. In vascular parts--for example the face--both ends of a divided artery bleed freely. The blood flowing from an artery may be dark in colour if the respiration is impeded. When the heart's action is weak and the blood tension low the flow may appear to be continuous and not in jets. The blood from a divided artery at the bottom of a deep wound, escapes on the surface in a steady flow.

_Venous_ bleeding is not pulsatile, but occurs in a continuous stream, which, although both ends of the vessel may bleed, is more copious from the distal end. The blood is dark red under ordinary conditions, but may be purplish, or even black, if the respiration is interfered with. When one of the large veins in the neck is wounded, the effects of respiration produce a rise and fall in the stream which may resemble arterial pulsation.

In _capillary_ haemorrhage, red blood escapes from numerous points on the surface of the wound in a steady ooze. This form of bleeding is serious in those who are the subjects of haemophilia.


INJURIES OF ARTERIES

The following description of the injuries of arteries refers to the larger, named trunks. The injuries of smaller, unnamed vessels are included in the consideration of wounds and contusions.

  1. Contusion.#--An artery may be contused by a blow or crush, or by the

oblique impact of a bullet. The bruising of the vessel wall, especially if it is diseased, may result in the formation of a thrombus which occludes the lumen temporarily or even permanently, and in rare cases may lead to gangrene of the limb beyond.

  1. Subcutaneous Rupture.#--An artery may be ruptured subcutaneously by a

blow or crush, or by a displaced fragment of bone. This injury has been produced also during attempts to reduce dislocations, especially those of old standing at the shoulder. It is most liable to occur when the vessels are diseased. The rupture may be incomplete or complete.

_Incomplete Subcutaneous Rupture._--In the majority of cases the rupture is incomplete--the inner and middle coats being torn, while the outer remains intact. The middle coat contracts and retracts, and the internal, because of its elasticity, curls up in the interior of the vessel, forming a valvular obstruction to the blood-flow. In most cases this results in the formation of a thrombus which occludes the vessel. In some cases the blood-pressure gradually distends the injured segment of the vessel wall and leads to the formation of an aneurysm.

The pulsation in the vessels beyond the seat of rupture is arrested--for a time at least--owing to the occlusion of the vessel, and the limb becomes cold and powerless. The pulsation seldom returns within five or six weeks of the injury, if indeed it is not permanently arrested, but, as a rule, a collateral circulation is rapidly established, sufficient to nourish the parts beyond. If the pulsation returns within a week of the injury, the presumption is that the occlusion was due to pressure from without--for example, by haemorrhage into the sheath or the pressure of a fragment of bone.

_Complete Subcutaneous Rupture._--When the rupture is complete, all the coats of the vessel are torn and the blood escapes into the surrounding tissues. If the original injury is attended with much shock, the bleeding may not take place until the period of reaction. Rupture of the popliteal artery in association with fracture of the femur, or of the axillary or brachial artery with fracture of the humerus or dislocation of the shoulder, are familiar examples of this injury.

Like incomplete rupture, this lesion is accompanied by loss of pulsation and power, and by coldness of the limb beyond; a tense and excessively painful swelling rapidly appears in the region of the injury, and, where the cellular tissue is loose, may attain a considerable size. The pressure of the effused blood occludes the veins and leads to congestion and oedema of the limb beyond. The interference with the circulation, and the damage to the tissues, may be so great that gangrene ensues.

_Treatment._--When an artery has been contused or ruptured, the limb must be placed in the most favourable condition for restoration of the circulation. The skin is disinfected and the limb wrapped in cotton wool to conserve its heat, and elevated to such an extent as to promote the venous return without at the same time interfering with the inflow of blood. A careful watch must be kept on the state of nutrition of the limb, lest gangrene occurs.

If no complications supervene, the swelling subsides, and recovery may be complete in six or eight weeks. If the extravasation is great and the skin threatens to give way, or if the vitality of the limb is seriously endangered, it is advisable to expose the injured vessel, and, after clearing away the clots, to attempt to suture the rent in the artery, or, if torn across, to join the ends after paring the bruised edges. If this is impracticable, a ligature is applied above and below the rupture. If gangrene ensues, amputation must be performed.

These descriptions apply to the larger arteries of the extremities. A good illustration of subcutaneous rupture of the arteries of the head is afforded by the tearing of the middle meningeal artery caused by the application of blunt violence to the skull; and of the arteries of the trunk--caused by the tearing of the renal artery in rupture of the kidney.

  1. Open Wounds of Arteries--Laceration.#--Laceration of large arteries is

a common complication of machinery and railway accidents. The violence being usually of a tearing, twisting, or crushing nature, such injuries are seldom associated with much haemorrhage, as torn or crushed vessels quickly become occluded by contraction and retraction of their coats and by the formation of a clot. A whole limb even may be avulsed from the body with comparatively little loss of blood. The risk in such cases is secondary haemorrhage resulting from pyogenic infection.

The _treatment_ is that applicable to all wounds, with, in addition, the ligation of the lacerated vessels.

  1. Punctured wounds# of blood vessels may result from stabs, or they may

be accidentally inflicted in the course of an operation.

The division of the coats of the vessel being incomplete, the natural haemostasis that results from curling up of the intima and contraction of the media, fails to take place, and bleeding goes on into the surrounding tissues, and externally. If the sheath of the vessel is not widely damaged, the gradually increasing tension of the extravasated blood retained within it may ultimately arrest the haemorrhage. A clot then forms between the lips of the wound in the vessel wall and projects for a short distance into the lumen, without, however, materially interfering with the flow through the vessel. The organisation of this clot results in the healing of the wound in the vessel wall.

In other cases the blood escapes beyond the sheath and collects in the surrounding tissues, and a traumatic aneurysm results. Secondary haemorrhage may occur if the wound becomes infected.

The _treatment_ consists in enlarging the external wound to permit of the damaged vessel being ligated above and below the puncture. In some cases it may be possible to suture the opening in the vessel wall. When circumstances prevent these measures being taken, the bleeding may be arrested by making firm pressure over the wound with a pad; but this procedure is liable to be followed by the formation of an aneurysm.

_Minute puncture of arteries_ such as frequently occur in the hypodermic administration of drugs and in the use of exploring needles, are not attended with any escape of blood, chiefly because of the elastic recoil of the arterial wall; a tiny thrombus of platelets and thrombus forms at the point where the intima is punctured.

  1. Incised Wounds.#--We here refer only to such incised wounds as partly

divide the vessel wall.

Longitudinal wounds show little tendency to gape, and are therefore not attended with much bleeding. They usually heal rapidly, but, like punctured wounds, are liable to be followed by the formation of an aneurysm.

When, however, the incision in the vessel wall is oblique or transverse, the retraction of the muscular coat causes the opening to gape, with the result that there is haemorrhage, which, even in comparatively small arteries, may be so profuse as to prove dangerous. When the associated wound in the soft parts is valvular the haemorrhage is arrested and an aneurysm may develop.

When a large arterial trunk, such as the external iliac, the femoral, the common carotid, the brachial, or the popliteal, has been partly divided, for example, in the course of an operation, the opening should be closed with sutures--_arteriorrhaphy_. The circulation being controlled by a tourniquet, or the artery itself occluded by a clamp, fine silk or catgut stitches are passed through the outer and middle coats after the method of Lembert, a fine, round needle being employed. The sheath of the vessel or an adjacent fascia should be stitched over the line of suture in the vessel wall. If infection be excluded, there is little risk of thrombosis or secondary haemorrhage; and even if thrombosis should develop at the point of suture, the artery is obstructed gradually, and the establishment of a collateral circulation takes place better than after ligation. In the case of smaller trunks, or when suture is impracticable, the artery should be tied above and below the opening, and divided between the ligatures.

  1. Gunshot Wounds of Blood Vessels.#--In the majority of cases injuries of

large vessels are associated with an external wound; the profusion of the bleeding indicates the size of the damaged vessel, and the colour of the blood and the nature of the flow denote whether an artery or a vein is implicated.

When an artery is wounded a firm _haematoma_ may form, with an expansile pulsation and a palpable thrill--whether such a haematoma remains circumscribed or becomes diffuse depends upon the density or laxity of the tissues around it. In course of time a _traumatic arterial aneurysm_ may develop from such a haematoma.

When an artery and its companion vein are injured simultaneously an _arterio-venous aneurysm_ (p. 310) may develop. This frequently takes place without the formation of a haematoma as the arterial blood finds its way into the vein and so does not escape into the tissues. Even if a haematoma forms it seldom assumes a great size. In time a swelling is recognised, with a palpable thrill and a systolic bruit, loudest at the level of the communication and accompanied by a continuous venous hum.

If leakage occurs into the tissues, the extravasated blood may occlude the vein by pressure, and the symptoms of arterial aneurysm replace those of the arterio-venous form, the systolic bruit persisting, while the venous hum disappears.

_Gangrene_ may ensue if the blood supply is seriously interfered with, or the signs of _ischaemia_ may develop; the muscles lose their elasticity, become hard and paralysed, and anaesthesia of the "glove" or "stocking" type, with other alterations of sensation ensue. Apart from ischaemia, _reflex paralysis_ of motion and sensation of a transient kind may follow injury of a large vessel.

_Treatment_ is carried out on the same lines as for similar injuries due to other causes.


INJURIES OF VEINS

Veins are subject to the same forms of injury as arteries, and the results are alike in both, such variations as occur being dependent partly on the difference in their anatomical structure, and partly on the conditions of the circulation through them.

  1. Subcutaneous rupture# of veins occur most frequently in association

with fractures and in the reduction of dislocations. The veins most commonly ruptured are the popliteal, the axillary, the femoral, and the subclavian. On account of the smaller amount of elastic and muscular tissue in the wall of a vein, the contraction and retraction of its walls are less than in an artery, and so bleeding may continue for a longer period. On the other hand, owing to the lower blood-pressure the outflow goes on more slowly, and the gradually increasing pressure produced by the extravasated blood is usually sufficient to arrest the haemorrhage before it becomes serious. As an aid in diagnosing the source of the bleeding, it should be remembered that the rupture of a vein does not affect the pulsation in the limb beyond. The risks are practically the same as when an artery is ruptured, excepting that of aneurysm, and the treatment is carried out on the same lines, but it is seldom necessary to operate for the purpose of applying a ligature to the injured vein.

  1. Wounds# of veins--punctured and incised--frequently occur in the course

of operations; for example, in the removal of tumours or diseased glands from the neck, the axilla, or the groin. They are also met with as a result of accidental stabs and of suicidal or homicidal injuries. The haemorrhage from a large vein so damaged is usually profuse, but it is more readily controlled by external pressure than that from an artery. When a vein is merely punctured, the bleeding may be arrested by pressure with a pad of gauze, or by a lateral ligature--that is, picking up the margins of the rent in the wall and securing them with a ligature without occluding the lumen. In the large veins, such as the internal jugular, the femoral, or the axillary, it is usually possible to suture the opening in the wall. This does not necessarily result in thrombosis in the vessel, or in obliteration of its lumen.

When an _artery and vein are simultaneously wounded_, the features peculiar to each are present in greater or less degree. In the limbs gangrene may ensue, especially if the wound is infected. Punctured and gun-shot wounds implicating both artery and vein are liable to be followed by the development of arterio-venous aneurysm.

  1. Entrance of Air into Veins--Air Embolism.#--This serious, though

fortunately rare, accident is apt to occur in the course of operations in the region of the thorax, neck, or axilla, if a large vein is opened and fails to collapse on account of the rigidity of its walls, its incorporation in a dense fascia, or from traction being made upon it. If the wound in a vein is thus held open, the negative pressure during inspiration sucks air into the right side of the heart. This is accompanied by a hissing or gurgling sound, and with the next expiration some frothy blood escapes from the wound. The patient instantly becomes pale, the pupils dilate, respiration becomes laboured, and although the heart may continue to beat forcibly, the peripheral pulse is weak, and may even be imperceptible. On auscultating the heart, a churning sound may be heard. Death may result in a few minutes; or the heart may slowly regain its power and recovery take place.

_Prevention._--In operations in the "dangerous area"--as the region of the root of the neck is called in this connection--care must be taken not to cut or divide any vein before it has been secured by forceps, and to apply ligatures securely and at once. Deep wounds in this region should be kept filled with normal salt solution. Immediately a cut is recognised in a vein, a finger should be placed over the vessel on the cardiac side of the wound, and kept there until the opening is secured.

_Treatment._--Little can be done after the air has actually entered the vein beyond endeavouring to maintain the heart's action by hypodermic injections of ether or strychnin and the application of mustard or hot cloths over the chest. The head at the same time should be lowered to prevent syncope. Attempts to withdraw the air by suction, and the employment of artificial respiration, have proved futile, and are, by some, considered dangerous. In a desperate case massage of the heart might be tried.


THE NATURAL ARREST OF HAEMORRHAGE AND THE REPAIR OF BLOOD VESSELS

  1. Primary Haemorrhage.#--The term primary haemorrhage is applied to the

bleeding which follows immediately on the wounding of a blood vessel. The natural process by which such haemorrhage is arrested varies with the character of the wound in the vessel and may be modified by accidental circumstances.

(a) _Repair of completely divided Artery._--When an artery is _completely_ divided, the circular fibres of the muscular coat contract, so that the lumen of the cut ends is diminished, and at the same time each segment retracts within its sheath in virtue of the recoil of the elastic elements in its walls, the tunica intima curls up in the interior of the vessel, and the tunica externa collapses over the cut ends. The blood that escapes from the injured vessel fills the interstices of the tissues, and, coagulating, forms a clot which temporarily arrests the bleeding. That part of the clot which lies between the divided ends of the vessel and in the cellular tissue outside, is known as the _external clot_, while the portion which projects into the lumen of the vessel is known as the _internal clot_, and it usually extends as far as the nearest collateral branch. These processes constitute what is known as the _temporary arrest of haemorrhage_, which, it will be observed, is effected by the contraction and retraction of the divided artery and by clotting.

The _permanent arrest_ takes place by the transformation of the clot into scar tissue. The internal clot plays the most important part in the process; it becomes invaded by leucocytes and proliferating endothelial and connective-tissue cells, and new blood vessels permeate the mass, which is thus converted into granulation tissue. This is ultimately replaced by fibrous tissue, which permanently occludes the end of the vessel. Concurrently and by the same process the external clot is converted into scar tissue.

If a divided artery is _ligated at its cut end_, the tension of the ligature is usually sufficient to rupture the inner and middle coats, which curl up within the lumen, the outer coat alone being held in the grasp of the ligature. An internal clot forms and, becoming organised, permanently occludes the vessel as above described. The ligature and the small portion of vessel beyond it are subsequently absorbed.

In course of time the collateral branches of the vessel above and below the level of section enlarge and their inter-communication becomes more free, so that even when large trunks have been divided the vascular supply of the parts beyond may be completely restored. This is known as the development of the _collateral circulation_.

_Imperfect Collateral Circulation._--While the development of the collateral circulation after the ligation or obstruction from other cause of a main arterial trunk may be sufficient to prevent gangrene of the limb, it may be insufficient for its adequate nourishment; it may be cold, bluish in colour, and there may be necrosis of the skin over bony points; this is notably the case in the lower extremity after ligation of the femoral or popliteal artery, when patches of skin may die over the prominence of the heel, the balls of the toes, the projecting base of the fifth metatarsal and the external malleolus.

If, during the period of reaction, the blood-pressure rises considerably, the occluding clot at the divided end of the vessel may be washed away or the ligature displaced, permitting of fresh bleeding taking place--_reactionary_ or _intermediary haemorrhage_ (p. 272).

In the event of the wound becoming infected with pyogenic organisms, the occluding blood-clot or the young fibrous tissue may become disintegrated in the suppurative process, and the bleeding start afresh--_secondary haemorrhage_ (p. 273).

(b) If an artery is only _partly cut across_, the divided fibres of the tunica muscularis contract and those of the tunica externa retract, with the result that a more or less circular hole is formed in the wall of the vessel, from which free bleeding takes place, as the conditions are unfavourable for the formation of an occluding clot. Even if a clot does form, when the blood-pressure rises it is readily displaced, leading to reactionary haemorrhage. Should the wound become infected, secondary haemorrhage is specially liable to occur. A further risk attends this form of injury, in that the intra-vascular tension may in time lead to gradual stretching of the scar tissue which closes the gap in the vessel wall, with the result that a localised dilatation or diverticulum forms, constituting a _traumatic aneurysm_.

(c) When the injury merely takes the form of a _puncture_ or _small incision_ a blood-clot forms between the edges, becomes organised, and is converted into cicatricial tissue which seals the aperture. Such wounds may also be followed by reactionary or secondary haemorrhage, or later by the formation of a traumatic aneurysm.

_Conditions which influence the Natural Arrest of Haemorrhage._--The natural arrest of bleeding is favoured by tearing or crushing of the vessel walls, owing to the contraction and retraction of the coats and the tendency of blood to coagulate when in contact with damaged tissue. Hence the primary haemorrhage following lacerated wounds is seldom copious. The occurrence of syncope or of profound shock also helps to stop bleeding by reducing the force of the heart's action.

On the other hand, there are conditions which retard the natural arrest. When, for example, a vessel is only partly divided, the contraction and retraction of the muscular coat, instead of diminishing the calibre of the artery, causes the wound in the vessel to gape; by completing the division of the vessel under these circumstances the bleeding can often be arrested. In certain situations, also, the arteries are so intimately connected with their sheaths, that when cut across they were unable to retract and contract--for example, in the scalp, in the penis, and in bones--and copious bleeding may take place from comparatively small vessels. This inability of the vessels to contract and retract is met with also in inflamed and oedematous parts and in scar tissue. Arteries divided in the substance of a muscle also sometimes bleed unduly. Any increase in the force of the heart's action, such as may result from exertion, excitement, or over-stimulation, also interferes with the natural arrest. Lastly, in bleeders, there are conditions which interfere with the natural arrest of haemorrhage.

  1. Repair of a Vessel ligated in its Continuity.#--When a ligature is

applied to an artery it should be pulled sufficiently tight to occlude the lumen without causing rupture of its coats. It often happens, however, that the compression causes rupture of the inner and middle coats, so that only the outer coat remains in the grasp of the ligature. While this weakens the wall of the vessel, it has the advantage of hastening coagulation, by bringing the blood into contact with damaged tissue. Whether the inner and middle coats are ruptured or not, blood coagulates both above and below the ligature, the proximal clot being longer and broader than that on the distal side. In small arteries these clots extend as far as the nearest collateral branch, but in the larger trunks their length varies. The permanent occlusion of those portions of the vessel occupied by clot is brought about by the formation of granulation tissue, and its replacement by cicatricial tissue, so that the occluded segment of the vessel is represented by a fibrous cord. In this process the coagulum only plays a passive role by forming a scaffolding on which the granulation tissue is built up. The ligature surrounding the vessel, and the elements of the clot, are ultimately absorbed.

  1. Repair of Veins.#--The process of repair in veins is the same as that

in arteries, but the thrombosed area may become canalised and the circulation through the vessel be re-established.


HAEMORRHAGE IN SURGICAL OPERATIONS

The management of the haemorrhage which accompanies an operation includes (a) preventive measures, and (b) the arrest of the bleeding.

  1. Prevention of Haemorrhage.#--Whenever possible, haemorrhage should be

controlled by _digital compression_ of the main artery supplying the limb rather than by a tourniquet. If efficiently applied compression reduces the immediate loss of blood to a minimum, and the bleeding from small vessels that follows the removal of the tourniquet is avoided. Further, the pressure of a tourniquet has been shown to be a material factor in producing shock.

In selecting a point at which to apply digital compression, it is essential that the vessel should be lying over a bone which will furnish the necessary resistance. The common carotid, for example, is pressed backward and medially against the transverse process (carotid tubercle) of the sixth cervical vertebra; the temporal against the temporal process (zygoma) in front of the ear; and the facial against the mandible at the anterior edge of the masseter.

In the upper extremity, the subclavian is pressed against the first rib by making pressure downwards and backwards in the hollow above the clavicle; the axillary and brachial by pressing against the shaft of the humerus.

In the lower extremity, the femoral is controlled by pressing in a direction backward and slightly upward against the brim of the pelvis, midway between the symphysis pubis and the anterior superior iliac spine.

The abdominal aorta may be compressed against the bodies of the lumbar vertebrae opposite the umbilicus, if the spine is arched well forwards over a pillow or sand-bag, or by the method suggested by Macewen, in which the patient's spine is arched forwards by allowing the lower extremities and pelvis to hang over the end of the table, while the assistant, standing on a stool, applies his closed fist over the abdominal aorta and compresses it against the vertebral column. Momburg recommends an elastic cord wound round the body between the iliac crest and the lower border of the ribs, but this procedure has caused serious damage to the intestine.

When digital compression is not available, the most convenient and certain means of preventing haemorrhage--say in an amputation--is by the use of some form of _tourniquet_, such as the elastic tube of Esmarch or of Foulis, or an elastic bandage, or the screw tourniquet of Petit. Before applying any of these it is advisable to empty the limb of blood. This is best done after the manner suggested by Lister: the limb is held vertical for three or four minutes; the veins are thus emptied by gravitation, and they collapse, and as a physiological result of this the arteries reflexly contract, so that the quantity of blood entering the limb is reduced to a minimum. With the limb still elevated the tourniquet is firmly applied, a part being selected where the vessel can be pressed directly against a bone, and where there is no risk of exerting injurious pressure on the nerve-trunks. The tourniquet should be applied over several layers of gauze or lint to protect the skin, and the first turn of the tourniquet must be rapidly and tightly applied to arrest completely the arterial flow, otherwise the veins only are obstructed and the limb becomes congested. In the lower extremity the best place to apply a tourniquet is the middle third of the thigh; in the upper extremity, in the middle of the arm. A tourniquet should never be applied tighter or left on longer than is absolutely necessary.

The screw tourniquet of Petit is to be preferred when it is desired to intermit the flow through the main artery as in operations for aneurysm.

When a tourniquet cannot conveniently be applied, or when its presence interferes with the carrying out of the operation--as, for example, in amputations at the hip or shoulder--the haemorrhage may be controlled by preliminary ligation of the main artery above the seat of operation--for instance, the external iliac or the subclavian. For such contingencies also the steel skewers used by Spence and Wyeth, or a special clamp or forceps, such as that suggested by Lynn Thomas, may be employed. In the case of vessels which it is undesirable to occlude permanently, such as the common carotid, the temporary application of a ligature or clamp is useful.

  1. Arrest of Haemorrhage.#--_Ligature._--This is the best means of securing

the larger vessels. The divided vessel having been caught with forceps as near to its cut end as possible, a ligature of catgut or silk is tied round it. When there is difficulty in applying a ligature securely, for example in a dense tissue like the scalp or periosteum, or in a friable tissue like the thyreoid gland or the mesentery, a stitch should be passed so as to surround the bleeding vessel a short distance from its end, in this way ensuring a better hold and preventing the ligature from slipping.

If the haemorrhage is from a partly divided vessel, this should be completely cut across to enable its walls to contract and retract, and to facilitate the application of forceps and ligatures.

_Torsion._--This method is seldom employed except for comparatively small vessels, but it is applicable to even the largest arteries. In employing torsion, the end of the vessel is caught with forceps, and the terminal portion twisted round several times. The object is to tear the inner and middle coats so that they curl up inside the lumen, while the outer fibrous coat is twisted into a cord which occludes the end of the vessel.

_Forci-pressure._--Bleeding from the smallest arteries and from arterioles can usually be arrested by firmly squeezing them for a few minutes with artery forceps. It is usually found that on the removal of the forceps at the end of an operation no further haemorrhage takes place. By the use of specially strong clamps, such as the angiotribes of Doyen, large trunks may be occluded by pressure.

_Cautery._--The actual cautery or Paquelin's thermo-cautery is seldom employed to arrest haemorrhage, but is frequently useful in preventing it, as, for example, in the removal of piles, or in opening the bowel in colostomy. It is used at a dull-red heat, which sears the divided ends of the vessel and so occludes the lumen. A bright-red or a white heat cuts the vessel across without occluding it. The separation of the slough produced by the charring of the tissues is sometimes attended with secondary bleeding.

_Haemostatics_ or _Styptics_.--The local application of haemostatics is seldom to be recommended. In the treatment of epistaxis or bleeding from the nose, of haemorrhage from the socket of a tooth, and sometimes from ulcerating or granulating surfaces, however, they may be useful. All clots must be removed and the drug applied directly to the bleeding surface. Adrenalin and turpentine are the most useful drugs for this purpose.

Haemorrhage from bone, for example the skull, may be arrested by means of Horsley's aseptic plastic wax. To stop persistent oozing from soft tissues, Horsley successfully applied a portion of living vascular tissue, such as a fragment of muscle, which readily adheres to the oozing surface and yields elements that cause coagulation of the blood by thrombo-kinetic processes. When examined after two or three days the muscle has been found to be closely adherent and undergoing organisation.

  1. Arrest of Accidental Haemorrhage.#--The most efficient means of

temporarily controlling haemorrhage is by pressure applied with the finger, or with a pad of gauze, directly over the bleeding point. While this is maintained an assistant makes digital pressure, or applies a tourniquet, over the main vessel of the limb on the proximal side of the bleeding point. A useful _emergency tourniquet_ may be improvised by folding a large handkerchief _en cravatte_, with a cork or piece of wood in the fold to act as a pad. The handkerchief is applied round the limb, with the pad over the main artery, and the ends knotted on the lateral aspect of the limb. With a strong piece of wood the handkerchief is wound up like a Spanish windlass, until sufficient pressure is exerted to arrest the bleeding.

When haemorrhage is taking place from a number of small vessels, its arrest may be effected by elevation of the bleeding part, particularly if it is a limb. By this means the force of the circulation is diminished and the formation of coagula favoured. Similarly, in wounds of the hand or forearm, or of the foot or leg, bleeding may be arrested by placing a pad in the flexure and acutely flexing the limb at the elbow or knee respectively.

  1. Reactionary Haemorrhage.#--Reactionary or intermediary haemorrhage

is really a recurrence of primary bleeding. As the name indicates, it occurs during the period of reaction--that is, within the first twelve hours after an operation or injury. It may be due to the increase in the blood-pressure that accompanies reaction displacing clots which have formed in the vessels, or causing vessels to bleed which did not bleed during the operation; to the slipping of a ligature; or to the giving way of a grossly damaged portion of the vessel wall. In the scrotum, the relaxation of the dartos during the first few hours after operation occasionally leads to reactionary haemorrhage.

As a rule, reactionary haemorrhage takes place from small vessels as a result of the displacement of occluding clots, and in many cases the haemorrhage stops when the bandages and soaked dressings are removed. If not, it is usually sufficient to remove the clots and apply firm pressure, and in the case of a limb to elevate it. Should the haemorrhage recur, the wound must be reopened, and ligatures applied to the bleeding vessels. Douching the wound with hot sterilised water (about 110 F.), and plugging it tightly with gauze, are often successful in arresting capillary oozing. When the bleeding is more copious, it is usually due to a ligature having slipped from a large vessel such as the external jugular vein after operations in the neck, and the wound must be opened up and the vessel again secured. The internal administration of heroin or morphin, by keeping the patient quiet, may prove useful in preventing the recurrence of haemorrhage.

  1. Secondary Haemorrhage.#--The term secondary haemorrhage refers to

bleeding that is delayed in its onset and is due to pyogenic infection of the tissues around an artery. The septic process causes softening and erosion of the wall of the artery so that it gives way under the pressure of the contained blood. The leakage may occur in drops, or as a rush of blood, according to the extent of the erosion, the size of the artery concerned, and the relations of the erosion to the surrounding tissues. When met with as a complication of a wound there is an interval--usually a week to ten days--between the receipt of the wound and the first haemorrhage, this time being required for the extension of the septic process to the wall of the artery and the consequent erosion of its coats. When secondary haemorrhage occurs apart from a wound, there is a similar septic process attacking the wall of the artery from the outside; for example in sloughing sore-throat, the separation of a slough may implicate the wall of an artery and be followed by serious and it may be fatal haemorrhage. The mechanical pressure of a fragment of bone or of a rubber drainage tube upon the vessel may aid the septic process in causing erosion of the artery. In pre-Listerian days, the silk ligature around the artery likewise favoured the changes that lead to secondary haemorrhage, and the interesting observation was often made, that when the collateral circulation was well established, the leakage occurred on the _distal_ side of the ligature. While it may happen that the initial haemorrhage is rapidly fatal, as for example when the external carotid or one of its branches suddenly gives way, it is quite common to have one, two or more _warning haemorrhages_ before the leakage on a large scale, which is rapidly fatal.

The _appearances of the wound_ in cases complicated by secondary haemorrhage are only characteristic in so far that while obviously infected, there is an absence of all reaction; instead of frankly suppurating, there is little or no discharge and the surrounding cellular tissue and the limb beyond are oedematous and pit on pressure.

The _general symptoms_ of septic poisoning in cases of secondary haemorrhage vary widely in severity: they may be so slight that the general health is scarcely affected and the convalescence from an operation, for example, may be apparently normal except that the wound does not heal satisfactorily. For example, a patient may be recovering from an operation such as the removal of an epithelioma of the mouth, pharynx or larynx and the associated lymph glands in the neck, and be able to be up and going about his room, when, suddenly, without warning and without obvious cause, a rush of blood occurs from the mouth or the incompletely healed wound in the neck, causing death within a few minutes.

On the other hand, the toxaemia may be of a profound type associated with marked pallor and progressive failure of strength, which, of itself, even when the danger from haemorrhage has been overcome, may have a fatal termination. The _prognosis_ therefore in cases of secondary haemorrhage can never be other than uncertain and unfavourable; the danger from loss of blood _per se_ is less when the artery concerned is amenable to control by surgical measures.

_Treatment._--The treatment of secondary haemorrhage includes the use of local measures to arrest the bleeding, the employment of general measures to counteract the accompanying toxaemia, and when the loss of blood has been considerable, the treatment of the bloodless state.

_Local Measures to arrest the Haemorrhage._--The occurrence of even slight haemorrhages from a septic wound in the vicinity of a large blood vessel is to be taken seriously; it is usually necessary to _open up the wound_, clear out the clots and infected tissues with a sharp spoon, disinfect the walls of the cavity with eusol or hydrogen peroxide, and _pack_ it carefully but not too tightly with gauze impregnated with some antiseptic, such as "bipp," so that, if the bleeding does not recur, it may be left undisturbed for several days. The packing should if possible be brought into actual contact with the leaking point in the vessel, and so arranged as to make pressure on the artery above the erosion. The dressings and bandage are then applied, with the limb in the attitude that will diminish the force of the stream through the main artery, for example, flexion at the elbow in haemorrhage from the deep palmar arch. Other measures for combating the local sepsis, such as the irrigation method of Carrel, may be considered.

If the wound involves one of the extremities, it may be useful; and it imparts confidence to the nurse, and, it may be, to the patient, if a Petit's tourniquet is loosely applied above the wound, which the nurse is instructed to tighten up in the event of bleeding taking place.

_Ligation of the Artery._--If the haemorrhage recurs in spite of packing the wound, or if it is serious from the outset and likely to be critical if repeated, ligation of the artery itself or of the trunk from which it springs, at a selected spot higher up, should be considered. This is most often indicated in wounds of the extremities.

As examples of proximal ligation for secondary haemorrhage may be cited ligation of the hypogastric artery for haemorrhage in the buttock, of the common iliac for haemorrhage in the thigh, of the brachial in the upper arm for haemorrhage from the deep palmar arch, and of the posterior tibial behind the medial malleolus for haemorrhage from the sole of the foot.

_Amputation_ is the last resource, and should be decided upon if the haemorrhage recurs after proximal ligation, or if this has been followed by gangrene of the limb; it should also be considered if the nature of the wound and the virulence of the sepsis would of themselves justify removal of the limb. Every surgeon can recall cases in which a timely amputation has been the means of saving life.

The _counteraction of the toxaemia_ and the _treatment of the bloodless state_, are carried out on the usual lines.

  1. Haemorrhage of Toxic Origin.#--Mention must also be made of haemorrhages

which depend upon infective or toxic conditions and in which no gross lesion of the vessels can be discovered. The bleeding occurs as an oozing, which may be comparatively slight and unimportant, or by its persistence may become serious. It takes place into the superficial layers of the skin, from mucous membranes, and into the substance of such organs as the pancreas. Haemorrhage from the stomach and intestine, attended with a brown or black discoloration of the vomit and of the stools, is one of the best known examples: it is not uncommonly met with in infective conditions originating in the appendix, intestine, gall-bladder, and other abdominal organs. Haemorrhage from the mucous membrane of the stomach after abdominal operations--apparently also due to toxic causes and not to the operation--gives rise to the so-called _post-operative haematemesis_.

  1. Constitutional Effects of Haemorrhage.#--The severity of the symptoms

resulting from haemorrhage depends as much on the rapidity with which the bleeding takes place as on the amount of blood lost. The sudden loss of a large quantity, whether from an open wound or into a serous cavity--for example, after rupture of the liver or spleen--is attended with marked pallor of the surface of the body and coldness of the skin, especially of the face, feet, and hands. The skin is moist with a cold, clammy sweat, and beads of perspiration stand out on the forehead. The pulse becomes feeble, soft, and rapid, and the patient is dull and listless, and complains of extreme thirst. The temperature is usually sub-normal; and the respiration rapid, shallow, and sighing in character. Abnormal visual sensations, in the form of flashes of light or spots before the eyes; and rushing, buzzing, or ringing sounds in the ears, are often complained of.

In extreme cases, phenomena which have been aptly described as those of "air-hunger" ensue. On account of the small quantity of blood circulating through the body, and the diminished haemoglobin content of the blood, the tissues are imperfectly oxygenated, and the patient becomes extremely restless, gasping for breath, constantly throwing about his arms and baring his chest in the vain attempt to breath more freely. Faintness and giddiness are marked features. The diminished supply of oxygen to the brain and to the muscles produces muscular twitchings, and sometimes convulsions. Finally the pupils dilate, the sphincters relax, and death ensues.

Young children stand the loss of blood badly, but they quickly recover, as the regeneration of blood takes place rapidly. In old people also, and especially when they are fat, the loss of blood is badly borne, and the ill effects last longer. Women, on the whole, stand loss of blood better than men, and in them the blood is more rapidly re-formed. A few hours after a severe haemorrhage there is usually a leucocytosis of from 15,000 to 30,000.

  1. Treatment of the Bloodless State.#--The patient should be placed in a

warm, well-ventilated room, and the foot of the bed elevated. Cardiac stimulants, such as strychnin or alcohol, must be judiciously administered, over-stimulation being avoided. The inhalation of oxygen has been found useful in relieving the urgent symptoms of dyspnoea.

The blood may be emptied from the limbs into the vessels of the trunk, where it is more needed, by holding them vertically in the air for a few minutes, and then applying a firm elastic bandage over a layer of cotton wool, from the periphery towards the trunk.

_Introduction of Fluids into the Circulation._--The most valuable measure for maintaining the circulation, however, is by transfusion of blood (_Op. Surg._, p. 37). If this is not immediately available the introduction of from one to three pints of physiological salt solution (a teaspoonful of common salt to a pint of water) into a vein, or a 6 per cent. solution of gum acacia, is a useful expedient. The solution is sterilised by boiling, and cooled to a temperature of about 105 F. The addition of 5 to 10 minims of adrenalin solution (1 in 1000) is advantageous in raising the blood-pressure (_Op. Surg._, p. 565).

When the intra-venous method is not available, one or two pints of saline solution with adrenalin should be slowly introduced into the rectum, by means of a long rubber tube and a filler. Satisfactory, although less rapidly obtained results follow the introduction of saline solution into the cellular tissue--for example, under the mamma, into the axilla, or under the skin of the back.

If the patient can retain fluids taken by the mouth--such as hot coffee, barley water, or soda water--these should be freely given, unless the injury necessitates operative treatment under a general anaesthetic.

Transfusion of blood is most valuable as _a preliminary to operation_ in patients who are bloodless as a result of haemorrhage from gastric and duodenal ulcers, and in bleeders.


HAEMOPHILIA

The term haemophilia is applied to an inherited disease which renders the patient liable to serious haemorrhage from even the most trivial injuries; and the subjects of it are popularly known as "bleeders."

The cause of the disease and its true nature are as yet unknown. There is no proof of any structural defect in the blood vessels, and beyond the fact that there is a diminution in the number of blood-plates, it has not been demonstrated that there is any alteration in the composition of the blood.

The affection is in a marked degree hereditary, all the branches of an affected family being liable to suffer. Its mode of transmission to individuals, moreover, is characteristic: the male members of the stock alone suffer from the affection in its typical form, while the tendency is transmitted through the female line. Thus the daughters of a father who is a bleeder, whilst they do not themselves suffer from the disease, transmit the tendency to their male offspring. The sons, on the other hand, neither suffer themselves nor transmit the disease to their children (Fig. 64). The female members of a haemophilic stock are often very prolific, and there is usually a predominance of daughters in their families.


FIG 64.--Genealogical Tree of a Haemophilic Family.

Great-Great-Grandmother Great-Great-Grandfather Mrs D. (Lancashire) F M (History not known

                  .|                  |  as to bleeding)
                  .|                  |
                  .+----------+-------+
                  ............|
                             .|
                          ....|
                          .+---------+--------+
        Great-Grandmother .|         |        |
          (Married three  .F        MB       MB
               times)     .|
                          .|
                          .|
     By First Husband     .|                  By Second           By Third
             ..............|                  Husband             Husband
  +-----------+------------+----------+-------+-------+-----------+------+
  |          .|            |          |       +-------+-----------+------+
  M          .F            F          F       |       |           +------+
  |          .|            |          |       MB      F Died in      No

Died Grandmother | | | Childbed Family

aet.         .|            |     +-----------+   +----+---
70           .|        +------+  |had family |   |
             .|        |      |  |but history|   |
             .|        MB    MB  |not known  |   MB
             .|
             .|
             .|.............................

+-----+----------+------------+------------+------------+-------------+ | | | | |. | | | | | | |. | | M M M MB F. F F

     |                                    |.           |             |
     |                                  Mother   +--+--+---+--+--+   |
   +----+                                 |.     |  |  |   |  |  |   |
   |    |                                 |.     M  M  MB  F  F  F   |
   M    F                                 |.                         |
    Not Married                           |.             +---+---+---+---+
                                          |.             |   |   |   |   |
                                          |.             MB  M   MB  M   M
                             .............|.
                        +-----+-----+-----+-----+-----+
                        |    .|    .|     |     |     |
                        |    .|*   .|*    |     |     |
                        M    MB    MB     F     F     F


F = Females. M = Males (not bleeders). MB = Males (bleeders)

** the patients observed by the authors. The dotted line shows the
   transmission of the disease to our patients through four
   generations.


The disease is met with in boys who are otherwise healthy, and usually manifests itself during the first few years of life. In rare instances profuse haemorrhage takes place when the umbilical cord separates. As a rule the first evidence is the occurrence of long-continued and uncontrollable bleeding from a comparatively slight injury, such as the scratch of a pin, the extraction of a tooth, or after the operation of circumcision. The blood oozes slowly from the capillaries; at first it appears normal, but after flowing for some days, or it may be weeks, it becomes pale, thin, and watery, and shows less and less tendency to coagulate.

Female members of haemophilia families sometimes show a tendency to excessive haemorrhage, but they seldom manifest the characteristic features met with in the male members.

Sometimes the haemorrhage takes place apparently spontaneously from the gums, the nasal or the intestinal mucous membrane. In other cases the bleeding occurs into the cellular tissue under the skin or mucous membrane, producing large areas of ecchymosis and discoloration. One of the commonest manifestations of the disease is the occurrence of haemorrhage into the cavities of the large joints, especially the knee, elbow, or hip. The patient suffers repeatedly from such haemorrhages, the determining injury being often so slight as to have passed unobserved.

There is evidence that the tendency to bleed is greater at certain times than at others--in some cases showing almost a cyclical character--although nothing is known as to the cause of the variation.

After a severe haemorrhage into the cellular tissue or into a joint, the patient becomes pale and anaemic, the temperature may rise to 102 or 103 F., the pulse become small and rapid, and haemic murmurs are sometimes developed over the heart and large arteries. The swelling is tense, fluctuating, and hot, and there is considerable pain and tenderness.

In exceptional cases, blisters form over the seat of the effusion, or the skin may even slough, and the clinical features may therefore come to simulate closely those of an acute suppurative condition. When the skin sloughs, an ulcer is formed with altered blood-clot in its floor like that seen in scurvy, and there is a remarkable absence of any attempt at healing.

The acute symptoms gradually subside, and the blood is slowly absorbed, the discoloration of the skin passing through the same series of changes as occur after an ordinary bruise. The patients seldom manifest the symptoms of the bloodless state, and the blood is rapidly regenerated.

The _diagnosis_ is easy if the patient or his friends are aware of the family tendency to haemorrhage and inform the doctor of it, but they are often sensitive and reticent regarding the fact, and it may only be elicited after close investigation. From the history it is usually easy to exclude scurvy and purpura. Repeated haemorrhages into a joint may result in appearances which closely simulate those of tuberculous disease. Recent haemorrhages into the cellular tissue often present clinical features closely resembling those of acute cellulitis or osteomyelitis. A careful examination, however, may reveal ecchymoses on other parts of the body which give a clue to the nature of the condition, and may prevent the disastrous consequences that may follow incision.

These patients usually succumb sooner or later to haemorrhage, although they often survive several severe attacks. After middle life the tendency to bleed appears to diminish.

_Treatment._--As a rule the ordinary means of arresting haemorrhage are of little avail. From among the numerous means suggested, the following may be mentioned: The application to the bleeding point of gauze soaked in a 1 in 1000 solution of adrenalin; prolonged inhalation of oxygen; freezing the part with a spray of ethyl-chloride; one or more subcutaneous injections of gelatin--5 ounces of a 2.5 per cent. solution of white gelatin in normal salt solution being injected at a temperature of about 100 F.; the injection of pituitary extract. The application of a pad of gauze soaked in the blood of a normal person sometimes arrests the bleeding.

To prevent bleeding in haemophilics, intra-venous or subcutaneous injections of fresh blood serum, taken from the human subject, the sheep, the dog, or the horse, have proved useful. If fresh serum is not available, anti-diphtheritic or anti-tetanic serum or trade preparations, such as hemoplastin, may be employed. We have removed the appendix and amputated through the thigh in haemophilic subjects without excessive loss of blood after a course of fresh sheep's serum given by the mouth over a period of several weeks.

The chloride and lactate of calcium, and extract of thymus gland have been employed to increase the coagulability of the blood. The patient should drink large quantities of milk, which also increases the coagulability of the blood. Monro has observed remarkable results from the hypodermic injection of emetin hydrochloride in 1/2-grain doses.


THROMBOSIS AND EMBOLISM

The processes known as thrombosis and embolism are so intimately associated with the diseases of blood vessels that it is convenient to define these terms in the first instance.

  1. Thrombosis.#--The term _thrombus_ is applied to a clot of blood formed

in the interior of the heart or of a blood vessel, and the process by which such a clot forms is known as _thrombosis_. It would appear that slowing or stagnation of the blood-stream, and interference with the integrity of the lining membrane of the vessel wall, are the most important factors determining the formation of the clot. Alterations in the blood itself, such as occur, for example, in certain toxaemias, also favour coagulation. When the thrombus is formed slowly, it consists of white blood cells with a small proportion of fibrin, and, being deposited in successive layers, has a distinctly laminated appearance on section. It is known as a _white thrombus_ or laminated clot, and is often met with in the sac of an aneurysm (Fig. 72). When rapidly formed in a vessel in which the blood is almost stagnant--as, for example, in a pouched varicose vein--the blood coagulates _en masse_, and the clot consists of all the elements of the blood, constituting a _red thrombus_ (Fig. 66). Sometimes the thrombus is _mixed_--a red thrombus being deposited on a white one, it may be in alternate layers.

When aseptic, a thrombus may become detached and be carried off in the blood-stream as an embolus; it may become organised; or it may degenerate and undergo calcification. Occasionally a small thrombus situated behind a valve in a varicose vein or in the terminal end of a dilated vein--for example in a pile--undergoes calcification, and is then spoken of as a _phlebolith_; it gives a shadow with the X-rays.

When infected with pyogenic bacteria, the thrombus becomes converted into pus and a localised abscess forms; or portions of the thrombus may be carried as emboli in the circulation to distant parts, where they give rise to secondary foci of suppuration--pyaemic abscesses.

  1. Embolism.#--The term _embolus_ is applied to any body carried along in

the circulation and ultimately becoming impacted in a blood vessel. This occurrence is known as _embolism_. The commonest forms of embolus are portions of thrombi or of fibrinous formations on the valves of the heart, the latter being usually infected with micro-organisms.

Embolism plays an important part in determining one form of gangrene, as has already been described. Infective emboli are the direct cause of the secondary abscesses that occur in pyaemia; and they are sometimes responsible for the formation of aneurysm.

Portions of malignant tumours also may form emboli, and their impaction in the vessels may lead to the development of secondary growths in distant parts of the body.

Fat and air embolism have already been referred to.


ARTERITIS

_Pyogenic._--Non-suppurative inflammation of the coats of an artery may so soften the wall of the vessel as to lead to aneurysmal dilatation. It is not uncommon in children, and explains the occurrence of aneurysm in young subjects.

When suppuration occurs, the vessel wall becomes disintegrated and gives way, leading to secondary haemorrhage. If the vessel ruptures into an abscess cavity, dangerous bleeding may occur when the abscess bursts or is opened.

_Syphilitic._--The inflammation associated with syphilis results in thickening of the tunica intima, whereby the lumen of the vessel becomes narrowed, or even obliterated--_endarteritis obliterans_. The middle coat usually escapes, but the tunica externa is generally thickened. These changes cause serious interference with the nutrition of the parts supplied by the affected arteries. In large trunks, by diminishing the elasticity of the vessel wall, they are liable to lead to the formation of aneurysm.

Changes in the arterial walls closely resembling those of syphilitic arteritis are sometimes met with in _tuberculous_ lesions.

  1. Arterio-sclerosis# or #Chronic Arteritis#.--These terms are applied to

certain changes which result in narrowing of the lumen and loss of elasticity in the arteries. The condition may affect the whole vascular system or may be confined to particular areas. In the smaller arteries there is more or less uniform thickening of the tunica intima from proliferation of the endothelium and increase in the connective tissue in the elastic lamina--a form of obliterative endarteritis. The narrowing of the vessels may be sufficient to determine gangrene in the extremities. In course of time, particularly in the larger arteries, this new tissue undergoes degeneration, at first of a fatty nature, but progressing in the direction of calcification, and this is followed by the deposit of lime salts in the young connective tissue and the formation of calcareous plates or rings over a considerable area of the vessel wall. To this stage in the process the term _atheroma_ is applied. The endothelium over these plates often disappears, leaving them exposed to the blood-stream.

Changes of a similar kind sometimes occur in the middle coat, the lime salts being deposited among the muscle fibres in concentric rings.

The primary cause of arterio-sclerosis is not definitely known, but its almost constant occurrence, to a greater or less degree, in the aged suggests that it is of the nature of a senile degeneration. It is favoured by anything which throws excessive strain on the vessel walls, such as heavy muscular work; by chronic alcoholism and syphilis; or by such general diseases as tend to raise the blood-pressure--for example, chronic Bright's disease or gout. It occurs with greater frequency and with greater severity in men than in women.

Atheromatous degeneration is most common in the large arterial trunks, and the changes are most marked at the arch of the aorta, opposite the flexures of joints, at the mouths of large branches, and at parts where the vessel lies in contact with bone. The presence of diseased patches in the wall of an artery diminishes its elasticity and favours aneurysmal dilatation. Such a vessel also is liable to be ruptured by external violence and so give rise to traumatic aneurysm. Thrombosis is liable to occur when calcareous plates are exposed in the lumen of the vessel by destruction of the endothelium, and this predisposes to embolism. Arterio-sclerosis also interferes with the natural arrest of haemorrhage, and by rendering the vessels brittle, makes it difficult to secure them by ligature. In advanced cases the accessible arteries--such as the radial, the temporal or the femoral--may be felt as firm, tortuous cords, which are sometimes so hard that they have been aptly compared to "pipe-stems." The pulse is smaller and less compressible than normal, and the vessel moves bodily with each pulsation. It must be borne in mind, however, that the condition of the radial artery may fail to afford a clue to that of the larger arteries. Calcified arteries are readily identified in skiagrams (Fig. 65).

[Illustration: FIG. 65.--Radiogram showing Calcareous Degeneration (Atheroma) of Arteries.]

We have met with a chronic form of arterial degeneration in elderly women, affecting especially the great vessels at the root of the neck, in which the artery is remarkably attenuated and dilated, and so friable that the wall readily tears when seized with an artery-forceps, rendering ligation of the vessel in the ordinary way well-nigh impossible. Matas suggests infolding the wall of the vessel with interrupted sutures that do not pierce the intima, and wrapping it round with a strip of peritoneum or omentum.

The most serious form of arterial _thrombosis_ is that met with _in the abdominal aorta_, which is attended with violent pains in the lower limbs, rapidly followed by paralysis and arrest of the circulation.


THROMBO-PHLEBITIS AND THROMBOSIS IN VEINS

  1. Thrombosis# is more common in veins than in arteries, because slowing

of the blood-stream and irritation of the endothelium of the vessel wall are, owing to the conditions of the venous circulation, more readily induced in veins.

Venous thrombosis may occur from purely mechanical causes--as, for example, when the wall of a vein is incised, or the vessel included in a ligature, or when it is bruised or crushed by a fragment of a broken bone or by a bandage too tightly applied. Under these conditions thrombosis is essentially a reparative process, and has already been considered in relation to the repair of blood vessels.

In other cases thrombosis is associated with certain constitutional diseases--gout, for example; the endothelium of the veins undergoing changes--possibly the result of irritation by abnormal constituents in the blood--which favour the formation of thrombi.

Under these various conditions the formation of a thrombus is not necessarily associated with the action of bacteria, although in any of them this additional factor may be present.

The most common cause of venous thrombosis, however, is inflammation of the wall of the vein--phlebitis.

  1. Phlebitis.#--Various forms of phlebitis are met with, but for practical

purposes they may be divided into two groups--one in which there is a tendency to the formation of a thrombus; the other in which the infective element predominates.

In surgical patients, the _thrombotic form_ is almost invariably met with in the lower extremity, and usually occurs in those who are debilitated and anaemic, and who are confined to bed for prolonged periods--for example, during the treatment of fractures of the leg or pelvis, or after such operations as herniotomy, prostatectomy, or appendectomy.

_Clinical Features._--The most typical example of this form of phlebitis is that so frequently met with in the great saphena vein, especially when it is varicose. The onset of the attack is indicated by a sudden pain in the lower limb--sometimes below, sometimes above the knee. This initial pain may be associated with shivering or even with a rigor, and the temperature usually rises one or two degrees. There is swelling and tenderness along the line of the affected vein, and the skin over it is a dull-red or purple colour. The swollen vein may be felt as a firm cord, with bead-like enlargements in the position of the valves. The patient experiences a feeling of stiffness and tightness throughout the limb. There is often oedema of the leg and foot, especially when the limb is in the dependent position. The acute symptoms pass off in a few days, but the swelling and tenderness of the vein and the oedema of the limb may last for many weeks.

When the deep veins--iliac, femoral, popliteal--are involved, there is great swelling of the whole limb, which is of a firm almost "wooden" consistence, and of a pale-white colour; the oedema may be so great that it is impossible to feel the affected vein until the swelling has subsided. This is most often seen in puerperal women, and is known as _phlegmasia alba dolens_.

_Treatment._--The patient must be placed at absolute rest, with the foot of the bed raised on blocks 10 or 12 inches high, and the limb immobilised by sand-bags or splints. It is necessary to avoid handling the parts, lest the clot be displaced and embolism occur. To avoid frequent movement of the limb, the necessary dressings should be kept in position by means of a many-tailed rather than a roller bandage.

To relieve the pain, warm fomentations or lead and opium lotion should be applied. Later, ichthyol-glycerin, or glycerin and belladonna, may be substituted.

When, at the end of three weeks, the danger of embolism is past, douching and gentle massage may be employed to disperse the oedema; and when the patient gets up he should wear a supporting elastic bandage.

The _infective_ form usually begins as a peri-phlebitis arising in connection with some focus of infection in the adjacent tissues. The elements of the vessel wall are destroyed by suppuration, and the thrombus in its lumen becomes infected with pyogenic bacteria and undergoes softening.

_Occlusion of the inferior vena cava_ as a result of infective thrombosis is a well-known condition, the thrombosis extending into the main trunk from some of its tributaries, either from the femoral or iliac veins below or from the hepatic veins above.

Portions of the softened thrombus are liable to become detached and to enter the circulating blood, in which they are carried as emboli. These may lodge in distant parts, and give rise to secondary foci of suppuration--pyaemic abscesses.

_Clinical Features._--Infective phlebitis is most frequently met with in the transverse sinus as a sequel to chronic suppuration in the mastoid antrum and middle ear. It also occurs in relation to the peripheral veins, but in these it can seldom be recognised as a separate entity, being merged in the general infective process from which it takes origin. Its occurrence may be inferred, if in the course of a suppurative lesion there is a sudden rise of temperature, with pain, redness, and swelling along the line of a venous trunk, and a rapidly developed oedema of the limb, with pitting of the skin on pressure. In rare cases a localised abscess forms in the vein and points towards the surface.

_Treatment._--Attention must be directed towards the condition with which the phlebitis is associated. Ligation of the vein on the cardiac side of the thrombus with a view to preventing embolism is seldom feasible in the peripheral veins, although, as will be pointed out later, the jugular vein is ligated with this object in cases of phlebitis of the transverse sinus.


VARIX--VARICOSE VEINS

The term varix is applied to a condition in which veins are so altered in structure that they remain permanently dilated, and are at the same time lengthened and tortuous. Two types are met with: one in which dilatation of a large superficial vein and its tributaries is the most obvious feature; the other, in which bunches of distended and tortuous vessels develop at one or more points in the course of a vein, a condition to which Virchow applied the term _angioma racemosum venosum_. The two types may occur in combination.

Any vein in the body may become varicose, but the condition is rare except in the veins of the lower extremity, in the veins of the spermatic cord (varicocele), and in the veins of the anal canal (haemorrhoids).

We are here concerned with varix as it occurs in the veins of the lower extremity.

_Etiology._--Considerable difference of opinion exists as to the essential cause of varix. The weight of evidence is in favour of the view that, when dilatation is the predominant element, it results from a congenital deficiency in the number, size, and strength of the valves of the affected veins, and in an inherent weakness in the vessel walls. The _angioma racemosum venosum_ is probably also due to a congenital alteration in the structure of the vessels, and is allied to tumours of blood vessels. The view that varix is congenital in origin, as was first suggested by Virchow, is supported by the fact that in a large proportion of cases the condition is hereditary; not only may several members of the same family in succeeding generations suffer from varix, but it is often found that the same vein, or segment of a vein, is involved in all of them. The frequent occurrence of varix in youth is also an indication of its congenital origin.

In the majority of cases it is only when some exciting factor comes into operation that the clinical phenomena associated with varix appear. The most common exciting cause is increased pressure within the veins, and this may be produced in a variety of ways. In certain diseases of the heart, lungs, and liver, for example, the venous pressure may be so raised as to cause a localised dilatation of such veins as are congenitally weak. The direct pressure of a tumour, or of the gravid uterus on the large venous trunks in the pelvis, may so obstruct the flow as to distend the veins of the lower extremity. It is a common experience in women that the signs of varix date from an antecedent pregnancy. The importance of the wearing of tight garters as a factor in the production of varicose veins has been exaggerated, although it must be admitted that this practice is calculated to aggravate the condition when it is once established. It has been proved experimentally that the backward pressure in the veins may be greatly increased by straining, a fact which helps to explain the frequency with which varicosity occurs in the lower limbs of athletes and of those whose occupation involves repeated and violent muscular efforts. There is reason to believe, moreover, that a sudden strain may, by rupturing the valves and so rendering them incompetent, induce varicosity independently of any congenital defect. Prolonged standing or walking, by allowing gravity to act on the column of blood in the veins of the lower limbs, is also an important determining factor in the production of varix.

Thrombosis of the deep veins--in the leg, for example--may induce marked dilatation of the superficial veins, by throwing an increased amount of work upon them. This is to be looked upon rather as a compensatory hypertrophy of the superficial vessels than as a true varix.

_Morbid Anatomy._--In the lower extremity the varicosity most commonly affects the vessels of the great saphena system; less frequently those of the small saphena system. Sometimes both systems are involved, and large communicating branches may develop between the two.

The essential lesion is the absence or deficiency of valves, so that they are incompetent and fail to support the column of blood which bears back upon them. Normally the valves in the femoral and iliac veins and in the inferior vena cava are imperfectly developed, so that in the erect posture the great saphena receives a large share of the backward pressure of the column of venous blood.

The whole length of the vein may be affected, but as a rule the disease is confined to one or more segments, which are not only dilated, but are also increased in length, so that they become convoluted. The adjacent loops of the convoluted vein are often bound together by fibrous tissue. All the coats are thickened, chiefly by an increased development of connective tissue, and in some cases changes similar to those of arterio-sclerosis occur. The walls of varicose veins are often exceedingly brittle. In some cases the thickening is uniform, and in others it is irregular, so that here and there thin-walled sacs or pouches project from the side of the vein. These pouches vary in size from a bean to a hen's egg, the larger forms being called _venous cysts_, and being most commonly met with in the region of the saphenous opening and of the opening in the popliteal fascia. Such pouches, being exposed to injury, are frequently the seat of thrombosis (Fig. 66).

[Illustration: FIG. 66.--Thrombosis in Tortuous and Pouched Great Saphena Vein, in longitudinal section.]

_Clinical Features._--Varix is most frequently met with between puberty and the age of thirty, and the sexes appear to suffer about equally.

The amount of discomfort bears no direct proportion to the extent of the varicosity. It depends rather upon the degree of pressure in the veins, as is shown by the fact that it is relieved by elevation of the limb. When the whole length of the main trunk of the great saphena is implicated, the pressure in the vein is high and the patient suffers a good deal of pain and discomfort. When, on the contrary, the upper part of the saphena and its valves are intact, and only the more distal veins are involved, the pressure is not so high and there is comparatively little suffering. The usual complaint is of a sense of weight and fulness in the limb after standing or walking, sometimes accompanied by actual pain, from which relief is at once obtained by raising the limb. Cramp-like pains in the muscles are often associated with varix of the deep veins.

The dilated and tortuous vein can be readily seen and felt when the patient is examined in the upright posture. In advanced cases, bead-like swellings are sometimes to be detected over the position of the valves, and, on running the fingers along the course of the vessel, a firm ridge, due to periphlebitis, may be detected on each side of the vein. When the limb is oedematous, the outline of the veins is obscured, but they can be identified on palpation as gutter-like tracks. When large veins are implicated, a distinct impulse on coughing may be seen to pass down as far as the knee; and if the vessel is sharply percussed a fluid wave may be detected passing both up and down the vein.

If the patient is placed on a couch and the limb elevated, the veins are emptied, and if pressure is then made over the region of the saphenous opening and the patient allowed to stand up, so long as the great saphena system alone is involved, the veins fill again very slowly from below. If the small saphena system also is involved, and if communicating branches are dilated, the veins fill up from below more rapidly. When the pressure over the saphenous opening is removed, the blood rapidly rushes into the varicose vessels from above; this is known as Trendelenburg's test.

The most marked dilatation usually occurs on the medial side of the limb, between the middle of the thigh and the middle of the calf, the arrangement of the veins showing great variety (Fig. 67).

There are usually one or more bunches of enlarged and tortuous veins in the region of the knee. Frequently a large branch establishes a communication between the systems of the great and small saphenous veins in the region of the popliteal space, or across the front of the upper part of the tibia. The superficial position of this last branch and its proximity to the bone render it liable to injury.

[Illustration: FIG. 67.--Extensive Varix of Internal Saphena System on Left Leg, of many years' standing.]

The small veins of the skin of the ankle and foot often show as fine blue streaks arranged in a stellate or arborescent manner, especially in women who have borne children.

_Complications._--When the varix is of long standing, the skin in the lower part of the leg sometimes assumes a mahogany-brown or bluish hue, as a result of the _deposit of blood pigment_ in the tissues, and this is frequently a precursor of ulceration.

_Chronic dermatitis_ (_varicose eczema_) is often met with in the lower part of the leg, and is due to interference with the nutrition of the skin. The incompetence of the valves allows the pressure in the varicose veins to equal that in the arterioles, so that the capillary circulation is impeded. From the same cause the blood in the deep veins is enabled to enter the superficial veins, where the backward pressure is so great that the blood flows down again, and so a vicious circle is established. The blood therefore loses more and more of its oxygen, and so fails to nourish the tissues.

The _ulcer_ of the leg associated with varicose veins has already been described.

_Haemorrhage_ may take place from a varicose vein as a result of a wound or of ulceration of its wall. Increased intra-venous pressure produced by severe muscular strain may determine rupture of a vein exposed in the floor of an ulcer. If the limb is dependent, the incompetency of the valves permits of rapid and copious bleeding, which may prove fatal, particularly if the patient is intoxicated when the rupture takes place and no means are taken to arrest the haemorrhage. The bleeding may be arrested at once by elevating the limb, or by applying pressure directly over the bleeding point.

_Phlebitis and thrombosis_ are common sequelae of varix, and may prove dangerous, either by spreading into the large venous trunks or by giving rise to emboli. The larger the varix the greater is the tendency for a thrombus to spread upwards and to involve the deep veins. Thrombi usually originate in venous cysts or pouches, and at acute bends on the vessel, especially when these are situated in the vicinity of the knee, and are subjected to repeated injuries--for example in riding. Phleboliths sometimes form in such pouches, and may be recognised in a radiogram. In a certain proportion of cases, especially in elderly people, the occurrence of thrombosis leads to cure of the condition by the thrombus becoming organised and obliterating the vein.

_Treatment._--At best the treatment of varicose veins is only palliative, as it is obviously impossible to restore to the vessels their normal structure. The patient must avoid wearing anything, such as a garter, which constricts the limb, and any obvious cause of direct pressure on the pelvic veins, such as a tumour, persistent constipation, or an ill-fitting truss, should be removed. Cardiac, renal, or pulmonary causes of venous congestion must also be treated, and the functions of the liver regulated. Severe forms of muscular exertion and prolonged standing or walking are to be avoided, and the patient may with benefit rest the limb in an elevated position for a few hours each day. To support the distended vessels, a closely woven silk or worsted stocking, or a light and porous form of elastic bandage, applied as a puttee, should be worn. These appliances should be put on before the patient leaves his bed in the morning, and should only be removed after he lies down at night. In this way the vessels are never allowed to become dilated. Elastic stockings, and bandages made entirely of india-rubber, are to be avoided. In early and mild cases these measures are usually sufficient to relieve the patient's discomfort.

_Operative Treatment._--In aggravated cases, when the patient is suffering pain, when his occupation is interfered with by repeated attacks of phlebitis, or when there are large pouches on the veins, operative treatment is called for. The younger the patient the clearer is the indication to operate. It may be necessary to operate to enable a patient to enter one of the public services, even although no symptoms are present. The presence of an ulcer does not contra-indicate operation; the ulcer should be excised, and the raw surface covered with skin grafts, before dealing with the veins.

The _operation of Trendelenburg_ is especially appropriate to cases in which the trunk of the great saphena vein in the thigh is alone involved. It consists in exposing three or four inches of the vein in its upper part, applying a ligature at the upper and lower ends of the exposed portion, and, after tying all tributary branches, resecting this portion of the vein.

The procedure of C. H. Mayo is adapted to cases in which it is desirable to remove longer segments of the veins. It consists in the employment of special instruments known as "ring-enucleators" or "vein-strippers," by means of which long portions of the vein are removed through comparatively small incisions.

An alternative procedure consists in avulsing segments of the vein by means of Babcock's stylet, which consists of a flexible steel rod, 30 inches in length, with acorn-shaped terminals. The instrument is passed along the lumen of the segment to be dealt with, and a ligature applied around the vein above the bulbous end of the stylet enables nearly the whole length of the great saphena vein to be dragged out in one piece. These methods are not suitable when the veins are brittle, when there are pouches or calcareous deposits in their walls, or where there has been periphlebitis binding the coils together.

Mitchell of Belfast advises exposing the varices at numerous points by half-inch incisions, and, after clamping the vein between two pairs of forceps, cutting it across and twisting out the segments of the vein between adjacent incisions. The edges of the incisions are sutured; and the limb is firmly bandaged from below upwards, and kept in an elevated position. We have employed this method with satisfactory results.

The treatment of the complications of varix has already been considered.


ANGIOMA[4]

[4] In the description of angiomas we have followed the teaching of the late John Duncan.

Tumours of blood vessels may be divided, according to the nature of the vessels of which they are composed, into the capillary, the venous, and the arterial angiomas.


CAPILLARY ANGIOMA

The most common form of capillary angioma is the naevus or congenital telangiectasis.

  1. Naevus.#--A naevus is a collection of dilated capillaries, the afferent

arterioles and the efferent venules of which often share in the dilatation. Little is known regarding the _etiology_ of naevi beyond the fact that they are of congenital origin. They often escape notice until the child is some days old, but attention is usually drawn to them within a fortnight of birth. For practical purposes the most useful classification of naevi is into the cutaneous, the subcutaneous, and the mixed forms.

_The cutaneous naevus_, "mother's mark," or "port-wine stain," consists of an aggregation of dilated capillaries in the substance of the skin. On stretching the skin the vessels can be seen to form a fine network, or to run in leashes parallel to one another. A dilated arteriole or a vein winding about among the capillaries may sometimes be detected. These naevi occur on any part of the body, but they are most frequently met with on the face. They may be multiple, and vary greatly in size, some being no bigger than a pin-head, while others cover large areas of the body. In colour they present every tint from purple to brilliant red; in the majority there is a considerable dash of blue, especially in cold weather.

Unlike the other forms of naevi, the cutaneous variety shows little tendency to disappear, and it is especially persistent when associated with overgrowth of the epidermis and of the hairs--_naevoid mole_.

The _treatment_ of the cutaneous naevus is unsatisfactory, owing to the difficulty of removing the naevus without leaving a scar which is even more disfiguring. Very small naevi may be destroyed by a fine pointed Paquelin thermo-cautery, or by escharotics, such as nitric acid. For larger naevi, radium and solidified carbon dioxide ("CO_2 snow") may be used. The extensive port-wine stains so often met with on the face are best left alone.

The _subcutaneous naevus_ is comparatively rare. It constitutes a well-defined, localised tumour, which may possess a distinct capsule, especially when it has ceased to grow or is retrogressing. On section, it presents the appearance of a finely reticulated sponge.

Although it may be noticed at, or within a few days of, birth, a subcutaneous naevus is often overlooked, especially when on a covered part of the body, and may not be discovered till the patient is some years old. It forms a rounded, lobulated swelling, seldom of large size and yielding a sensation like that of a sponge; the skin over it is normal, or may exhibit a bluish tinge, especially in cold weather. In some cases the tumour is diminished by pressing the blood out of it, but slowly fills again when the pressure is relaxed, and it swells up when the child struggles or cries. From a cold abscess it is diagnosed by the history and progress of the swelling and by the absence of fluctuation. When situated over one of the hernial openings, it closely simulates a hernia; and when it occurs in the middle line of the face, head, or back, it may be mistaken for such other congenital conditions as meningocele or spina bifida. When other means fail, the use of an exploring needle clears up the diagnosis.

_Mixed Naevus._--As its name indicates, the mixed naevus partakes of the characters of the other two varieties; that is, it is a subcutaneous naevus with involvement of the skin.

It is frequently met with on the face and head, but may occur on any part of the body. It also affects parts covered by mucous membrane, such as the cheek, tongue, and soft palate. The swelling is rounded or lobulated, and projects beyond the level of its surroundings. Sometimes the skin is invaded by the naevoid tissue over the whole extent of the tumour, sometimes only over a limited area. Frequently the margin only is of a bright-red colour, while the skin in the centre resembles a cicatrix. The swelling is reduced by steady pressure, and increases in size and becomes tense when the child cries.

[Illustration: FIG. 68.--Mixed Naevus of Nose which was subsequently cured by Electrolysis.]

_Prognosis._--The rate of growth of the subcutaneous and mixed forms of naevi varies greatly. They sometimes increase rapidly, especially during the first few months of life; after this they usually grow at the same rate as the child, or more slowly. There is a decided tendency to disappearance of these varieties, fully 50 per cent. undergoing natural cure by a process of obliteration, similar to the obliteration of vessels in cicatricial tissue. This usually begins about the period of the first dentition, sometimes at the second dentition, and sometimes at puberty. On the other hand, an increased activity of growth may be shown at these periods. The onset of natural cure is recognised by the tumour becoming firmer and less compressible, and, in the mixed variety, by the colour becoming less bright. Injury, infection, or ulceration of the overlying skin may initiate the curative process.

Towards adult life the spaces in a subcutaneous naevus may become greatly enlarged, leading to the formation of a cavernous angioma.

_Treatment._--In view of the frequency with which subcutaneous and mixed naevi disappear spontaneously, interference is only called for when the growth of the tumour is out of proportion to that of the child, or when, from its situation--for example in the vicinity of the eye--any marked increase in its size would render it less amenable to treatment.

The methods of treatment most generally applicable are the use of radium and carbon dioxide snow, igni-puncture, electrolysis, and excision.

For naevi situated on exposed parts, where it is desirable to avoid a scar, the use of _radium_ is to be preferred. The tube of radium is applied at intervals to different parts of the naevus, the duration and frequency of the applications varying with the strength of the emanations and the reaction produced. The object aimed at is to induce obliteration of the naevoid tissue by cicatricial contraction without destroying the overlying skin. _Carbon-dioxide snow_ may be employed in the same manner, but the results are inferior to those obtained by radium.

_Igni-puncture_ consists in making a number of punctures at different parts of the naevus with a fine-pointed thermo-cautery, with the object of starting at each point a process of cicatrisation which extends throughout the naevoid tissue and so obliterates the vessels.

_Electrolysis_ acts by decomposing the blood and tissues into their constituent elements--oxygen and acids appearing at the positive, hydrogen and bases at the negative electrode. These substances and gases being given off in a nascent condition, at once enter into new combinations with anything in the vicinity with which they have a chemical affinity. In the naevus the practical result of this reaction is that at the positive pole nitric acid, and at the negative pole caustic potash, both in a state of minute subdivision, make their appearance. The effect on the tissues around the positive pole, therefore, is equivalent to that of an acid cauterisation, and on those round the negative pole, to an alkaline cauterisation.

As the process is painful, a general anaesthetic is necessary. The current used should be from 20 to 80 milliamperes, gradually increasing from zero, without shock; three to six large Bunsen cells give a sufficient current, and no galvanometer is required. Steel needles, insulated with vulcanite to within an eighth of an inch of their points, are the best. Both poles are introduced into the naevus, the positive being kept fixed at one spot, while the negative is moved about so as to produce a number of different tracks of cauterisation. On no account must either pole be allowed to come in contact with the skin, lest a slough be formed. The duration of the sitting is determined by the effect produced, as indicated by the hardening of the tumour, the average duration being from fifteen to twenty minutes. If pallor of the skin appears, it indicates that the needles are too near the surface, or that the blood supply to the integument is being cut off, and is an indication to stop. To cauterise the track and so prevent bleeding, the needles should be slowly withdrawn while the current is flowing. When the skin is reached the current is turned off. The punctures are covered with collodion. Six or eight weeks should be allowed to elapse before repeating the procedure. From two to eight or ten sittings may be necessary, according to the size and character of the naevus.

_Excision_ is to be preferred for naevi of moderate size situated on covered parts of the body, where a scar is of no importance. Its chief advantages over electrolysis are that a single operation is sufficient, and that the cure is speedy and certain. The operation is attended with much less haemorrhage than might be expected.

  1. Cavernous Angioma.#--This form of angioma consists of a series of large

blood spaces which are usually derived from the dilatation of the capillaries of a subcutaneous naevus. The spaces come to communicate freely with one another by the disappearance of adjacent capillary walls. While the most common situation is in the subcutaneous tissue, a cavernous angioma is sometimes met with in internal organs. It may appear at any age from early youth to middle life, and is of slow growth and may become stationary. The swelling is rounded or oval, there is no pulsation or bruit, and the tumour is but slightly compressible. The treatment consists in dissecting it out.

  1. Aneurysm by Anastomosis# is the name applied to a vascular tumour in

which the arteries, veins, and capillaries are all involved. It is met with chiefly on the upper part of the trunk, the neck, and the scalp. It tends gradually to increase in size, and may, after many years, attain an enormous size. The tumour is ill-defined, and varies in consistence. It is pulsatile, and a systolic bruit or a "thrilling" murmur may be heard over it. The chief risk is haemorrhage from injury or ulceration.

[Illustration: FIG. 69.--Cirsoid Aneurysm of Forehead in a boy aet. 10.

(Mr. J. W. Dowden's case.)]

The _treatment_ is conducted on the same lines as for naevus. When electrolysis is employed, it should be directed towards the afferent vessels; and if it fails to arrest the flow through these, it is useless to persist with it. In some cases ligation of the afferent vessels has been successful.

  1. Arterial Angioma# or #Cirsoid Aneurysm#.--This is composed of the

enlarged branches of an arterial trunk. It originates in the smaller branches of an artery--usually the temporal--and may spread to the main trunk, and may even involve branches of other trunks with which the affected artery anastomoses.

The condition is probably congenital in origin, though its appearance is frequently preceded by an injury. It almost invariably occurs in the scalp, and is usually met with in adolescent young adults.

The affected vessels slowly increase in size, and become tortuous, with narrowings and dilatations here and there. Grooves and gutters are frequently found in the bone underlying the dilated vessels.

There is a constant loud bruit in the tumour, which greatly troubles the patient and may interfere with sleep. There is no tendency either to natural cure or to rupture, but severe and even fatal haemorrhage may follow a wound of the dilated vessels.

[Illustration: FIG. 70.--Cirsoid Aneurysm of Orbit and Face, which developed after a blow on the Orbit with a cricket ball.

(From a photograph lent by Sir Montagu Cotterill.)]

The condition may be treated by excision or by electrolysis. In excision the haemorrhage is controlled by an elastic tourniquet applied horizontally round the head, or by ligation of the feeding trunks. In large tumours the bleeding is formidable. In many cases electrolysis is to be preferred, and is performed in the same way as for naevus. The positive pole is placed in the centre of the tumour, while the negative is introduced into the main affluents one after another.


ANEURYSM

An aneurysm is a sac communicating with an artery, and containing fluid or coagulated blood.

Two types are met with--the pathological and the traumatic. It is convenient to describe in this section also certain conditions in which there is an abnormal communication between an artery and a vein--arterio-venous aneurysm.


PATHOLOGICAL ANEURYSM

In this class are included such dilatations as result from weakening of the arterial coats, combined, in most cases, with a loss of elasticity in the walls and increase in the arterial tension due to arterio-sclerosis. In some cases the vessel wall is softened by arteritis--especially the embolic form--so that it yields before the pressure of the blood.

Repeated and sudden raising of the arterial tension, as a result, for example, of violent muscular efforts or of excessive indulgence in alcohol, plays an important part in the causation of aneurysm. These factors probably explain the comparative frequency of aneurysm in those who follow such arduous occupations as soldiers, sailors, dock-labourers, and navvies. In these classes the condition usually manifests itself between the ages of thirty and fifty--that is, when the vessels are beginning to degenerate, although the heart is still vigorous and the men are hard at work. The comparative immunity of women may also be explained by the less severe muscular strain involved by their occupations and recreations.

Syphilis plays an important part in the production of aneurysm, probably by predisposing the patient to arterio-sclerosis and atheroma, and inducing an increase in the vascular tension in the peripheral vessels, from loss of elasticity of the vessel wall and narrowing of the lumen as a result of syphilitic arteritis. It is a striking fact that aneurysm is seldom met with in women who have not suffered from syphilis.

  1. Varieties--Fusiform Aneurysm.#--When the _whole circumference_ of an

artery has been weakened, the tension of the blood causes the walls to dilate uniformly, so that a fusiform or tubular aneurysm results. All the coats of the vessel are stretched and form the sac of the aneurysm, and the affected portion is not only dilated but is also increased in length. This form is chiefly met with in the arch of the aorta, but may occur in any of the main arterial trunks. As the sac of the aneurysm includes all three coats, and as the inner and outer coats are usually thickened by the deposit in them of connective tissue, this variety increases in size slowly and seldom gives rise to urgent symptoms.

As a rule a fusiform aneurysm contains fluid blood, but when the intima is roughened by disease, especially in the form of calcareous plates, shreds of clot may adhere to it.

It has little tendency to natural cure, although this is occasionally effected by the emerging artery becoming occluded by a clot; it has also little tendency to rupture.

  1. Sacculated Aneurysm.#--When a _limited area_ of the vessel wall is

weakened--for example by atheroma or by other form of arteritis--this portion yields before the pressure of the blood, and a sacculated aneurysm results. The internal and middle coats being already damaged, or, it may be, destroyed, by the primary disease, the stress falls on the external coat, which in the majority of cases constitutes the sac. To withstand the pressure the external coat becomes thickened, and as the aneurysm increases in size it forms adhesions to surrounding tissues, so that fasciae, tendons, nerves, and other structures may be found matted together in its wall. The wall is further strengthened by the deposit on its inner aspect of blood-clot, which may eventually become organised.

The contents of the sac consist of fluid blood and a varying amount of clot which is deposited in concentric layers on the inner aspect of the sac, where it forms a pale, striated, firm mass, which constitutes a laminated clot. Near the blood-current the clot is soft, red, and friable (Fig. 72). The laminated clot not only strengthens the sac, enabling it to resist the blood-pressure and so prevent rupture, but, if it increases sufficiently to fill the cavity, may bring about cure. The principle upon which all methods of treatment are based is to imitate nature in producing such a clot.

Sacculated aneurysm, as compared with the fusiform variety, tends to rupture and also to cure by the formation of laminated clot; natural cure is sometimes all but complete when extension and rupture occur and cause death.

An aneurysm is said to be _diffused_ when the sac ruptures and the blood escapes into the cellular tissue.

  1. Clinical Features of Aneurysm.#--Surgically, the sacculated is by far

the most important variety. The outstanding feature is the existence in the line of an artery of a globular swelling, which pulsates. The pulsation is of an expansile character, which is detected by observing that when both hands are placed over the swelling they are separated with each beat of the heart. If the main artery be compressed on the cardiac side of the swelling, the pulsation is arrested and the tumour becomes smaller and less tense, and it may be still further reduced in size by gentle pressure being made over it so as to empty it of fluid blood. On allowing the blood again to flow through the artery, the pulsation returns at once, but several beats are required before the sac regains its former size. In most cases a distinct thrill is felt on placing the hand over the swelling, and a blowing, systolic murmur may be heard with the stethoscope. It is to be borne in mind that occasionally, when the interchange of blood between an aneurysm and the artery from which it arises is small, pulsation and bruit may be slight or even absent. This is also the case when the sac contains a considerable quantity of clot. When it becomes filled with clot--_consolidated aneurysm_--these signs disappear, and the clinical features are those of a solid tumour lying in contact with an artery, and transmitting its pulsation.

A comparison of the pulse in the artery beyond the seat of the aneurysm with that in the corresponding artery on the healthy side, shows that on the affected side the wave is smaller in volume, and delayed in time. A pulse tracing shows that the normal impulse and dicrotic waves are lost, and that the force and rapidity of the tidal wave are diminished.

[Illustration: FIG. 71.--Radiogram of Aneurysm of Aorta, showing laminated clot and erosion of bodies of vertebrae. The intervertebral discs are intact.]

An aneurysm exerts pressure on the surrounding structures, which are usually thickened and adherent to it and to one another. Adjacent veins may be so compressed that congestion and oedema of the parts beyond are produced. Pain, disturbances of sensation, and muscular paralyses may result from pressure on nerves. Such bones as the sternum and vertebrae undergo erosion and are absorbed by the gradually increasing pressure of the aneurysm. Cartilage, on the other hand, being elastic, yields before the pressure, so that the intervertebral discs or the costal cartilages may escape while the adjacent bones are destroyed (Fig. 71). The skin over the tumour becomes thinned and stretched, until finally a slough forms, and when it separates haemorrhage takes place.

[Illustration: FIG. 72.--Sacculated Aneurysm of Abdominal Aorta nearly filled with laminated clot. Note greater density of clot towards periphery.]

In the progress of an aneurysm towards rupture, timely clotting may avert death for the moment, but while extension in one direction has been arrested there is apt to be extension in another, with imminence of rupture, or it may be again postponed.

  1. Differential Diagnosis.#--The diagnosis is to be made from other

pulsatile swellings. Pulsation is sometimes transmitted from a large artery to a tumour, a mass of enlarged lymph glands, or an inflammatory swelling which lies in its vicinity, but the pulsation is not expansile--a most important point in differential diagnosis. Such swellings may, by appropriate manipulation, be moved from the artery and the pulsation ceases, and compression of the artery on the cardiac side of the swelling, although it arrests the pulsation, does not produce any diminution in the size or tension of the swelling, and when the pressure is removed the pulsation is restored immediately.

Fluid swellings overlying an artery, such as cysts, abscesses, or enlarged bursae, may closely simulate aneurysm. An apparent expansion may accompany the pulsation, but careful examination usually enables this to be distinguished from the true expansion of an aneurysm. Compression of the artery makes no difference in the size or tension of the swelling.

Vascular tumours, such as sarcoma and goitre, may yield an expansile pulsation and a soft, whifling bruit, but they differ from an aneurysm in that they are not diminished in size by compression of the main artery, nor can they be emptied by pressure.

The exaggerated pulsation sometimes observed in the abdominal aorta, the "pulsating aorta" seen in women, should not be mistaken for aneurysm.

  1. Prognosis.#--When _natural cure_ occurs it is usually brought about by

the formation of laminated clot, which gradually increases in amount till it fills the sac. Sometimes a portion of the clot in the sac is separated and becomes impacted as an embolus in the artery beyond, leading to thrombosis which first occludes the artery and then extends into the sac.

The progress of natural cure is indicated by the aneurysm becoming smaller, firmer, less expansile, and less compressible; the murmur and thrill diminish and the pressure effects become less marked. When the cure is complete the expansile pulsation is lost, and there remains a firm swelling attached to the vessel (_consolidated aneurysm_). While these changes are taking place the collateral arteries become enlarged, and an anastomotic circulation is established.

An aneurysm may prove _fatal_ by exerting pressure on important structures, by causing syncope, by rupture, or from the occurrence of suppuration. _Pressure_ symptoms are usually most serious from aneurysms situated in the neck, thorax, or skull. Sudden fatal _syncope_ is not infrequent in cases of aneurysm of the thoracic aorta.

_Rupture_ may take place through the skin, on a mucous or serous surface, or into the cellular tissue. The first haemorrhage is often slight and stops naturally, but it soon recurs, and is so profuse, especially when the blood escapes externally, that it rapidly proves fatal. When the bleeding takes place into the cellular tissue, the aneurysm is said to become _diffused_, and the extravasated blood spreads widely through the tissues, exerting great pressure on the surrounding structures.

The _clinical features_ associated with rupture are sudden and severe pain in the part, and the patient becomes pale, cold, and faint. If a comparatively small escape of blood takes place into the tissues, the sudden alteration in the size, shape, and tension of the aneurysm, together with loss of pulsation, may be the only local signs. When the bleeding is profuse, however, the parts beyond the aneurysm become greatly swollen, livid, and cold, and the pulse beyond is completely lost. The arrest of the blood supply may result in gangrene. Sometimes the pressure of the extravasated blood causes the skin to slough and, later, give way, and fatal haemorrhage results.

The _treatment_ is carried out on the same lines as for a ruptured artery (p. 261), it being remembered, however, that the artery is diseased and does not lend itself to reconstructive procedures.

_Suppuration_ may occur in the vicinity of an aneurysm, and the aneurysm may burst into the abscess which forms, so that when the latter points the pus is mixed with broken-down blood-clot, and finally free haemorrhage takes place. It has more than once happened that a surgeon has incised such an abscess without having recognised its association with aneurysm, with tragic results.

  1. Treatment.#--In treating an aneurysm, the indications are to imitate

Nature's method of cure by means of laminated clot.

_Constitutional treatment_ consists in taking measures to reduce the arterial tension and to diminish the force of the heart's action. The patient must be kept in bed. A dry and non-stimulating diet is indicated, the quantity being gradually reduced till it is just sufficient to maintain nutrition. Saline purges are employed to reduce the vascular tension. The benefit derived from potassium iodide administered in full doses, as first recommended by George W. Balfour, probably depends on its depressing action on the heart and its therapeutic benefit in syphilis. Pain or restlessness may call for the use of opiates, of which heroin is the most efficient.

_Local Treatment._--When constitutional treatment fails, local measures must be adopted, and many methods are available.

  1. Endo-aneurysmorrhaphy.#--The operation devised by Rudolf Matas in 1888

aims at closing the opening between the sac and its feeding artery, and in addition, folding the wall of the sac in such a way as to leave no vacant space. If there is marked disease of the vessel, Matas' operation is not possible and recourse is then had to ligation of the artery just above the sac.

_Extirpation of the Sac--The Old Operation._--The procedure which goes by this name consists in exposing the aneurysm, incising the sac, clearing out the clots, and ligating the artery above and below the sac. This method is suitable to sacculated aneurysm of the limbs, so long as they are circumscribed and free from complications. It has been successfully practised also in aneurysm of the subclavian, carotid, and external iliac arteries. It is not applicable to cases in which there is such a degree of atheroma as would interfere with the successful ligation of the artery. The continuity of the artery may be restored by grafting into the gap left after excision of the sac a segment of the great saphena vein.

_Ligation of the Artery._--The object of tying the artery is to diminish or to arrest the flow of blood through the aneurysm so that the blood coagulates both in the sac and in the feeding artery. The ligature may be applied on the cardiac side of the aneurysm--proximal ligation, or to the artery beyond--distal ligation.

_Proximal Ligation._--The ligature may be applied immediately above the sac (Anel, 1710) or at a distance above (John Hunter, 1785). The _Hunterian operation_ ensures that the ligature is applied to a part of the artery that is presumably healthy and where relations are undisturbed by the proximity of the sac; the best example is the ligation of the superficial femoral artery in Scarpa's triangle or in Hunter's canal for popliteal aneurysm; it is on record that Syme performed this operation with cure of the aneurysm on thirty-nine occasions.

It is to be noted that the Hunterian ligature does not aim at _arresting_ the flow of blood through the sac, but is designed so to diminish its volume and force as to favour the deposition within the sac of laminated clot. The development of the collateral circulation which follows upon ligation of the artery at a distance above the sac may be attended with just that amount of return stream which favours the deposit of laminated clot, and consequently the cure of the aneurysm; the return stream may, however, be so forcible as to prevent coagulation of the blood in the sac, or only to allow of the formation of a red thrombus which may in its turn be dispersed so that pulsation in the sac recurs. This does not necessarily imply failure to cure, as the recurrent pulsation may only be temporary; the formation of laminated clot may ultimately take place and lead to consolidation of the aneurysm.

The least desirable result of the Hunterian ligature is met with in cases where, owing to widespread arterial disease, the collateral circulation does not develop and gangrene of the limb supervenes.

_Anel's ligature_ is only practised as part of the operation which deals with the sac directly.

_Distal Ligation._--The tying of the artery beyond the sac, or of its two branches where it bifurcates (Brasdor, 1760, and Wardrop, 1825), may arrest or only diminish the flow of blood through the sac. It is less successful than the proximal ligature, and is therefore restricted to aneurysms so situated as not to be amenable to other methods; for example, in aneurysm of the common carotid near its origin, the artery may be ligated near its bifurcation, or in aneurysm of the innominate artery, the carotid and subclavian arteries are tied at the seat of election.

_Compression._--Digital compression of the feeding artery has been given up except as a preparation for operations on the sac with a view to favouring the development of a collateral circulation.

_Macewen's acupuncture or "needling"_ consists in passing one or more fine, highly tempered steel needles through the tissues overlying the aneurysm, and through its outer wall. The needles are made to touch the opposite wall of the sac, and the pulsation of the aneurysm imparts a movement to them which causes them to scarify the inner surface of the sac. White thrombus forms on the rough surface produced, and leads to further coagulation. The needles may be left in position for some hours, being shifted from time to time, the projecting ends being surrounded with sterile gauze.

The _Moore-Corradi method_ consists in introducing through the wall of the aneurysm a hollow insulated needle, through the lumen of which from 10 to 20 feet of highly drawn silver or other wire is passed into the sac, where it coils up into an open meshwork (Fig. 73). The positive pole of a galvanic battery is attached to the wire, and the negative pole placed over the patient's back. A current, varying in strength from 20 to 70 milliamperes, is allowed to flow for about an hour. The hollow needle is then withdrawn, but the wire is left _in situ_. The results are somewhat similar to those obtained by needling, but the clot formed on the large coil of wire is more extensive.

[Illustration: FIG. 73.--Radiogram of Innominate Aneurysm after treatment by the Moore-Corradi method. Two feet of finely drawn silver wire were introduced. The patient, a woman, aet. 47, lived for ten months after operation, free from pain (cf. Fig. 75).]

Colt's method of wiring has been mainly used in the treatment of abdominal aneurysm; gilt wire in the form of a wisp is introduced through the cannula and expands into an umbrella shape.

_Subcutaneous Injections of Gelatin._--Three or four ounces of a 2 per cent. solution of white gelatin in sterilised water, at a temperature of about 100 F., are injected into the subcutaneous tissue of the abdomen every two, three, or four days. In the course of a fortnight or three weeks improvement may begin. The clot which forms is liable to soften and be absorbed, but a repetition of the injection has in several cases established a permanent cure.

_Amputation of the limb_ is indicated in cases complicated by suppuration, by secondary haemorrhage after excision or ligation, or by gangrene. Amputation at the shoulder was performed by Fergusson in a case of subclavian aneurysm, as a means of arresting the blood-flow through the sac.


TRAUMATIC ANEURYSM

The essential feature of a traumatic aneurysm is that it is produced by some form of injury which divides all the coats of the artery. The walls of the injured vessel are presumably healthy, but they form no part of the sac of the aneurysm. The sac consists of the condensed and thickened tissues around the artery.

The injury to the artery may be a subcutaneous one such as a tear by a fragment of bone: much more commonly it is a punctured wound from a stab or from a bullet.

The aneurysm usually forms soon after the injury is inflicted; the blood slowly escapes into the surrounding tissues, gradually displacing and condensing them, until they form a sac enclosing the effused blood.

Less frequently a traumatic aneurysm forms some considerable time after the injury, from gradual stretching of the fibrous cicatrix by which the wound in the wall of the artery has been closed. The gradual stretching of this cicatrix results in condensation of the surrounding structures which form the sac, on the inner aspect of which laminated clot is deposited.

A traumatic aneurysm is almost always sacculated, and, so long as it remains circumscribed, has the same characters as a pathological sacculated aneurysm, with the addition that there is a scar in the overlying skin. A traumatic aneurysm is liable to become diffuse--a change which, although attended with considerable risk of gangrene, has sometimes been the means of bringing about a cure.

The treatment is governed by the same principles as apply to the pathological varieties, but as the walls of the artery are not diseased, operative measures dealing with the sac and the adjacent segment of the affected artery are to be preferred.


ARTERIO-VENOUS ANEURYSM

An abnormal communication between an artery and a vein constitutes an arterio-venous aneurysm. Two varieties are recognised--one in which the communication is direct--_aneurysmal varix_; the other in which the vein communicates with the artery through the medium of a sac--_varicose aneurysm_.

Either variety may result from pathological causes, but in the majority of cases they are traumatic in origin, being due to such injuries as stabs, punctured wounds, and gun-shot injuries which involve both artery and vein. In former times the most common situation was at the bend of the elbow, the brachial artery being accidentally punctured in blood-letting from the median basilic vein. Arterio-venous aneurysm is a frequent result of injuries by modern high-velocity bullets--for example, in the neck or groin.

In _aneurysmal varix_ the higher blood pressure in the artery forces arterial blood into the vein, which near the point of communication with the artery tends to become dilated, and to form a thick-walled sac, beyond which the vessel and its tributaries are distended and tortuous. The clinical features resemble those associated with varicose veins, but the entrance of arterial blood into the dilated veins causes them to pulsate, and produces in them a vibratory thrill and a loud murmur. In those at the groin, the distension of the veins may be so great that they look like sinuses running through the muscles, a feature that must be taken into account in any operation.

As the condition tends to remain stationary, the support of an elastic bandage is all that is required; but when the condition progresses and causes serious inconvenience, it may be necessary to cut down and expose the communication between the artery and vein, and, after separating the vessels, to close the opening in each by suture; this may be difficult or impossible if the parts are matted from former suppuration. If it is impossible thus to obliterate the communication, the artery should be ligated above and below the point of communication; although the risk of gangrene is considerable unless means are taken to develop the collateral circulation beforehand (Makins).

_Varicose aneurysm_ usually develops in relation to a traumatic aneurysm, the sac becoming adherent to an adjacent vein, and ultimately opening into it. In this way a communication between the artery and the vein is established, and the clinical features are those of a combination of aneurysm and aneurysmal varix.

As there is little tendency to spontaneous cure, and as the aneurysm is liable to increase in size and finally to rupture, operative treatment is usually called for. This is carried out on the same lines as for aneurysmal varix, and at the same time incising the sac, turning out the clots, and ligating any branches which open into the sac. If it can be avoided, the vein should not be ligated.


ANEURYSMS OF INDIVIDUAL ARTERIES

  1. Thoracic Aneurysm.#--All varieties of aneurysm occur in the aorta, the

fusiform being the most common, although a sacculated aneurysm frequently springs from a fusiform dilatation.

The _clinical features_ depend chiefly on the direction in which the aneurysm enlarges, and are not always well marked even when the sac is of considerable size. They consist in a pulsatile swelling--sometimes in the supra-sternal notch, but usually towards the right side of the sternum--with an increased area of dulness on percussion. With the X-rays a dark shadow is seen corresponding to the sac. Pain is usually a prominent symptom, and is largely referable to the pressure of the aneurysm on the vertebrae or the sternum, causing erosion of these bones. Pressure on the thoracic veins and on the air-passage causes cyanosis and dyspnoea. When the oesophagus is pressed upon, the patient may have difficulty in swallowing. The left recurrent nerve may be stretched or pressed upon as it hooks round the arch of the aorta, and hoarseness of the voice and a characteristic "brassy" cough may result from paralysis of the muscles of the larynx which it supplies. The vagus, the phrenic, and the spinal nerves may also be pressed upon. When the aneurysm is on the transverse part of the arch, the trachea is pulled down with each beat of the heart--a clinical phenomena known as the "tracheal tug." Aneurysm of the descending aorta may, after eroding the bodies of the vertebrae (Fig. 71) and posterior portions of the ribs, form a swelling in the back to the left of the spine.

Inasmuch as obliteration of the sac and the feeding artery is out of the question, surgical treatment is confined to causing coagulation of the blood in an extension or pouching of the sac, which, making its way through the parietes of the chest, threatens to rupture externally. This may be achieved by Macewen's needles or by the introduction of wire into the sac. We have had cases under observation in which the treatment referred to has been followed by such an amount of improvement that the patient has been able to resume a laborious occupation for one or more years. Christopher Heath found that improvement followed ligation of the left common carotid in aneurysm of the transverse part of the aortic arch.

[Illustration: FIG. 74.--Thoracic Aneurysm, threatening to rupture externally, but prevented from doing so by Macewen's needling. The needles were left in for forty-eight hours.]

  1. Abdominal Aneurysm.#--Aneurysm is much less frequent in the abdominal

than in the thoracic aorta. While any of the large branches in the abdomen may be affected, the most common seats are in the aorta itself, just above the origin of the coeliac artery and at the bifurcation.

The _clinical features_ vary with the site of the aneurysm and with its rapidity and direction of growth. A smooth, rounded swelling, which exhibits expansile pulsation, forms, usually towards the left of the middle line. It may extend upwards under cover of the ribs, downwards towards the pelvis, or backward towards the loin. On palpation a systolic thrill may be detected, but the presence of a murmur is neither constant nor characteristic. Pain is usually present; it may be neuralgic in character, or may simulate renal colic. When the aneurysm presses on the vertebrae and erodes them, the symptoms simulate those of spinal caries, particularly if, as sometimes happens, symptoms of compression paraplegia ensue. In its growth the swelling may press upon and displace the adjacent viscera, and so interfere with their functions.

The _diagnosis_ has to be made from solid or cystic tumours overlying the artery; from a "pulsating aorta"; and from spinal caries; much help is obtained by the use of the X-rays.

The condition usually proves fatal, either by the aneurysm bursting into the peritoneal cavity, or by slow leakage into the retro-peritoneal tissue.

The Moore-Corradi method has been successfully employed, access to the sac having been obtained by opening the abdomen. Ligation of the aorta has so far been unsuccessful, but in one case operated upon by Keen the patient survived forty-eight days.

  1. Innominate aneurysm# may be of the fusiform or of the sacculated

variety, and is frequently associated with pouching of the aorta. It usually grows upwards and laterally, projecting above the sternum and right clavicle, which may be eroded or displaced (Fig. 75). Symptoms of pressure on the structures in the neck, similar to those produced by aortic aneurysm, occur. The pulses in the right upper extremity and in the right carotid and its branches are diminished and delayed. Pressure on the right brachial plexus causes shooting pain down the arm and muscular paresis on that side. Vaso-motor disturbances and contraction of the pupil on the right side may result from pressure on the sympathetic. Death may take place from rupture, or from pressure on the air-passage.

[Illustration: FIG. 75.--Innominate Aneurysm in a woman, aet. 47, eight months after treatment by Moore-Corradi method (cf. Fig. 73).]

The available methods of treatment are ligation of the right common carotid and third part of the right subclavian (Wardrop's operation), of which a number of successful cases have been recorded. Those most suitable for ligation are cases in which the aneurysm is circumscribed and globular (Sheen). If ligation is found to be impracticable, the Moore-Corradi method or Macewen's needling may be tried.

  1. Carotid Aneurysms.#--Aneurysm of the _common carotid_ is more frequent

on the right than on the left side, and is usually situated either at the root of the neck or near the bifurcation. It is the aneurysm most frequently met with in women. From its position the swelling is liable to press on the vagus, recurrent and sympathetic nerves, on the air-passage, and on the oesophagus, giving rise to symptoms referable to such pressure. There may be cerebral symptoms from interference with the blood supply of the brain.

Aneurysm near the origin has to be diagnosed from subclavian, innominate, and aortic aneurysm, and from other swellings--solid or fluid--met with in the neck. It is often difficult to determine with precision the trunk from which an aneurysm at the root of the neck originates, and not infrequently more than one vessel shares in the dilatation. A careful consideration of the position in which the swelling first appeared, of the direction in which it has progressed, of its pressure effects, and of the condition of the pulses beyond, may help in distinguishing between aortic, innominate, carotid, and subclavian aneurysms. Skiagraphy is also of assistance in recognising the vessel involved.

Tumours of the thyreoid, enlarged lymph glands, and fatty and sarcomatous tumours can usually be distinguished from aneurysm by the history of the swelling and by physical examination. Cystic tumours and abscesses in the neck are sometimes more difficult to differentiate on account of the apparently expansile character of the pulsation transmitted to them. The fact that compression of the vessel does not affect the size and tension of these fluid swellings is useful in distinguishing them from aneurysm.

_Treatment._--Digital compression of the vessel against the transverse process of the sixth cervical vertebra--the "carotid tubercle"--has been successfully employed in the treatment of aneurysm near the bifurcation. Proximal ligation in the case of high aneurysms, or distal ligation in those situated at the root of the neck, is more certain. Extirpation of the sac is probably the best method of treatment, especially in those of traumatic origin. These operations are attended with considerable risk of hemiplegia from interference with the blood supply of the brain.

The _external carotid_ and the cervical portion of the _internal carotid_ are seldom the primary seat of aneurysm, although they are liable to be implicated by the upward spread of an aneurysm at the bifurcation of the common trunk. In addition to the ordinary signs of aneurysm, the clinical manifestations are chiefly referable to pressure on the pharynx and larynx, and on the hypoglossal nerve. Aneurysm of the internal carotid is of special importance on account of the way in which it bulges into the pharynx in the region of the tonsil, in some cases closely simulating a tonsillar abscess. Cases are on record in which such an aneurysm has been mistaken for an abscess and incised, with disastrous results.

_Aneurysmal varix_ may occur in the neck as a result of stabs or bullet wounds. The communication is usually between the common carotid artery and the internal jugular vein. The resulting interference with the cerebral circulation causes headache, giddiness, and other brain symptoms, and a persistent loud murmur is usually a source of annoyance to the patient and may be sufficient indication for operative treatment.

  1. Intracranial aneurysm# involves the internal carotid and its branches,

or the basilar artery, and appears to be more frequently associated with syphilis and with valvular disease of the heart than are external aneurysms. It gives rise to symptoms similar to those of other intracranial tumours, and there is sometimes a loud murmur. It usually proves fatal by rupture, and intracranial haemorrhage. The treatment is to ligate the common carotid or the vertebral artery in the neck, according to the seat of the aneurysm.

  1. Orbital Aneurysm.#--The term pulsating exophthalmos is employed to

embrace a number of pathological conditions, including aneurysm, in which the chief symptoms are pulsation in the orbit and protrusion of the eyeball. There may be, in addition, congestion and oedema of the eyelids, and a distinct thrill and murmur, which can be controlled by compression of the common carotid in the neck. Varying degrees of ocular paralysis and of interference with vision may also be present.

These symptoms are due, in the majority of cases, to an aneurysmal varix of the internal carotid artery and cavernous sinus, which is often traumatic in origin, being produced either by fracture of the base of the skull or by a punctured wound of the orbit. In other cases they are due to aneurysm of the ophthalmic artery, to thrombosis of the cavernous sinus, and, in rare instances, to cirsoid aneurysm.

If compression of the common carotid is found to arrest the pulsation, ligation of this vessel is indicated.

  1. Subclavian Aneurysm.#--Subclavian aneurysm is usually met with in men

who follow occupations involving constant use of the shoulder--for example, dock-porters and coal-heavers. It is more common on the right side.

The aneurysm usually springs from the third part of the artery, and appears as a tense, rounded, pulsatile swelling just above the clavicle and to the outer side of the sterno-mastoid muscle. It occasionally extends towards the thorax, where it may become adherent to the pleura. The radial pulse on the same side is small and delayed. Congestion and oedema of the arm, with pain, numbness, and muscular weakness, may result from pressure on the veins and nerves as they pass under the clavicle; and pressure on the phrenic nerve may induce hiccough. The aneurysm is of slow growth, and occasionally undergoes spontaneous cure.

The conditions most likely to be mistaken for it are a soft, rapidly growing sarcoma, and a normal artery raised on a cervical rib.

On account of the relations of the artery and of its branches, treatment is attended with greater difficulty and danger in subclavian than in almost any other form of external aneurysm. The available operative measures are proximal ligation of the innominate, and distal ligation. In some cases it has been found necessary to combine distal ligation with amputation at the shoulder-joint, to prevent the collateral circulation maintaining the flow through the aneurysm. Matas' operation has been successfully performed by Hogarth Pringle.

  1. Axillary Aneurysm.#--This is usually met with in the right arm of

labouring men and sailors, and not infrequently follows an injury in the region of the shoulder. The vessel may be damaged by the head of a dislocated humerus or in attempts to reduce the dislocation, by the fragments of a fractured bone, or by a stab or cut. Sometimes the vein also is injured and an arterio-venous aneurysm established.

Owing to the laxity of the tissues, it increases rapidly, and it may soon attain a large size, filling up the axilla, and displacing the clavicle upwards. This renders compression of the third part of the subclavian difficult or impossible. It may extend beneath the clavicle into the neck, or, extending inwards may form adhesions to the chest wall, and, after eroding the ribs, to the pleura.

The usual symptoms of aneurysm are present, and the pressure effects on the veins and nerves are similar to those produced by an aneurysm of the subclavian. Intra-thoracic complications, such as pleurisy or pneumonia, are not infrequent when there are adhesions to the chest wall and pleura. Rupture may take place externally, into the shoulder-joint, or into the pleura.

Extirpation of the sac is the operation of choice, but, if this is impracticable, ligation of the third part of the subclavian may be had recourse to.

  1. Brachial aneurysm# usually occurs at the bend of the elbow, is of

traumatic origin, and is best treated by excision of the sac.

_Aneurysmal varix_, which was frequently met with in this situation in the days of the barber-surgeons,--usually as a result of the artery having been accidentally wounded while performing venesection of the median basilic vein,--may be treated, according to the amount of discomfort it causes, by a supporting bandage, or by ligation of the artery above and below the point of communication.

Aneurysms of the vessels of the #forearm and hand# call for no special mention; they are almost invariably traumatic, and are treated by excision of the sac.

  1. Inguinal Aneurysm# (_Aneurysm of the Iliac and Femoral

Arteries_).--Aneurysms appearing in the region of Poupart's ligament may have their origin in the external or common iliac arteries or in the upper part of the femoral. On account of the tension of the fascia lata, they tend to spread upwards towards the abdomen, and, to a less extent, downwards into the thigh. Sometimes a constriction occurs across the sac at the level of Poupart's ligament.

The pressure exerted on the nerves and veins of the lower extremity causes pain, congestion, and oedema of the limb. Rupture may take place externally, or into the cellular tissue of the iliac fossa.

These aneurysms have to be diagnosed from pulsating sarcoma growing from the pelvic bones, and from an abscess or a mass of enlarged lymph glands overlying the artery and transmitting its pulsation.

The method of treatment that has met with most success is ligation of the common or external iliac, reached either by reflecting the peritoneum from off the iliac fossa (extra-peritoneal operation), or by going through the peritoneal cavity (trans-peritoneal operation).

  1. Gluteal Aneurysm.#--An aneurysm in the buttock may arise from the

superior or from the inferior gluteal artery, but by the time it forms a salient swelling it is seldom possible to recognise by external examination in which vessel it takes origin. The special symptoms to which it gives rise are pain down the limb from pressure on the sciatic nerve, and interference with the movements at the hip.

Ligation of the hypogastric (internal iliac) by the trans-peritoneal route is the most satisfactory method of treatment. Extirpation of the sac is difficult and dangerous, especially when the aneurysm has spread into the pelvis.

  1. Femoral Aneurysm.#--Aneurysm of the femoral artery beyond the origin of

the profunda branch is usually traumatic in origin, and is more common in Scarpa's triangle than in Hunter's canal. Any of the methods already described is available for their treatment--the choice lying between Matas' operation and ligation of the external iliac.

Aneurysm of the _profunda femoris_ is distinguished from that of the main trunk by the fact that the pulses beyond are, in the former, unaffected, and by the normal artery being felt pulsating over or alongside the sac.

In _aneurysmal varix_, a not infrequent result of a bullet wound or a stab, the communication with the vein may involve the main trunk of the femoral artery. Should operative interference become necessary as a result of progressive increase in size of the tumour, or progressive distension of the veins of the limb, an attempt should be made to separate the vessels concerned and to close the opening in each by suture. If this is impracticable, the artery is tied above and below the communication; gangrene of the limb may supervene, and we have observed a case in which the gangrene extended up to the junction of the middle and lower thirds of the thigh, and in which recovery followed upon amputation of the thigh.

  1. Popliteal Aneurysm.#--This is the most common surgical aneurysm, and is

not infrequently met with in both limbs. It is generally due to disease of the artery, and repeated slight strains, which are so liable to occur at the knee, play an important part in its formation. In former times it was common in post-boys, from the repeated flexion and extension of the knee in riding.

The aneurysm is usually of the sacculated variety, and may spring from the front or from the back of the vessel. It may exert pressure on the bones and ligaments of the joint, and it has been known to rupture into the articulation. The pain, stiffness, and effusion into the joint which accompany these changes often lead to an erroneous diagnosis of joint disease. The sac may press upon the popliteal artery or vein and their branches, causing congestion and oedema of the leg, and lead to gangrene. Pressure on the tibial and common peroneal nerves gives rise to severe pain, muscular cramp, and weakness of the leg.

The differential diagnosis is to be made from abscess, bursal cyst, enlarged glands, and sarcoma, especially pulsating sarcoma of one of the bones entering into the knee joint.

The choice of operation lies between ligation of the femoral artery in Hunter's canal, and Matas' operation of aneurysmo-arteriorrhaphy. The success which attends the Hunterian operation is evidenced by the fact that Syme performed it thirty-seven times without a single failure. If it fails, the old operation should be considered, but it is a more serious operation, and one which is more liable to be followed by gangrene of the limb. Experience shows that ligation of the vein, or even the removal of a portion of it, is not necessarily followed by gangrene. The risk of gangrene is diminished by a course of digital compression of the femoral artery, before operating on the aneurysm.

_Aneurysmal varix_ is sometimes met with in the region of the popliteal space. It is characterised by the usual symptoms, and is treated by palliative measures, or by ligation of the artery above and below the point of communication.

_Aneurysm_ in the #leg and foot# is rare. It is almost always traumatic, and is treated by excision of the sac.