Fig. 76.—Congenital Cystic Tumour or Hygroma of Axilla. (From a photograph lent by Dr. Lediard.)Fig. 76.—Congenital Cystic Tumour or Hygroma of Axilla.(From a photograph lent by Dr. Lediard.)
Fig. 76.—Congenital Cystic Tumour or Hygroma of Axilla.
(From a photograph lent by Dr. Lediard.)
Thecystic lymphangioma,lymphatic cyst, orcongenital cystic hygromais most often met with in the neck—hydrocele of the neck; it is situated beneath the deep fascia, and projects either in front of or behind the sterno-mastoid muscle. It may attain a large size, the overlying skin and cyst wall may be so thin as to be translucent, and it has been known to cause serious impairment of respiration through pressing on the trachea. In the axilla also the cystic tumour may attain a considerable size(Fig. 76); less frequent situations are the groin, and the floor of the mouth, where it constitutes one form of ranula.
The nature of these swellings is to be recognised by their situation, by their having existed from infancy, and, if necessary, by drawing off some of the contents of the cyst through a fine needle. They are usually remarkably indolent, persisting often for a long term of years without change, and, like the hæmangioma, they sometimes undergo spontaneous cicatrisation and cure. Sometimes the cystic tumour becomes infected and forms an abscess—another, although less desirable, method of cure. Those situated in the neck are most liable to suppurate, probably because of pyogenic organisms being brought to them by the lymphatics taking origin in the scalp, ear, or throat.
If operative interference is called for, the cysts may be tapped and injected with iodine, or excised; the operation for removal may entail a considerable dissection amongst the deeper structures at the root of the neck, and should not be lightly undertaken; parts left behind may be induced to cicatrise by inserting a tube of radium and leaving it for a few days.
Lymphangiomas are met with in the abdomen in the form ofomental cysts.
Lymphadenitis.—Inflammation of lymph glands results from the advent of an irritant, usually bacterial or toxic, brought to the glands by the afferent lymph vessels. These vessels may share in the inflammation and be the seat of lymphangitis, or they may show no evidence of the passage of the noxa. It is exceptional for the irritant to reach the gland through the blood-stream.
A strain or other form of trauma is sometimes blamed for the onset of lymphadenitis, especially in the glands of the groin (bubo), but it is usually possible to discover some source of pyogenic infection which is responsible for the mischief, or to obtain a history of some antecedent infection such as gonorrhœa. It is possible for gonococci to lie latent in the inguinal glands for long periods, and only give rise to lymphadenitis if the glands be subsequently subjected to injury. The glands most frequently affected are those in the neck, axilla, and groin.
The characters of the lymphadenitis vary with the nature of the irritant. Sometimes it is mild and evanescent, as in the glandular enlargement in the neck which attends tonsillitis and other forms of sore throat. Sometimes it is more persistent, asin the enlargement that is associated with adenoids, hypertrophied tonsils, carious teeth, eczema of the scalp, and otorrhœa; and it is possible that this indolent enlargement predisposes to tuberculous infection. A similar enlargement is met with in the axilla in cases of chronic interstitial mastitis, and in the groin as a result of chronic irritation about the external genitals, such as balanitis.
Sometimes the lymphadenitis is of an acute character, and the tendency is towards the formation of an abscess. This is illustrated in the axillary glands as a result of infected wounds of the fingers; in the femoral glands in infected wounds or purulent blisters on the foot; in the inguinal glands in gonorrhœa and soft sore; and in the cervical glands in the severer forms of sore throat associated with diphtheria and scarlet fever. The most acute suppurations result from infection with streptococci.
Superficial glands, when inflamed and suppurating, become enlarged, tender, fixed, and matted to one another. In the glands of the groin the suppurative process is often remarkably sluggish; purulent foci form in the interior of individual glands, and some time may elapse before the pus erupts through their respective capsules. In the deeply placed cervical glands, especially in cases of streptococcal throat infections, the suppuration rapidly involves the surrounding cellular tissue, and the clinical features are those of an acute cellulitis and deeply seated abscess. When this is incised the necrosed glands may be found lying in the pus, and on bacteriological examination are found to be swarming with streptococci. In suppuration of the axillary glands the abscess may be quite superficial, or it may be deeply placed beneath the strong fascia and pectoral muscles, according to the group of glands involved.
Thediagnosisof septic lymphadenitis is usually easy. The indolent enlargements are not always to be distinguished, however, from commencing tuberculous disease, except by the use of the tuberculin test, and by the fact that they usually disappear on removing the peripheral source of irritation.
Treatment.—The first indication is to discover and deal with the source of infection, and in the indolent forms of lymphadenitis this will usually be followed by recovery. In the acute forms following on pyogenic infection, the best results are obtained from the hyperæmic treatment carried out by means of suction bells. If suppuration is not thereby prevented, or if it has already taken place, each separate collection of pus is punctured with a narrow-bladed knife and the use of the suctionbell is persevered with. If there is a large periglandular abscess, as is often the case, in the neck and axilla, the opening may require to be made by Hilton's method, and it may be necessary to insert a drainage-tube.
Fig. 77.—Tuberculous Cervical Gland with abscess formation in subcutaneous cellular tissue, in a boy æt. 10.Fig. 77.—Tuberculous Cervical Gland with abscess formation in subcutaneous cellular tissue, in a boy æt. 10.
Fig. 77.—Tuberculous Cervical Gland with abscess formation in subcutaneous cellular tissue, in a boy æt. 10.
Tuberculous Disease of Glands.—This is a disease of great frequency and importance. The tubercle bacilli usually gain access to the gland through the afferent lymph vessels, which convey them from some lesion of the surface within the areadrained by them. Tuberculous infection may supervene in glands that are already enlarged as a result of chronic septic irritation. While any of the glands in the body may be affected, the disease is most often met with in the cervical groups which derive their lymph from the mouth, nose, throat, and ear.
The appearance of the glands on sectionvaries with the stage of the disease. In the early stages the gland is enlarged, it may be to many times its natural size, is normal in appearance and consistence, and as there is no peri-adenitis it is easily shelled out from its surroundings. On microscopical examination, however, there is evidence of infection in the shape of bacilli and of characteristic giant and epithelioid cells. At a later stage, the gland tissue is studded with minute yellow foci which tend to enlarge and in time to become confluent, so that the whole gland is ultimately converted into a caseous mass. This caseous material is surrounded by the thickened capsule which, as a result of peri-adenitis, tends to become adherent to and fused with surrounding structures, and particularly with layers of fascia and with the walls of veins. The caseated tissue often remains unchanged for long periods; it may become calcified, but more frequently it breaks down and liquefies.
Tuberculous disease in the cervical glandsis a common accompaniment or sequel of adenoids, enlarged tonsils, carious teeth, pharyngitis, middle-ear disease, and conjunctivitis. These lesions afford the bacilli a chance of entry into the lymph vessels, in which they are carried to the glands, where they give rise to disease.
The enlargement may affect only one gland, usually below the angle of the mandible, and remain confined to it, the gland reaching the size of a hazel-nut, and being ovoid, firm, and painless. More commonly the disease affects several glands, on one or on both sides of the neck. When the disease commences in the pre-auricular or submaxillary glands, it tends to spread to those along the carotid sheath: when the posterior auricular and occipital glands are first involved, the spread is to those along the posterior border of the sterno-mastoid. In many cases all the chains in front of, beneath, and behind this muscle are involved, the enlarged glands extending from the mastoid to the clavicle. They are at first discrete and movable, and may even vary in size from time to time; but with the addition of peri-adenitis they become fixed and matted together, forming lobulated or nodular masses (Fig. 78). They become adherent not only to one another, but also to the structures in theirvicinity,—and notably to the internal jugular vein,—a point of importance in regard to their removal by operation.
At any stage the disease may be arrested and the glands remain for long periods without further change. It is possible that the tuberculous tissue may undergo cicatrisation. More commonly suppuration ensues, and a cold abscess forms, but if there is a mixed infection, the pyogenic factor being usually derived from the throat, it may take on active features.
Fig. 78.—Mass of Tuberculous Glands removed from Axilla (cf. Fig. 79).Fig. 78.—Mass of Tuberculous Glands removed from Axilla (cf.Fig. 79).
Fig. 78.—Mass of Tuberculous Glands removed from Axilla (cf.Fig. 79).
The transition from the solid to the liquefied stage is attended with pain and tenderness in the gland, which at the same time becomes fixed and globular, and finally fluctuation can be elicited.
If left to itself, the softened tubercle erupts through the capsule of the gland and infects the cellular tissue. The cervical fascia is perforated and a cold abscess, often much larger than the gland from which it took origin, forms between the fascia and the overlying skin. The further stages—reddening, undermining of skin and external rupture, with the formation of ulcersand sinuses—have been described with tuberculous abscess. The ulcers and sinuses persist indefinitely, or they heal and then break out again; sometimes the skin becomes infected, and a condition like lupus spreads over a considerable area. Spontaneous healing finally takes place after the caseous tubercle has been extruded; the resulting scars are extremely unsightly, being puckered or bridled, or hypertrophied like keloid.
While the disease is most common in childhood and youth, it may be met with even in advanced life; and although often associated with impaired health and unhealthy surroundings, it may affect those who are apparently robust and are in affluent circumstances.
Diagnosis.—The chief importance lies in differentiating tuberculous disease from lympho-sarcoma and from lymphadenoma, and this is usually possible from the history and from the nature of the enlargement. Signs of liquefaction and suppuration support the diagnosis of tubercle. If any doubt remains, one of the glands should be removed and submitted to microscopical examination. Other forms of sarcoma, and the enlargement of an accessory thyreoid, are less likely to be confused with tuberculous glands. Calcified tuberculous glands give definite shadows with the X-rays.
Enlargement of the cervical glands from secondary cancer may simulate tuberculosis, but is differentiated by its association with cancer in the mouth or throat, and by the characteristic, stone-like induration of epithelioma.
The cold abscess which results from tuberculous glands is to be distinguished from that due to disease in the cervical spine, retro-pharyngeal abscess, as well as from congenital and other cystic swellings in the neck.
Prognosis.—Next to lupus, glandular disease is of all tuberculous lesions the least dangerous to life; but while it is the rule to recover from tuberculous disease of glands with or without an operation, it is unfortunately quite common for such persons to become the subjects of tuberculosis in other parts of the body at any subsequent period of life.
Treatment.—There is considerable difference of opinion regarding the treatment of glandular tuberculosis. Some authorities, impressed with the undoubted possibility of natural cure, are satisfied with promoting this by measures directed towards improving the general health, by the prolonged administration of tuberculin, and by repeated exposures to the X-rays and to sunlight. Others again, influenced by the risk of extension of the disease and by the destruction of tissue anddisfigurement caused by breaking down of the tuberculous tissue and mixed infection, advocate the removal of the glands by operation.
The conditions vary widely in different cases, and the treatment should be adapted to the individual requirements. If the disease remains confined to the glands originally infected and there are no signs of breaking down, “expectant measures” may be persevered with.
Fig. 79.—Tuberculous Axillary Glands (cf. Fig. 78).Fig. 79.—Tuberculous Axillary Glands (cf.Fig. 78).
Fig. 79.—Tuberculous Axillary Glands (cf.Fig. 78).
If, on the other hand, the disease exhibits aggressive tendencies, the question of operation should be considered. The undesirable results of the breaking down and liquefaction of the diseased gland may be avoided by the timely withdrawal of the fluid contents through a hollow needle.
The excision of tuberculous glandsis often a difficult operation, because of the number and deep situation of the glands to be removed, and of the adhesions to surrounding structures. The skin incision must be sufficiently extensive to give access to the whole of the affected area, and to avoid disfigurement should, whenever possible, be made in the line of the natural creases ofthe skin. In exposing the glands the common facial and other venous trunks may require to be clamped and tied. Care must be taken not to injure the important nerves, particularly the accessory, the vagus, and the phrenic. The inframaxillary branches of the facial, the hypoglossal and its descending branches, and the motor branches of the deep cervical plexus, are also liable to be injured. The dissection is rendered easier and is attended with less risk of injury to the nerves, if the patient is placed in the sitting posture so as to empty the veins, and, instead of a knife, the conical scissors of Mayo are employed. When the glands are extensively affected on both sides of the neck, it is advisable to allow an interval to elapse rather than to operate on both sides at one sitting. (Op. Surg., p. 189.)
If the tonsils are enlarged they should not be removed at the same time, as, by so doing, there is a risk of pyogenic infection from the throat being carried to the wound in the neck, but they should be removed, after an interval, to prevent relapse of disease in the glands.
When the skin is brokenand caseous tuberculous tissue is exposed, healing is promoted by cutting away diseased skin, removing the granulation tissue with the spoon, scraping sinuses, and packing the cavity with iodoform worsted and treating it by the open method and secondary suture if necessary. Exposure to the sunshine on the seashore and to the X-rays is often beneficial in these cases.
Tuberculous disease in the axillary glandsmay be a result of extension from those in the neck, from the mamma, ribs, or sternum, or more rarely from the upper extremity. We have seen it from an infected wound of a finger. In some cases no source of infection is discoverable. The individual glands attain a considerable size, and they fuse together to form a large tumour which fills up the axillary space. The disease progresses more rapidly than it does in the cervical glands, and almost always goes on to suppuration with the formation of sinuses. Conservative measures need not be considered, as the only satisfactory treatment is excision, and that without delay.
Tuberculous disease in the glands of the groinis comparatively rare. We have chiefly observed it in the femoral glands as a result of inoculation tubercle on the toes or sole of the foot. The affected glands nearly always break down and suppurate, and after destroying the overlying skin give rise to fungating ulcers. The treatment consists in excising the glands and the affected skin. The dissection may be attendedwith troublesome hæmorrhage from the numerous veins that converge towards the femoral trunk.
Tuberculous disease in themesentericandbronchial glandsis described with the surgery of regions.
Syphilitic Disease of Glands.—Enlargement of lymph glands is a prominent feature of acquired syphilis, especially in the form of the indolent or bullet-bubo which accompanies the primary lesion, and the general enlargement of glands that occurs in secondary syphilis. Gummatous disease in glands is extremely rare; the affected gland rapidly enlarges to the size of a walnut, and may then persist for a long period without further change; if it breaks down, the overlying skin is destroyed and the caseated tissue of the gumma exposed.
Lymphadenoma.—Hodgkin's Disease(Pseudo-leukæmia of German authors).—This is a rare disease, the origin of which is as yet unknown, but analogy would suggest that it is due to infection with a slowly growing micro-organism. It is chiefly met with in young subjects, and is characterised by a painless enlargement of a particular group of glands, most commonly those in the cervical region (Fig. 80).
Fig. 80.—Chronic Hodgkin's Disease in a boy æt. 11.Fig. 80.—Chronic Hodgkin's Disease in a boy æt. 11.
Fig. 80.—Chronic Hodgkin's Disease in a boy æt. 11.
The glands are usually larger than in tuberculosis, and they remain longer discrete and movable; they are firm in consistence, and on section present a granular appearance due to overgrowth of the connective-tissue framework. In time the glandular masses may form enormous projecting tumours, the swelling being added to by lymphatic œdema of the overlying cellular tissue and skin.
The enlargement spreads along the chain of glands to those above the clavicle, to those in the axilla, and to those of the opposite side (Fig. 81). Later, the glands in the groin become enlarged, and it is probable that the infection has spread from the neck along the mediastinal, bronchial, retro-peritoneal, and mesenteric glands, and has branched off to the iliac and inguinal groups.
Two clinical types are recognised, one in which the disease progresses slowly and remains confined to the cervical glands for two or more years; the other, in which the disease is more rapidly disseminated and causes death in from twelve to eighteen months.
Fig. 81.—Lymphadenoma (Hodgkin's Disease) affecting left side of neck and left axilla, in a woman æt. 44. Three years' duration.Fig. 81.—Lymphadenoma (Hodgkin's Disease) affecting left side of neck and left axilla, in a woman æt. 44. Three years' duration.
Fig. 81.—Lymphadenoma (Hodgkin's Disease) affecting left side of neck and left axilla, in a woman æt. 44. Three years' duration.
In the acute form, the health suffers, there is fever, and the glands may vary in size with variations in the temperature; the blood presents the characters met with in secondary anæmia. The spleen, liver, testes, and mammæ may be enlarged; theglandular swellings press on important structures, such as the trachea, œsophagus, or great veins, and symptoms referable to such pressure manifest themselves.
Diagnosis.—Considerable difficulty attends the diagnosis of lymphadenoma at an early stage. The negative results of tuberculin tests may assist in the differentiation from tuberculous disease, but the more certain means of excising one of the suspected glands and submitting it to microscopical examination should be had recourse to. The sections show proliferation of endothelial cells, the formation of numerous giant cells quite unlike those of tuberculosis and a progressive fibrosis. Lympho-sarcoma can usually be differentiated by the rapid assumption of the local features of malignant disease, and in a gland removed for examination, a predominance of small round cells with scanty protoplasm. The enlargement associated with leucocythæmia is differentiated by the characteristic changes in the blood.
Treatment.—In the acute form of lymphadenoma, treatment is of little avail. Arsenic may be given in fulldoseseither by the mouth or by subcutaneous injection; the intravenousadministration of neo-salvarsan may be tried. Exposure to the X-rays and to radium has been more successful than any other form of treatment. Excision of glands, although sometimes beneficial, seldom arrests the progress of the disease. The ease and rapidity with which large masses of glands may be shelled out is in remarkable contrast to what is observed in tuberculous disease. Surgical interference may give relief when important structures are being pressed upon—tracheotomy, for example, may be required where life is threatened by asphyxia.
Leucocythæmia.—This is a disease of the blood and of the blood-forming organs, in which there is a great increase in the number, and an alteration of the character, of the leucocytes present in the blood. It may simulate lymphadenoma, because, in certain forms of the disease, the lymph glands, especially those in the neck, axilla, and groin, are greatly enlarged.
Primary Tumours.—Lympho-sarcoma, which may be regarded as a sarcoma starting in a lymph gland, appears in the neck, axilla, or groin as a rapidly growing tumour consisting of one enlarged gland with numerous satellites. As the tumour increases in size, the sarcomatous tissue erupts through the capsule of the gland, and infiltrates the surrounding tissues, whereby it becomes fixed to these and to the skin.
Fig. 82.—Lympho-Sarcoma removed from Groin. It will be observed that there is one large central parent tumour surrounded by satellites.Fig. 82.—Lympho-Sarcoma removed from Groin. It will be observed that there is one large central parent tumour surrounded by satellites.
Fig. 82.—Lympho-Sarcoma removed from Groin. It will be observed that there is one large central parent tumour surrounded by satellites.
The prognosis is grave in the extreme, and the only hope is in early excision, followed by the use of radium and X-rays. We have observed a case of lympho-sarcoma above the clavicle, in which excision of all that was removable, followed by the insertion of a tube of radium for ten days, was followed by a disappearance of the disease over a period which extended to nearly five years, when death resulted from a tumour in the mediastinum. In a second case in which the growth was in the groin, the patient, a young man, remained well for over two years and was then lost sight of.
Secondary Tumours.—Next to tuberculosis,secondary canceris the most common disease of lymph glands. In the neck it is met with in association with epithelioma of the lip, tongue, or fauces. The glands form tumours of variable size, and are often larger than the primary growth, the characters of which they reproduce. The glands are at first movable, but soon become fixed both to each other and to their surroundings; when fixed to the mandible they form a swelling of bone-like hardness; in time they soften, liquefy, and burst through theskin, forming foul, fungating ulcers. A similar condition is met with in the groin from epithelioma of the penis, scrotum, or vulva. In cancer of the breast, the infection of the axillary glands is an important complication.
Inpigmentedormelanotic cancersof the skin, the glands are early infected and increase rapidly, so that, when the primary growth is still of small size—as, for example, on the sole of the foot—the femoral glands may already constitute large pigmented tumours.
Fig. 83.—Cancerous Glands in Neck secondary to Epithelioma of Lip. (Mr. G.L. Chiene's case.)Fig. 83.—Cancerous Glands in Neck secondary to Epithelioma of Lip.(Mr. G. L. Chiene's case.)
Fig. 83.—Cancerous Glands in Neck secondary to Epithelioma of Lip.
(Mr. G. L. Chiene's case.)
The implication of the glands in other forms of cancer will be considered with regional surgery.
Secondary sarcomais seldom met with in the lymph glands except when the primary growth is a lympho-sarcoma and is situated in the tonsil, thyreoid, or testicle.
Anatomy.—A nerve-trunk is made up of a variable number of bundles of nerve fibres surrounded and supported by a framework of connective tissue. The nerve fibres are chiefly of the medullated type, and they run without interruption from a nerve cell orneuronin the brain or spinal medulla to their peripheral terminations in muscle, skin, and secretory glands.
Each nerve fibre consists of a number of nerve fibrils collected into a central bundle—the axis cylinder—which is surrounded by an envelope, the neurolemma or sheath of Schwann. Between the neurolemma and the axis cylinder is the medullated sheath, composed of a fatty substance known as myelin. This medullated sheath is interrupted at the nodes of Ranvier, and in each internode is a nucleus lying between the myelin and the neurolemma. The axis cylinder is the essential conducting structure of the nerve, while the neurolemma and the myelin act as insulating agents. The axis cylinder depends for its nutrition on the central neuron with which it is connected, and from which it originally developed, and it degenerates if it is separated from its neuron.
The connective-tissue framework of a nerve-trunk consists of theperineurium, or general sheath, which surrounds all the bundles; theepineurium, surrounding individual groups of bundles; and theendoneurium, a delicate connective tissue separating the individual nerve fibres. The blood vessels and lymphatics run in these connective-tissue sheaths.
According to Head and his co-workers, Sherren and Rivers, the afferent fibres in the peripheral nerves can be divided into three systems:—
Those which subservedeep sensibilityand conduct the impulses produced by pressure as well as those which enable the patient to recognise the position of a joint on passive movement (joint-sensation), and the kinæsthetic sense, which recognises that active contraction of the muscle is taking place (active muscle-sensation). The fibres of this system run with the motor nerves, and pass to muscles, tendons, and joints. Even division of both the ulnar and the median nerves above the wrist produces little loss of deep sensibility, unless the tendons are alsocut through. The failure to recognise this form of sensibility has been largely responsible for the conflicting statements as to the sensory phenomena following operations for the repair of divided nerves.
Those which subserveprotopathicsensibility—that is, are capable of responding to painful cutaneous stimuli and to the extremes of heat and cold. These also endow the hairs with sensibility to pain. They are the first to regenerate after division.
Those which subserveepicriticsensibility, the most highly specialised, capable of appreciating light touch,e.g.with a wisp of cotton wool, as a well-localised sensation, and the finer grades of temperature, called cool and warm (72°–104° F.), and of discriminating as separate the points of a pair of compasses 2 cms. apart. These are the last to regenerate.
A nerve also exerts a trophic influence on the tissues in which it is distributed.
The researches of Stoffel on the minute anatomy of the larger nerves, and the disposition in them of the bundles of nerve fibres supplying different groups of muscles, have opened up what promises to be a fruitful field of clinical investigation and therapeutics. He has shown that in the larger nerve-trunks the nerve bundles for special groups of muscles are not, as was formerly supposed, arranged irregularly and fortuitously, but that on the contrary the nerve fibres to a particular group of muscles have a typical and practically constant position within the nerve.
In the large nerve-trunks of the limbs he has worked out the exact position of the bundles for the various groups of muscles, so that in a cross section of a particular nerve the component bundles can be labelled as confidently and accurately as can be the cortical areas in the brain. In the living subject, by using a fine needle-like electrode and a very weak galvanic current, he has been able to differentiate the nerve bundles for the various groups of muscles. In several cases of spastic paralysis he succeeded in picking out in the nerve-trunk of the affected limb the nerve bundles supplying the spastic muscles, and, by resecting portions of them, in relieving the spasm. In a case of spastic contracture of the pronator muscles of the forearm, for example, an incision is made along the line of the median nerve above the bend of the elbow. At the lateral side of the median nerve, where it lies in contact with the biceps muscle, is situated a well-defined and easily isolated bundle of fibres which supplies the pronator teres, the flexor carpi radialis, and the palmaris longus muscles. On incising the sheath of the nerve this bundle can be readily dissected up and its identity confirmed by stimulating it with a very weak galvanic current. An inch or more of the bundle is then resected.
Nerves are liable to be cut or torn across, bruised, compressed, stretched, or torn away from their connections with the spinal medulla.
Complete Division of a Mixed Nerve.—Complete division is a common result of accidental wounds, especially above the wrist, where the ulnar, median, and radial nerves are frequently cut across, and in gun-shot injuries.
Changes in Structure and Function.—The mere interruption of the continuity of a nerve results in degeneration of its fibres, the myelin being broken up into droplets and absorbed, while the axis cylinders swell up, disintegrate, and finally disappear. Both the conducting and the insulating elements are thus lost. The degeneration in the central end of the divided nerve is usually limited to the immediate proximity of the lesion, and does not even involve all the nerve fibres. In the distal end, it extends throughout the entire peripheral distribution of the nerve, and appears to be due to the cutting off of the fibres from their trophic nerve cells in the spinal medulla. Immediate suturing of the ends does not affect the degeneration of the distal segment. The peripheral end undergoes complete degeneration in from six weeks to two months.
The physiological effects of complete division are that the muscles supplied by the nerve are immediately paralysed, the area to which it furnishes the sole cutaneous supply becomes insensitive, and the other structures, including tendons, bones, and joints, lose sensation, and begin to atrophy from loss of the trophic influence.
Nerves divided in Amputation.—In the case of nerves divided in an amputation, there is an active, although necessarily abortive, attempt at regeneration, which results in the formation of bulbous swellings at the cut ends of the nerves. When there has been suppuration, and especially if the nerves have been cut so as to be exposed in the wound, these bulbous swellings may attain an abnormal size, and are then known as “amputation” or “stump neuromas” (Fig. 84).
When the nerves in a stump have not been cut sufficiently short, they may become involved in the cicatrix, and it may be necessary, on account of pain, to free them from their adhesions, and to resect enough of the terminal portions to prevent them again becoming adherent. When this is difficult, a portion may be resected from each of the nerve-trunks at a higher level; and if this fails to give relief, a fresh amputation may be performed.When there is agonising pain dependent upon an ascending neuritis, it may be necessary to resect the corresponding posterior nerve roots within the vertebral canal.
Fig. 84.—Stump Neuromas of Sciatic Nerve, excised forty years after the original amputation by Mr. A.G. Miller.Fig. 84.—Stump Neuromas of Sciatic Nerve, excised forty years after the original amputation by Mr. A. G. Miller.
Fig. 84.—Stump Neuromas of Sciatic Nerve, excised forty years after the original amputation by Mr. A. G. Miller.
Other Injuries of Nerves.—Contusionof a nerve-trunk is attended with extravasation of blood into the connective-tissue sheaths, and is followed by degeneration of the contused nerve fibres. Function is usually restored, the conducting paths being re-established by the formation of new nerve fibres.
When a nerve istorn acrossor badlycrushed—as, for example, by a fractured bone—the changes are similar to those in a divided nerve, and the ultimate result depends on the amount of separation between the ends and the possibility of the young axis cylinders bridging the gap.
Involvement of Nerves in Scar Tissue.—Pressure or traction may be exerted upon a nerve by contracting scar tissue, or a process of neuritis or perineuritis may be induced.
When terminal filaments are involved in a scar, it is best to dissect out the scar, and along with it the ends of the nerves pressed upon. When a nerve-trunk, such as the sciatic, is involved in cicatricial tissue, the nerve must be exposed and freed from its surroundings (neurolysis), and then stretched so as to tear any adhesions that may be present above or below thepart exposed. It may be advisable to displace the liberated nerve from its original position so as to minimise the risk of its incorporation in the scar of the original wound or in that resulting from the operation—for example, the radial nerve may be buried in the substance of the triceps, or it may be surrounded by a segment of vein or portion of fat-bearing fascia.
Injuries of nerves resulting fromgun-shot woundsinclude: (1) those in which the nerve is directly damaged by the bullet, and (2) those in which the nerve-trunk is involved secondarily either by scar tissue in its vicinity or by callus following fracture of an adjacent bone. The primary injuries include contusion, partial or complete division, and perforation of the nerve-trunk. One of the most constant symptoms is the early occurrence of severe neuralgic pain, and this is usually associated with marked hyperæsthesia.
Regeneration.—Process of Repair when the Ends are in Contact.—If the wound is aseptic, and the ends of the divided nerve are sutured or remain in contact, they become united, and the conducting paths are re-established by a regeneration of nerve fibres. There is a difference of opinion as to the method of regeneration. The Wallerian doctrine is that the axis cylinders in the central end grow downwards, and enter the nerve sheaths of the distal portion, and continue growing until they reach the peripheral terminations in muscle and skin, and in course of time acquire a myelin sheath; the cells of the neurolemma multiply and form long chains in both ends of the nerve, and are believed to provide for the nourishment and support of the actively lengthening axis cylinders. Another view is that the formation of new axis cylinders is not confined to the central end, but that it goes on also in the peripheral segment, in which, however, the new axis cylinders do not attain maturity until continuity with the central end has been re-established.
If the wound becomes infectedand suppuration occurs, the young nerve fibres are destroyed and efficient regeneration is prevented; the formation of scar tissue also may constitute a permanent obstacle to new nerve fibres bridging the gap.
When the ends are not in contact, reunion of the divided nerve fibres does not take place whether the wound is infected or not. At the proximal end there forms a bulbous swelling, which becomes adherent to the scar tissue. It consists of branching axis cylinders running in all directions, these having failed to reach the distal end because of the extent of the gap. The peripheral end is completely degenerated, and is represented by a fibrous cord, the cut end of which is often slightly swollenor bulbous, and is also incorporated with the scar tissue of the wound.
Clinical Features.—The symptoms resulting from division and non-union of a nerve-trunk necessarily vary with the functions of the affected nerve. The following description refers to a mixed sensori-motor trunk, such as the median or radial (musculo-spiral) nerve.
Sensory Phenomena.—Superficial touch is tested by means of a wisp of cotton wool stroked gently across the skin; the capacity of discriminating two points as separate, by a pair of blunt-pointed compasses; the sensation of pressure, by means of a pencil or other blunt object; of pain, by pricking or scratching with a needle; and of sensibility to heat and cold, by test-tubes containing water at different temperatures. While these tests are being carried out, the patient's eyes are screened off.
After division of a nerve containing sensory fibres, there is an area of absolute cutaneous insensibility to touch (anæsthesia), to pain (analgesia), and to all degrees of temperature—loss of protopathic sensibility; surrounded by an area in which there is loss of sensation to light touch, inability to recognise minor differences of temperature (72°–104° F.), and to appreciate as separate impressions the contact of the two points of a compass—loss of epicritic sensibility(Head and Sherren) (Figs. 91,92).
Motor Phenomena.—There is immediate and complete loss of voluntary power in the muscles supplied by the divided nerve. The muscles rapidly waste, and within from three to five days, they cease to react to the faradic current. When tested with the galvanic current, it is found that a stronger current must be used to call forth contraction than in a healthy muscle, and the contraction appears first at the closing of the circuit when the anode is used as the testing electrode. The loss of excitability to the interrupted current, and the specific alteration in the type of contraction with the constant current, is known as thereaction of degeneration. After a few weeks all electric excitability is lost. The paralysed muscles undergo fatty degeneration, which attains its maximum three or four months after the division of the nerve. Further changes may take place, and result in the transformation of the muscle into fibrous tissue, which by undergoing shortening may cause deformity known asparalytic contracture.
Vaso-motor Phenomena.—In the majority of cases there is an initial rise in the temperature of the part (2° to 3° F.), with redness and increased vascularity. This is followed by a fallin the local temperature, which may amount to 8° or 10° F., the parts becoming pale and cold. Sometimes the hyperæmia resulting from vaso-motor paralysis is more persistent, and is associated with swelling of the parts from œdema—the so-calledangio-neurotic œdema. The vascularity varies with external influences, and in cold weather the parts present a bluish appearance.
Trophic Phenomena.—Owing to the disappearance of the subcutaneous fat, the skin is smooth and thin, and may be abnormally dry. The hair is harsh, dry, and easily shed. The nails become brittle and furrowed, or thick and curved, and the ends of the fingers become club-shaped. Skin eruptions, especially in the form of blisters, occur, or there may be actual ulcers of the skin, especially in winter. In aggravated cases the tips of the fingers disappear from progressive ulceration, and in the sole of the foot a perforating ulcer may develop. Arthropathies are occasionally met with, the joints becoming the seat of a painless effusion or hydrops, which is followed by fibrous thickening of the capsular and other ligaments, and terminates in stiffness and fibrous ankylosis. In this way the fingers are seriously crippled and deformed.
Treatment of Divided Nerves.—The treatment consists in approximating the divided ends of the nerve and placing them under the most favourable conditions for repair, and this should be done at the earliest possible opportunity. (Op. Surg., pp. 45, 46.)
Primary Suture.—The reunion of a recently divided nerve is spoken of as primary suture, and for its success asepsis is essential. As the suturing of the ends of the nerve is extremely painful, an anæsthetic is required.
When the wound is healed and while waiting for the restoration of function, measures are employed to maintain the nutrition of the damaged nerve and of the parts supplied by it. The limb is exercised, massaged, and douched, and protected from cold and other injurious influences. The nutrition of the paralysed muscles is further improved by electricity. The galvanic current is employed, using at first a mild current of not more than 5 milliampères for about ten minutes, the current being made to flow downwards in the course of the nerve, with the positive electrode applied to the spine, and the negative over the affected nerve near its termination. It is an advantage to have a metronome in the circuit whereby the current is opened and closed automatically at intervals, so as to cause contraction of the muscles.
The resultsof primary suture, when it has been performed under favourable conditions, are usually satisfactory. In a series of cases investigated by Head and Sherren, the period between the operation and the first return of sensation averaged 65 days. According to Purves Stewart protopathic sensation commences to appear in about six weeks and is completely restored in six months; electric sensation and motor power reappear together in about six months, and restoration is complete in a year. When sensation returns, the area of insensibility to pain steadily diminishes and disappears; sensibility to extremes of temperature appears soon after; and last of all, after a considerable interval, there is simultaneous return of appreciation of light touch, moderate degrees of temperature, and the points of a compass.
A clinical means of estimating how regeneration in a divided nerve is progressing has been described by Tinel. He found that a tingling sensation, similar to that experienced in the foot, when it is recovering from the “sleeping” condition induced by prolonged pressure on the sciatic nerve from sitting on a hard bench, can be elicited on percussing overgrowingaxis cylinders. Tapping over the proximal end of anewly divided nerve,e.g.the common peroneal behind the head of thefibula, produces no tingling, but when in about three weeks axis cylinders begin to grow in the proximal end-bulb, local tingling is induced by tapping there. The downward growth of the axis cylinders can be traced by tapping over the distal segment of the nerve, the tingling sensation being elicited as far down as the young axis cylinders have reached. When the regeneration of the axis cylinders is complete, tapping no longer causes tingling. It usually takes about one hundred days for this stage to be reached.
Tinel's sign is present before voluntary movement, muscular tone, or the normal electrical reactions reappear.
In cases of complete nerve paralysis that have not been operated upon, the tingling test is helpful in determining whether or not regeneration is taking place. Its detection may prevent an unnecessary operation being performed.
Primary suture should not be attempted so long as the wound shows signs of infection, as it is almost certain to end in failure. The ends should be sutured, however, as soon as the wound is aseptic or has healed.
Secondary Suture.—The term secondary suture is applied to the operation of stitching the ends of the divided nerve after the wound has healed.
Results of Secondary Suture.—When secondary suture has been performed under favourable conditions, the prognosis is good, but a longer time is required for restoration of function than after primary suture. Purves Stewart says protopathic sensation is sometimes observed much earlier than in primary suture, because partial regeneration of axis cylinders in the peripheral segment has already taken place. Sensation is recovered first, but it seldom returns before three or four months. There then follows an improvement or disappearance of any trophic disturbances that may be present. Recovery of motion may be deferred for long periods—rather because of the changes in the muscles than from want of conductivity in the nerve—and if the muscles have undergone complete degeneration, it may never take place at all. While waiting for recovery, every effort should be made to maintain the nutrition of the damaged nerve, and of the parts which it supplies.
When suture is found to be impossible, recourse must be had to other methods, known as nerve bridging and nerve implantation.
Incomplete Division of a Mixed Nerve.—The effects of partial division of a mixed nerve vary according to the destination of the nerve bundles that have been interrupted. Within their area of distribution the paralysis is as complete as if the whole trunk had been cut across. The uninjured nerve-bundles continue to transmit impulses with the result that there is adissociated paralysiswithin the distribution of the affected nerve, some muscles continuing to act and to respond normally to electric stimulation, while others behave as if the whole nerve-trunk had been severed.
In addition to vasomotor and trophic changes, there is often severe pain of a burning kind (causalgiaorthermalgia) which comes on about a fortnight after the injury and causes intense and continuous suffering which may last for months. Paroxysms of pain may be excited by the slightest touch or by heat, and the patient usually learns for himself that the constant application of cold wet cloths allays the pain. The thermalgic area sweats profusely.
Operative treatment is indicated where there is no sign of improvement within three months, when recovery is arrested before complete restoration of function is attained, or when thermalgic pain is excessive.
Subcutaneous Injuries of Nerves.—Several varieties of subcutaneous injuries of nerves are met with. One of the best known is the compression paralysis of the nerves of the upperarm which results from sleeping with the arm resting on the back of a chair or the edge of a table—the so-called “drunkard's palsy”; and from the pressure of a crutch in the axilla—“crutch paralysis.” In some of these injuries, notably “drunkard's palsy,” the disability appears to be due not to damage of the nerve, but to overstretching of the extensors of the wrist and fingers (Jones). A similar form of paralysis is sometimes met with from the pressure of a tourniquet, from tight bandages or splints, from the pressure exerted by a dislocated bone or by excessive callus, and from hyper-extension of the arm during anæsthesia.
In all these forms there is impaired sensation, rarely amounting to anæsthesia, marked muscular wasting, and diminution or loss of voluntary motor power, while—and this is a point of great importance—the normal electrical reactions are preserved. There may also develop trophic changes such as blisters, superficial ulcers, and clubbing of the tips of the fingers. The prognosis is usually favourable, as recovery is the rule within from one to three months. If, however, neuritis supervenes, the electrical reactions are altered, the muscles degenerate, and recovery may be retarded or may fail to take place.
Injuries which act abruptly or instantaneously are illustrated in the crushing of a nerve by the sudden displacement of a sharp-edged fragment of bone, as may occur in comminuted fractures of the humerus. The symptoms include perversion or loss of sensation, motor paralysis, and atrophy of muscles, which show the reaction of degeneration from the eighth day onwards. The presence of the reaction of degeneration influences both the prognosis and the treatment, for it implies a lesion which is probably incapable of spontaneous recovery, and which can only be remedied by operation.
Thetreatmentvaries with the cause and nature of the lesion. When, for example, a displaced bone or a mass of callus is pressing upon the nerve, steps must be taken to relieve the pressure, by operation if necessary. When there is reason to believe that the nerve is severely crushed or torn across, it should be exposed by incision, and, after removal of the damaged ends, should be united by sutures. When it is impossible to make a definite diagnosis as to the state of the nerve, it is better to expose it by operation, and thus learn the exact state of affairs without delay; in the event of the nerve being torn, the ends should be united by sutures.
Dislocation of Nerves.—This injury, which resembles the dislocation of tendons from their grooves, is seldom met withexcept in the ulnar nerve at the elbow, and is described with injuries of that nerve.
Traumatic Neuritis.—This consists in an overgrowth of the connective-tissue framework of a nerve, which causes irritation and pressure upon the nerve fibres, sometimes resulting in their degeneration. It may originate in connection with a wound in the vicinity of a nerve, as, for example, when the brachial nerves are involved in scar tissue subsequent to an operation for clearing out the axilla for cancer; or in contusion and compression of a nerve—for example, by the pressure of the head of the humerus in a dislocation of the shoulder. Some weeks or months after the injury, the patient complains of increasing hyperæsthesia and of neuralgic pains in the course of the nerve. The nerve is very sensitive to pressure, and, if superficial, may be felt to be swollen. The associated muscles are wasted and weak, and are subject to twitchings. There are also trophic disturbances. It is rare to have complete sensory and motor paralysis. The disease is commonest in the nerves of the upper extremity, and the hand may become crippled and useless.
Treatment.—Any constitutional condition which predisposes to neuritis, such as gout, diabetes, or syphilis, must receive appropriate treatment. The symptoms may be relieved by rest and by soothing applications, such as belladonna, ichthyol, or menthol, by the use of hot-air and electric baths, and in obstinate cases by blistering or by the application of Corrigan's button. When such treatment fails the nerve may be stretched, or, in the case of a purely sensory trunk, a portion may be excised. Local causes, such as involvement of the nerve in a scar or in adhesions, may afford indications for operative treatment.
Multiple Peripheral Neuritis.—Although this disease mainly comes under the cognizance of the physician, it may be attended with phenomena which call for surgical interference. In this country it is commonly due to alcoholism, but it may result from diabetes or from chronic poisoning with lead or arsenic, or from bacterial infections and intoxications such as occur in diphtheria, gonorrhœa, syphilis, leprosy, typhoid, influenza, beri-beri, and many other diseases.
It is, as a rule, widely distributed throughout the peripheral nerves, but the distribution frequently varies with the cause—the alcoholic form, for example, mainly affecting the legs, the diphtheritic form the soft palate and pharynx, and that associated with lead poisoning the forearms. The essential lesion is a degeneration of the conducting fibres of the affected nerves, and the prominent symptoms are the result of this. In alcoholic neuritis there is great tenderness of the muscles. When the legs are affected the patient may be unable to walk, and the toes may droop and the heel be drawn up, resulting in one variety of pes equino-varus. Pressure sores and perforating ulcer of the foot are the most important trophic phenomena.
Apart from the medicaltreatment, measures must be taken to prevent deformity, especially when the legs are affected. The bedclothes are supported by a cage, and the foot maintained at right angles to the leg by sand-bags or splints. When the disease is subsiding, the nutrition of the damaged nerves and muscles should be maintained by massage, baths, passive movements, and the use of the galvanic current. When deformity has been allowed to take place, operative measures may be required for its correction.
[5]We have followed the classification adopted by Alexis Thomson in his workOn Neuroma, and Neuro-fibromatosis(Edinburgh: 1900).
Neuroma is a clinical term applied to all tumours, irrespective of their structure, which have their seat in nerves.
A tumour composed of newly formed nerve tissue is spoken of as atrue neuroma; when ganglionic cells are present in addition to nerve fibres, the nameganglionic neuromais applied. These tumours are rare, and are chiefly met with in the main cords or abdominal plexuses of the sympathetic system of children or young adults. They are quite insensitive, and their removal is only called for if they cause pain or show signs of malignancy.
Afalse neuromais an overgrowth of the sheath of a nerve. This overgrowth may result in the formation of a circumscribed tumour, or may take the form of a diffuse fibromatosis.
The circumscribed or solitary tumourgrows from the sheath of a nerve which is otherwise healthy, and it may be innocent or malignant.
The innocentform is usually fibrous or myxomatous, and is definitely encapsulated. It may become cystic as a result of hæmorrhage or of myxomatous degeneration. It grows veryslowly, is usually elliptical in shape, and the solid form is rarely larger than a hazel-nut. The nerve fibres may be spread out all round the tumour, or may run only on one side of it. When subcutaneous and related to the smaller unnamed cutaneous nerves, it is known as apainful subcutaneous noduleortubercle. It is chiefly met with about the ankle, and most often in women. It is remarkably sensitive, even gentle handling causing intense pain, which usually radiates to the periphery of the nerve affected. When related to a deeper, named nerve-trunk, it is known as atrunk-neuroma. It is usually less sensitive than the “subcutaneous nodule,” and rarely gives rise to motor symptoms unless it involves the nerve roots where they pass through bony canals.
A trunk-neuroma is recognised clinically by its position in the line of a nerve, by the fact that it is movable in the transverse axis of the nerve but not in its long axis, and by being unduly painful and sensitive.