Surgery, with Special Reference to Podiatry Part 15

C+AUSES OF GANGRENE+

_Traumatic._ The sudden cessation of the blood supply to a part in consequence of a cutting or crus.h.i.+ng accident, will obviously produce the moist form of gangrene. It is not essential that the part be entirely severed, or even nearly so, for if only the main artery is severed, gangrene will ensue.

The crus.h.i.+ng or pressure upon a large vein will act similarly, owing to there being no outflow possible, back pressure will cause the total arrest of circulation in the part.

_Const.i.tutional Diseases._ Certain diseases affect the lumen or calibre of the blood vessels, gradually diminis.h.i.+ng and finally arresting the stream of blood carried through them.

In these diseases it would be logical to invariably expect dry gangrene. This does not regularly occur, for the reason just given, and the mere presence of a moist or dry condition therefore cannot be regarded as diagnostic.

In diabetes, either form may obtain, and a diagnosis can be a.s.sured by the discovery of sugar in the urine.

The thickened condition of the arteries leading to senile gangrene must be thought of and proven in aged subjects. Dry gangrene is the rule in arteriosclerosis.

Reynaud's disease, or synthetic gangrene, is due to a vasomotor spasmodic condition of the terminal vessels and is of central nerve origin. The tips of the toes and fingers, of both sides, are the most common sites, though the lobes of the ears, cheeks and tip of the nose may be affected.

A coldness of the parts, with mottling of blue and white, and a subsequent diffuse blueness, becoming darker and finally black, are characteristic signs of this disease, and the dry form of gangrene is usual.

_Obliterating Endarteritis_, is a condition in which the walls of an artery become inflamed and thickened, thus obliterating its lumen.

_Thromboangiitis Obliterans_ is similar to the above and differs only in that a thrombotic growth occurs in an artery obliterating its lumen.

_Thrombosis and Embolism._ Thrombosis and embolism cause a sudden or gradual stoppage of the blood stream in a vessel, and in consequence, either moist or dry gangrene occurs, depending on the time required for the obstruction to become complete.

The stoppage of the outflow because of thrombosis in a large vein, will cause moist gangrene; the part being unable to drain, will, by back pressure, arrest circulation.

_Cold._ Frost bite causes gangrene of varying degrees. A small circ.u.mscribed patch of tissue may succ.u.mb, or an entire finger or extremity may be affected. The variety is invariably moist. The diagnosis is easily made from the history of exposure (See "Frost bite").

_Chemicals._ Carbolic acid, even in weak solution, often causes gangrene of a finger or toe, because of its frequent use as a wet dressing, and therefore should never be employed in this manner.

Gangrene of a single part, (especially in a young subject), incident to a slight injury or infection, should always excite suspicion that phenol has been employed. Moist gangrene is the rule. The part presents a hard, shriveled, black appearance which is characteristic.

Weak solutions of other chemicals such as lysol, acetic acid, and pota.s.sium or sodium hydroxide, employed as a wet dressing, are also capable of producing gangrene.

+Symptoms.+ (_Dry Gangrene_). Typical dry gangrene usually develops in the toes and the feet, and the princ.i.p.al symptoms which point to its advent are, coldness, numbness, pain and tingling in the feet and muscles of the legs. Persons about to be affected with dry gangrene often complain for months, before any local signs of gangrene are present, of severe burning pain in the feet at night when warm in bed.

A trivial injury, such as a bruise, the friction of the shoe, or the cutting of a corn, may act as the exciting cause of the affection. The part becomes congested and gradually a.s.sumes a dark purple color, finally becoming black and dry; it is insensitive, but the surrounding parts are congested and may be the seat of intense pain. The dead part becomes black, shriveled, and dry, and emits little odor.

Dry gangrene usually spreads very slowly; one or two toes may first be involved and the disease may gradually spread to the rest of the foot and the leg. There may be little fever at first, but if a large extent of tissue is involved, a certain amount of fever develops. During the progress of the disease, pain is usually present to a greater or lesser degree, sometimes being intense; this is accounted for by the fact that the nerves are usually the last structures to die.

During the course of the disease, the patient loses much sleep from continued pain, and becomes worn out and may die of exhaustion.

In dry gangrene there is usually no well marked attempt at the formation of lines of demarcation and separation, but in some cases, if the amount of tissue involved is small, say one or two toes, or a part of the foot, for instance, and if the patient's strength can be sustained, the line of separation forms, and the dead tissue may be cast off, leaving the bones exposed in the wound.

+Moist Gangrene.+ When a part which has had its vitality seriously interfered with becomes gangrenous, pain, which may have been present, suddenly ceases, the part becomes insensitive, and the skin is cold, pale, and mottled purple, green, and red, and finally dark colored; blebs containing brownish serum form upon the surface; the wound, if one is present, a.s.sumes a grayish color, and an offensive discharge escapes from it; the dead tissue rapidly undergoes putrefactive changes. Coincidentally with these changes in the dead tissues, the living tissue in contact with it becomes red and swollen, and the separation of the dead tissue from the living is affected by an ulcerative inflammation, granulations from the living tissue lifting off the slough.

The patient, at the same time, if the gangrenous process involves any considerable extent of surface, exhibits the unconst.i.tutional signs of inflammation (fever, rapid pulse, etc.) and, in some cases, if the septic infection is intense, may die from septicemia.

In both dry and moist gangrene, when the gangrenous process is arrested, the dead tissue is separated from the living by a process of inflammation; the living tissue, at its point of contact with the dead tissue, and for some distance from it, becomes red and swollen, and exhibits all the signs of acute inflammation. The line of contact between the dead and the living tissue is known as _the line of demarcation_, and the line of granulations which separates the dead tissue from the living, is known as _the line of separation_.

The separation of the dead tissue is affected by granulations, which spring up from the living tissue as a result of inflammation, and there is also a certain amount of pus secreted from the granulations.

In moist gangrene, the lines of demarcation and separation are fairly well developed. In dry gangrene, on the other hand, these lines are usually imperfectly developed.

+Early Diagnosis.+ From the foregoing it will be observed that gangrene is most common in those past middle life, and that its actual onset is only a stage in an insidious process. This may be either due to senility or to some const.i.tutional disease. A slight abrasion alone is sufficient to set up a train of symptoms out of all proportion to the cause. In such a case, the operation of a small verruca or papilloma may be followed by a violent inflammatory reaction, with rapid extension into the entire foot or leg, resulting in gangrene.

Such cases have occurred, but could have been prevented if a proper survey of the field had been taken and would have saved the chiropodist much responsibility.

Before operating on subjects past middle life, it should be a routine practice to note the color and temperature of the foot, both in the dependent and horizontal positions. The _anterior tibial pulse_ should also be felt for and its absence or intensity noted. A question to the patient as to diabetes or thickened arteries may also elicit valuable information. A very weak or absent anterior tibial pulse (the knack of feeling the pulse here must be acquired), or peculiar nodules about the nail grooves, are evidences of an enc.u.mbered arterial supply.

Extreme redness or blueness in a foot in the hanging position, and pallor when elevated, also indicate a similar condition, or one in which the valves in the veins are impaired.

It is in such conditions that the greatest care should be taken to avoid deep incisions except in the presence of positive indications.

+Treatment.+ In general, amputation through healthy tissue is the rule in gangrene affecting any extremity through its entire thickness. The complete devitalization of even a digital phalanx requires that amputation be made beyond the next joint above.

In traumatic gangrene it is the rule to amputate immediately through healthy tissue when rest.i.tution of the injured parts is known to be impossible. In senile gangrene the appearance of the line of demarcation indicates the extent of the devitalized area and establishes the point of amputation beyond the next joint above.

Diabetic gangrene presents the peculiarity of a slow and steady advance, unless an unusually high amputation be performed. Thus, if the great toe is the site of the beginning of a true diabetic gangrene, amputation through the lower third of the thigh is indicated; otherwise the prognosis is very bad.

Inflammatory gangrene, or as it is more properly called _gangrenous cellulitis_, is a rapidly spreading infective process which destroys tissue as it advances. It is an acute suppurative process causing large sloughs. It is a form of cellulitis requiring drainage and disinfection.

Frost bite may involve tissues to any depth and to any surface extent.

Lesions of circ.u.mscribed contour result in the sloughing away of the area involved and never require amputation. (See "Frost bite.")

In the event of a phalanx, toe, finger, foot, or hand being involved, the same rules as above laid down must apply. In this variety, however, it is important to allow sufficient time to elapse in order that the depth of the gangrenous process may be ascertained. Should the line of demarcation be apparent, after a few days the complete death of the tissues below is certain, and amputation becomes necessary. If, however, after a few days some slight bleeding or the appearance of a red point be apparent, the bone, and in all probability some tissue around it, is still viable. Haste in these cases should therefore be avoided.

CHAPTER XII

+DISEASES OF VEINS+

Varicose veins are unnatural, irregular, and permanently dilated veins which elongate and pursue a tortuous course. This condition is very common, and twenty per cent. of adults exhibit it in some degree in one region or another.

The causes of varicose veins are obstruction to venous return, and weakness of cardiac action, which lessens the propulsion of the blood stream.

Varicose veins may occur in any portion of the body, but are chiefly met with on the inner side of the lower extremity.

Varix in the leg is met with during and after pregnancy, and in persons who stand upon their feet for long periods.

It especially appears in the long saphenous vein, which, being subcutaneous, has no muscular aid in supporting the blood-column and in urging it on. The deep as well as the superficial veins may become varicose.

Varicose veins are in rare instances congenital; they are most often seen in the aged, but usually begin at the ages of twenty to forty.

A vein, under pressure, usually dilates more at one spot than at another, the distention being greatest back of a valve or near the mouth of a tributary. The valves become incompetent and the dilatation becomes still greater. The vein wall may become fibrous, but usually it is thin, and ruptures. The veins not only dilate, but they also become longer, and hence do not remain straight but twist and turn into a characteristic form.

Varicose veins are apt to cause edema, and the watery elements in the tissues cause eczema of the skin. When eczema is once inaugurated, excoriation is to be expected. Infection of the excoriated area produces inflammation, suppuration, and an ulcer.

The skin over varicose veins in the legs is often discolored by pigmentation due to the red cells having escaped from the vessel and then being broken up.