A system of practical medicine. By American authors. Vol. 2

by Unknown

Pressure on the vena cava causes oedema of the inferior extremities in a small number of cases; and on the vena porta, ascites. There may occur thrombosis of the portal, in which event the ascites will form very quickly, and return as quickly after tapping.

The usually placid course pursued by echinococcus of the liver may be much modified by inflammation and suppuration. Some external injury may develop the inflammation. Having occurred, the clinical history corresponds to other cases of hepatic abscess, and the reader is therefore referred to the section on that topic for fuller information.

DIAGNOSIS.—At the outset of echinococcus of the liver the differentiation of the tumor from other tumors, and of the disturbances produced by it as contrasted with the effects of other morbid growths, becomes exceedingly difficult, if not impossible. The size, painlessness, elasticity, the purring tremor of the echinococcus tumor, afford a sure basis for constructing a diagnosis, and as ultimately developed they become the means of accurate differentiation from other morbid growths of that locality. All doubt as to the nature of a given hydatid tumor of the liver may be set at rest by the use of the aspirator. The discovery of the characteristic hooklets of the scolex in the fluid withdrawn from the tumor will be conclusive as to the presence of echinococci. The hooklets may be absent, as in the case of acephalocysts, but the fluid is characteristic in other respects: it contains a large quantity of chloride of sodium and is free from albumen.

Very great difficulty is experienced in diagnosticating an echinococcus tumor developing from the upper surface of the liver, pushing the diaphragm and lungs upward and displacing the heart to the left. Whilst the physical signs may be, and are, usually alike when the condition calling for diagnosis has existed for some time, there are means of differentiating in the history of the cases and in the initial symptoms.

The origin and growth of the echinococcus tumor are obscure and free from constitutional disturbance; the onset of a pleuritic exudation is marked by pain, fever, and hurried respiration and by physical signs of a characteristic kind. It is true there are cases of so-called latent pleurisy in which a hydrothorax forms without any well-marked indications, but it will usually be found that some local pain, hurried breathing, or other symptoms existed from the beginning. Those cases of hydrothorax accompanying renal and cardiac diseases are readily enough associated with their original cause.

Echinococcus of the liver may be confounded with abscess of the liver, but a differentiation can be readily made by attention to a few considerations, except in the rare condition of the Echinococcus multilocularis which has proceeded to suppuration. In this latter condition there are no means of differentiation, since an abscess-formation has already occurred, nor is there any need to attempt a distinction without the occasion of a difference. Echinococcus differs from abscess in history, in the character of the swelling, and in progress. Abscess of the liver is preceded by paroxysms of hepatic colic, by inflammatory ulceration of some part of the intestinal tract, or by local injury—traumatism. The onset of a hydatid tumor is silent and painless. The swelling of the liver when an abscess forms is not considerable at any time, and appears to be a uniform enlargement of the organ, except when the pus tends to make its way through the walls of the abdomen externally. An enlarging echinococcus tumor is an obvious projection from the surface of the liver at some point, and it does not have the characteristic tenderness, the fluctuation of an abscess matured and ready to discharge, and the constitutional disturbance; but it does have a peculiar elasticity, and now and then may present that eminently characteristic sign, the purring tremor. The use of the exploring-trocar will usually suffice to clear up all doubts by the withdrawal of the characteristic fluid of the hydatid cyst or of pus.

DURATION AND TERMINATION.—The progress of an echinococcus tumor is exceedingly slow, and the development of symptoms produced by its extension is early or late according to its position and to the nature of the parts impinged on. A spontaneous cure may take place under the rather rare circumstances of an opening into the hepatic duct or one of its principal divisions, and the gradual discharge of the cysts by this outlet into the intestine. Next to this mode of termination, the most fortunate direction taken by the enlarging cysts is through the walls of the abdomen externally. When the growth is upward through the lungs, the symptoms belonging to empyema or hydrothorax, with pulmonary abscess, ensue, and the termination is fatal after a protracted course. Rupture into the peritoneal cavity is a fatal event. Ulceration into the intestine, and the discharge of the cysts through the route thus made, may effect a cure, but more frequently the fistulous communication becomes a means of forming a fecal abscess.

The result in any case of hydatids of the liver is much influenced by the mode of treatment adopted and the period at which it is undertaken. As these parasites can be readily reached and destroyed by safe means, obviously the more early the diagnosis is made and the treatment carried out, the less the injury done to the hepatic structures and neighboring parts.

TREATMENT.—Prophylactic.—As the intestine of the dog is the natural habitat of the Tænia echinococcus, and as the hydatid is the first stage in the development of the ovum and the second in the life-history of the parasite, the means of prophylaxis consist in preventing contamination of human food and water with the dog's excrement, which contains the ova of the parasite. In Iceland, where hydatid disease is very prevalent, dogs and human beings living in the same huts and obtaining their water-supply by melting the snow just about them, contamination of food and drink must readily occur. In this country such conditions cannot exist; nevertheless, cases of hydatids are not infrequent. The chief, if not the only, source of contamination is through the consumption of such uncooked vegetables as lettuce, celery, cabbage, etc., in the folds of which the ova may be retained, and from which an ordinary washing does not suffice to detach them. It follows that such articles of food should be minutely inspected and cleansed before being placed on the table.

Boiling and filtration are the means of removing impurities of this kind from potable waters.