DEFINITION.—By the terms at the head of this section are meant the various pathological processes which induce coagulation of the blood in some part of the portal system. As the portal vein is made up of many branches coming from the various organs of the abdominal cavity except the kidneys, and as it empties, so to speak, into the liver, it is obvious that various and complex derangements will ensue on the formation of thrombi.
CAUSES.—Thrombosis of the portal vein occurs under three general conditions: the blood is in a readily coagulable state; the action of the heart is weak and the blood-current sluggish; the circulation through the vein is impeded by external pressure. The coagulability of the blood is increased in diseases characterized by an excess of its fibrin-producing constituents, of which cirrhosis of the liver may be mentioned as one having this peculiarity. In chronic maladies of a depressing kind there may be simply a weak action of the heart, or the muscular tissue of the organ may be affected by a fatty and atrophic degeneration. The external pressure by which the blood-current through the vein is impeded may be caused by the newly-formed connective tissue of Glisson's capsule, by enlarged lymphatics in the hilus of the liver, or by tumors of various kinds. The first named of these causes of compression—atrophic cirrhosis—is most frequently acting. Very rarely, organized exudations of the peritoneum may be so situated as to compress the portal vein. This result can only happen when the hepatic portion of the peritoneum is involved.
Pylephlebitis exists in two forms: the adhesive and suppurative. The former results in changes not unlike those of simple thrombosis. The blood coagulates in the affected part of the vessel, the clot is organized, and the vessel ultimately forms a solid rounded cord which is permanently occluded. The suppurative variety is so different in its origin and in its results that it requires separate treatment, and I therefore postpone the consideration of it to the next section.
SYMPTOMS OF THROMBOSIS AND ADHESIVE PYLEPHLEBITIS.—It is a remarkable fact that the biliary function of the liver is not necessarily affected in cases of occlusion of the portal vein. It is true, in advanced cases of cirrhosis, when the interlobular veins are obliterated by the pressure of the contracting newly-formed connective tissue, the functions of the liver are arrested in so far as the damage thus caused extends. Notwithstanding the blocking of the portal, sufficient blood reaches the hepatic cells by the anastomosis between the hepatic artery and the interlobular veins—an anatomical connection demonstrated by Cohnheim and Litten.209 So long as this anastomosis continues bile will be formed, although the portal vein is occluded.
209 Virchow's Archiv, Band lxvii. p. 153, "Ueber Circulationsstörungen in der Leber."
The most significant symptoms of thrombosis of the portal vein are the sudden formation of ascites, which quickly assumes a very high grade, and equally sudden passive congestion of the gastro-intestinal mucous membrane, enlargement of the spleen, and distension of the superficial veins of the abdominal parietes. When these symptoms succeed to cirrhosis of the liver, or appear after the formation of a tumor in the hepatic region, or come on in the course of phthisis or chronic inflammation of the hepatic peritoneum, the existence of thrombus of the portal vein may be reasonably suspected.
Coincidently with the occlusion of the portal vein the gastro-intestinal mucous membrane becomes the seat of a catarrhal process, and to the fluid thus produced is added a much more abundant transudation from the distended capillaries. Nausea, vomiting, and diarrhoea result, the rejected matters being serous, watery, and in many cases tinged with blood. Now and then quite a severe hemorrhage takes place, and the blood is brought up by vomiting (hæmatemesis) or is discharged by stool. Hemorrhoids form, and, in large masses protruding, much pain is experienced, and free bleeding may result from rupture of a distended vein.
The veins of the abdominal parietes, which in the normal state are invisible or at least not prominent, and which form anastomoses with the portal, when the obstruction occurs dilate, sometimes to a remarkable extent. The most important anastomosis is that between the femoral and saphena and internal mammary and epigastric veins. When the hepatic branches of the portal are closed, but the trunk remains pervious, the parumbilical vein enlarges greatly, and, communicating with the superficial veins of the anterior part of the abdominal walls, forms a radiating network of tortuous veins to which is given the striking title of caput Medusæ.
The most significant symptom of portal thrombosis is a quickly-forming ascites. It is true, ascites is a common symptom in advanced cirrhosis, but the rapid accumulation of fluid and the prompt filling of the cavity after tapping distinguish that which arises from portal thrombosis from all others. Besides its excessive extent, the ascites presents the usual symptoms.
Due to the same cause as the enlargement of the superficial veins, the hemorrhages, the ascites, etc., there occurs considerable hypertrophy of the spleen in many of the cases. It sometimes happens that the new compensatory circulation and the hemorrhages from some part in the usual route of the portal so dispose of the blood that the spleen does not enlarge sufficiently to be readily made out.
COURSE AND TERMINATION.—It is obvious that a condition such as that induced by thrombosis of the portal must be comparatively quickly fatal; but the cases vary in duration as the compensatory circulation is more or less complete. Whilst the majority of cases terminate within two weeks, instances of several months' duration are not unknown, but a fatal termination, sooner or later, is inevitable in all cases.
Coming on in the course of some chronic affection of the liver or some obstructing cause exterior to the organ, there soon follow ascites, nausea and vomiting, hæmatemesis, bloody stools of a liquid character, enlargement of the spleen, distension of the abdominal veins, and the distressing symptoms produced by an excessive accumulation of fluid in the peritoneal cavity.
DIAGNOSIS.—As there is no symptom of thrombosis of the portal which may not be caused by advanced cirrhosis, the diagnosis rests on the rapid production of the attendant phenomena and their conjoint appearance.
TREATMENT.—A symptomatic treatment is alone possible. The highly irritable and congested intestinal mucous membrane precludes the employment of hydragogue cathartics. Salines which cause outward diffusion from the vessels are the only cathartics which can be used with propriety. Action of the kidneys and of the skin must be maintained. To this end the resin of copaiba in pilular form and pilocarpine subcutaneously may be used. If the strength of the patient will permit, leeches around the anus can be applied, and much relief may be expected from free bleeding. It is probable that opening a swollen hemorrhoid would give the same kind of relief as that caused by a free hemorrhage. In any case the benefit derived from treatment must be merely palliative and temporary.
PATHOGENY.—Primary pylephlebitis rarely if ever occurs. On the other hand, the secondary form is by no means uncommon; it succeeds to ulcerative or purulent inflammation at some point in the circuit of origin of the portal radicles. The most frequently-occurring cause is ulceration and suppuration of some part of the intestinal tube, and hence the most common result is multiple abscess of the liver. Pylephlebitis has often resulted from typhlitis; from ulcers of the large intestine, as in dysentery; from such traumatic injuries as tying hemorrhoids; from proctitis; from ulcers of the stomach and similar morbid processes elsewhere within the range of origin of the portal system. The pathogeny is clear. The inflammatory or ulcerative action extends to and involves the walls of the veins, or some morbid material diffuses through the vein walls. In either case coagulation of the blood in the vessel ensues, and the clot undergoes a series of changes resulting in the formation of emboli, which, carried into the main current, are subsequently lodged in the hepatic capillaries.
There are three steps in the morbid process: the changes in the vein wall; the production and transformation of the thrombus; and the formation of secondary suppurating foci in the liver.
The appearance of the tunics of the inflamed vessels varies with the stage at which they are examined. At first the walls of the vessels are reddish from congestion, succulent, and swollen, infiltrated by leucocytes and inflammatory exudation and the cellular elements undergoing proliferation. The intima especially is much altered in its appearance and structure, becoming thick, opaque, grayish or yellowish in color, and having adherent to it a thrombus passing through its characteristic changes. Ulceration of the intima then occurs, and the purulent elements, with shreds of tissue, mingle with the degenerating blood-clot, and ultimately there remains a purulent dépôt lined with sloughing, even gangrenous, contents. Emboli detached from such decomposing thrombus are arrested in the vessels of the liver, and there set up a suppurating phlebitis, ending in an abscess formation, or a quantity of pus from the original point of ulcerative phlebitis passes into the portal vein, and is generally distributed through the hepatic branches, here and there foci of suppuration being established by the deposit of decomposing emboli. There may be numerous small abscesses irregularly distributed through the liver, or there may be one or two larger collections of pus. Very often the vessel whose occlusion by a suppurating embolus has caused the mischief is destroyed, and hence no communication with the abscess-cavity can then be traced. These abscesses are not limited by a line of inflammatory demarcation or by a limiting membrane, but the hepatic tissue adjacent is congested and infiltrated with pus.
Ulceration, abscesses, or purulent inflammation occurring at any point within the area of origin of the radicles of the portal vein may induce pylephlebitis and consequent hepatic abscess. There are two points at which, suppuration established, secondary pylephlebitis is most apt to occur: the cæcum; the rectum. As respects the former, the symptoms of typhlitis precede the hepatic disturbance; and as respects the latter, usually dysentery, or rather proctitis, is the initial disease. In both sources of the hepatic trouble the inferior hemorrhoidal veins are chiefly concerned—a fact explicable by reference to the sluggishness of the circulation and the distended condition of these veins, whence it is that thrombus is very readily induced. Numerous instances of pylephlebitis following suppurative lesions of the cæcum have been reported. One of the most recent, and at the same time typical, examples of such conditions is that published by Bradbury210 of Cambridge, England. The initial lesion was "an ulcer the size of a split pea" situated near "the junction of the vermiform appendix and cæcum." "The hemorrhoidal veins and the inferior mesenteric above were filled with breaking-down clot and pus," and "the liver contained many abscesses of various sizes, the largest about the size of a lemon, which had burst through the diaphragm." As is so often the case, the ulcer of the cæcum produced no recognizable disturbance, and important symptoms were manifest only when the emboli lodged in the liver set up suppuration, when there occurred the usual signs of hepatic abscess. In the West and South hepatic abscess due to pylephlebitis, induced by proctitis, with ulceration of the rectum, is a common incident. Various examples of this kind have fallen under my own observation. The relatively greater frequency of this form of pylephlebitis is due to the fact above stated, that the inferior hemorrhoidal veins are voluminous, have a sluggish current, and are liable to over-distension by pressure of feces and by external abdominal bands and clothing. Cases of a corresponding character arise from suppuration and ulceration elsewhere within the portal circuit. Thus, Bristowe211 reports a case in which pylephlebitis resulted from an ulcer of the stomach, the neighboring veins becoming implicated and the usual results following.
210 The Medical Times and Gazette, Sept. 27, 1884, p. 450, "Proceedings of the Cambridge Medical Society."
211 Transactions of the Pathological Society of London, vol. ix. p. 278.
When inflammation has begun in a radicle of the portal vein, it may proceed to the liver by contiguity of tissue, the whole intervening portion of the vessel being affected. Probably more frequently the intra-hepatic portion of the portal is inflamed by emboli, and the adjacent hepatic tissue then undergoes suppuration, as has been already set forth.
SYMPTOMS.—There being two points of disease—the primary lesion of the peripheral vessel and the secondary results in the hepatic portion of the portal—the symptomatology must have a corresponding expression. The stomach, the cæcum, or the rectum, or some other organ or tissue, being occupied by a morbid process, there will be a characteristic complex of symptoms. Taking up the most usual primary disturbance, a typhlitis or an ulcer of the cæcum, there will be pain, tenderness, and possibly fever, occupying in point of time the period proper to such a malady and an amount of disturbance of function determined by the extent of the lesion. The symptoms caused by a single small ulcer of the cæcum, as in the example narrated by Bradbury, may present no characteristic features and may have little apparent importance, and yet the lesion is productive of very grave consequences.
When from any of the causes mentioned above a thrombus forms in a vein of the portal system in consequence of the extension of the inflammation about it, the case, what importance soever it previously had, now takes on new characters. The onset of the inflammation of the vein walls and the puriform degeneration of the thrombus is announced by a chill—a severe rigor, or chilly sensations at least. At the time of the chill, and sometimes before it, pain is felt, significant of the lesion in the vein. When proctitis or typhlitis precedes the pylephlebitis, pain appropriate to the malady is a significant symptom; but the pain which comes on with the beginning of the inflammation in the liver is a new sign. The most frequent sites of the pain are the right hypochondrium and the epigastrium, but it may also be felt in the left hypochondrium or in either iliac fossa. Unless there be diffuse peritonitis the pain is accompanied by a strictly-localized tenderness to pressure. The situation of the pain may afford an indication of the vein attacked, and when there are two points at which pain is experienced, one may originate at the first situation of the morbid action; the other will be due to pylephlebitis.
The fever succeeding the chill is decided, and in some cases may attain to extraordinary height—a manifestation indicative of the pyæmic character of the affection. The fever intermits or remits, with a more or less profuse perspiration. The febrile phenomena are similar in their objective expression to malarial fever, but there is an important difference in respect to the periods of recurrence of the chills. The paroxysms are very irregular as to time: there may a daily seizure at different hours, or there may be several chills on the same day. In other words, the paroxysms have the pyæmic characteristics rather than the malarial. After a time the intermittent phenomenon ceases, and there occurs a remission merely, the exacerbation being preceded by chilliness and succeeded by sweating. The sweats are characteristically profuse and exhausting. During the sweating the temperature begins to decline, and reaches its lowest point just before the chilly sensations during the early morning announce the onset of the daily exacerbation of the afternoon and evening. The thermal line exhibits many irregularities until the febrile movement assumes the remittent type, when there occur the morning remission and nocturnal exacerbation. The maxima may be from 103° F. to 105°, even to 106°.
When the pain and chill come on, disturbances of the digestive organs ensue. When a large vein of the portal system is occluded, the remaining veins must be over-distended, and congestion of a part or of all of the digestive tract will be a result. An acute gastric catarrh is set up. The appetite is lost, the stomach becomes irritable, and vomiting is a usual incident. Sometimes the disgust for food is extreme, and the nausea and vomiting are almost incessant. The vomited matters consist of a watery mucus mixed with thin bile after a time, and now and then of a bloody mucus. Thrombosis of a stomach vein may occur, to be followed by an acute ulcer, and from this considerable hemorrhage may proceed, when the vomit will consist of blood. Such an accident, happening to the mucous membrane of the intestine, will be indicated by bloody stools if the ulceration is low down, or by brownish, blackish, or chocolate-colored stools if higher up in the small bowel.
The tongue has usually a characteristic coating in these cases. Large patches of a rather heavy and darkish fur form, and, cast off from time to time, leave a glazed and somewhat raw surface. Sometimes there is a profuse salivary flow, but more frequently the mouth is dry. The lips are fissured or contain patches of herpes, and the buccal cavity may be more or less completely lined by patches of aphthæ.
Diarrhoea is a usual symptom, the stools being dark when mixed with blood, or grayish and pasty or clay-colored when there is jaundice.
Three-fourths of the cases of pylephlebitis are free from jaundice. This symptom may occur at the onset when the common duct is obstructed by a calculus, but in other cases it appears when the formation of pus in the liver exerts sufficient compression of the hepatic ducts to prevent the passage of the bile.
When jaundice occurs, it is accompanied by the usual symptoms. The urine, previously unchanged, is now colored by bile-pigment, and the alterations in the renal structure and function belonging to jaundice also take place.
It sometimes happens that the obstruction of the portal vein is sufficient to cause enlargement of the superficial veins of the abdomen, but the duration of the disease is usually too brief to permit much deviation from the normal, except rarely. In the cases characterized by the occurrence of diffuse peritonitis the abdomen will present a swollen and tense appearance, and there will be acute tenderness to pressure. The area of hepatic and splenic dulness is not increased from the outset, but is evident, as respects the spleen, soon after the obstruction at the liver, and as respects the liver when the formation of abscesses occurs.
COURSE, DURATION, AND TERMINATION.—The course of pylephlebitis is compounded of the disturbance at the original point of disease, and of the secondary inflammation at the several points in the liver where emboli set up purulent inflammation. There are, therefore, two distinct symptom-groups, and a short intervening period in which the first is being merged into the second. The duration is variable, but the extreme limits are not remote from each other, the condition of pylephlebitis terminating in from two weeks to three months, the shorter being the more usual. The termination is death, doubtless invariably; for, as in true pyæmia arising from other causes, the septic changes in the blood are such as to preclude the possibility of a return to the normal condition.
DIAGNOSIS.—The main point in the diagnosis consists in the occurrence of an evident local inflammation, followed by the signs of suppuration in the hepatic region coming on subsequent to ulceration and suppuration at some point in the peripheral expansion of the portal system. Thus, when a proctitis with ulceration of the rectum has been in existence for some time, there occur pain and tenderness in the hepatic region, accompanied by an irregularly intermittent fever and by profuse sweating, it can be assumed with considerable certainty that emboli have been deposited in some one or more of the terminal branches of the portal. The evidences of hepatic trouble—swelling of the organ, jaundice, etc.—and of portal obstruction, which then supervene, indicate with some precision the nature of the case.
TREATMENT.—Although pylephlebitis wears a most unfavorable aspect, the possibility of a favorable result should always be entertained by the therapeutist.
As absorption of medicaments must be slow—indeed, uncertain—by the gastro-intestinal mucous membrane when there is portal occlusion, it is well to attempt treatment by the skin and subcutaneous connective tissue. Gastro-intestinal disturbance—nausea, vomiting, and diarrhoea—should be treated by a combination of bismuth, creasote, and glycerin—remedies acting locally chiefly. Ammonia—the carbonate and solution of the acetate—is indicated, and should be given for the purpose of dissolving thrombi and emboli. Corrosive sublimate, carbolic acid, and quinine can be administered by the subcutaneous areolar tissue. Quinine may also be introduced by friction with lard, and in considerable quantity.
DEFINITION.—The echinococcus is the intermediate or larval stage in the development of the Tænia echinococcus—the completed parasite—whose chief habitat is the intestine of the dog. As the natural and clinical history of parasites is elsewhere treated of, the subject is here confined to the development of echinococci cysts in the liver, its ducts, and vessels.
CAUSES.—The presence of echinococcus vesicles in the liver is due to the migration of the embryo from the intestinal canal. As Davaine212 has ascertained by analysis of all the recorded examples previous to the publication of his treatise, echinococci are found in as large a proportion in the liver as in all the other organs combined. This statement is repeated with approval by Cobbold213 and by Heller.214 The embryo, set free in the intestine from the food or drink containing the ova, starts on its migration. There are several reasons why the liver is selected for its habitat: it is the largest accessible organ; the common duct and the portal vein offer the most convenient roadway for reaching and penetrating its substance. The exact route or routes of which the parasite avails itself in migrating have not been definitely settled, although Friedreich has shown that the portal vein is the medium of transmission of the Echinococcus multilocularis. The comparative frequency with which the liver is entered indicates that the portal vein is the favorite route of migration.
212 Traité des Entozoaires et des Maladies vermineuses, etc., par C. Davaine, Paris, 1877, p. 383.
213 Entozoa, by T. Spencer Cobbold, M.D., F.R.S., London, 1874, p. 275.
214 In vol. iii of Ziemssen's Cyclopædia, p. 561.
PATHOLOGY AND SYMPTOMS.—The number of echinococci reaching the liver varies from one to ten or twelve or more. They increase in size from the time of their deposit in the organ, and ultimately attain to large proportions. The rapidity of growth depends somewhat on the character of the tissue in which imbedded, and the amount of disturbance of function is determined by the position of the parasite in the organ. Echinococci may be deposited in any part of the liver—in the substance of the organ, in the ducts, or in the vessels—but the most usual site is near the capsule, and, developing outwardly in the direction of least resistance, impart to the outline of the organ an irregular contour. As the echinococci develop, the adjacent parts of the liver pressed upon undergo atrophy, but the connective tissue of the organ contributes to the formation of the dense capsule which envelops them. But as the increase in size is not rapid, although continuous, if the cysts are situated at the periphery and adjacent to the capsule, they may be present for many months without causing any distinct symptoms. In a case occurring under my own observation last year the only symptom which attracted attention was an enlargement of the hepatic region, and on examination a characteristic elastic, irregular, and painless tumor could be readily detected by sight and touch occupying the right hypochondrium and extending into the epigastric and umbilical regions. When the echinococci cysts impinge on the portal vein or on the hepatic duct, there will be caused the usual results of such pressure—ascites or jaundice, or both conditions may occur simultaneously, with obstruction of both vein and duct. When the cysts develop downwardly, the stomach and intestines will be displaced, and nausea and vomiting, diarrhoea or constipation, and, it may be, considerable pain of a colic-like character, will be caused. An upward development of the cysts gives rise to more pronounced disturbances. The diaphragm is pushed upward, the heart displaced, and the lungs, especially the right, compressed. Occasionally the diaphragm is softened and perforated by the pressure of the enlarging cysts, and the lungs are ultimately tunnelled, the parasites being discharged by the bronchi.
The growth of an echinococcus tumor may spontaneously cease, and then retrograde changes take place, leading to its final disappearance. This arrest of development may occur without any obvious cause, but now and then such a change from the ordinary course of tumors may be effected by an external injury, as a blow on the abdomen, but more frequently the death of the parasite is caused by ulceration into a bile-duct, and the entrance of bile, which is a poison to these hydatids. It sometimes happens that, opening into a duct of large size, the daughter and granddaughter vesicles are slowly discharged through it into the intestine, and thus a cure is effected. Inflammatory action occurring in the cysts, adhesions may form and rupture into a neighboring cavity take place. Direct communication may be established with the intestine, or the cavity of the pleura or peritoneum be entered, with results entirely disastrous.
A necessarily fatal termination must also ensue when the hydatids penetrate the ascending vena cava, but this accident is, fortunately, very rare.
The passage outward through the abdominal wall is an exceedingly uncommon but fortunate issue of echinococcus of the liver, for in this mode the hydatids may be discharged without much difficulty.
The echinococcus vesicle is enveloped in a dense, resisting, and elastic capsule, constructed out of the connective tissue of the part in which it is deposited. The innermost layer of the vesicle is the germinative (endocyst), and from its granular surface are developed the brood-capsules and their scolices—i.e. the head with its suckers and crown of hooklets.215 Each vesicle may contain not only daughter, but also granddaughter, progeny, numbering from a dozen up to many thousands, and they will vary in size from the head of a pin to a pullet's egg. It follows that the mother vesicles must also greatly vary in size: they range from a large pin's head to a child's head. The vesicles or sacs contain a clear, faintly yellowish, or opalescent fluid, neutral or slightly alkaline in reaction, and holding in solution a large per cent. of sodium chloride, but free from albumen. The specific gravity of the fluid ranges from 1007 to 1015, according to the quantity of sodium chloride present. Succinic acid and also hæmatoidin are usual constituents, besides the ingredients already mentioned.
215 Entozoa, Cobbold, p. 273 et seq., chapter viii.
Although the form of hydatid or echinococcus cyst above described is the usual one, there is occasionally produced an anomalous development of the parasite, which from its resemblance to colloid cancer was supposed to have this character until Virchow216 unravelled the mystery by demonstrating its true structure. This form of the parasite is designated Echinococcus multilocularis. Its resemblance to colloid cancer is the more striking because of the tendency of the interior of the mass to undergo degeneration, to disintegrate, and to break up into pus-sacs with greenish, cheesy, and bilious contents. An Echinococcus multilocularis tumor is of almost stony hardness; it has a very dense fibrous structure, intersected by cavities with thick gelatinous contents. These minor cavities217 are sacs of echinococci, but they depart widely from the typical form, well-defined scolices being seldom encountered.
216 Archiv für Anat., Virchow, vol. xi. p. 80.
217 Carrière, quoted by Davaine, op. cit., p. 961.
Echinococci of the liver develop very slowly, and it is characteristic of them to attain to very large proportions in most cases without causing any very pronounced symptoms. There are certain signs common to hydatids in any situation; there are others which are due to particular circumstances.
A hydatid tumor of the liver is smooth but somewhat irregular in outline, and elastic, when it develops downward, extending below the margin of the ribs. If, however, it grows upward, the area of hepatic dulness extends in that direction beyond the usual limits; the diaphragm is pushed up, the lungs forced upward to the left and compressed, and the heart also displaced upward toward the left. The extension of the tumor downward, in the direction of least resistance, is more usual. If the walls of the abdomen are sufficiently thin, the tumor large enough, and if made up of many daughter vesicles, there may be evoked by palpation the very characteristic sign known as hydatid purring. To produce this effect an oscillation must be caused by a sudden impulse communicated to the tumor on one side, the hand resting against the other side. This sensation is likened to the impression on the eye of the vibration of a bowl of jelly. Even when there is a well-defined tumor this symptom is comparatively infrequent, but if present it is pathognomonic, since no other kind of tumor possesses the property of oscillation and elastic collision of its several constituents.
When the tumor is so situated as to occlude the hepatic or common duct, jaundice will be a symptom, and when the stomach is pressed upon there will be epigastric oppression and nausea. If the vena cava is impinged on or the portal vein, the usual results—ascites and oedema of the lower extremities and of the scrotum—will be manifest. There is, of course, nothing distinctive in these results.
The Echinococcus multilocularis, situated in the substance of the liver, causes the usual disturbances of a new formation in such a position. Much of the hepatic tissue is destroyed by its growth, and many of the minor ducts closed. Jaundice is an early symptom—the first, indeed, in many cases—and is also one of the most persistent. It is present, according to Griesinger, in 10 out of 13 cases. The usual gastro-intestinal disorders belonging to jaundice occur under these circumstances; also the nervous disturbances of cholæmia.218
218 Davaine, op. cit., p. 962.
Enlargement of the spleen is a very frequent symptom, being present, according to Davaine, in 11 out of 13 cases, and, according to Heller, in 25 out of 29 cases, in which this fact was made the subject of direct inquiry.
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.
Therapeutical.—The remedial management of cases of Tænia echinococcus is necessarily restricted to that stage in their development when by increasing size the functions of organs begin to be affected. Internal medicines given with the view to arrest the growth of the parasite are useless. Formerly, such attempts were made and successes were claimed, but it is now known that no medicine can act on organisms enclosed as these are in a dense capsule. It is needless to occupy space with therapeutical details of this kind, but mention may be made of the agents that were supposed to be effective. Laennec held that baths of a solution of common salt had a distinct curative effect. The internal use of iodide of potassium and the local application of iodine paint were believed to cure a case in St. George's Hospital, London, in the practice of Mr. Cæsar Hawkins. Kameela was, in Iceland, supposed to have a curative effect, but notwithstanding this the physicians of that island resort to very heroical surgical methods in the treatment of this affection.
The one means of relief consists in the removal of the vesicles, either by suitable incisions or by compassing the death of the parasite, after which the power of nature may be adequate to the cure. In Iceland large incisions are made into the tumor at its most prominent part, and, although accidents are not uncommon, the results in many cases are eminently satisfactory. The accidents are shock, hemorrhage, and especially peritonitis. Under favorable circumstances now no procedure is more satisfactory in its results than free incision and drainage. The tumor should be prominent, adherent all round to the peritoneum, and the walls of the abdomen thin to ensure complete success without accident. At the present time, so great have been the advances in abdominal surgery, this operative procedure may be preferable in some few cases presenting the favoring conditions above mentioned.
Very simple expedients, however, suffice in most cases. The most simple is puncture. This is now much practised in Iceland, and, as the statistics show, with considerable success. Thus, Hjaltelin219 reports 100 cases cured in this way, and in his own hands this expedient proved successful in 41 out of 50 cases operated on. In Australia, where hydatid disease is also quite common, simple puncture has effected a large proportion of cures,220 and is the method of treatment usually pursued. In England puncture has the approval of some of the best authorities.221
219 Davaine, op. cit., p. 605.
220 The Medical Times and Gazette, August, 1873, p. 164.
221 Transactions of the Clinical Society for 1872: discussion participated in by Gull, Bryant, Greenhow, etc.
The mode of performing this operation consists in the introduction of an exploring-trocar into the most prominent part of the tumor. It may be withdrawn at once or be permitted to remain for a few minutes to several hours. The dangers are suppuration in the sac and peritonitis; but the former, although sometimes accompanied by severe constitutional symptoms, is not likely to endanger life, and even formidable disturbances due to the latter are usually recovered from. The facts show that puncture very rarely indeed causes dangerous, especially fatal, symptoms. An eruption of urticaria has been observed to follow puncture with the trocar, and also aspiration, in a considerable proportion of the cases, but it has no special significance.
Since the introduction of the aspirateur, puncture and withdrawal of the fluid by means of this instrument has been practised more frequently, and this appears to be a more effective procedure, than simple puncture with an exploring-trocar, although in most cases the escape of the contained fluids suffices to destroy the parasite. The aspirateur is less likely to permit the escape of fluid into the peritoneal cavity or the entrance of air into a vein punctured by accident. If puncture with the trocar or aspiration be practised, shall all the fluid be withdrawn at once? The answer to this question may be decided by the character of the sac. Does it contain daughter and granddaughter vesicles? If so, one puncture may not permit the escape of much fluid; but in any event it is the practice of the most judicious and experienced authorities222 to withdraw as much as possible of the contents of the cysts at the first operation. Formerly, a method practised by some French surgeons consisted in successive tappings, a small quantity of fluid being drawn off each time.223 There is no good reason for this method of treatment now, and it seems to have been discontinued.
222 Transactions of the Clinical Society, loc. cit.
223 Davaine, supra.
Yet another method of treatment, but less effective than puncture or aspiration, consists in injecting into the sac, after the removal of its contained fluid, certain agents toxic to hydatids. A solution of the extract of fern, alcohol, solution or tincture of iodine, and bile, are the chief remedies thus employed. It has long been known that bile is destructive of these parasites, and cases have occurred of spontaneous cure in which the opening of the growing cysts into a bile-duct has secured the entrance of bile and consequent arrest of growth and atrophy of the hydatids. Several successful cases have been reported in which the injection of aspidium (male fern) was the effective agent, but the threatening symptoms produced by it, and the comparative freedom of other methods of treatment from such disturbances, do not recommend the injections of fern. In the case reported by Pavy224 the extract of fern was mixed with a solution of potassa.
224 Lancet (London), July, 1865.
Injections of iodine in solution or in the form of tincture have been more frequently practised than of any other material. Davaine,225 who finds it less successful than simple puncture and aspiration, recommends, as affording the best results, a dilute aqueous solution of iodine. Alcohol, a solution of permanganate of potassium, and various antiseptic agents have been used to some extent, but none of them possess any advantages over more simple measures.
225 Op. cit., p. 650.
The latest proposal for the treatment of hydatid cysts, and probably the most effective consistent with entire safety, is electrolysis. Originally suggested by Althaus226 to those who first employed the measure on any considerable scale, it had been mentioned thirty years before by Budd, and appears to have been first practised in Iceland on a single case. The first elaborate attempt to establish electrolysis on a sound basis as a regular procedure was made by C. Hilton Fagge and Mr. Arthur E. Durham.227 They operated on eight cases, and all were successful. The method consists in the introduction of two needles connected with the negative pole, and the application of the positive—a moistened sponge—on the exterior in the neighborhood of the hepatic region. The strength of current employed by Fagge and Durham was that furnished by a battery of ten cells, and which by previous trial was found to decompose a saline solution. The two electrolytic needles, connected with wires attached to the negative pole, were introduced into the most prominent part of the tumor about two inches apart. The current was allowed to pass about ten minutes usually, sometimes a little longer, the sponge on the exterior—the positive pole—being shifted occasionally. The immediate effects are not considerable. The tumor may be rendered somewhat more tense and appear to be enlarged, but more frequently it becomes softer and is lessened in size, the increase of size being due to the disengagement of hydrogen gas, and the diminution caused by the escape of more or less fluid. The immediate effects of the operation varied. In one case no symptom followed, and in this the result was regarded as doubtful, although a cure was considered probable. In the others more or less constitutional disturbance followed, the symptoms being pain and fever, the temperature ranging between 100° and 103° F. The duration of the fever was from two to nineteen days, the latter in one case only. As has been observed in some of the cases treated by puncture or by aspiration, a rash appeared on the skin—in some instances scarlatinous, in others of urticaria. It is a curious circumstance that an eruption of urticaria is reported to have appeared in one subject in whom a rupture of the sac into the peritoneal cavity is supposed to have occurred.
226 On the Electrolytic Treatment of Tumors, etc., London, 1867.
227 Medico-Chirurgical Transactions, 1871, p. 1 et seq.
Although so little change in the tumor occurs immediately after the operation, yet it undergoes slow absorption, and ultimately disappears. The time occupied in the disappearance of the tumor varies from a few weeks to many months, the difference being due probably to the situation of the growth, those occupying the substance of the liver requiring a longer time to fill up.
Fagge and Durham report a case in which simple acupuncture was followed by a result apparently as good as obtained by electrolysis, and other similar experiences have been published. If the simple introduction of a needle suffices to arrest the growth of a hydatid cyst and induce its atrophy, of course the more complex procedures will be abandoned.
The tendency of the treatment of hydatid cysts has constantly been toward simplicity, and the success occurs in a direct ratio thereto. In forming an estimate of the relative value of the methods of treatment, the average of mortality of each plan becomes the most important factor. Simple tapping and paracentesis, the most frequently adopted mode of treatment, is not without immediate and remote danger. Of 46 cases carefully tabulated by Murchison,228 there were 3 deaths properly attributable to the operation; but the after results—suppuration of the cyst and its consequences, peritonitis, etc.—cannot be measured so accurately. About two-thirds of the cases thus treated result in cure, and in a majority of these a single operation suffices. The injection of the various substances which have been employed for that purpose does not seem to increase the proportion of cures, and their use distinctly enhances the dangers of the treatment. At present, the decision as to the method of treatment to be employed in any case should be made between simple tapping, electrolysis, and acupuncture. Of these, the last mentioned, it can hardly be doubted, is the method which is most desirable, for although it has not been employed so largely as the others, thus far the results have been better: the percentage of recoveries without accident has been higher relatively than by other methods of treatment. As acupuncture presents no special difficulties or dangers, and is but little painful, it may be tried first, reserving more formidable measures for the failures by this simple expedient.
228 Clinical Lectures on Diseases of the Liver, loc. cit.