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.