The termination may be accelerated by the manner of discharge, as when the abscess opens into the ascending vena cava, into the sac of the pericardium, or into the peritoneal cavity. In my own cases, carefully selected for these observations, death occurred in one during discharge by the right lung, one within twelve hours after discharge by the intestine, and one within ten days after discharge by the stomach and intestine, the mortality of the whole being 75 per cent. In Waring's collection of 300 fatal cases, 169 died whilst the abscess was still intact—that is, in the liver.
The mortality from abscess of the liver is very large. In Rouis's collection of 203 cases, 162 died, 39 recovered entirely, and 2 improved; 80 per cent., therefore, proved fatal. According to De Castro,111 whose observations were made at Alexandria, Egypt, 93 in 208 cases died, this being 72.5 per cent. According to Ramirez,112 of 11 cases of which an account is given in his memoir, 10 died and 1 recovered—a mortality of 90 per cent. De Castro (p. 40) also gives the results arrived at by the Medico-chirurgical Society of Alexandria, who collected 72 cases of abscess, of which 58 died, making the percentage of deaths 80.5. Various circumstances besides the abscess affect the result. An early successful operation, the mode of discharge, the amount of hepatic tissue destroyed by the suppuration, the extent of pre-existing lesions—especially ulcerations of the intestinal canal—are important factors in the result. In respect to some of these we have valuable statistical data. The discharge through the lungs is the most favorable route, next by the parietes of the abdomen, and lastly by the intestinal canal. One-half of those cases in which discharge is effected by the right lung get well. This is my own experience, and it accords with the observations of Rouis, of De Castro, and others. Rouis gives the result in 30 cases of hepatic abscess discharging by the right lung; of these 15 recovered. Of 25 cases observed by De Castro, discharging by the lungs, 19 recovered. Next to the discharge by the bronchi, the most favorable mode of exit is externally, through the parietes of the abdomen; much less favorable is by the stomach or intestine; but still more fatal is the discharge into the cavity of the peritoneum. When the abscesses are multiple and due to pyæmia, the termination is always in death. The numerous lesions besides the hepatic accelerate the fatal issue. In the case of large single abscesses the result is in a great measure due to exhaustion from protracted suppuration. When in addition to the formation of a great quantity of pus there is frequent vomiting and rejection of aliment, the failure of strength is proportionally rapid. In favorable cases, after an abscess is evacuated through the right lung, recovery takes place promptly. When the discharge occurs through the abdominal wall, the process is much slower, and often fistulous passages with several orifices, very slow to heal, are formed. Complete recovery may ultimately take place. The recovery will be incomplete in those cases with large loss of hepatic substance, especially when this coincides, as it usually does, with catarrh, ulceration, and other lesions of the intestinal tube. Again, the recovery will be incomplete in those cases where there are imperfect healing of the abscess site and a fistulous communication with the exterior.
111 Des Abcès du Foie des Pays chauds, et de leur Traitement chirurgical, loc. cit., p. 40, Paris, 1870.
112 Du Traitement des Abcès du Foie, Observations receuilles à Mexico et en Espagne, par Lino Ramirez, M.D., Paris, 1867, loc. cit.
It is possible for the arrest and healing of a suppurative inflammation of the liver to take place without discharge. Under such circumstances the watery part of the pus is absorbed, the solid constituents undergo a fatty metamorphosis, are emulsionized, and thus absorbed, and gradually closure of the damaged area is effected by a connective-tissue formation. We must, however, accept with caution those examples of this process which are supposed to have occurred because radiating cicatrices are discovered on the surface of the liver. In a case of hepatic abscess discharging through the lung, known to the writer, after death, which occurred fifteen years subsequently, there was no trace of the mischief, so perfectly had repair been effected. Radiating cicatrices are so often of syphilitic origin that they cannot be accepted as proof of the former existence of an abscess.
DIAGNOSIS.—He who finds the diagnosis of abscess of the liver easy under all circumstances can have had but little experience with the numerous difficulties in the way of a correct opinion. There are cases so plain that the most casual inspection suffices to form a conclusion; there are cases so difficult that the most elaborate study fails to unravel the mystery. The maladies with which hepatic abscess may be confounded are echinococcus of the liver, dropsy of the gall-bladder, cancer, abscess of the abdominal wall, empyema, or hydrothorax, etc. As regards echinococcus, the difference consists in the slow and painless enlargement characteristic of echinococcus, and the absence of any symptoms other than those due to the mere pressure of the enlarging mass. In abscess there may be no apparent enlargement, or the increase in the area of dulness may be very great, or after a period of increase of size there may be contraction due to the formation of pus, and hence limitation of the inflammation; finally, the accumulation of fluid may be sufficient to cause dulness up to the inferior margin of the second rib. There are no corresponding changes of size in the echinococcus cyst. Furthermore, abscess of the liver large enough to be recognized by the increased dimensions of the organ will be accompanied by more or less pain in the right hypochondrium and by a septicæmic fever. On the other hand, an echinococcus tumor is not accompanied by fever, pain, or tenderness, and it has that peculiar elastic trembling known as the purring tremor. The most certain means of differential diagnosis is the use of an aspiration-needle and the withdrawal of a portion of the fluid. The presence of pus with hepatic cells will be conclusive of abscess, whilst a serous fluid with echinococci hooklets will prove the existence of the echinococcus cyst.
In cases of dropsy of the gall-bladder there are no febrile symptoms, no chills, and the tenderness when present is limited to the pyriform body, the seat of the accumulation of fluid, and no general enlargement of the liver can be made out. At the point of swelling fluctuation may be detected, or if the gall-bladder is filled with calculi the sensation imparted to the touch is that of a hard, nodular body of an area and position corresponding to that of the gall-bladder. Tapping the gall-bladder, an easy and safe procedure, will resolve all doubts. When an impaction of a gall-stone is the cause of abscess, the clinical history is eminently characteristic: there are attacks of hepatic colic, after one of which the chills, fever, and sweats belonging to hepatic abscess occur.
The differentiation of cancer of the liver from abscess rests on the following considerations: In cancer there is slow enlargement, with pain; a more or less nodular state of the organ without fluctuation; usually ascites; no rigors; no fever and sweats. In abscess the liver may or may not be enlarged; there are rigors, fever, and sweating, and the surface of the organ, so far as it can be reached, is smooth and elastic, and it may be fluctuating. Cancer happens in persons after middle life, develops very slowly, and is accompanied by a peculiar cachexia; abscess occurs at any period, very often succeeds to or is accompanied by dysentery and by the usual phenomena of suppuration.
It is extremely difficult to separate an abscess in the abdominal wall, in the right hypochondrium, or a tumor in this region, from an abscess of the liver. The history of the case, the existence of a dysentery or of an apparent intermittent or remittent fever before the appearance of a purulent collection, will indicate the liver as the probable source of the trouble. Attention has already been called to a case in which an abscess of the liver was supposed by an eminent surgeon to be a tumor of the abdominal wall. The history in this case of an obstinate remittent fever, followed by the appearance of a tumor of the hypochondrium and by a preliminary discharge at the umbilicus, clearly indicated the nature of the trouble. In the absence of any history of the case it is extremely difficult to fix the origin of a suppurating tumor originating, apparently, in the depth of the right hypochondrium.
Mistakes are frequently made in the case of an abscess developing in the convexity of the right lobe of the liver and pushing the diaphragm up to the third, even to the second, rib, and thus producing conditions identical with empyema of the right thorax. Such instances of hepatic abscess are peculiarly difficult of recognition, because, the physical signs being the same as those of empyema, the differentiation must rest on the clinical history. In cases of empyema proper the effusion in the chest is preceded by pain and accompanied by an increasing difficulty of breathing; in hepatic abscess there are, as a rule, symptoms of disturbance in the hepatic functions, fluctuation in the hepatic region, dysentery, etc., long anterior to any disturbance in the thoracic organs. Again, empyema may be a latent affection, without any symptom except some obscure pain and a progressive increase in the difficulty of breathing; on the other hand, abscess of the liver is preceded by symptoms of liver disease and of associated maladies. A dry, purposeless cough is present in many cases of abscess; a painful cough with bloody expectoration occurs when preparation is making for discharge through the lungs.