DIAGNOSIS.—The following are the most important points in forming a diagnosis: 1. A source exists from which an embolus might be derived. 2. Profuse and even exhaustive intestinal hemorrhage sets in, which can neither be explained by primary disease of the intestinal walls nor by hindrance to the portal circulation. 3. There is a rapid and considerable fall of the temperature. 4. Pain in the abdomen comes on, which may resemble colic and be very severe. 5. Finally, tension and tympanitic swelling of the abdomen occur, and there may be fluid in the abdominal cavity. 6. Evidence of embolism of other arteries may have been obtained before the symptoms of embolism of the superior mesenteric artery come on, or such evidence may appear at the same time as the latter. 7. Palpation may reveal the presence of collections of blood between the folds of the mesentery.
PROGNOSIS.—The prognosis in embolism of the superior mesenteric artery, though not absolutely bad, is exceedingly grave. It must be borne in mind that the symptoms of occlusion of one of the large branches are similar to those where the main stem is involved, while the probabilities of recovery in the former are much greater, as already explained, from the shorter extent of the anastomosis. There is evidence that recovery from the immediate effects of embolism may take place even where subsequent ulceration has been so great as to cause complete closure of the intestine through cicatrization. (A case is related by Parenski where the patient was operated on for stricture of the bowel, and only at the autopsy was it discovered that the stricture was due to cicatrization from ulceration caused by embolism of one of the branches of the superior mesenteric.) There are at least three cases of recovery on record where occlusion of the main stem was supposed to have taken place; but inasmuch as the situation of the embolus cannot be determined with certainty if the patient recovers, these cases are open to the suspicion that one or more of the larger branches only were occluded. The profuseness of the hemorrhage, though it may imperil the life of the patient from exhaustion, bears no constant relation to the gravity of the case. Copious and repeated hemorrhages per anum took place in cases of recovery, while in other fatal cases this symptom was entirely absent. Extreme fetor of the stools must be regarded as of evil omen, as it may be the evidence that gangrene of the bowel has taken place.
TREATMENT.—One of the first symptoms calling for relief is the colic, which is best met by morphia given subcutaneously or by suppository. For the hemorrhage ergot by the mouth and alum enemata have proved serviceable, or the application of ice to the abdomen. The lowering of the heart's action by sedatives is to be avoided when we remember that their use would lower the blood-pressure, and thus tend to retard the establishment of the collateral circulation.
Thrombosis.
The symptoms of thrombosis have not been determined apart from embolism, and it is doubtful if the affection proves fatal unless the extent of artery involved is very considerable or the formation of the thrombus is very rapid, for the anastomosis is gradually made compensatory. In either of the latter cases the symptoms are identical with embolism, and the pathological appearances are the same. With regard to treatment, general indications must be pursued.
Endarteritis.
This disease is met with, but it is usually slight and unaccompanied by symptoms.
DISEASES OF THE INFERIOR MESENTERIC ARTERY.
Aneurism.