Vascular disease of the intestines

Use of selective mesenteric vasodilator peptides in experimental nonocclusive mesenteric ischemia in the dog

Three structurally related peptides, ovine corticotropin-releasing factor, sauvagine, and urotensin I are selective mesenteric vasodilators in dogs. To assess the possible benefit of these peptides in nonocclusive mesenteric ischemia, they were compared with a nonselective vasodilator, sodium nitroprusside, in the anesthetized dog. Mesenteric blood flow was reduced by approximately 30%, without lowering of systemic arterial pressure, by either digoxin or pericardial tamponade. In the digoxin model, i.v. infusions of corticotropin-releasing factor, sauvagine, and urotensin I restored intestinal vascular resistance and mesenteric blood flow to control values, without causing a fall in systemic arterial blood pressure. In the tamponade model, only urotensin I was assessed, and it produced the same restoration of hemodynamic variables. On the other hand, in both models, i.v. infusions of nitroprusside, which were effective in correcting intestinal vascular resistance, produced a fall in arterial blood pressure (presumably because of systemic dilatation), which prevented restoration of mesenteric blood flow. Intestinal oxygen uptake was not altered by tamponade, but was reduced by 23% in the digoxin model, where it was restored to control values by both the peptides and nitroprusside. The increased oxygen extraction seen in both models was corrected by the peptides but not by nitroprusside, suggesting that nitroprusside may have a direct and offsetting metabolic effect on the gut.

Abdominal pain, atherosclerosis, and atrial fibrillation. The case for mesenteric ischemia

DT, a 63-year-old white male with insulin-dependent diabetes mellitus and severe peripheral vascular disease, was admitted with a five-day history of vague abdominal pain and diarrhea. On the day of admission he vomited three times, was noted to have a bloody stool, and came to the emergency room. DT denied hematemesis, fever, or chills. He had bilateral leg amputations and had sustained three myocardial infarctions, the last one 15 months before this admission. He had never experienced symptoms of abdominal angina. Of significance was his history of congestive heart failure, mitral regurgitation, and atrial fibrillation. His medications on admission included digoxin 0.25mg per day, furosemide 40mg per day, and NPH insulin 15 units per day. On admission to the hospital his oral temperature was 38 degrees C, pulse was 90/min, respiratory rate was 24/min, and blood pressure was 134/80mmHg. Abdominal examination revealed a distended abdomen with hypoactive bowel sounds and mild tenderness. Chest x ray revealed cardiomegaly. The electrocardiogram demonstrated atrial fibrillation. A plain film of the abdomen was positive for gallstones and edema of the bowel wall (thumb-printing). Laboratory results included blood urea nitrogen 48mg%, creatinine 1.2mg%, hemoglobin 18g/dl, and hematocrit 52.9%. White blood cell count was 11,900 cells/cc with 33% polymorphonuclear leukocytes, 47% bands, 8% lymphocytes, 11% monocytes, and 1% atypical lymphocytes. The prime considerations for differential diagnosis were mesenteric ischemia and infectious gastroenteritis. While it was appreciated that mesenteric ischemia, if present, might warrant surgical intervention, the risk of anesthesia itself in this patient was felt by his attending physicians to exceed 30%. Furthermore, the clinical findings were only "suggestive" of mesenteric eschemia. They were certainly not "diagnostic." In view of this dilemma, a consultation with the Division of Clinical Decision Making was requested.

Ischaemic strictures of the small intestine in Nigeria

Eleven specimens of small intestinal strictures were seen at the Pathology Department of the University of Benin Teaching Hospital, Benin City, Nigeria, during a period of two and a half years. Eight of them were ischaemic in origin and the clinical and pathological features of these eight cases are described. In five of the cases, the ischaemia could be related to inguinal hernia, with herniorrhaphy a few weeks before surgery for stricture in four cases. The most important factor in making a clinical or pathological diagnosis of ischaemic stricture of the small intestine appears to be awareness of the condition. The importance is emphasised of studying the mesentery, with particular attention to lymph nodes and blood vessels, before making a final diagnosis on intestinal lesions.