Ileal Arteriovenous Malformation: An Uncommon Cause of Gastrointestinal Hemorrhage

Abstract

A 32-year-old man was admitted with melena that was found to be due to a small arteriovenous malformation in the terminal ileum. The use of 99m technetium-labeled erythrocyte scanning and selective superior mesenteric artery arteriography established the diagnosis before laparotomy was done, and aided in achieving permanent cure. The importance of this rare cause of lower gastrointestinal bleeding is discussed. Case ReportA 32-year-old man, who was a long-distance runner and a bank employee by profession, was admitted because he had been passing two to four melenotic stools for one week. He also complained of easy fatigability and mild dyspnea on exertion that had persisted for one week. His friends noticed that he was becoming progressively paler during the 4 to 6 weeks before admission. There was no associated history of diabetes mellitus, hypertension, ischemic heart disease, valvular disease, or tuberculosis. He was not taking any ulcerogenic medicines but had taken three tablets of Aspirin two weeks earlier for flu-like symptoms. He was a nonsmoker and consumed alcohol on social occasions only. He was a trained athlete who specialized in long-distance running. Past history revealed that at birth he had had two vascular hemangiomas on the forehead and neck that were treated by contact radiation when he was 3 months old. There was minimal scarring at these two sites. The patient had had hepatitis A10 years previously and had recovered without problems.On examination he was found to be very pale with a pulse of 94 beats/min and supine blood pressure of 130/60 mm Hg, with a drop of 10 mm Hg in the systolic blood pressure on standing. He was afebrile. Systemic findings were normal. PR and proctoscopy yielded unremarkable findings except for melena. Laboratory investigations revealed a hemoglobin level of 56 g/L; white blood cell count, 8.7 x 10 9 /L; erythrocyte sedimentation rate, 5 mm in the first hour; and platelet count, 189 x 10 9 /L. Prothrombin time and activated partial thromboplastin time were normal. Mean corpuscular volume was 85.4 fl; mean corpuscular hemoglobin, 21.1 pg; mean corpuscular hemoglobin concentration, 330 g/L; serum iron, 99 µmol/ L; serum ferritin, 3.2 µg/L; random blood sugar 5.9 mmol/L; urinalysis was normal; stool was positive for occult blood; and chest x-ray study and electrocardiogram were normal.Upper gastrointestinal endoscopy and barium swallow, meal, and follow-through examination did not show any significant lesion. Technetium 99m-labeled erythrocyte scanning showed a collection of contrast agent close to the bifurcation of the common iliac artery. This started at about 5 minutes after injection and was maximal at 45 minutes, when the test was completed. Following this, colonoscopy was attempted but beyond the mid-transverse colon. Examination was not possible because of the presence of thick maroonish stools and blood clots, indicating a bleeding lesion proximal to the mid-transverse colon. An emergency arteriography was performed on the celiac axis, superior mesenteric arte...