SYSTEMIC-PORTAL arteriovenous fistulas are uncommon vascular anomalies. A review of the literature revealed only 16 cases with clinical descriptions. Although the site of origin varied, drainage in each instance was ultimately into the portal vein. In one patient the fistula arose from the main superior mesenteric artery,' in three the secondary branches of the superior mesenteric artery,24 in five the hepatic artery,5-9 and in seven the splenic artery.'0-l6 Five of the 16 patients died of causes related to this lesion. It would appear that patients with sueh shunts have a poor prognosis.The diagnosis of an arteriovenous fistula between the superior mesenteric artery and vein was recently established in our laboratory by radiographic technics. As this patient is the only such case known to have had a successful surgical repair, a detailed report is indicated.Case Report E. R., a 27-year-old white single man, was admitted to the Duke Medical Center on March 31, 1962, for evaluation of a painful monoplegia of the right lower extremity, which followed a gunshot wound to the upper abdomen 3 months previously. A .22-caliber bullet had entered the epigastrium and lodged in the posterior thorax at the level of the second lumbar vertebra. Immediate exploratory laparotomy at another hospital was said to have revealed lacerations of the liver and right kidney. A right nephrectomy was performed and 14 units of blood were administered during the procedure. Postoperatively the patient improved slowly. The right leg, however, remained paralyzed and painful. At no time did he com-From the Cardiovascular plain of symptoms referable to the gastrointestinal tract.Physical examination at the time of admission to the Duke Medical Center revealed a blood pressure of 110/70 mm. Hg and a pulse of 80. The right lower extremity was erythematous. A sensory level was present over the hip with associated loss of inotor function and muscle atrophy. The sear from the previous laparotomy extended from the umbilicus to the epigastrium. Of considerable interest was the presence of a systolic thrill and continuous murmur over the entire upper abdomen.Initial laboratory work included a hematocrit value of 46 per cent; white blood-cell count of 12,500, and an unremarkable urinalysis. Total phenolsulfonphthalein excretion in 2 hours was 55 per cent. Blood chemistries were normal.The electrocardiogram and chest x-rays were within normal limits. An esophagram and upper gastrointestinal and ileal series were all normal. Films of the lumbosacral spine showed metallic fragments at the level of the second lumbar vertebra. An intravenous pyelogram demonstrated prompt function on the left side but none on the right side; the right renal shadow could not be seen. Liver biopsy (obtained at laparotomy) was interpreted as "normal liver."Because of the presence of the abdominal bruit, maximal in the supraumbilical region, catheters were inserted percutaneously into the right femoral artery and the right antecubital vein. Hepatic vein catheterization revealed the...