Superior Mesenteric Arteriovenous Fistula Presenting with Massive Lethal Upper Gastrointestinal Bleeding 14 Years after Small Bowel Resection

Background: Arteriovenous fistulas (AVFs) of the superior mesenteric vasculature are rarely encountered. We present a case of an iatrogenic superior mesenteric AVF in a patient who had undergone a small bowel resection 14 years previously. Case Report: The 45-year-old male was admitted with bloody diarrhea, fatigue, weight loss and moderate ascites. On the fifth hospital day, while being evaluated for suspected liver cirrhosis, the patient developed severe gastrointestinal (GI) bleeding. An upper GI endoscopy revealed bleeding, esophago-gastric varices. A thorough clinical examination pointed to a paraumbilical murmur and thrill, while a contrast enhanced computerized tomography (CT) scan of the abdomen revealed the presence of cystic dilatation of the superior mesenteric vein (SMV), hepatomegaly and ascites. Duplex ultrasonography and 3D-computed tomography angiography (3D-CTA) confirmed the existence of AVF between the superior mesenteric artery (SMA) and SMV, which was the cause of portal hypertension and variceal bleeding. Despite the fact that AVF was ultimately recognized, uncontrollable hypovolemic shock caused by hematemesis, precluded the probable efficiency of further therapeutic attempts. Conclusion: Successful management of mesenteric blood vessel AVFs involves timely and the accurate diagnosis and early treatment in order to prevent the development of life threatening complications