Spontaneous inferior mesenteric arteriovenous fistula as a cause of severe portal hypertension and cardiomyopathy

Inferior mesenteric artery (IMA) and inferior mesenteric vein (IMV) fistulas or malformations are extremely rare, with only 36 cases reported. Low incidence and nonspecific clinical signs and symptoms make mesenteric arteriovenous fistulas difficult to diagnose. We describe a case of a primary IMA-IMV fistula. Our patient presented with severe portal hypertension and cardiomyopathy along with robust arteriovenous connections between the IMA and IMV. Arterial embolization in this patient had to be followed by venous embolization for successful resolution of portal hypertension and cardiomyopathy. This case also highlights that close outpatient monitoring for treatment failure and recurrence is necessary for this disease process.