Arteriovenous malformation of the rectum: report of a case

Trans-arterial embolization of a Yakes type IIb inferior mesenteric arteriovenous malformation: A case report and literature review for angio-architecture analysis

We herein report a case of acute, massive lower gastrointestinal bleeding caused by Yakes type IIb inferior mesenteric arteriovenous malformation, which was successfully treated with endovascular embolization. The Yakes arteriovenous malformation classification provides curative treatment strategies based on specific angioarchitecture, thus serving as a valuable guide during treatment planning. We reviewed reported cases from 1988 to 2022 and conducted an angioarchitecture analysis based on the Yakes classification. We analyzed these reported cases to estimate the treatment success rates of surgery and embolization.

Unusual Presentation of Anal Pain and Tenesmus from Rectal Arteriovenous Malformation Successfully Treated with Ethanol Sclerotherapy

Gastrointestinal arteriovenous malformation (AVM) is reported as one of the possible causes of intestinal bleeding, and its occurrence in the rectum is rare. We report the case of a rectal AVM patient who experienced uncommon symptoms of anal pain and tenesmus and was treated successfully with percutaneous transarterial ethanol sclerotherapy. The patient underwent routine colonoscopy with biopsy at the time of visit; however, an accurate diagnosis was difficult. Subsequent contrast-enhanced computed tomography (CT) and angiography revealed a rectal AVM emerging from the distal inferior mesenteric artery with engorged superior rectal veins. The feeding artery was catheterized, and concurrent transarterial sclerotherapy with 80% ethanol was performed. There was no major complication related to the procedure. Disappearance of AVM nidus and improvement of associated venous congestion were shown by follow-up CT. There was no recurrence of symptoms after 10 months of clinical observation. Transarterial ethanol sclerotherapy is safe and effective in treating rectal AVM and can be considered as one of the nonsurgical treatment options.

Rectal arterio-portal fistula: An unusual cause of persistent bleeding per rectum following a proximal spleno-renal shunt

Gastrointestinal arterio-venous malformations are a known cause of gastrointestinal bleeding. We present a rare case of persistent rectal bleeding due to a rectal arterio-portal venous fistula in the setting of portal hypertension secondary to portal vein thrombosis. The portal hypertension was initially surgically treated with splenectomy and a proximal splenorenal shunt. However, rectal bleeding persisted even after surgery, presenting us with a diagnostic dilemma. The patient was re-evaluated with a computed tomography mesenteric angiogram which revealed a rectal arterio-portal fistula. Arterio-portal fistulas are a known but rare cause of portal hypertension, and possibly the underlying cause of continued rectal bleeding in this case. This was successfully treated using angiographic localization and super-selective embolization of the rectal arterio-portal venous fistula via the right internal iliac artery.The patient subsequently went on to have a full term pregnancy. Through this case report, we hope to highlight awareness of this unusual condition, discuss the diagnostic workup and our management approach.