Annals of Vascular Surgery - Brief Reports and Innovations (Dec 2022)
Novel endovascular technique for repair of superior mesenteric arteriovenous fistula with portal vein aneurysm
Abstract
Background: A superior mesenteric arteriovenous fistula (SMAVF) is a rare, aberrant connection between the superior mesenteric artery (SMA) and the superior mesenteric vein (SMV). Management includes either open surgical repair or endovascular repair with embolization coils or covered stents. We report a novel in-stent coil embolization technique successfully used for repair of a challenging SMAVF. Case presentation: A 56-year-old man presented with an enlarging SMV and portal vein aneurysm. His history was significant for a small bowel resection of a desmoid tumor 14 years prior. Computed tomography (CT) angiography revealed a high-flow SMAVF in the midsegment of the SMA, and the patient was taken to the operating room for endovascular repair. Embolization was initially attempted with detachable coils, but this approach was aborted as the coils did not have sufficient purchase to anchor securely and would migrate into the portal venous system prior to full release and deployment. Placement of a covered stent in the SMA to exclude the fistulous connection was not feasible due to the presence of multiple adjacent major SMA branches. Therefore, a balloon-expandable covered stent was placed across the fistula and crushed distally to create a blind end into which embolization coils were able to nest without migrating. This was achieved with the use of multiple buddy wires to deploy a VBX balloon-expandable stent graft (WL Gore, Flagstaff, AZ) across the fistulous connection and crush the distal end of the stent with a buddy balloon. The funneled covered stent then served as a backstop for packing with embolization coils, and completion angiography demonstrated complete occlusion of the SMAVF and filling of all SMA branches. Both 6-month and 1-year postoperative surveillance CT scans confirmed continued resolution of the fistula. Conclusion: This case demonstrates a novel endovascular technique to create a funneled covered stent across a high-flow SMAVF as a platform to enable embolization and prevent coil migration. This in-stent coil embolization technique is a viable option for cases in which embolization coils and covered stents fail or are unsuitable.
