Single-Institution Learning Curve for Management of Mega-Fistulae Revision

Mega-fistulae are generalized aneurysmal dilations of a high flow (1500-4000 mL/min) autogenous arteriovenous (AV) access which may result in hemorrhage and/or high-output cardiac failure. Current treatments include ligation, ligation with prosthetic jump graft, and imbrication; however, these may not be suitable for advanced disease, or may result in loss of functioning access, poor cosmesis, or recurrence. We describe our early experience with a technique of complete mega-fistula resection and replacement with an early use prosthetic graft that both maintains existing AV access and eliminates the need for long-term catheter (LTC) placement; including lessons learned. A single-center, retrospective review of medical records was conducted from March 2018-February 2021. Outcomes were technical success, LTC use, time to cannulation, and complications. Mega-fistulae were completely resected from the proximal to distal aneurysmal segment, including all pseudoaneurysms, followed by tunneling a prosthetic graft (Propaten later converted to Acuseal; W.L. Gore Assoc.) with an end-to-end anastomosis to the remaining arterial and venous ends of the previous AV access. We had 100% immediate technical success (n=12). Pre-operative long-term catheters were placed in all eight Propaten patients; one was already placed in an Acuseal patient. Average time to cannulation was six weeks with Propaten and 4.5 days with Acuseal. At 30 days, three Propaten patients developed complications including one instance of skin necrosis, one seroma, and one hematoma. Two Acuseal patients developed complications including one central venous occlusion (CVO) and one graft infection. Of the six patients with long-term follow-up, five continue to use their access, however, two required thrombectomies and central venous angioplasties. One patient required a new contralateral access due to CVO. Complete mega-fistula resection and replacement with Acuseal graft maintains existing AV access and may eliminate the need for long-term catheter placement. Our early experience with this technique is encouraging, but further follow-up is required to determine the durability of this approach.