A mechanism of banding failure in excessively dilated fistulas

Abstract

Introduction: We present an unreported cause of banding failure for flow restriction in dramatically enlarged arteriovenous fistulas (AVFs). Case series: Four patients operated in different institutions by two different surgeons experienced band failure within 6 months of the initially successful operation for AVF flow restriction. Prior to the initial banding procedure, each patient’s AVF was noted to have major dilatation of the post-anastomotic segment (>2 cm). All patients required a second operation for flow reduction with reconstruction of the AVF anastomosis to a tapered, smaller size. During this second procedure, the suture tie used for banding in each patient was found to have eroded a portion of the vessel wall and was extending into the fistula lumen. No thrombosis or bleeding was encountered and all AVFs have remained functional after revision. Conclusions: Identical findings in these four patients suggest that the extensive infolding and caliber diameter reduction created by banding these massively dilated fistulas, when combined with the pulsatility induced in the pre-banding segment, leads to a gradual incorporation of the suture tie into the vessel wall and finally within the lumen. We suggest erosion of banding material and failure of flow reduction may occur with any technique but may be more likely with a single polypropylene suture restricting very large AVF. We suggest such excessively dilated fistulas requiring flow reduction may be successfully treated by reconstruction of the AVF anastomosis to a much smaller size with tapering of the outflow vein to accommodate the revision.