Is Surgical Thrombectomy to Salvage Failed Autogenous Arteriovenous Fistulae Worthwhile?

The Dialysis Outcomes Quality Initiatives guidelines emphasize placement of autogenous arteriovenous (AV) fistulae for patients on hemodialysis. This recommendation is based on studies that demonstrate enhanced patency for AV fistulae compared with grafts. However, closer review of the data demonstrates that although primary patency of AV fistulae is superior to grafts, the secondary patency rates are equivalent. This suggests that secondary procedures to maintain fistula patency are inferior to those performed on arteriovenous grafts. Surgical thrombectomy of AV fistulae can be challenging. It is often difficult to completely remove thrombus adjacent to the anastomosis of the fistula, and pseudoaneurysms within the fistula can prevent passage of the thrombectomy catheter and complete removal of thrombus from the fistula. Consequently, some surgeons simply abandon thrombosed AV fistulae and place a new access. We have developed a method for completely clearing thrombus from failed AV fistulae by locating the fistulotomy close to the arterial anastomosis and using a technique to manually extract thrombus from the fistula before passing a thrombectomy catheter. The purpose of this study was to review our results with this procedure. Between 2001 and 2004, 10 patients with a previously functioning AV fistula presented with thrombosis. There were seven brachiocephalic fistulae and three radiocephalic fistulae. All patients underwent surgical thrombectomy and fistulography. Five patients underwent balloon angioplasty of a venous stenosis and one patient underwent surgical revision of an arterial stenosis. Technical success, defined as being able to completely clear thrombus from the fistula and treat the cause for fistula failure, was achieved in 70 per cent (7/10) of cases. Technical failure was caused by vein rupture during the balloon angioplasty in two cases and a central venous occlusion that could not be treated in one case. The 6-month primary and secondary patency for cases that were technically successful was 51 and 69 per cent, respectively. Our conclusion was that surgical thrombectomy can significantly extend fistula functionality in patients who present with thrombosis.