Remote distal arteriovenous fistula to improve infrapopliteal bypass patency

Abstract

The results of the use of prosthetic materials for femorocrural bypass surgery have been less than optimal. The creation of a distal anastomotic arteriovenous fistula to augment blood flow and velocity through the graft is well known. However, it may create turbulence at the anastomosis and steal blood flow away from the distal artery. A canine model was developed to evaluate the effect of fistula size on graft/arterial hemodynamics. In 16 patients we have constructed a distal arteriovenous fistula, which is remote from the distal anastomosis, and we studied the effect of such fistulas on bypass patency and distal arterial hemodynamics. Patients selected for this procedure had multiple previously failed reconstructions and limb-threatening ischemia and did not have usable autogenous vein. Femorotibial bypass graft reconstructions were performed with polytetrafluoroethylene followed by the creation of a side-to-side arteriovenous fistula 5 to 15 cm below the distal anastomosis in the same artery and accompanying veins. We have achieved a 1-year patency of 67% with a 75% limb salvage rate. We also serially measured blood flow and velocity within the bypass, the arteriovenous fistula, and the distal outflow vessel using duplex scanning after surgery. Mean estimated blood flow through the bypass during the immediate postoperative period was 264 ml/min, the arteriovenous fistula was 157 ml/min, and the distal artery was 19 ml/min. Unlike an arteriovenous fistula created at the distal anastomosis, a remote distal arteriovenous fistula not only increases graft blood flow but also augments native arterial blood flow between the distal anastomosis and fistula and thus may improve distal limb perfusion.

Pedal bypass with deep venous arterialization: the therapeutic option in critical limb ischemia and unreconstructable distal arteries

“…The heavily calcified and severely stenotic pedal artery and the long segment of arterial occlusion are the major causes of situations that are unreconstructable either by intervention therapy or conventional arterial bypass. 1 Two types of therapeutic options that have been proposed for this problem are the creation of arteriovenous fistula at the distal anastomosis [8][9][10][11] and distal venous arterialization. 3,[12][13][14][15][16][17] The advantage of the first procedure is the decrease of outflow resistance and the improvement of graft hemodynamic.…”

Salvage of a Radial Forearm Flap Transferred onto a By-Pass Graft with Conversion from a High-to-Low-Resistance Circulatory Pattern: Case Report

“…10 Distal arteriovenous fistulas have been used as an adjunct to improve infrapopliteal by-pass patency. 11,12 Similarly, combining microvascular muscle transfer with vascular by-pass grafting has improved patency rates by decreasing outflow resistance and increasing graft flow. 5 Several types of tissue are available for microvascular transfer, including muscle flaps, composite bone and soft-tissue flaps, and fasciocutaneous flaps.…”

Adjuncts to Improve Patency of Infrainguinal Prosthetic Bypass Grafts

“…Another small series of 16 distal bypass procedures that included the creation of an arteriovenous fistula distal to the graft-arterial anastomosis reported a 67% 1-year patency. 22 Ascer has documented a 61% graft patency at 3 years with a technique that interposes an arteriovenous fistula between the distal anastomosis of a PTFE graft and an infrapopliteal artery. 19 A deep vein adjacent to the recipient artery is anastomosed to the artery in an end-to-side manner.…”