Background: The addition of a distal arteriovenous fistula (dAVF) to improve patency in lower extremity bypass is well described. We have previously illustrated the technique of enhancing a distal vein patch bypass (DVP) with a dAVF ("patch-ula") for those patients with no autogenous conduit and severely disadvantaged arterial runoff. This report describes the results of our initial patient cohort using this patchula bypass for limb salvage.
Methods: From May 2002 to May 2007, 270 tibial bypasses were performed. A retrospective review revealed 95 bypasses using DVP as the conduit including 30 with the addition of a dAVF (patchula). Patient demographics included; 16 males, 14 females, diabetes mellitus (20, 66.7%), and chronic renal failure (6, 20%). All patients had limb threatening ischemia manifest as rest pain and/or tissue loss with 20 cases (66.7%) referred after failed prior revascularization; 11 failed bypasses and 9 failed endovascular interventions. The recipient artery was an isolated tibial segment, or, a severely diseased sole vessel runoff not ordinarily deemed suitable for bypass. At surgery, a common channel AVF was created between the recipient tibial artery and corresponding tibial vein prior to construction of the DVP. All patients were discharged on coumadin. Follow-up ranged from 1-60 months with graft function evaluated by pulse exam and Duplex graft surveillance. Primary patency and limb salvage ± SE were determined by life-table analysis using Rutherford criteria.
Results: The proximal anastomosis originated from the external iliac (7, 23.3%), CFA (13, 43.3%), or SFA (10, 33.3%). Recipient arteries included the anterior tibial (12,40%), posterior tibial (9,30%), or peroneal (9,30%). Venous hypertension in the bypassed limb was occasionally noted, but not considered problematic. Perioperative graft failure occurred in 1 patient with a total of 6 graft failures leading to 6 major amputations (1 AKA, 5 BKA). One patent graft was excised due to infection. Primary patency and limb salvage rates are noted below.
| 6 month | 12 months | 18 months | 24 months | + 24 months | |
| Primary patency | 78.3% + 6.8% N = 29 | 78.3% + 10.5% N = 12 | 62.6% + 11.1% N = 12 | 62.6% + 15.6% N = 6 | N = 3 |
| Limb Salvage | 78.7% + 6.7% N = 29 | 78.7% + 10.1% N = 13 | 78.7% + 10.1% N = 13 | 57.7% + 12.5% N = 9 | N = 4 |