Comparison of Graft Patency, Limb Salvage, and Antithrombotic Therapy Between Prosthetic and Autogenous Below-Knee Bypass for Critical Limb Ischemia

Abstract

Background The autogenous vein is the preferred conduit in below-knee vascular reconstructions. However, many argue that prosthetic grafts can perform well in crural bypass with adjunctive antithrombotic therapy. We therefore compared outcomes of below-knee prosthetic versus autologous vein bypass grafts for critical limb ischemia and the use of adjunctive antithrombotic therapy in both settings. Methods Utilizing the registry of the Vascular Study Group of New England (2003–2009), we studied 1227 patients who underwent below-knee bypass for critical limb ischemia, 223 of whom received a prosthetic graft to the below-knee popliteal artery (70%) or more distal target (30%). We used propensity matching to identify a patient cohort receiving single-segment saphenous vein yet had remained similar to the prosthetic cohort in terms of characteristics, graft origin/target, and antithrombotic regimen. Main outcome measures were graft patency and major limb amputation within 1 year. Secondary outcomes were bleeding complications (reoperation or transfusion) and mortality. We performed comparisons by conduit type and by antithrombotic therapy. Results Patients receiving prosthetic conduit were more likely to be treated with warfarin than those with greater saphenous vein (57% vs. 24%, P < 0.001). After propensity score matching, we found no significant difference in primary graft patency (72% vs. 73%, P = 0.81) or major amputation rates (17% vs. 13%, P = 0.31) between prosthetic and single-segment saphenous vein grafts. In a subanalysis of grafts to tibial versus popliteal targets, we noted equivalent primary patency and amputation rates between prosthetic and venous conduits. Whereas overall 1-year prosthetic graft patency rates varied from 51% (aspirin + clopidogrel) to 78% (aspirin + warfarin), no significant differences were seen in primary patency or major amputation rates by antithrombotic therapy (P = 0.32 and 0.17, respectively). Further, the incidence of bleeding complications and 1-year mortality did not differ by conduit type or antithrombotic regimen in the propensity-matched analysis. Conclusions Although limited in size, our study demonstrates that, with appropriate patient selection and antithrombotic therapy, 1-year outcomes for below-knee prosthetic bypass grafting can be comparable to those for greater saphenous vein conduit.

Results of peripheral bypass surgery in patients with critical limb ischemia (CRITISCH registry)

“…This was also demonstrated by Suckow et al. [ 2 ]. Patients receiving a vein bypass to the popliteal artery below the knee showed a primary graft patency rate of 78 % (prosthetic graft 74 %).…”

“…Whereas synthetic materials can be effectively used for bypasses to the popliteal artery below the knee, according to the guidelines a prosthetic femorotibial bypass should only be used when amputation is imminent and the prospects of success are limited. On the other hand, out of 1227 patients in the registry of the Vascular Study Group of New England for 2003–2006 undergoing below-knee bypasses for CLI, 223 patients (18.2 %) received a prosthetic graft [ 2 ]. Of these bypasses 70 % were to the popliteal artery and 30 % to a more distal target.…”

Outcomes of cold-stored venous allograft for below-knee bypasses in patients with critical limb ischemia

“…31,32 McPhee et al 32 suggested in 2012 that prosthetic conduits appear comparable to alternative vein sources in terms of graft patency for below-knee popliteal bypass targets. Their cohort was not limited to CLI, and they excluded from analysis patients with infrapopliteal targets, including tibial and pedal targets.…”

Intraluminal delivery of thrombospondin‐2 small interfering RNA inhibits the vascular response to injury in a rat carotid balloon angioplasty model

“…Endovascular and surgical revascularization procedures are often necessary to alleviate ischemic symptoms after failed medical treatment. Whereas endovascular interventions are increasingly used, autologous vein grafts are preferred in select patients and associated with significantly lower long‐term amputation rates and improved overall survival (2, 3). Durability of vascular interventions, however, is limited by the development of intimal hyperplasia (IH) that leads to restenosis.…”