Antiplatelet agents for preventing thrombosis after peripheral arterial bypass surgery

Abstract

BackgroundPeripheral arterial disease (PAD) may cause occlusions (blockages) in the main arteries of lower limbs. One treatment option is bypass surgery using autologous (the patient's own tissue) vein graft or artificial graft. A number of factors influence occlusion rates, including the material used. To prevent graft occlusion patients are usually treated with antiplatelet, antithrombotic drugs, or a combination of both. ObjectivesTo evaluate whether antiplatelet treatment in patients with symptomatic PAD undergoing infrainguinal bypass surgery improves graft patency, limb salvage and survival. Search strategyThe authors searched the Cochrane Peripheral Vascular Diseases Group Specialised Register (January 2008) and the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 4). Additional trials were sought through reference lists of papers and proceedings from the vascular surgical society meetings. Selection criteriaFor this update the methodological quality of each original trial was assessed independently by review authors (JB, HM, AW) with emphasis on concealment of allocation.1 Antiplatelet agents for preventing thrombosis after peripheral arterial bypass surgery (Review)

Aspirin usage is associated with improved prosthetic infrainguinal bypass graft patency

“…8 Patients placed on antiplatelet therapy with aspirin postoperatively had an overall positive effect on patency 12 months after the procedure when compared with no antiplatelet therapy. In fact, for patients undergoing bypass with a prosthetic conduit a statistically significant improvement in patency was seen at 1-, 3-, 6-and 12-month intervals postoperatively.…”

Antiplatelet Therapy in Endovascular Surgery: The RENDOVASC Study

“…The prosthetic bypass benefits more from antiplatelet treatment than the venous bypass procedure, and the venous bypass procedure benefits more from anticoagulants, although ASA and clopidogrel combined are just as effective. 14 What about treatments using endovascular techniques? Do they offer similar performance?…”

A Critical Analysis on the Impact of Antiplatelet Therapy in the Patency of Infrainguinal Bypass Grafts

“…In total, 73 patients were assigned to pentoxifylline and 78 to aspirin or aspirin and dipyridamole. The Peto OR was 1.40 (95% CI 0.63 to 3.11, fixed-effect model) showing a slightly favorable but statistically nonsignificant effect of pentoxifylline on primary graft patency [21]. Only Raithel's study provided data at 12 months and showed a similar effect of both drugs on graft patency (Peto OR 0.92 (95% CI 0.41 to 2.07) [28].…”

“…A Cochrane metaanalysis published in 2008 [21] included 6 randomised controlled trials (RCTs) comparing aspirin or aspirin and dipyridamole to placebo [9][10][11]13,16,22]. The Peto odds ratio (Peto OR) for primary occlusion at 12 months for all grafts was 0.59 (95% CI 0.45 to 0.79, fixed-effect model), showing a positive, statistically significant effect of aspirin on infrainguinal grafts at one year [21]. When the analysis was performed for venous grafts alone [10,22], the effect was attenuated (OR 0.69; 95% CI 0.48 to 0.99).…”

“…When the analysis was performed for venous grafts alone [10,22], the effect was attenuated (OR 0.69; 95% CI 0.48 to 0.99). Analysis for prosthetic grafts, calculated from four RCTs, [9,11,13,16] showed a much stronger positive and statistically significant effect of ASA on primary patency at 12 months: Peto ORs of 0.22 (95% CI 0.12 to 0.38) [21].…”