Antithrombotic Therapy in Peripheral Arterial Occlusive Disease: Vein femoral-popliteal bypass
A large multicenter trial (level I) from Great Britain focused on patients undergoing saphenous vein femoral-popliteal bypass. These investigators found no differences in patency rates between patients treated with aspirin and dipyridamole and control patients at an average follow-up of 24 months. However, they found that patients who received antiplatelet therapy had a significantly lower incidence of MI and stroke during follow-up; there was no significant difference in overall mortality between the two groups. Another important finding from the British study, in which aspirin plus dipyridamole therapy was begun preoperatively, was that twice the number of wound hematomas and significantly greater transfusion requirements occurred in treated patients compared with control patients. The British trial is limited in that only saphenous vein femoral-popliteal bypass reconstructions were studied. In North America, most low-er-extremity bypass reconstructions involve tibial arteries. These longer and smaller reconstructions with lower flow rates are more vulnerable to thrombotic occlusion than femoral-popliteal bypasses, and the possibility remains that antithrombotic therapy would be beneficial in maintaining patency review buy ventolin inhaler. The British trial was also plagued with problems in compliance (both among control and treated patients). In a subsequent retrospective subgroup analysis of patients in this trial, those with detectable serum salicylate as a marker of aspirin ingestion had significantly better patency than those with undetectable levels.
The effect of ticlopidine on the patency of saphenous vein grafts performed for lower-extremity occlusive disease was assessed in a multicenter, placebo-controlled, randomized clinical trial of 243 patients (level I). Unlike the British study on aspirin and dipyridamole, patients undergoing both femoropopliteal and femorotibial bypass were included. At 24 months, the primary patency rate was 82% in the ticlopidine group and 63% in the placebo group (p — 0.002). There were no differences in mortality or major ischemic events. Ticlopidine was well-tolerated and there was no difference in hematologic adverse events; however, the incidence of GI disorders (primarily diarrhea) was higher in the ticlopidine group.
The Antiplatelet Trialists’ Collaboration performed an overview analysis of the effects of antiplatelet therapy on arterial or vascular graft patency from 11 randomized controlled trials containing more than 2,000 patients. Antiplatelet therapy, most often with aspirin, produced a highly significant (p < 0.0001) reduction in occlusion during a mean follow-up period of 19 months.