Carotid-subclavian bypass for subclavian artery revascularization: long-term follow-up and effect of antiplatelet therapy.

Subclavian artery stenosis is found in up to 25% of supraaortic lesions. Bypass grafting is the procedure of choice but controversies exist concerning the optimal technique and the effect of postoperative antithrombotic therapy on long-term patency. The authors retrospectively analyzed 40 patients with carotid-subclavian bypasses. Stenoses were documented preoperatively by arteriography. Patency was determined by clinical, ultrasound, or arteriographic examinations. Cumulative patency rates were calculated by Kaplan-Meier method and analyzed by Tarone-Ware test. Graft materials were Dacron (32), polytetrafluoroethylene (seven) or saphenous vein (one). Indications for surgery included vertebrobasilar insufficiency (22.5%), upper extremity ischemia (22.5%), and the combination of both (55.0%). Perioperative mortality and morbidity were 2.5% and 10.0%, respectively. Patients were followed up from 0 to 134 months (mean 61+/-39 months). Cumulative 5-year patency rate was 83.3%. Anticoagulation with acetylsalicylic acid (ASA) led to significantly better 5-year patency rates (100%) as compared with the combination of ASA and dipyridamole (64.0%, p=0.013) or no anticoagulation (70.0%, p=0.016). Carotid-subclavian bypass led to excellent long-term patency rates and can provide durable relief of symptoms with minimal perioperative morbidity and mortality. Therefore, it is a worthwhile procedure to correct proximal subclavian artery stenosis. Postoperative medication with ASA seems to increase long-term bypass function significantly.