DILATED OR VARICOSE-VEINS USED AS ARTERIAL BYPASS GRAFTS AFTER EXTERNAL MESH TUBE CONSTRICTION - EXPERIMENTAL AND CLINICAL-RESULTS

Dilated and varicose veins are usually not used as arterial bypass-grafts despite they are lined with functional endothelium. External support by a constrictive mesh tube could conform these veins into evently calibrated bypass-grafts. Ovine jugular veins could be constricted from 15 to 6 mm diameter without forming folds on the inner flow surface. 6 months after implantation of 5 cm long jugular vein segments into the carotid arteries of 7 sheep the inner diameter was 19.5 +/- 3.3 mm for native veins (n = 4) and 7.6 +/- 0.8 mm for constricted veins (n = 10). Intimal hyperplasia was reduced from 0.4 +/- 0.2 mm in native to 0.23 +/- 0.07 mm in reinforced veins (p = 0.03). Mesh tube constricted varicose veins were used as bypass material in 11 infrainguinal reconstructions. All grafts were well calibrated at control angiography. External constriction by mesh tubes is a means to convert varicose veins into suitable bypass grafts.