Underwood M J, More R, Weeresena N, Firmin R K, De Bono D P
University Department of Cardiology, Glenfield General Hospital, Leicester, U.K.
Eur J Vasc Surg. 1993 Sep;7(5):518-22. doi: 10.1016/s0950-821x(05)80363-9.
The objective of this study was to assess the effect of distension on the intrinsic fibrinolytic activity of human saphenous vein during its preparation for use as a bypass conduit prior to coronary artery surgery. Fibrinolytic activity was studied using fibrin plate techniques and Chromogenic assays for extractable tPA and uPA. Samples were obtained from patients undergoing routine coronary surgery. Fibrinolytic activity was compared in control vein (untouched) vein that had been prepared for use as a bypass conduit (surgical dissection, ligation of side branches and careful but uncontrolled manual distension) and segments of dissected vein distended in vitro to pressures of 230 or 120 mmHg. Uncontrolled distension and distension to 230 mmHg impaired fibrinolytic activity as determined by areas of lysis on fibrin plates (p < 0.05), (p < 0.005), tPA activity (p < 0.005) (p < 0.005) and uPA activity (p < 0.05), (p < 0.005). Distension to 120 mmHg had no effect on the fibrinolytic activity of human saphenous vein. Impaired fibrinolytic activity caused by uncontrolled distension of saphenous vein prior to its use as a vascular conduit may contribute to early vein graft thrombosis and can be avoided using controlled distension to < 120 mmHg.
