VEIN QUALITY IN INFRAINGUINAL REVASCULARIZATION - ASSESSMENT BY ANGIOSCOPY AND HISTOLOGY

The concept of vein quality has been slow to gain widespread acceptanc e, but an increasing body of evidence suggests that vein quality is re levant to the success of bypass grafting for peripheral vascular disea se. The angioscope represents an additional tool for monitoring and pr eparing vein grafts during infrainguinal revascularisation. Within the overall theme of vein quality, this paper presents the cumulative exp erience with vascular endoscopy at Bristol Royal Infirmary. In clinica l studies, the diagnostic role of angioscopy in quality control was ev aluated by grafting preexisting, angioscopically detected, intralumina l abnormalities and correlating them with histological appearances. Th ere were significant associations between angioscopy/histology grades and graft patency. To enable quantification of images, an innovative c omputerised video image processing method has been developed and valid ated against simultaneous ultrasound measurements of segments of saphe nous vein. The therapeutic applications of angioscopy in vein graft pr eparation were studied prospectively in patients undergoing in situ fe moropopliteal/distal bypasses by randomisation to full angioscopic or conventional preparation. There was a significant reduction in wound m orbidity. Completion angioscopy and arteriography were complementary i n the detection of technical defects. Harvested vein was maintained in organ culture to assess further the influence of pre-existing patholo gy and the potentially traumatic effects of angioscopy on development of neointimal hyperplasia. There was a significant correlation between the extent of pre-existing abnormality and smooth muscle cell prolife rative activity in culture and although angioscopy caused endothelial cell loss, this did not stimulate neointimal hyperplasia in vitro. Thi s work confirms that vein quality can be evaluated prospectively by an gioscopy and that substandard vein is associated with inferior patency rates. Angioscopic and histological evaluation, together with vein or gan culture studies, have definite application in helping to elucidate the mechanisms underlying graft failure.