Vein quality in infrainguinal revascularisation: assessment by angioscopy and histology

The concept of vein quality has been slow to gain widespread acceptance, but an increasing body of evidence suggests that vein quality is relevant to the success of bypass grafting for peripheral vascular disease. The angioscope represents an additional tool for monitoring and preparing vein grafts during infrainguinal revascularisation. Within the overall theme of vein quality, this paper presents the cumulative experience with vascular endoscopy at Bristol Royal Infirmary. In clinical studies, the diagnostic role of angioscopy in quality control was evaluated by grafting preexisting, angioscopically detected, intraluminal abnormalities and correlating them with histological appearances. There were significant associations between angioscopy/histology grades and graft patency. To enable quantification of images, an innovative computerised video image processing method has been developed and validated against simultaneous ultrasound measurements of segments of saphenous vein. The therapeutic applications of angioscopy in vein graft preparation were studied prospectively in patients undergoing in situ femoropopliteal/distal bypasses by randomisation to full angioscopic or conventional preparation. There was a significant reduction in wound morbidity. Completion angioscopy and arteriography were complementary in the detection of technical defects. Harvested vein was maintained in organ culture to assess further the influence of pre-existing pathology 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 proliferative activity in culture and although angioscopy caused endothelial cell loss, this did not stimulate neointimal hyperplasia in vitro. This work confirms that vein quality can be evaluated prospectively by angioscopy and that substandard vein is associated with inferior patency rates. Angioscopic and histological evaluation, together with vein organ culture studies, have definite application in helping to elucidate the mechanisms underlying graft failure.