CLINICAL AND MOLECULAR EFFECTS OF ENDOSCOPIC VEIN HARVESTING.

Abstract

Coronary artery bypass grafting (CABG) is the most commonly performed surgical cardiac procedure. Despite a worldwide increase in the use of arterial grafts, the long saphenous vein (LSV) still remains the most frequently used conduit in coronary artery bypass grafts since its introduction in 1968. Traditionally, the LSV is harvested by a continuous long incision in the donor leg, which can result in major wound complications and various studies have reported an incidence of wound infection ranging from 20% to 40%. Newer minimally invasive techniques (MIVH) such as bridging and endoscopic vein harvesting (EVH) can reduce the incidence of wound infection and significantly improve healing. Although the effect of MIVH vein techniques on wound related problems has been extensively investigated in the literature, its effect on the quality of the harvested conduit remains unclear. More recently, a major article has been published which suggests EVH is associated with increased sudden death and >75% graft occlusion (within a 12 month period) compared to open vein harvesting (OVH). This has resulted in many centres stopping their EVH programmes. However, a potential issue with this article is that 2 endoscopic vein harvesting systems were utilised. One system requires 1kPa pressure of CO2, which compresses the long saphenous vein. Potentially this may result in endothelial dysfunction and denudation, leading to graft failure. The second system utilises an open tunnel dissection method with no venal collapse. The aim of this study was to characterise the effects of the two EVH techniques on endothelial damage and to observe post-clinical outcome at 6 months. One hundred and forty vein samples were allocated non-randomly into EVH1 (closed CO2 tunnel - 70 samples) and EVH2 (open CO2 tunnel - 70 samples). Vein specimens were stained using immunohistochemistry (to detect the expression of CD34), and then blindly scored by three independent assessors. The student's t-test was used to evaluate statistical differences between the groups. In this study, significantly greater conduit integrity was observed in EVH2 compared to EVH1 (mean 65.0% vs. 11.4%, p

Date of Award	1 Aug 2014
Original language	English
Awarding Institution	The University of Manchester
Supervisor	James Fildes (Supervisor) & Nizar Yonan (Supervisor)