Impact of the Learning Curve for Endoscopic Vein Harvest on Conduit Quality and Early Graft Patency

Abstract

Background Recent studies have suggested that endoscopic vein harvest (EVH) compromises graft patency. To test whether the learning curve for EVH alters conduit integrity owing to increased trauma compared with an open harvest, we analyzed the quality and early patency of conduits procured by technicians with varying EVH experience. Methods During coronary artery bypass grafting, veins were harvested open (n = 10) or by EVH (n = 85) performed by experienced (>900 cases, >30/month) versus novice <100 cases, <3/month) technicians. Harvested conduits were imaged intraoperatively using optical coherence tomography and on day 5 to assess graft patency using computed tomographic angiography. Results Conduits from experienced (n = 55) versus novice (n = 30) harvesters had similar lengths (33 versus 34 cm) and harvest times (32.4 versus 31.8 minutes). Conduit injury was noted in both EVH groups with similar distribution among disruption of the adventitia (62%), intimal tears at branch points (23%), and intimal or medial dissections (15%), but the incidence of these injuries was less with experienced harvesters and rare in veins procured with an open technique. Overall, the rate of graft attrition was similar between the two EVH groups (6.45% versus 4.34% of grafts; p = 0.552). However, vein grafts with at least 4 intimal or medial dissections showed significantly worse patency (67% versus 96% patency; p = 0.05). Conclusions High-resolution imaging confirmed that technicians inexperienced with EVH are more likely to cause intimal and deep vessel injury to the saphenous vein graft, which increases graft failure risk. Endoscopic vein harvest remains the most common technique for conduit harvest, making efforts to better monitor the learning curve an important public health issue.

Endoscopic vein harvest does not negatively affect patency of great saphenous vein lower extremity bypass

“…Previous studies have also discussed the impact of the operator's learning curve on vein injury during harvest, 31,38 with reports suggesting a minimum number ranging from 20 to 100 cases to complete the learning curve. 15,31,38 In their study, Desai et al 38 showed that inexperienced operators are 50% more likely to cause intimal and deep vessel injury to the saphenous vein graft, which increases risk of failure.…”

“…15,31,38 In their study, Desai et al 38 showed that inexperienced operators are 50% more likely to cause intimal and deep vessel injury to the saphenous vein graft, which increases risk of failure. This underlines the importance of safe and reliable training and monitoring to minimize the negative impact of the learning curve on vein graft quality.…”

Saphenous Vein Conduit in Coronary Artery Bypass Surgery — Patency Rates and Proposed Mechanisms for Failure

“…However, this has changed in the past years with "novice" level practitioners becoming experts. It has recently been found that when procured by expert level harvesters the physical damage to the vein is similar to that of open harvest [12], [13]. Thus, it is hypothesized that EVH and open harvest when performed by an expert will have similar patency rates if all other factors are equal.…”

Conduit Selection for Improved Outcomes in Coronary Artery Bypass Surgery

“…However, EVH has been associated with increased endothelial injury, which may have significant negative consequences including graft patency and possibly long-term survival [68,69]. Desai et al recently demonstrated using optical coherence tomography that EVH operators had a steep learning curve with regard to subtle RSVG injuries and that vein grafts with four or more intimal or medial dissections showed significantly worse early patency rates than those with fewer intimal injuries (67% vs. 96%) [70]. In contrast, when RSVGs are harvested using a "no touch" technique, better patency results have been noted.…”