Structured Vs Conventional Endoscopic Vein Harvesting Training: Vein Integrity and Learning Curve Performance

Background Endoscopic Vein Harvesting (EVH) reduces wound complications compared with open vein harvesting. However, concerns remain that conduit injury may occur during the learning curve . The impact of EVH training on vein integrity and progression to independent practice remains unclear . We evaluated whether a structured EVH training programme improved vein quality, technical skill and trainee confidence. Methods This study was originally designed as a multicentre cluster-randomised trial but was prematurely halted and completed as a two-centre study with cluster allocation. Four EVH trainees were included: Two received Structured Training (ST) incorporating simulation, psychomotor reinforcement, video review and competency-based progression. Two underwent Conventional Training (CT), consisting of standard company-led training. Endothelial integrity was assessed using CD34 immunohistochemistry across proximal, random and distal sections. Endothelial stretching and muscle hypertrophy were graded. Trainee performance, anxiety and consultant-rated vein quality were recorded. Patients were followed to 12 months for Major Adverse Cardiac Events and 24 months for survival. Analyses were descriptive. Results Forty-six patients underwent EVH (ST n = 40; CT n = 6). Technical performance improved in all trainees but CT trainees discontinued independent EVH practice during the study period. ST trainees demonstrated better endothelial integrity with less stretching and muscle hypertrophy. CT vein samples showed greater endothelial variability. Clinical event rates were low. At 6–24 months, MACE was infrequent with repeat angina (4.3%), myocardial infarction (2.2%), re-intervention (6.5%) and non-cardiac death (2.2%). Among the 38 vein grafts assessed by computed tomography angiography in asymptomatic patients, 23 (60.5%) were patent, five (13.2%) demonstrated flow-limiting stenosis, and 10 (26.3%) were occluded. These findings were predominantly observed in small-calibre target vessels in patients with diabetes. Conclusion Structured EVH training was associated with better endothelial preservation during the learning curve. Given the small sample size and incomplete imaging follow-up, these findings are hypothesis-generating and require validation in larger multicentre studies. Clinical registration: ISRCTN27493194; February 2022; amended 2024. This work has been presented at International Society of Minimally Invasive Surgery (ISMICS) annual conference meeting as a e-poster online on 10-13 th June 2026. e-poster online; Available at ismics2026.109014b.NORMAL.pdf