The Impact of Endoscopic Vein Harvest by Less Experienced Operators on Conduit Quality and Early Graft Patency

The Impact of Endoscopic Vein Harvest by Less Experienced Operators on Conduit Quality and Early Graft Patency | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article The Impact of Endoscopic Vein Harvest by Less Experienced Operators on Conduit Quality and Early Graft Patency Ken Nakamura, Kentaro Akabane, Shusuke Arai, Kimihiro Kobayashi, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7280259/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objective: The saphenous-vein graft (SVG) is a key graft commonly used in coronary-artery bypass grafting (CABG), and its quality affects postoperative outcomes. endoscopic vein harvest (EVH) is an effective technique for wound healing and prevention of infection, but there is a learning curve, and there is no established assessment of how harvesting by a novice surgeon affects the patient's postoperative outcome. In this study, we investigated the effect of graft harvesting proficiency on the outcome of postoperative CABG patients. Methods: From 2005 to 2017, the patients who completed EVH were included in the analysis. Propensity score-matched EVH-experienced surgeon group and novice surgeon group, respectively, were compared for the graft patency and major adverse cardiac and cerebrovascular events (MACCE) extending into the remote phase. Results: A total of 719 patients underwent either isolated or combined CABG at the two institutions, and of those, the 173 patients with SVG harvested by EVH were divided into 60 Propensity score-matched groups, respectively. SVG occlusion in early postoperative period was 3 (5%) in group of novice surgeons (group A) and 6 (10%) in group of experienced surgeons (group B) (P=0.355). Similarly, there were 5 cases (8.3%) in group A and 1 case (1.7%) in group B for SVG stenosis (P = 0.272). Inpatient surgical mortality, 30-day mortality and 30-day in-hospital deaths were 1.7 % (Group A) vs 0 % (Group B) (P = 1.0). MACCE free rate of 1-, 3-, and 5-year was 96.4%/90.7%/90.7% vs. 96%/91.3%/84.8% (P = 0.175) (Group A vs. Group B), respectively. Conclusions: Among the patients undergoing CABG with EVH, a significant difference was not found between the surgeons of novice vein-graft harvesting and experienced in the risk of graft occlusion and major adverse cardiac events. Figures Figure 1 Figure 2 Figure 3 Introduction Left internal mammary artery (LIMA) is the first choice of graft used for bypass to left anterior descending artery (LAD) and has a high cardiac event avoidance rate and improves life expectancy 1 . The second graft used in coronary artery bypass grafting (CABG) is selected according to the target vessel and the degree of stenosis, however saphenous vein graft (SVG) is frequently used because it is not affected by the degree of stenosis of the autologous coronary artery and relatively long grafts can be obtained 2 , 3 . The advantages of SVG were good accessibility and ease of preparation, however long-term patency, wound infection, and opening in the incision were major problems 4 , 5 . Endoscopic vein harvest (EVH) is one of the novel innovative strategies that have been implemented in the last 25 years to solve this problem and is now widely used. EVH is considered to ameliorate postoperative pain and improve cosmetic outcomes compared to traditional harvesting methods, while there is still no consensus on graft patency 6 – 10 . SVG harvest is a technique that can be performed by relatively inexperienced surgeons, but there are no detailed reports on how practitioner inexperience affects graft patency, and there is no established evaluation. In this study, we compared the impact of EVH on graft patency by novice surgeons based on postoperative coronary angiography (CAG) evaluations. Patients and Methods This was a retrospective observational study conducted at two centers, Nihonkai General Hospital and Yamagata University Hospital. A total of 719 consecutive patients who underwent isolated or combined CABG between December 2005 and December 2017 were included. The study protocol was approved by the Institutional Review Board of Nihonkai General Hospital (Approval No. 005-2-10) and the Institutional Review Board of Yamagata University Hospital (Approval No. D-59). Owing to the retrospective study design, the requirement for additional written informed consent was waived, although all patients had provided appropriate informed consent for treatment and data use at the time of care. The research was performed in compliance with the principles of the Declaration of Helsinki. Data were accessed on June 10, 2023, and the study was registered at both institutions (Trial Registration No. 00380, June 25, 2023). The aim of the study was to compare early graft patency and stenosis after CABG between novice and experienced operators of EVH, as well as to assess long-term graft patency and the incidence of major adverse cardiac and cerebrovascular events (MACCE). Eligible patients were those who underwent CABG using at least one SVG harvested endoscopically, without conversion to open harvest. Patients in whom postoperative CAG could not be obtained were excluded. Surgeons with no prior EVH experience were categorized as “novice,” whereas those with > 30 EVH cases or more than 12 months of experience were defined as “experienced.” Patients with lower-limb varicose veins were not considered candidates for SVG harvesting. Preoperative CT vein mapping was routinely used to assess venous quality. EVH was performed by an assistant surgeon concurrently with harvesting of the left internal mammary artery, using a standardized approach (VirtuoSaph; Terumo Cardiovascular, Ann Arbor, MI). The technical details of the EVH procedure, including incision, blunt dissection, branch management, and preparation of the graft, followed conventional methods previously described in the literature 11 . The primary outcome was early graft-related complications, including occlusion, stenosis, or wound infection. Secondary outcomes were long-term graft patency and MACCE, defined as death, myocardial infarction, stroke, or repeat revascularization by percutaneous coronary intervention or CABG. Postoperative atrial fibrillation was diagnosed when episodes lasting > 30 seconds were documented during hospitalization. Neurological events required corroboration with CT or MRI and confirmation by a neurosurgeon; transient ischemic attacks without imaging findings were not included. Comorbid conditions such as dental infection, uncontrolled diabetes, and carotid artery stenosis were treated before surgery. Perioperative rehabilitation programs were supervised by physical therapists. The decision to perform on-pump or off-pump CABG (OPCAB) was made in a preoperative conference based on patient characteristics and surgical complexity. On-pump CABG was considered in patients with large ventricles, impaired cardiac function, or technically demanding targets. OPCAB was attempted when complete revascularization was deemed feasible on a beating heart. Intraoperative conversion to cardiopulmonary bypass (CPB) was undertaken if hemodynamic instability (e.g., ventricular arrhythmia, hypotension ≤ 80 mmHg, or cardiac arrest) developed. During OPCAB, cardiac exposure and stabilization were achieved with posterior pericardial stitches, gauze, a tissue stabilizer (Octopus; Medtronic, Minneapolis, MN), positional adjustments, and CO₂ blower/saline misting as needed. For on-pump CABG, the same grafting strategy was used, with beating-heart technique preferred whenever possible. Preoperative intra-aortic balloon pump (IABP) support was employed in selected high-risk patients. In all cases, the left internal mammary artery was grafted to the left anterior descending artery, followed by revascularization of the circumflex and right coronary arteries with radial artery or SVGs. A no-touch aortic technique using bilateral internal mammary arteries was selected when ascending aortic calcification or sclerosis was suspected by imaging or intraoperative palpation. Graft quality was routinely assessed intraoperatively with a transit-time flow probe (Butterfly Flowmeter; Medistim, Oslo, Norway). Statistical analysis Continuous variables were expressed as the mean and standard deviation or the median and interquartile range, and categorical variables were expressed as frequencies or percentages. Matched-group analysis was performed by propensity matching between patients with preoperative rehabilitation and controls. Propensity scores were generated in two steps using logistic regression analysis. Potential predictors were selected from published data review (age, sex, height, weight, body mass index, hypertension, hyperlipidemia, smoking, NYHA classification of III or IV, left ventricular ejection fraction (LVEF), coronary stenosis ≥ 50 and EuroSCORE II), known confounding covariates for the outcome of interest, differences between the two patient groups (Table 1 ), and clinical judgment. Continuous data were analyzed with an independent Student’s t-test or the Mann-Whitney U-test. Categorical variables were analyzed with a chi-square analysis and Fischer’s exact test. The MACCE-free rates after surgery for the two groups were determined by Kaplan-Meier survival analysis and compared with the log-rank test. Analyses were conducted with JMP software, version 18.2.0 (SAS Institute Japan, Tokyo, Japan). Table 1 Baseline patient characteristics (preoperative data) SD: standard deviation IQR: interquartile range BMI: body mass index OMI: old myocardial infarction PCI: percutaneous coronary intervention PAD: peripheral arterial disease SCr: serum creatinine CRF: chronic renal failure AMI: acute myocardial infarction NYHA: New York Heart Association LVEF: left ventricular ejection fraction LMT: left main coronary trunk EuroSCORE: European system for cardiac operative risk evaluation Results A total of 448 consecutive patients were included in this study (EVH by 85 novice surgeons vs. 88 experienced surgeons) (Figs. 1 ). Patient preoperative clinical data are listed in Table 1 . Before matching, no difference was obtained between the two groups when comparing the EVH novice and experienced groups. After matching, EVH experienced group had more patients with diabetes mellitus (40% vs. 60%, respectively; p = 0.044), and more insulin users (10% vs. 23.3%, respectively; p = 0.085). There was no other difference between groups in baseline characteristics. The Euro SCORE II was 2.5 ± 3.3 vs. 2.3 ± 2.4, respectively (p = 0.705), and the LVEF was 54% ± 15% vs. 57% ± 13%, respectively (p = 0.298). The mean follow-up time was 22.7 ± 22.3 months vs. 26.1 ± 16.8 months, respectively. One hundred seventy-three patients met the inclusion criteria and were completed with EVH harvest, of whom 64.7% had a history of smoking (novice surgeons vs. experienced surgeons; 55.6% vs. 60.8%, respectively; p = 0.627) when hospitalized. There were 12 smokers, 6.9% (novice surgeons vs. experienced surgeons; 4.9% vs. 9.4%, respectively; p = 0.371) of all EVH Harvest patients (out of 173 patients). Also, there were 14 dialysis patients, which was 8.1% (novice surgeons vs. experienced surgeons; 7.1% vs. 9.1%, respectively; p = 0.782) of the total EVH Harvest patients (out of 173 patients). In addition, there were 31 heart failure patients with NYHA III or IV, accounting for 18% of the patients with EVH Harvest (novice surgeons vs. experienced surgeons; 31.0% vs. 28.4%, respectively; p = 0.741). After matching, Group A (score-matched novice surgeon group) had fewer distal anastomoses (Group A vs. Group B; 2.8 ± 0.8 vs. 3.4 ± 1.0, respectively; P < 0.001) and used fewer SVGs (Group A vs. Group B; 1.3 ± 0.5 vs. 1.8 ± 0.9, respectively; P < 0.001). The number of SVGs used was significantly higher in group B (score-matched experienced surgeon group) (Group A vs. Group B; 1.0 ± 0.2 vs. 1.2 ± 0.4, respectively; P = 0.001), but the frequency of use of other grafts did not differ between the two groups. SVG occlusion in early postoperative period was 3 (5%) in group A and 6 (10%) in group B, but no significant difference appeared (P = 0.355). Similarly, there were 5 cases (8.3%) in group A and 1 case (1.7%) in group B for SVG stenosis, with no significant difference (P = 0.272). SVG anastomotic stenosis occurred in 1 case (1.7%) in both groups, and additional intervention was required in 2 cases (3.3%) only in Group A. There was no significant difference between the two groups. Wound dehiscence occurred in one case (1.7%) in both groups, and only one case (1.7%) in Group B was associated with infection (Table 2 ) . The graft patency tended to be higher in the Novice group without score match (Figs. 2 − 1 ), while after score match, the 1-, 3-, and 5-year patency rates were 95%/95%/95% vs. 93.1%/89%/89% (Group A vs. Group B), respectively. In conclusion, SVG patency was not affected by technical proficiency (P = 0.712) (Figs. 2 – 2 ). Table 2 Assessment of bypass graft anastomosis and wound complication SVG: saphenous vein graft LIMA: left internal mammary artery RIMA: right internal mammary artery RA: radial artery GEA: gastroepiploic artery Intra- and postoperative results are shown in Table 3 . There were no significant differences between groups in operation time, use of cardiopulmonary bypass, conversion to on-pump CABG, reoperation for bleeding, required transfusion of red blood cells, occurrence of mediastinitis and neurologic events. Only pump time was significantly different between the two groups (P = 0.028). When comparing groups, A and B, the duration of mechanical ventilation (1.4 ± 2.2 days vs 1.2 ± 1.3 days, respectively; p = 0.598), the length of ICU stay (5.2 ± 4.3 days vs 4.5 ± 1.9 days, respectively; p = 0.244) and the length of hospital stay (23 ± 14 days vs 25 ± 14 days, respectively; p = 0.519) were not significantly different. Table 3 Clinical outcomes and complications of endoscopic vein harvesting. IQR: Interquartile Range SD: Standard Deviation CABG: Coronary Artery Bypass Grafting SCr: Serum Creatinine ICU: Intensive Care Unit MACCE: Major Adverse Cardiac and Cerebrovascular Events Inpatient surgical mortality, 30-day mortality and 30-day in-hospital deaths were 1.7% (Group A) vs 0% (Group B) (P = 1.0). The postoperative MACCE (1 year) was 8.3% (Group A) vs 8.3% (Group B) (P = 1.0) (Table 3 ). After matching, MACCE free rate of 1-, 3-, and 5-year was 96.4%/90.7%/90.7% vs. 96%/91.3%/84.8% (Group A vs. Group B), respectively. There was no significant difference between the two groups (P = 0.175) (Figs. 3 ). Discussion The SVG plays a key role in CABG, and its quality may affect postoperative outcomes and avoidance of long-term cardiac events. In addition to simple incisional harvest, endoscopic harvest is significant option, and there is a report that the method of harvest may affect the outcome of CABG 10 . The greatest advantages of endoscopic vein harvest are patient cosmetic satisfaction and reduction of wound infection. Several RCTs have reported that endoscopic SV harvest can reduce infection at the harvest site and may be an important option in high-risk patients such as diabetes or dialysis 13 – 15 . As reported by Zenati et al, in a recent RCT comparing EVH and open harvest, the relative risk of leg wound infection was 2.26 for open compared to EVH 16 , and the advantage of EVH in wound infection was similar trend in our results. We did not examine the economic benefits of EVH in this study, but there are reports that there is no difference between the two groups 17 and that EVH is cost-effective 18 . Further study of the economic effects of EVH is warranted. From these, the 2018 ESC/EACTS guidelines recommend “Endoscopic vein harvesting, if performed by experienced surgeons, should be considered to reduce the incidence of wound complications” as class IIa 19 . No-touch SVG (NT-SVG) has been reported to be protective to the endothelium and vein wall and to improve long-term patency of grafts 20 – 23 , but it is also widely recognized to have the disadvantage of delayed healing of the harvest site. It is considered an option that should be selected according to its advantages and disadvantages, not as a substitute for EVH. Although it is now concluded that endoscopic SV is not inferior to incisional SV in terms of clinical outcomes such as graft patency and later mortality, there is a clear learning curve for endoscopic harvesting 9 , and it remains inconclusive what impact the results during this learning curve will have on the patient's postoperative outcome and prognosis. In this study, we investigated the relationship between SVG harvest and mid-term patency in novice and experienced surgeons, and found no significant differences between the two groups. This may be due to the fact that EVH reaches a plateau relatively quickly despite the existence of a learning curve, does not require complicated manipulation in the procedure, and is easy to deal with problems such as pulling out of the branch. Novice surgeons have been reported to be more prone to SV endothelial injury than experienced surgeons during endoscopic harvest 24 , 25 , but our results show that there is no difference in patency and MACCE rates between novice and experienced surgeons over the short to mid term. In a recent report, a pedicle SV with perivascular adipose tissue was also attempted, utilizing the advantages of both EVH and NT-SVG, and good initial results have been reported, but it has not yet reached a certain level of evaluation 15 , 26 . This study has several limitations. First, the number of patients was relatively small. Second, patient selection was not random; the patient to be treated by the novice surgeon was selected by the surgeon. Third, the nonrandomized design might have affected our results, owing to unmeasured confounding factors, or detection bias. Fourth, the fact that postoperative coronary angiography in the remote phase was not performed in all patients, and therefore could not be evaluated in qualitative detail. In addition, cost-effectiveness evaluation of hospitalization will be required in the future for this program; the benefits of EVH will need to be evaluated from multiple perspectives. It is also unclear whether similar programs can be replicated in other countries. Conclusion EVH showed no difference in graft patency or occurrence of cardiovascular complications between novice and experienced surgeons, and wound problems did not correlate with proficiency. The results of this study suggest that the use of EVH by novice surgeons under the supervision of experienced surgeons does not worsen the prognosis, which is a favorable outcome for the aggressive use of EVH. Declarations Acknowledgments This study did not receive any specific support. Author Contributions Conceptualization: Ken Nakamura, Hideaki Uchino, Takao Shimanuki, Tetsuro Uchida Data curation: Ken Nakamura, Kentaro Akabane, Shusuke Arai, Kimihiro Kobayashi, Miku Konaka, Jun Hayashi, Eiichi Ohba Formal analysis: Ken Nakamura Investigation: Ken Nakamura, Kimihiro Kobayashi, Tetsuro Uchida Methodology: Ken Nakamura, Cholsu Kim, Hideaki Uchino, Tetsuro Uchida Project administration: Ken Nakamura, Shusuke Arai Resources: Ken Nakamura Supervision: Takao Shimanuki, Tetsuro Uchida Writing –original draft: Ken Nakamura Writing-review and editing: Ken Nakamura, Hideaki Uchino, Tetsuro Uchida Data Availability Statement Data is provided within the supplementary information file. Ethics, Consent to Participate, and Consent to Publish declarations This study was reviewed and approved by the Institutional Review Board of Nihonkai General Hospital (Approval No. 005-2-10) and the Institutional Review Board of Yamagata University Hospital (Approval No. D-59). Appropriate informed consent for treatment and data use was obtained from all participants. However, the requirement for additional written informed consent to participate in this retrospective study was waived by both committees. The research was conducted in accordance with the principles outlined in the Declaration of Helsinki. Consent for publication Not Applicable Trial registration This clinical study was registered at Nihonkai General Hospital and Yamagata University Hospital with the trial registration number #00380 on June 25, 2023. Funding This study did not receive any specific support from funding agencies in the public, commercial or not-for-profit sectors. Conflict of interest statement None of the authors have any conflicts of interest to declare References Cameron A, Davis KB, Green G, Schaff HV. Coronary bypass surgery with internal-thoracic-artery grafts–effects on survival over a 15-year period. N Engl J Med. 1996;334:216–9. Glineur D, et al. Comparison of saphenous vein graft versus right gastroepiploic artery to revascularize the right coronary artery: a prospective randomized clinical, functional, and angiographic midterm evaluation. J Thorac Cardiovasc Surg. 2008;136:482–8. Nakajima H, et al. Competitive flow in arterial composite grafts and effect of graft arrangement in Off-Pump coronary revascularization. Ann Thorac Surg. 2004;78:481–6. De Vries MR, Simons KH, Jukema JW, Braun J, Quax PH. A. Vein graft failure: from pathophysiology to clinical outcomes. Nat Rev Cardiol. 2016;13:451–70. L’Ecuyer PB, Murphy D, Little JR, Fraser VJ. The Epidemiology of Chest and Leg Wound Infections Following Cardiothoracic Surgery. Clin Infect Dis. 1996;22:424–9. Kirmani BH, et al. Mid-term outcomes for Endoscopic versus Open Vein Harvest: a case control study. J Cardiothorac Surg. 2010;5:44. Dacey LJ, et al. Long-term outcomes of endoscopic vein harvesting after coronary artery bypass grafting. Circulation. 2011;123:147–53. Ouzounian M, et al. Impact of endoscopic versus open saphenous vein harvest techniques on outcomes after coronary artery bypass grafting. Ann Thorac Surg. 2010;89:403–8. Desai P et al. Impact of the learning curve for endoscopic vein harvest on conduit quality and early graft patency. Ann Thorac Surg 91, 1385–1391; discussion 1391–1392 (2011). Lopes RD, et al. Endoscopic versus Open Vein-Graft Harvesting in Coronary-Artery Bypass Surgery. N Engl J Med. 2009;361:235–44. Nakamura K, et al. Safe and promising outcomes of in-hospital preoperative rehabilitation for coronary artery bypass grafting after an acute coronary syndrome. BMC Cardiovasc Disord. 2024;24:139. Nakamura K, et al. The use of prophylactic intra-aortic balloon pump in high-risk patients undergoing coronary artery bypass grafting. PLoS ONE. 2019;14:e0224273. Puskas JD, et al. A randomized trial of endoscopic versus open saphenous vein harvest in coronary bypass surgery. Ann Thorac Surg. 1999;68:1509–12. Kiaii B, et al. A prospective randomized trial of endoscopic versus conventional harvesting of the saphenous vein in coronary artery bypass surgery. J Thorac Cardiovasc Surg. 2002;123:204–12. Allen KB et al. Endoscopic versus traditional saphenous vein harvesting: a prospective, randomized trial. Ann Thorac Surg 66, 26–31; discussion 31–32 (1998). Zenati MA, et al. Randomized Trial of Endoscopic or Open Vein-Graft Harvesting for Coronary-Artery Bypass. N Engl J Med. 2019;380:132–41. Wagner TH, et al. Costs of Endoscopic vs Open Vein Harvesting for Coronary Artery Bypass Grafting: A Secondary Analysis of the REGROUP Trial. JAMA Netw Open. 2022;5:e2217686. Eckey H, Heseler S, Hiligsmann M. Economic Evaluation of Endoscopic vs Open Vein Harvesting. Ann Thorac Surg. 2023;115:1144–50. Neumann F-J, et al. 2018 ESC/EACTS Guidelines on myocardial revascularization. Eur Heart J. 2019;40:87–165. Ritman EL, Lerman A. The dynamic vasa vasorum. Cardiovasc Res. 2007;75:649–58. Lescalié F, et al. Extrinsic arterial supply of the great saphenous vein: an anatomic study. Ann Vasc Surg. 1986;1:273–7. Crotty TP. The path of retrograde flow from the lumen of the lateral saphenous vein of the dog to its vasa vasorum. Microvasc Res. 1989;37:119–22. Dreifaldt M, et al. The ‘no-touch’ harvesting technique for vein grafts in coronary artery bypass surgery preserves an intact vasa vasorum. J Thorac Cardiovasc Surg. 2011;141:145–50. Rousou LJ, et al. Saphenous vein conduits harvested by endoscopic technique exhibit structural and functional damage. Ann Thorac Surg. 2009;87:62–70. Cheng DCH, et al. Endoscopic vein-graft harvesting: balancing the risk and benefits. Innovations (Phila). 2010;5:70–3. Katayama Y et al. Endoscopic Pedicle Saphenous Vein Graft Harvesting. ATCS 30, n/a (2024). Additional Declarations No competing interests reported. Supplementary Files DatasetEVHbiginervsExpertpostmatching.xlsx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7280259","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":518820917,"identity":"9e10b248-fcad-4b85-a02f-6589042725eb","order_by":0,"name":"Ken Nakamura","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABD0lEQVRIiWNgGAWjYBACCQiVAKE+VNjIgegDD4jVwjjjTJoxWEsCsVqYOdsOJzYg2YoVSLb3HmAuqEmT152R+/AzAxtz+vywww+BttjJ6TZg1yLNcy6BecaxHMNtN9KNpQt42HI33k4zAGpJNjY7gF2LnESOATMPWwXjthtpDNIzJHhyN85OAGk5kLgNlxb5N0At/yrsgVqYf/MYSKQbzk7/gFeLtASPATNvW04iUAubNE+CQYK8dA5+WyR7cgwO8/alJW8784zNcsaBBMMN0jkFBxIMcPtF4vgZw8c835Jttx1PY77x8d9/efnZ6Zs/fKiwk8OlBQRQpQzAXAPcyjGBfAMpqkfBKBgFo2AkAABE7WBOoyycywAAAABJRU5ErkJggg==","orcid":"","institution":"Nihonkai General Hospital","correspondingAuthor":true,"prefix":"","firstName":"Ken","middleName":"","lastName":"Nakamura","suffix":""},{"id":518820918,"identity":"5dcbb0e3-a59e-47b8-9b25-7bd0265d4700","order_by":1,"name":"Kentaro Akabane","email":"","orcid":"","institution":"Yamagata University Faculty of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Kentaro","middleName":"","lastName":"Akabane","suffix":""},{"id":518820919,"identity":"e681c357-7787-46c2-8564-2e854b3c1cbf","order_by":2,"name":"Shusuke Arai","email":"","orcid":"","institution":"Nihonkai General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Shusuke","middleName":"","lastName":"Arai","suffix":""},{"id":518820920,"identity":"d67ab562-9025-409c-98d5-270289d6bb93","order_by":3,"name":"Kimihiro Kobayashi","email":"","orcid":"","institution":"Yamagata University Faculty of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Kimihiro","middleName":"","lastName":"Kobayashi","suffix":""},{"id":518820921,"identity":"f6708ed2-f539-45ae-a6d8-54e2b74ab8fa","order_by":4,"name":"Miku Konaka","email":"","orcid":"","institution":"Yamagata University Faculty of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Miku","middleName":"","lastName":"Konaka","suffix":""},{"id":518820922,"identity":"6c06197b-3588-459f-813b-1137be37aeee","order_by":5,"name":"Jun Hayashi","email":"","orcid":"","institution":"Yamagata University Faculty of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Jun","middleName":"","lastName":"Hayashi","suffix":""},{"id":518820923,"identity":"6ba35f4f-8199-4620-b3e7-41243f868372","order_by":6,"name":"Eiichi Ohba","email":"","orcid":"","institution":"Nihonkai General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Eiichi","middleName":"","lastName":"Ohba","suffix":""},{"id":518820924,"identity":"8a339959-d33c-48f4-8136-f81d62e5fb19","order_by":7,"name":"Cholsu Kim","email":"","orcid":"","institution":"Nihonkai General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Cholsu","middleName":"","lastName":"Kim","suffix":""},{"id":518820925,"identity":"cf2611d7-f42d-4992-acaa-0c1bd856bb67","order_by":8,"name":"Hideaki Uchino","email":"","orcid":"","institution":"Nihonkai General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Hideaki","middleName":"","lastName":"Uchino","suffix":""},{"id":518820926,"identity":"ebd9e601-b92b-4f36-bbe4-682665c94ade","order_by":9,"name":"Takao Shimanuki","email":"","orcid":"","institution":"Nihonkai General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Takao","middleName":"","lastName":"Shimanuki","suffix":""},{"id":518820927,"identity":"2a35e619-e69f-4fe0-b8ae-719951954382","order_by":10,"name":"Tetsuro Uchida","email":"","orcid":"","institution":"Yamagata University Faculty of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Tetsuro","middleName":"","lastName":"Uchida","suffix":""}],"badges":[],"createdAt":"2025-08-02 20:38:09","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7280259/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7280259/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":92233304,"identity":"a4e9037d-582b-494a-a834-fe87267af009","added_by":"auto","created_at":"2025-09-26 06:55:33","extension":"tiff","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":878246,"visible":true,"origin":"","legend":"","description":"","filename":"BMCver1Fig1EVHbeginnervsExpert.tiff","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/3f17d020e5a30a0b54ccee44.tiff"},{"id":92233297,"identity":"fc611a19-e007-4192-b80e-61e3ff08a630","added_by":"auto","created_at":"2025-09-26 06:55:33","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":72359,"visible":true,"origin":"","legend":"","description":"","filename":"ver3BMCCardiothoracDisordersver1.EVHnovicevsExperienced.docx","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/7a9dc4581949fc07c59b8932.docx"},{"id":92233299,"identity":"cc535320-64e6-40ba-a02d-5769818b6f17","added_by":"auto","created_at":"2025-09-26 06:55:33","extension":"xlsx","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":23388,"visible":true,"origin":"","legend":"","description":"","filename":"BMCtablever1.EVHbeginnervsExpert.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/17293b09c7c712917fbe4302.xlsx"},{"id":92233307,"identity":"0196fc2f-908f-4b75-bf1e-eb4c0a755971","added_by":"auto","created_at":"2025-09-26 06:55:34","extension":"tiff","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":878246,"visible":true,"origin":"","legend":"","description":"","filename":"BMCver1Fig2EVHbeginnervsExpert.pptx.tiff","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/c03b2f6ecb04357890ab7d35.tiff"},{"id":92233309,"identity":"f12c791d-a972-4982-bb61-1dacea30d447","added_by":"auto","created_at":"2025-09-26 06:55:34","extension":"tiff","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":878246,"visible":true,"origin":"","legend":"","description":"","filename":"BMCver1Fig3EVHbeginnervsExpert.tiff","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/886a1e4f1b76b9b1869babe2.tiff"},{"id":92234408,"identity":"94d58be4-f3bb-47f4-a007-3db92bd5eb50","added_by":"auto","created_at":"2025-09-26 07:03:33","extension":"json","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":11660,"visible":true,"origin":"","legend":"","description":"","filename":"37d38c15f7ab4957bb15b4730c09d570.json","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/78c0a17964718f20207d6d5c.json"},{"id":92233308,"identity":"39b3ca9e-29ab-4654-ae02-37534910e8ec","added_by":"auto","created_at":"2025-09-26 06:55:34","extension":"xlsx","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":214117,"visible":true,"origin":"","legend":"","description":"","filename":"DatasetEVHbiginervsExpertpostmatching.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/ae1c75a170df0b73c622e3aa.xlsx"},{"id":92233314,"identity":"0f165337-9438-4ab6-bb02-1ded1050b40c","added_by":"auto","created_at":"2025-09-26 06:55:34","extension":"xml","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":69650,"visible":true,"origin":"","legend":"","description":"","filename":"37d38c15f7ab4957bb15b4730c09d5701enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/9de685498d46026568d9ef91.xml"},{"id":92233312,"identity":"573b5f24-68be-4158-a3cf-686b68088083","added_by":"auto","created_at":"2025-09-26 06:55:34","extension":"tiff","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":878246,"visible":true,"origin":"","legend":"","description":"","filename":"BMCver1Fig1EVHbeginnervsExpert.tiff","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/12f8c269a40da4240b863a58.tiff"},{"id":92233310,"identity":"f9fbd7e1-c08d-43a2-a6e8-7671bc97393e","added_by":"auto","created_at":"2025-09-26 06:55:34","extension":"tiff","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":878246,"visible":true,"origin":"","legend":"","description":"","filename":"BMCver1Fig2EVHbeginnervsExpert.pptx.tiff","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/50c3fe6d5a0e21df13dfc70d.tiff"},{"id":92234412,"identity":"c5a4e208-3e8c-4853-b0dd-c11f124a145f","added_by":"auto","created_at":"2025-09-26 07:03:34","extension":"tiff","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":878246,"visible":true,"origin":"","legend":"","description":"","filename":"BMCver1Fig3EVHbeginnervsExpert.tiff","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/2c5dea84965e247daeecec54.tiff"},{"id":92234411,"identity":"205d4b97-5fe9-43ac-88d4-0c05211ebd5a","added_by":"auto","created_at":"2025-09-26 07:03:34","extension":"png","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":33852,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineBMCver1Fig1EVHbeginnervsExpert.png","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/868b72965d57bee11e20ebd6.png"},{"id":92233305,"identity":"63b83a73-773d-4735-91e4-50522f2b9b65","added_by":"auto","created_at":"2025-09-26 06:55:33","extension":"png","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":12632,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineBMCver1Fig2EVHbeginnervsExpert.pptx.png","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/b971d9f0c3a18c37dd201373.png"},{"id":92233306,"identity":"620c0f6f-f5a2-4b1b-bc61-09ac5768f312","added_by":"auto","created_at":"2025-09-26 06:55:34","extension":"png","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":13037,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineBMCver1Fig3EVHbeginnervsExpert.png","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/69dce27a09cc3a7cd4724292.png"},{"id":92233313,"identity":"0fba7b2c-fb46-4d46-b2c8-96e6df02ef70","added_by":"auto","created_at":"2025-09-26 06:55:34","extension":"xml","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":64829,"visible":true,"origin":"","legend":"","description":"","filename":"37d38c15f7ab4957bb15b4730c09d5701structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/0b0a0185c0c673d91bc67be9.xml"},{"id":92233315,"identity":"154a2d34-1318-4f60-b4d5-9505a9e4ce34","added_by":"auto","created_at":"2025-09-26 06:55:34","extension":"html","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":75957,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/9269aaeae516ebbceb406ad8.html"},{"id":92233296,"identity":"d45e25b0-ca49-4ca5-95a7-d7f60567221c","added_by":"auto","created_at":"2025-09-26 06:55:33","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":154058,"visible":true,"origin":"","legend":"\u003cp\u003eSummary flow diagram of patient disposition.\u003c/p\u003e\n\u003cp\u003eCABG: coronary-artery bypass grafting, SVG: saphenous-vein graft, EVH: endoscopic vein harvest, CAG: coronary angiography\u003c/p\u003e","description":"","filename":"BMCver1Fig1EVHbeginnervsExpert.png","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/2358523be667b980513269d8.png"},{"id":92234407,"identity":"7b34e36b-1c24-4496-af10-4cca19857060","added_by":"auto","created_at":"2025-09-26 07:03:33","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":219232,"visible":true,"origin":"","legend":"\u003cp\u003eKaplan-Meier curves of SVG-patency of 173 patients with isolated and combined CABG in our institution. All SVGs were harvested with EVH. (1) The raw data of novice surgeon group (85 patients) and EVH-experienced surgeon (88 patients) group. (2) Propensity score-matched novice surgeons group (n=60) and EVH-experienced surgeons group (n=60).\u003c/p\u003e\n\u003cp\u003eSVG: saphenous-vein graft, CABG: coronary-artery bypass grafting, EVH: endoscopic vein harvest\u003c/p\u003e","description":"","filename":"BMCver1Fig2EVHbeginnervsExpert.pptx.png","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/b7fc88e5fafa2d7fa72df069.png"},{"id":92233301,"identity":"813e2678-5974-46be-b4ee-ac934eb161a9","added_by":"auto","created_at":"2025-09-26 06:55:33","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":226794,"visible":true,"origin":"","legend":"\u003cp\u003eKaplan-Meier curves of MACCE-free rates of 173 patients with isolated and combined CABG in our institution. All SVGs were harvested with EVH. (1) Raw data from a group of novice surgeons, 85 patients, and a group of EVH-experienced surgeons, 88 patients.\u003c/p\u003e\n\u003cp\u003e(2) Propensity score-matched novice surgeons group (n=60) and EVH-experienced surgeons group (n=60).\u003c/p\u003e\n\u003cp\u003eMACCE: major adverse cardiac and cerebrovascular events, SVG: saphenous-vein graft, CABG: coronary-artery bypass grafting, EVH: endoscopic vein harvest\u003c/p\u003e","description":"","filename":"BMCver1Fig3EVHbeginnervsExpert.png","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/b51d5dc2170cba79c107ce8c.png"},{"id":92827751,"identity":"2387aa36-9e89-4d79-af93-40b268c2cd47","added_by":"auto","created_at":"2025-10-06 05:01:45","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1378481,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/591dfb71-0402-488d-a814-ce5a549499a2.pdf"},{"id":92235259,"identity":"15eb96fc-4fb3-4e58-a088-05ebdc3d9120","added_by":"auto","created_at":"2025-09-26 07:11:33","extension":"xlsx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":214117,"visible":true,"origin":"","legend":"","description":"","filename":"DatasetEVHbiginervsExpertpostmatching.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-7280259/v1/6db279037f61e8c9cbd2ac98.xlsx"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Impact of Endoscopic Vein Harvest by Less Experienced Operators on Conduit Quality and Early Graft Patency","fulltext":[{"header":"Introduction","content":"\u003cp\u003eLeft internal mammary artery (LIMA) is the first choice of graft used for bypass to left anterior descending artery (LAD) and has a high cardiac event avoidance rate and improves life expectancy\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. The second graft used in coronary artery bypass grafting (CABG) is selected according to the target vessel and the degree of stenosis, however saphenous vein graft (SVG) is frequently used because it is not affected by the degree of stenosis of the autologous coronary artery and relatively long grafts can be obtained\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e,\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. The advantages of SVG were good accessibility and ease of preparation, however long-term patency, wound infection, and opening in the incision were major problems\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e,\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. Endoscopic vein harvest (EVH) is one of the novel innovative strategies that have been implemented in the last 25 years to solve this problem and is now widely used. EVH is considered to ameliorate postoperative pain and improve cosmetic outcomes compared to traditional harvesting methods, while there is still no consensus on graft patency\u003csup\u003e\u003cspan additionalcitationids=\"CR7 CR8 CR9\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. SVG harvest is a technique that can be performed by relatively inexperienced surgeons, but there are no detailed reports on how practitioner inexperience affects graft patency, and there is no established evaluation. In this study, we compared the impact of EVH on graft patency by novice surgeons based on postoperative coronary angiography (CAG) evaluations.\u003c/p\u003e"},{"header":"Patients and Methods","content":"\u003cp\u003eThis was a retrospective observational study conducted at two centers, Nihonkai General Hospital and Yamagata University Hospital. A total of 719 consecutive patients who underwent isolated or combined CABG between December 2005 and December 2017 were included. The study protocol was approved by the Institutional Review Board of Nihonkai General Hospital (Approval No. 005-2-10) and the Institutional Review Board of Yamagata University Hospital (Approval No. D-59). Owing to the retrospective study design, the requirement for additional written informed consent was waived, although all patients had provided appropriate informed consent for treatment and data use at the time of care. The research was performed in compliance with the principles of the Declaration of Helsinki. Data were accessed on June 10, 2023, and the study was registered at both institutions (Trial Registration No. 00380, June 25, 2023).\u003c/p\u003e\u003cp\u003eThe aim of the study was to compare early graft patency and stenosis after CABG between novice and experienced operators of EVH, as well as to assess long-term graft patency and the incidence of major adverse cardiac and cerebrovascular events (MACCE). Eligible patients were those who underwent CABG using at least one SVG harvested endoscopically, without conversion to open harvest. Patients in whom postoperative CAG could not be obtained were excluded. Surgeons with no prior EVH experience were categorized as \u0026ldquo;novice,\u0026rdquo; whereas those with \u0026gt;\u0026thinsp;30 EVH cases or more than 12 months of experience were defined as \u0026ldquo;experienced.\u0026rdquo; Patients with lower-limb varicose veins were not considered candidates for SVG harvesting. Preoperative CT vein mapping was routinely used to assess venous quality. EVH was performed by an assistant surgeon concurrently with harvesting of the left internal mammary artery, using a standardized approach (VirtuoSaph; Terumo Cardiovascular, Ann Arbor, MI). The technical details of the EVH procedure, including incision, blunt dissection, branch management, and preparation of the graft, followed conventional methods previously described in the literature\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eThe primary outcome was early graft-related complications, including occlusion, stenosis, or wound infection. Secondary outcomes were long-term graft patency and MACCE, defined as death, myocardial infarction, stroke, or repeat revascularization by percutaneous coronary intervention or CABG. Postoperative atrial fibrillation was diagnosed when episodes lasting\u0026thinsp;\u0026gt;\u0026thinsp;30 seconds were documented during hospitalization. Neurological events required corroboration with CT or MRI and confirmation by a neurosurgeon; transient ischemic attacks without imaging findings were not included. Comorbid conditions such as dental infection, uncontrolled diabetes, and carotid artery stenosis were treated before surgery. Perioperative rehabilitation programs were supervised by physical therapists.\u003c/p\u003e\u003cp\u003eThe decision to perform on-pump or off-pump CABG (OPCAB) was made in a preoperative conference based on patient characteristics and surgical complexity. On-pump CABG was considered in patients with large ventricles, impaired cardiac function, or technically demanding targets. OPCAB was attempted when complete revascularization was deemed feasible on a beating heart. Intraoperative conversion to cardiopulmonary bypass (CPB) was undertaken if hemodynamic instability (e.g., ventricular arrhythmia, hypotension\u0026thinsp;\u0026le;\u0026thinsp;80 mmHg, or cardiac arrest) developed. During OPCAB, cardiac exposure and stabilization were achieved with posterior pericardial stitches, gauze, a tissue stabilizer (Octopus; Medtronic, Minneapolis, MN), positional adjustments, and CO₂ blower/saline misting as needed. For on-pump CABG, the same grafting strategy was used, with beating-heart technique preferred whenever possible. Preoperative intra-aortic balloon pump (IABP) support was employed in selected high-risk patients.\u003c/p\u003e\u003cp\u003eIn all cases, the left internal mammary artery was grafted to the left anterior descending artery, followed by revascularization of the circumflex and right coronary arteries with radial artery or SVGs. A no-touch aortic technique using bilateral internal mammary arteries was selected when ascending aortic calcification or sclerosis was suspected by imaging or intraoperative palpation. Graft quality was routinely assessed intraoperatively with a transit-time flow probe (Butterfly Flowmeter; Medistim, Oslo, Norway).\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eContinuous variables were expressed as the mean and standard deviation or the median and interquartile range, and categorical variables were expressed as frequencies or percentages. Matched-group analysis was performed by propensity matching between patients with preoperative rehabilitation and controls. Propensity scores were generated in two steps using logistic regression analysis. Potential predictors were selected from published data review (age, sex, height, weight, body mass index, hypertension, hyperlipidemia, smoking, NYHA classification of III or IV, left ventricular ejection fraction (LVEF), coronary stenosis\u0026thinsp;\u0026ge;\u0026thinsp;50 and EuroSCORE II), known confounding covariates for the outcome of interest, differences between the two patient groups (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), and clinical judgment. Continuous data were analyzed with an independent Student\u0026rsquo;s t-test or the Mann-Whitney U-test. Categorical variables were analyzed with a chi-square analysis and Fischer\u0026rsquo;s exact test. The MACCE-free rates after surgery for the two groups were determined by Kaplan-Meier survival analysis and compared with the log-rank test. Analyses were conducted with JMP software, version 18.2.0 (SAS Institute Japan, Tokyo, Japan).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eBaseline patient characteristics (preoperative data)\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"1\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSD: standard deviation\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIQR: interquartile range\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI: body mass index\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOMI: old myocardial infarction\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePCI: percutaneous coronary intervention\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePAD: peripheral arterial disease\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSCr: serum creatinine\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCRF: chronic renal failure\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAMI: acute myocardial infarction\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNYHA: New York Heart Association\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLVEF: left ventricular ejection fraction\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLMT: left main coronary trunk\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eEuroSCORE: European system for cardiac operative risk evaluation\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 448 consecutive patients were included in this study (EVH by 85 novice surgeons vs. 88 experienced surgeons) (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Patient preoperative clinical data are listed in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Before matching, no difference was obtained between the two groups when comparing the EVH novice and experienced groups. After matching, EVH experienced group had more patients with diabetes mellitus (40% vs. 60%, respectively; p\u0026thinsp;=\u0026thinsp;0.044), and more insulin users (10% vs. 23.3%, respectively; p\u0026thinsp;=\u0026thinsp;0.085). There was no other difference between groups in baseline characteristics. The Euro SCORE II was 2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;3.3 vs. 2.3\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4, respectively (p\u0026thinsp;=\u0026thinsp;0.705), and the LVEF was 54% \u0026plusmn; 15% vs. 57% \u0026plusmn; 13%, respectively (p\u0026thinsp;=\u0026thinsp;0.298). The mean follow-up time was 22.7\u0026thinsp;\u0026plusmn;\u0026thinsp;22.3 months vs. 26.1\u0026thinsp;\u0026plusmn;\u0026thinsp;16.8 months, respectively. One hundred seventy-three patients met the inclusion criteria and were completed with EVH harvest, of whom 64.7% had a history of smoking (novice surgeons vs. experienced surgeons; 55.6% vs. 60.8%, respectively; p\u0026thinsp;=\u0026thinsp;0.627) when hospitalized. There were 12 smokers, 6.9% (novice surgeons vs. experienced surgeons; 4.9% vs. 9.4%, respectively; p\u0026thinsp;=\u0026thinsp;0.371) of all EVH Harvest patients (out of 173 patients). Also, there were 14 dialysis patients, which was 8.1% (novice surgeons vs. experienced surgeons; 7.1% vs. 9.1%, respectively; p\u0026thinsp;=\u0026thinsp;0.782) of the total EVH Harvest patients (out of 173 patients).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eIn addition, there were 31 heart failure patients with NYHA III or IV, accounting for 18% of the patients with EVH Harvest (novice surgeons vs. experienced surgeons; 31.0% vs. 28.4%, respectively; p\u0026thinsp;=\u0026thinsp;0.741).\u003c/p\u003e\u003cp\u003eAfter matching, Group A (score-matched novice surgeon group) had fewer distal anastomoses (Group A vs. Group B; 2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8 vs. 3.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0, respectively; P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and used fewer SVGs (Group A vs. Group B; 1.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5 vs. 1.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9, respectively; P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The number of SVGs used was significantly higher in group B (score-matched experienced surgeon group) (Group A vs. Group B; 1.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.2 vs. 1.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4, respectively; P\u0026thinsp;=\u0026thinsp;0.001), but the frequency of use of other grafts did not differ between the two groups. SVG occlusion in early postoperative period was 3 (5%) in group A and 6 (10%) in group B, but no significant difference appeared (P\u0026thinsp;=\u0026thinsp;0.355). Similarly, there were 5 cases (8.3%) in group A and 1 case (1.7%) in group B for SVG stenosis, with no significant difference (P\u0026thinsp;=\u0026thinsp;0.272). SVG anastomotic stenosis occurred in 1 case (1.7%) in both groups, and additional intervention was required in 2 cases (3.3%) only in Group A. There was no significant difference between the two groups. Wound dehiscence occurred in one case (1.7%) in both groups, and only one case (1.7%) in Group B was associated with infection (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. The graft patency tended to be higher in the Novice group without score match (Figs.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e\u0026thinsp;\u003cb\u003e\u0026minus;\u0026thinsp;1\u003c/b\u003e), while after score match, the 1-, 3-, and 5-year patency rates were 95%/95%/95% vs. 93.1%/89%/89% (Group A vs. Group B), respectively. In conclusion, SVG patency was not affected by technical proficiency (P\u0026thinsp;=\u0026thinsp;0.712) (Figs.\u0026nbsp;\u0026lt;link rid=\"fig2\"\u0026gt;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u0026lt;/link\u0026gt;\u003c/span\u003e\u0026ndash;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eAssessment of bypass graft anastomosis and wound complication\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"1\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSVG: saphenous vein graft\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLIMA: left internal mammary artery\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRIMA: right internal mammary artery\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRA: radial artery\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGEA: gastroepiploic artery\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eIntra- and postoperative results are shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. There were no significant differences between groups in operation time, use of cardiopulmonary bypass, conversion to on-pump CABG, reoperation for bleeding, required transfusion of red blood cells, occurrence of mediastinitis and neurologic events. Only pump time was significantly different between the two groups (P\u0026thinsp;=\u0026thinsp;0.028). When comparing groups, A and B, the duration of mechanical ventilation (1.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.2 days vs 1.2\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3 days, respectively; p\u0026thinsp;=\u0026thinsp;0.598), the length of ICU stay (5.2\u0026thinsp;\u0026plusmn;\u0026thinsp;4.3 days vs 4.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.9 days, respectively; p\u0026thinsp;=\u0026thinsp;0.244) and the length of hospital stay (23\u0026thinsp;\u0026plusmn;\u0026thinsp;14 days vs 25\u0026thinsp;\u0026plusmn;\u0026thinsp;14 days, respectively; p\u0026thinsp;=\u0026thinsp;0.519) were not significantly different.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eClinical outcomes and complications of endoscopic vein harvesting.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"1\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIQR: Interquartile Range\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSD: Standard Deviation\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCABG: Coronary Artery Bypass Grafting\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSCr: Serum Creatinine\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eICU: Intensive Care Unit\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMACCE: Major Adverse Cardiac and Cerebrovascular Events\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eInpatient surgical mortality, 30-day mortality and 30-day in-hospital deaths were 1.7% (Group A) vs 0% (Group B) (P\u0026thinsp;=\u0026thinsp;1.0). The postoperative MACCE (1 year) was 8.3% (Group A) vs 8.3% (Group B) (P\u0026thinsp;=\u0026thinsp;1.0) (Table \u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). After matching, MACCE free rate of 1-, 3-, and 5-year was 96.4%/90.7%/90.7% vs. 96%/91.3%/84.8% (Group A vs. Group B), respectively. There was no significant difference between the two groups (P\u0026thinsp;=\u0026thinsp;0.175) (Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe SVG plays a key role in CABG, and its quality may affect postoperative outcomes and avoidance of long-term cardiac events. In addition to simple incisional harvest, endoscopic harvest is significant option, and there is a report that the method of harvest may affect the outcome of CABG\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. The greatest advantages of endoscopic vein harvest are patient cosmetic satisfaction and reduction of wound infection. Several RCTs have reported that endoscopic SV harvest can reduce infection at the harvest site and may be an important option in high-risk patients such as diabetes or dialysis\u003csup\u003e\u003cspan additionalcitationids=\"CR14\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e. As reported by Zenati et al, in a recent RCT comparing EVH and open harvest, the relative risk of leg wound infection was 2.26 for open compared to EVH \u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e, and the advantage of EVH in wound infection was similar trend in our results. We did not examine the economic benefits of EVH in this study, but there are reports that there is no difference between the two groups\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e and that EVH is cost-effective\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e. Further study of the economic effects of EVH is warranted. From these, the 2018 ESC/EACTS guidelines recommend \u0026ldquo;Endoscopic vein harvesting, if performed by experienced surgeons, should be considered to reduce the incidence of wound complications\u0026rdquo; as class IIa \u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. No-touch SVG (NT-SVG) has been reported to be protective to the endothelium and vein wall and to improve long-term patency of grafts\u003csup\u003e\u003cspan additionalcitationids=\"CR21 CR22\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e, but it is also widely recognized to have the disadvantage of delayed healing of the harvest site. It is considered an option that should be selected according to its advantages and disadvantages, not as a substitute for EVH.\u003c/p\u003e\u003cp\u003eAlthough it is now concluded that endoscopic SV is not inferior to incisional SV in terms of clinical outcomes such as graft patency and later mortality, there is a clear learning curve for endoscopic harvesting\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e, and it remains inconclusive what impact the results during this learning curve will have on the patient's postoperative outcome and prognosis. In this study, we investigated the relationship between SVG harvest and mid-term patency in novice and experienced surgeons, and found no significant differences between the two groups. This may be due to the fact that EVH reaches a plateau relatively quickly despite the existence of a learning curve, does not require complicated manipulation in the procedure, and is easy to deal with problems such as pulling out of the branch. Novice surgeons have been reported to be more prone to SV endothelial injury than experienced surgeons during endoscopic harvest\u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e,\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e, but our results show that there is no difference in patency and MACCE rates between novice and experienced surgeons over the short to mid term. In a recent report, a pedicle SV with perivascular adipose tissue was also attempted, utilizing the advantages of both EVH and NT-SVG, and good initial results have been reported, but it has not yet reached a certain level of evaluation\u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e,\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eThis study has several limitations. First, the number of patients was relatively small. Second, patient selection was not random; the patient to be treated by the novice surgeon was selected by the surgeon. Third, the nonrandomized design might have affected our results, owing to unmeasured confounding factors, or detection bias. Fourth, the fact that postoperative coronary angiography in the remote phase was not performed in all patients, and therefore could not be evaluated in qualitative detail. In addition, cost-effectiveness evaluation of hospitalization will be required in the future for this program; the benefits of EVH will need to be evaluated from multiple perspectives. It is also unclear whether similar programs can be replicated in other countries.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eEVH showed no difference in graft patency or occurrence of cardiovascular complications between novice and experienced surgeons, and wound problems did not correlate with proficiency. The results of this study suggest that the use of EVH by novice surgeons under the supervision of experienced surgeons does not worsen the prognosis, which is a favorable outcome for the aggressive use of EVH.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study did not receive any specific support.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConceptualization: Ken Nakamura, Hideaki Uchino, Takao Shimanuki, Tetsuro Uchida\u003c/p\u003e\n\u003cp\u003eData curation: Ken Nakamura,\u0026nbsp;Kentaro Akabane,\u0026nbsp;Shusuke Arai, Kimihiro Kobayashi,\u0026nbsp;Miku Konaka,\u0026nbsp;Jun Hayashi, Eiichi Ohba\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFormal analysis: Ken Nakamura\u003c/p\u003e\n\u003cp\u003eInvestigation: Ken Nakamura, Kimihiro Kobayashi, Tetsuro Uchida\u003c/p\u003e\n\u003cp\u003eMethodology: Ken Nakamura, Cholsu Kim, Hideaki Uchino, Tetsuro Uchida\u003c/p\u003e\n\u003cp\u003eProject administration: Ken Nakamura, Shusuke Arai\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eResources: Ken Nakamura\u003c/p\u003e\n\u003cp\u003eSupervision: Takao Shimanuki, Tetsuro Uchida\u003c/p\u003e\n\u003cp\u003eWriting –original draft: Ken Nakamura\u003c/p\u003e\n\u003cp\u003eWriting-review and editing: Ken Nakamura, Hideaki Uchino, Tetsuro Uchida\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData is provided within the supplementary information file.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics, Consent to Participate, and Consent to Publish declarations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was reviewed and approved by the Institutional Review Board of Nihonkai General Hospital (Approval No. 005-2-10) and the Institutional Review Board of Yamagata University Hospital (Approval No. D-59). Appropriate informed consent for treatment and data use was obtained from all participants. However, the requirement for additional written informed consent to participate in this retrospective study was waived by both committees. The research was conducted in accordance with the principles outlined in the Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot Applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial registration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis clinical study was registered at Nihonkai General Hospital and Yamagata University Hospital with the trial registration number #00380 on June 25, 2023.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study did not receive any specific support from funding agencies in the public, commercial or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone of the authors have any conflicts of interest to declare\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eCameron A, Davis KB, Green G, Schaff HV. Coronary bypass surgery with internal-thoracic-artery grafts\u0026ndash;effects on survival over a 15-year period. N Engl J Med. 1996;334:216\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGlineur D, et al. Comparison of saphenous vein graft versus right gastroepiploic artery to revascularize the right coronary artery: a prospective randomized clinical, functional, and angiographic midterm evaluation. J Thorac Cardiovasc Surg. 2008;136:482\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNakajima H, et al. Competitive flow in arterial composite grafts and effect of graft arrangement in Off-Pump coronary revascularization. Ann Thorac Surg. 2004;78:481\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDe Vries MR, Simons KH, Jukema JW, Braun J, Quax PH. A. Vein graft failure: from pathophysiology to clinical outcomes. Nat Rev Cardiol. 2016;13:451\u0026ndash;70.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eL\u0026rsquo;Ecuyer PB, Murphy D, Little JR, Fraser VJ. The Epidemiology of Chest and Leg Wound Infections Following Cardiothoracic Surgery. Clin Infect Dis. 1996;22:424\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKirmani BH, et al. Mid-term outcomes for Endoscopic versus Open Vein Harvest: a case control study. J Cardiothorac Surg. 2010;5:44.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDacey LJ, et al. Long-term outcomes of endoscopic vein harvesting after coronary artery bypass grafting. Circulation. 2011;123:147\u0026ndash;53.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOuzounian M, et al. Impact of endoscopic versus open saphenous vein harvest techniques on outcomes after coronary artery bypass grafting. Ann Thorac Surg. 2010;89:403\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDesai P et al. Impact of the learning curve for endoscopic vein harvest on conduit quality and early graft patency. \u003cem\u003eAnn Thorac Surg\u003c/em\u003e 91, 1385\u0026ndash;1391; discussion 1391\u0026ndash;1392 (2011).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLopes RD, et al. Endoscopic versus Open Vein-Graft Harvesting in Coronary-Artery Bypass Surgery. N Engl J Med. 2009;361:235\u0026ndash;44.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNakamura K, et al. Safe and promising outcomes of in-hospital preoperative rehabilitation for coronary artery bypass grafting after an acute coronary syndrome. BMC Cardiovasc Disord. 2024;24:139.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNakamura K, et al. The use of prophylactic intra-aortic balloon pump in high-risk patients undergoing coronary artery bypass grafting. PLoS ONE. 2019;14:e0224273.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePuskas JD, et al. A randomized trial of endoscopic versus open saphenous vein harvest in coronary bypass surgery. Ann Thorac Surg. 1999;68:1509\u0026ndash;12.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKiaii B, et al. A prospective randomized trial of endoscopic versus conventional harvesting of the saphenous vein in coronary artery bypass surgery. J Thorac Cardiovasc Surg. 2002;123:204\u0026ndash;12.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAllen KB et al. Endoscopic versus traditional saphenous vein harvesting: a prospective, randomized trial. \u003cem\u003eAnn Thorac Surg\u003c/em\u003e 66, 26\u0026ndash;31; discussion 31\u0026ndash;32 (1998).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZenati MA, et al. Randomized Trial of Endoscopic or Open Vein-Graft Harvesting for Coronary-Artery Bypass. N Engl J Med. 2019;380:132\u0026ndash;41.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWagner TH, et al. Costs of Endoscopic vs Open Vein Harvesting for Coronary Artery Bypass Grafting: A Secondary Analysis of the REGROUP Trial. JAMA Netw Open. 2022;5:e2217686.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEckey H, Heseler S, Hiligsmann M. Economic Evaluation of Endoscopic vs Open Vein Harvesting. Ann Thorac Surg. 2023;115:1144\u0026ndash;50.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNeumann F-J, et al. 2018 ESC/EACTS Guidelines on myocardial revascularization. Eur Heart J. 2019;40:87\u0026ndash;165.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRitman EL, Lerman A. The dynamic vasa vasorum. Cardiovasc Res. 2007;75:649\u0026ndash;58.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLescali\u0026eacute; F, et al. Extrinsic arterial supply of the great saphenous vein: an anatomic study. Ann Vasc Surg. 1986;1:273\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCrotty TP. The path of retrograde flow from the lumen of the lateral saphenous vein of the dog to its vasa vasorum. Microvasc Res. 1989;37:119\u0026ndash;22.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDreifaldt M, et al. The \u0026lsquo;no-touch\u0026rsquo; harvesting technique for vein grafts in coronary artery bypass surgery preserves an intact vasa vasorum. J Thorac Cardiovasc Surg. 2011;141:145\u0026ndash;50.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRousou LJ, et al. Saphenous vein conduits harvested by endoscopic technique exhibit structural and functional damage. Ann Thorac Surg. 2009;87:62\u0026ndash;70.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCheng DCH, et al. Endoscopic vein-graft harvesting: balancing the risk and benefits. Innovations (Phila). 2010;5:70\u0026ndash;3.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKatayama Y et al. Endoscopic Pedicle Saphenous Vein Graft Harvesting. \u003cem\u003eATCS\u003c/em\u003e 30, n/a (2024).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-7280259/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7280259/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjective: \u003c/strong\u003eThe saphenous-vein graft (SVG) is a key graft commonly used in coronary-artery bypass grafting (CABG), and its quality affects postoperative outcomes.\u003c/p\u003e\n\u003cp\u003eendoscopic vein harvest (EVH) is an effective technique for wound healing and prevention of infection, but there is a learning curve, and there is no established assessment of how harvesting by a novice surgeon affects the patient's postoperative outcome. In this study, we investigated the effect of graft harvesting proficiency on the outcome of postoperative CABG patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods: \u003c/strong\u003eFrom 2005 to 2017, the patients who completed EVH were included in the analysis. Propensity score-matched EVH-experienced surgeon group and novice surgeon group, respectively, were compared for the graft patency and major adverse cardiac and cerebrovascular events (MACCE) extending into the remote phase.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e A total of 719 patients underwent either isolated or combined CABG at the two institutions, and of those, the 173 patients with SVG harvested by EVH were divided into 60 Propensity score-matched groups, respectively. SVG occlusion in early postoperative period was 3 (5%) in group of novice surgeons (group A) and 6 (10%) in group of experienced surgeons (group B) (P=0.355). Similarly, there were 5 cases (8.3%) in group A and 1 case (1.7%) in group B for SVG stenosis (P = 0.272). Inpatient surgical mortality, 30-day mortality and 30-day in-hospital deaths were 1.7 % (Group A) vs 0 % (Group B) (P = 1.0). MACCE free rate of 1-, 3-, and 5-year was 96.4%/90.7%/90.7% vs. 96%/91.3%/84.8% (P = 0.175) (Group A vs. Group B), respectively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAmong the patients undergoing CABG with EVH, a significant difference was not found between the surgeons of novice vein-graft harvesting and experienced in the risk of graft occlusion and major adverse cardiac events.\u003c/p\u003e","manuscriptTitle":"The Impact of Endoscopic Vein Harvest by Less Experienced Operators on Conduit Quality and Early Graft Patency","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-26 06:55:29","doi":"10.21203/rs.3.rs-7280259/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"02a9a7aa-48d6-41e1-890b-9d8fee64d474","owner":[],"postedDate":"September 26th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-10-06T04:53:40+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-26 06:55:29","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7280259","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7280259","identity":"rs-7280259","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}