A comprehensive review on learning curve associated problems in endoscopic vein harvesting and the requirement for a standardised training programme

The Current Status of Minimally Invasive Conduit Harvesting for Coronary Artery Bypass Grafting

The harvesting of conduits for coronary artery bypass surgery has evolved over the last decade to include endoscopic approaches to access the saphenous vein, radial artery, and internal mammary artery. These minimally invasive techniques reduce the morbidity associated with open procedures by decreasing pain and recovery time and increasing mobility post operatively. This review highlights the differences in morbidity, quality, and patency between the most common conduits that are harvested minimally invasively for coronary artery bypass grafting surgery.

Consensus statement-graft treatment in cardiovascular bypass graft surgery

Coronary artery bypass grafting (CABG) is and continues to be the preferred revascularization strategy in patients with multivessel disease. Graft selection has been shown to influence the outcomes following CABG. During the last almost 60 years saphenous vein grafts (SVG) together with the internal mammary artery have become the standard of care for patients undergoing CABG surgery. While there is little doubt about the benefits, the patency rates are constantly under debate. Despite its acknowledged limitations in terms of long-term patency due to intimal hyperplasia, the saphenous vein is still the most often used graft. Although reendothelialization occurs early postoperatively, the process of intimal hyperplasia remains irreversible. This is due in part to the persistence of high shear forces, the chronic localized inflammatory response, and the partial dysfunctionality of the regenerated endothelium. "No-Touch" harvesting techniques, specific storage solutions, pressure controlled graft flushing and external stenting are important and established methods aiming to overcome the process of intimal hyperplasia at different time levels. Still despite the known evidence these methods are not standard everywhere. The use of arterial grafts is another strategy to address the inferior SVG patency rates and to perform CABG with total arterial revascularization. Composite grafting, pharmacological agents as well as latest minimal invasive techniques aim in the same direction. To give guide and set standards all graft related topics for CABG are presented in this expert opinion document on graft treatment.

Effectiveness of a Game-Based Mobile App for Educating Intensive Critical Care Specialist Nurses in Extracorporeal Membrane Oxygenation Pipeline Preflushing: Quasi-Experimental Trial

Background

In the context of training specialist nurses and nursing education, a game-based mobile app was used as a simulation to teach intensive critical care specialist nurses the knowledge and skills of extracorporeal membrane oxygenation (ECMO) pipeline preflushing.

Objective

This study aimed to evaluate the impact of a game-based mobile app on improving ECMO pipeline preflushing skills in intensive critical care specialist nurses.

Methods

A total of 86 intensive critical care specialist nurses who were learning ECMO for the first time were included in this study. The nurses were divided into 2 groups: a control group (n=43) and an experimental group (n=43). Participants in the experimental group used a game-based mobile app for simulation exercises; the control group received no additional intervention. All participants took a theoretical test and a skill operation test at the beginning of the study and 1 week later. The differences in scores between the 2 groups were compared, and the learning curve of the experimental group was observed.

Results

The final theoretical test scores (88.44 and 85.02) and skill operation test scores (89.42 and 86.33) of the experimental group and control group, respectively, were significantly higher than those of the initial tests (theoretical test scores: 75.88 and 74.42; skill operation test scores: 75.44 and 75.93; all P<.001). The scores of the final theoretical test (88.44) and the final skill operation test (89.42) in the experimental group were higher than the scores of the control group (85.02; P<.001 and 86.33; P<.001, respectively). Learning curve analysis showed that the experimental group needed an average of 17 operations to master the skill.

Conclusions

This study suggests that a game-based mobile app may be more effective for intensive critical care specialist nurses in ECMO pipeline preflushing education than traditional Chinese lecture-practice education.

Influence of Three Different Surgical Techniques on Microscopic Damage of Saphenous Vein Grafts-A Randomized Study

Background and Objectives: The saphenous vein is one of the most common used grafts (SVG) for surgical revascularization. The mechanism of the SVGs occlusion is still unknown. Surgical preparation techniques have an important role in the early and late graft occlusion. Our study analyzed the influence of the three different surgical techniques on the histological and immunohistochemical characteristics of the vein grafts. Methods: Between June 2019 and December 2020, 83 patients who underwent surgical revascularization were prospectively randomly assigned to one of the three groups, according to saphenous vein graft harvesting (conventional (CVH), no-touch (NT) and endoscopic (EVH)) technique. The vein graft samples were sent on the histological (hematoxylin-eosin staining) and immunohistochemical (CD31, Factor VIII, Caveolin and eNOS) examinations. Results: The CVH, NT, and EVH groups included 27 patients (mean age 67.66 ± 5.6), 31 patients (mean age 66.5 ± 7.4) and 25 patients (mean age 66 ± 5.5), respectively. Hematoxylin-eosin staining revealed a lower grade of microstructural vein damage in the NT group (2, IQR 1-2) in comparison with CVH and EVH (3, IQR 2-4), (4, IQR 2-4) respectively (p < 0.001). Immunohistochemical examination revealed a high grade of staining in the NT group compared to the CVH and EVH group (CD 31 antibody p = 0.02, FVIII, p < 0.001, Caveolin, p = 0.001, and eNOS, p = 0.003). Conclusion: The best preservation of the structural vein integrity was in the NT group, while the lowest rate of leg wound complication was in the EVH group. These facts increase the interest in developing and implementing the endoscopic no-touch technique.

Endoscopic vein harvesting: a guide for approaching difficult cases and assessing patients preoperatively

Coronary artery bypass grafting remains the most commonly performed cardiac surgical procedure worldwide. The long saphenous vein still presides as the first choice conduit as a second graft in multivessel coronary artery bypass grafting surgery. Traditionally, the long saphenous vein has been harvested with an open approach which can potentially result in significant wound complications in certain circumstances. Endoscopic vein harvesting is a minimally invasive vein harvesting technique, which requires a single 2–3 cm incision and is associated with a quicker return to normal daily activities, decreased wound complications and better quality of life in the longer term. There is a learning curve associated with endoscopic vein harvesting adoption and there are certain patient factors that can prove to be challenging when adopting an endoscopic approach. This commentary aims to provide a concise guide of certain challenging patient factors that operators may encounter during endoscopic vein harvesting, and how to approach these patients in both the preoperative and intraoperative settings. We suggest that with appropriate planning and awareness of the challenging patient factors and problematic venous anatomy that exists, the operator can consistently formulate a strategy for ensuring a successful endoscopic harvest.

Effectiveness of a game-based mobile application in educating nursing students on flushing and locking venous catheters with pre-filled saline syringes: A randomized controlled trial

AIM

This study aimed to determine the effect of a game-based mobile application on the skill levels of nursing students in respect of flushing and locking of venous catheters with pre-filled saline syringes.

BACKGROUND

In the context of the education of nursing students, a game-based mobile application was used as a motivational aid to improve nursing students' skills in flushing and locking of venous catheters.

DESIGN

A single-blind randomized controlled trial was conducted from August 2020, in a university-affiliated hospital in China.

METHODS

A total of 154 nursing students were divided randomly into two groups: a control group (n = 77) and an experimental group (n = 77). All the participants received a 30-min theoretical interpretation, 30-min demonstration, and one opportunity to practice. For the next seven days, the participants in the experimental group used a game-based mobile application as a motivational aid to practice their skills in flushing and locking of venous catheters; the control group received no additional intervention. We observed the skill performance and the incidence of errors in the procedural steps of the participants in the two groups at first and seven days later, along with the learning curve of the skills of the experimental group in respect of flushing and locking of venous catheters.

RESULTS

The final skill performance scores of the nursing students in the experimental group were higher than the average scores of the nursing students in the control group (p = 0.003); The incidence of errors in material preparation rate, hand hygiene, and flushing and locking in the experimental group were lower than that in the control group (p = 0.027, p = 0.035, p = 0.045). Analysis of the learning curve revealed that the experimental group needed an average of 11 repeat practices sessions to master the skills.

CONCLUSIONS

In the short term, the game-based mobile application was effective in improving the skills of nursing students in flushing and locking venous catheters with pre-filled saline syringes. It is an effective complement to existing training methods.

A multicentre review comparing long term outcomes of endoscopic vein harvesting versus open vein harvesting for coronary artery bypass surgery

Background

Utilisation of the Endoscopic Vein Harvesting (EVH) technique has been increasing for coronary artery bypass grafting (CABG) for the last two decades. Some surgeons remain concerned about the long-term patency of the long saphenous vein harvested endoscopically compared to traditional Open Vein Harvesting (OVH). The aim of this study was to perform a retrospective analysis of the outcomes between EVH and OVH from three UK centres with 10 years follow-up.

Methods

27,024 patients underwent CABG with long saphenous vein harvested by EVH (n=13,794) or OVH (n=13,230) in three UK centres between 2007 and 2019. Propensity modelling was used to calculate the Inverse Probability of Treatment Weights (IPTW). The primary endpoint was mortality from all causes and secondary endpoints were length of hospital stay, postoperative complications, and incidence of repeat coronary re-vascularisation for symptomatic patients. IPTW was used to balance the two intervention groups for baseline and preoperative co-morbidities.

Results

Median follow-up time was 4.54 years for EVH and 6.00 years for OVH. Death from any cause occurred in 13.8% of the EVH group versus 20.8% in the OVH group over the follow-up period. The hazard ratio of death (EVH to OVH) was 0.823 (95% CI: 0.767, 0.884). Length of hospital stay was similar between the groups (p=0.86). Post-operative pulmonary complications were more common in EVH vs OVH (14.7% vs. 12.8%, p<0.001), but repeat coronary re-vascularisation was similar between the groups.

Conclusions

This large retrospective multicentre analysis indicates that EVH has a lower risk of mortality compared with OVH during the follow-up period of the study. The observed benefits of EVH may outweigh the risks but should be considered on a case-by-case basis. We hope this review gives confidence to other cardiac centres that offering an EVH approach to conduit harvesting does not affect long term patient outcomes.

External stenting and disease progression in saphenous vein grafts two years after coronary artery bypass grafting: A multicenter randomized trial

OBJECTIVES

Little data exist regarding the potential of external stents to mitigate long-term disease progression in saphenous vein grafts. We investigated the effect of external stents on the progression of saphenous vein graft disease.

METHODS

A total of 184 patients undergoing isolated coronary artery bypass grafting, using an internal thoracic artery graft and at least 2 additional saphenous vein grafts, were enrolled in 14 European centers. One saphenous vein graft was randomized to an external stent, and 1 nonstented saphenous vein graft served as the control. The primary end point was the saphenous vein graft Fitzgibbon patency scale assessed by angiography, and the secondary end point was saphenous vein graft intimal hyperplasia assessed by intravascular ultrasound in a prespecified subgroup at 2 years.

RESULTS

Angiography was completed in 128 patients and intravascular ultrasound in the entire prespecified cohort (n = 51) at 2 years. Overall patency rates were similar between stented and nonstented saphenous vein grafts (78.3% vs 82.2%, P = .43). However, the Fitzgibbon patency scale was significantly improved in stented versus nonstented saphenous vein grafts, with Fitzgibbon patency scale I, II, and III rates of 66.7% versus 54.9%, 27.8% versus 34.3%, and 5.5% versus 10.8%, respectively (odds ratio, 2.02; P = .03). Fitzgibbon patency scale was inversely related to saphenous vein graft minimal lumen diameter, with Fitzgibbon patency scale I, II, and III saphenous vein grafts having an average minimal lumen diameter of 2.62 mm, 1.98 mm, and 1.32 mm, respectively (P < .05). Externally stented saphenous vein grafts also showed significant reductions in mean intimal hyperplasia area (22.5%; P < .001) and thickness (23.5%; P < .001).

CONCLUSIONS

Two years after coronary artery bypass grafting, external stenting improves Fitzgibbon patency scales of saphenous vein grafts and significantly reduces intimal hyperplasia area and thickness. Whether this will eventually lead to improved long-term patency is still unknown.

Intermediate-Term Outcomes of Endoscopic or Open Vein Harvesting for Coronary Artery Bypass Grafting: The REGROUP Randomized Clinical Trial

This randomized clinical trial examines intermediate-term outcomes of endoscopic vs open vein harvesting for coronary artery bypass grafting as part of the Randomized Endo-Vein Graft Perspective (REGROUP) trial.

Endoscopic vein harvesting

Coronary artery bypass grafting is the most common cardiac surgical procedure performed worldwide and the long saphenous vein the most common conduit for this. When performed as an open vein harvest (OVH), the incision on each leg can be up to 85cm long, making it the longest incision of any routine procedure. This confers a high degree of morbidity to the procedure. Endoscopic vein harvest (EVH) methods were popularised over two decades ago, demonstrating significant benefits over OVH in terms of leg wound complications including surgical site infections. They also appeared to hasten return to usual activities and wound healing and became popular particularly in North America. Subgroup analyses of two trials designed for other purposes created a period of uncertainty between 2009–2013 while the impact of endoscopic vein harvesting on vein graft patency and major adverse cardiac events was scrutinised. Large observational studies debunked the findings of increased mortality in the short-term, allowing practitioners and governing bodies to regain some confidence in the procedure. A well designed, adequately powered, randomised controlled trial published in 2019 also definitively demonstrated that there was no increase in death, myocardial infarction or repeat revascularisation with endoscopic vein harvest. Endoscopic vein harvest is a Class IIa indication in European Association of Cardio-Thoracic Surgery (EACTS) and a Class I indication in International Society of Minimally Invasive Cardiac Surgery (ISMICS) guidelines.

Prospective randomized trial of endoscopic vs open radial artery harvest for CABG: Clinical outcome, patient satisfaction, and midterm RA graft patency

BACKGROUND AND AIM

Endoscopic radial artery (RA) harvest (ERAH) is an alternative to open RA harvest (ORAH) technique. Our aim was to ascertain clinical outcomes, patent satisfaction, and 1-year angiographic patency rates after ERAH and ORAH.

PATIENTS AND METHODS

A total of 50 patients undergoing coronary artery bypass grafting were prospectively randomized to two groups. In the ERAH group (25 patients) the RA was harvested endoscopically and in the ORAH group (25 patients) openly.

RESULTS

There were not differences between the groups in preoperative characteristics. Length of skin incision was shorter in ERAH (P < .001) but there were not differences in the length of RA, harvest time, blood flow, and pulsatility index after ERAH and ORAH. Wound healing was uniformly smooth in ERAH and there were two hematomas and one infection in ORAH. Postoperatively, major neuralgias were present in five patients in ORAH and none in ERAH and minor neuralgias in 11 and 3 patients (P = .02) respectively. Twenty-four patients in ERAH and four in ORAH graded their experience as excellent (P < .001). One-year angiographic RA patency was 90% without intergroup difference. Target vessel stenosis less than 90% adversely affected RA patency (P < .0001).

CONCLUSIONS

In expert center, ERAH does not appear to have negative impact on the time harvest, the length, and quality of RA conduit, the wound healing, and the occurrence of hand and forearm complications. In addition, provides excellent cosmetic result and patient satisfaction. RA graft patency is gratifying when placed to a target coronary artery vessel with stenosis greater than 90%.

Training of Residents in Cardiac Surgery-Does It Have Impact on the Outcome?

OBJECTIVES

In many centers, training in cardiac surgery is considered to increase perioperative risk. This study aims to test whether a resident working as the main operator is a genuine risk factor.

METHODS

We analyzed patients who underwent elective isolated aortic valve replacement, elective isolated coronary artery bypass grafting, or both, in our institution, from 2008 to 2016. Redo- and off-pump surgery, ejection fraction < 30%, and other concomitant procedures were the exclusion criteria. After this selection, we included 3,077 patients in our study. Within this group, 357 (11.6%) had been operated by residents and 2,720 (88.4%) by senior surgeons. We performed propensity score matching using the nearest neighbor method with a ratio of 1:2, considering the most important preoperative conditions. In this way, the 357 patients operated by residents were matched with the 714 patients who were operated by senior surgeons. The standardized mean differences were highly reduced after matching, so both groups had similar risk profiles. We compared surgical data, postoperative adverse events, and the 30-day mortality between the two groups.

RESULTS

The times of surgery, cardiopulmonary bypass, and cross-clamp were longer if residents operated (p < 0.001). There were no differences regarding postoperative adverse events, time of mechanical ventilation, and the intensive care unit length of stay. The 30-day mortality rates of the two groups were very similar (p = 0.75, power = 0.8).

CONCLUSION

Training in cardiac surgery is safe, and carefully selected patients can be operated by residents without increased risk of perioperative mortality and complications.

Use of endoscopic vein harvesting (EVH) during coronary artery bypass grafting in United Kingdom: The EVH survey

OBJECTIVE

Endoscopic vein harvesting (EVH) is growing in popularity and is the method of choice in many centers worldwide as it is associated with lower complication rates compared to the open vein harvesting. The aim of this study was to determine the current use of EVH during coronary artery bypass grafting among cardiac surgeons in United Kingdom and identify the main concerns that limit the use of this technique.

METHODS

We developed an online survey with 16 questions about the use of EVH. An invitation to participate was sent to all the adult cardiac surgeons currently in practice in United Kingdom.

RESULTS

A total of 139 surgeons (52%) of 267 currently in practice across 48 different hospitals completed the survey. Twenty five percent of responding surgeons always use EVH while 44% use it for <10% cases. Forty eight percent of responders regard EVH as an expensive technique and 90% believe that EVH is associated with fewer leg wound issues. Seventy five percent of responding surgeons will use it for their patients due to no leg wound issues while 25% believe that the concerns about patency of EVH are genuine.

CONCLUSION

The majority of UK cardiac surgeons responding to this survey will preferentially consider EVH for obese and diabetic patients and are convinced by its beneficial impact in reducing leg wound complications. However, the reported routine use of EVH is low. Concerns about cost and patency of the endoscopically harvested vein are the possible barriers for universal adoption of EVH in the United Kingdom.

Patient Satisfaction and Clinical Complications after Endoscopic or Surgical Saphenous Vein Harvesting

BACKGROUND

Endoscopic saphenous vein harvesting (EVH) for coronary artery bypass grafting (CABG) has been developed to reduce leg wound problems. This study was undertaken to evaluate postoperative complications and patient's subjective satisfaction comparing EVH and surgical vein harvesting (SVH).

METHODS

From January to December 2017, patients undergoing elective cardiac surgery (CABG, CABG + Valve repair or replacement) underwent saphenous vein graft harvesting either by EVH (n = 136) or SVH (n = 104). Clinical follow-up was scheduled for day 7 and > 45 days after surgery. Primary end points were divided into two subgroups. The first one included postoperative extent of subjective pain and satisfaction with the cosmetic results described by the patients themselves, while the second subgroup included objective postoperative complications including wound healing disturbances, hematoma, and neuropathy. Secondary end point was length of hospital stay.

RESULTS

At 7 days follow-up, EVH patients were more satisfied with the cosmetic results than those of the SVH group (p < 0.001) and expressed a significant tendency toward lower subjective pain compared with the SVH patients (p < 0.001), exhibited significantly lower cellulitis (p-0.002), neuropathy (p-0.005), and superficial wound healing disturbance (p-0.007). During further follow-up at > 45 days, patients with EVH were still more satisfied with the cosmetic results (p < 0.001) and expressed lower subjective pain (p < 0.001), while the other objective wound parameters did not show significant differences between both groups. Mean length of hospital stay of EVH patients was 0.7 days less compared with SVH patients.

CONCLUSIONS

Our findings demonstrate the noninferiority of EVH in the short term and in the early medium term.

Randomized Trial of Endoscopic or Open Vein-Graft Harvesting for Coronary-Artery Bypass

BACKGROUND

The saphenous-vein graft is the most common conduit for coronary-artery bypass grafting (CABG). The influence of the vein-graft harvesting technique on long-term clinical outcomes has not been well characterized.

METHODS

We randomly assigned patients undergoing CABG at 16 Veterans Affairs cardiac surgery centers to either open or endoscopic vein-graft harvesting. The primary outcome was a composite of major adverse cardiac events, including death from any cause, nonfatal myocardial infarction, and repeat revascularization. Leg-wound complications were also evaluated.

RESULTS

A total of 1150 patients underwent randomization. Over a median follow-up of 2.78 years, the primary outcome occurred in 89 patients (15.5%) in the open-harvest group and 80 patients (13.9%) in the endoscopic-harvest group (hazard ratio, 1.12; 95% confidence interval [CI], 0.83 to 1.51; P=0.47). A total of 46 patients (8.0%) in the open-harvest group and 37 patients (6.4%) in the endoscopic-harvest group died (hazard ratio, 1.25; 95% CI, 0.81 to 1.92); myocardial infarctions occurred in 34 patients (5.9%) in the open-harvest group and 27 patients (4.7%) in the endoscopic-harvest group (hazard ratio, 1.27; 95% CI, 0.77 to 2.11), and revascularization occurred in 35 patients (6.1%) in the open-harvest group and 31 patients (5.4%) in the endoscopic-harvest group (hazard ratio, 1.14; 95% CI, 0.70 to 1.85). Leg-wound infections occurred in 18 patients (3.1%) in the open-harvest group and in 8 patients (1.4%) in the endoscopic-harvest group (relative risk, 2.26; 95% CI, 0.99 to 5.15).

CONCLUSIONS

Among patients undergoing CABG, we did not find a significant difference between open vein-graft harvesting and endoscopic vein-graft harvesting in the risk of major adverse cardiac events. (Funded by the Cooperative Studies Program, Office of Research and Development, Department of Veterans Affairs; REGROUP ClinicalTrials.gov number, NCT01850082 .).

Randomized Study Comparing the Effect of Carbon Dioxide Insufflation on Veins Using 2 Types of Endoscopic and Open Vein Harvesting

OBJECTIVE

The aim of the study was to assess whether the use of carbon dioxide insufflation has any impact on integrity of long saphenous vein comparing 2 types of endoscopic vein harvesting and traditional open vein harvesting.

METHODS

A total of 301 patients were prospectively randomized into 3 groups. Group 1 control arm of open vein harvesting (n = 101), group 2 closed tunnel (carbon dioxide) endoscopic vein harvesting (n = 100) and Group 3 open tunnel (carbon dioxide) endoscopic vein harvesting (open tunnel endoscopic vein harvesting) (n = 100). Each group was assessed to determine the systemic level of partial arterial carbon dioxide, end-tidal carbon dioxide, and pH. Three blood samples were obtained at baseline, 10 minutes after start of endoscopic vein harvesting, and 10 minutes after the vein was retrieved. Vein samples were taken immediately after vein harvesting without further surgical handling to measure the histological level of endothelial damage. A modified validated endothelial scoring system was used to compare the extent of endothelial stretching and detachment.

RESULTS

The level of end-tidal carbon dioxide was maintained in the open tunnel endoscopic vein harvesting and open vein harvesting groups but increased significantly in the closed tunnel endoscopic vein harvesting group (P = 0.451, P = 0.385, and P < 0.001). Interestingly, partial arterial carbon dioxide also did not differ over time in the open tunnel endoscopic vein harvesting group (P = 0.241), whereas partial arterial carbon dioxide reduced significantly over time in the open vein harvesting group (P = 0.001). A profound increase in partial arterial carbon dioxide was observed in the closed tunnel endoscopic vein harvesting group (P < 0.001). Consistent with these patterns, only the closed tunnel endoscopic vein harvesting group demonstrated a sudden drop in pH over time (P < 0.001), whereas pH remained stable for both open tunnel endoscopic vein harvesting and open vein harvesting groups (P = 0.105 and P = 0.869, respectively). Endothelial integrity was better preserved in the open vein harvesting group compared with open tunnel endoscopic vein harvesting or closed tunnel endoscopic vein harvesting groups (P = 0.012) and was not affected by changes in carbon dioxide or low pH. Significantly greater stretching of the endothelium was observed in the open tunnel endoscopic open tunnel endoscopic vein harvesting group compared with the other groups (P = 0.003).

CONCLUSIONS

This study demonstrated that the different vein harvesting techniques impact on endothelial integrity; however, this does not seem to be related to the increase in systemic absorption of carbon dioxide or to the pressurized endoscopic tunnel. The open tunnel endoscopic harvesting technique vein had more endothelial stretching compared with the closed tunnel endoscopic technique; this may be due to manual dissection of the vein. Further research is required to evaluate the long-term clinical outcome of these vein grafts.

Study Comparing Vein Integrity and Clinical Outcomes in Open Vein Harvesting and 2 Types of Endoscopic Vein Harvesting for Coronary Artery Bypass Grafting: The VICO Randomized Clinical Trial (Vein Integrity and Clinical Outcomes)

BACKGROUND

Current consensus statements maintain that endoscopic vein harvesting (EVH) should be standard care in coronary artery bypass graft surgery, but vein quality and clinical outcomes have been questioned. The VICO trial (Vein Integrity and Clinical Outcomes) was designed to assess the impact of different vein harvesting methods on vessel damage and whether this contributes to clinical outcomes after coronary artery bypass grafting.

METHODS

In this single-center, randomized clinical trial, patients undergoing coronary artery bypass grafting with an internal mammary artery and with 1 to 4 vein grafts were recruited. All veins were harvested by a single experienced practitioner. We randomly allocated 300 patients into closed tunnel CO₂ EVH (n=100), open tunnel CO₂ EVH (n=100), and traditional open vein harvesting (n=100) groups. The primary end point was endothelial integrity and muscular damage of the harvested vein. Secondary end points included clinical outcomes (major adverse cardiac events), use of healthcare resources, and impact on health status (quality-adjusted life-years).

RESULTS

The open vein harvesting group demonstrated marginally better endothelial integrity in random samples (85% versus 88% versus 93% for closed tunnel EVH, open tunnel EVH, and open vein harvesting; P<0.001). Closed tunnel EVH displayed the lowest longitudinal hypertrophy (1% versus 13.5% versus 3%; P=0.001). However, no differences in endothelial stretching were observed between groups (37% versus 37% versus 31%; P=0.62). Secondary clinical outcomes demonstrated no significant differences in composite major adverse cardiac event scores at each time point up to 48 months. The quality-adjusted life-year gain per patient was 0.11 (P<0.001) for closed tunnel EVH and 0.07 (P=0.003) for open tunnel EVH compared with open vein harvesting. The likelihood of being cost-effective, at a predefined threshold of £20 000 per quality-adjusted life-year gained, was 75% for closed tunnel EVH, 19% for open tunnel EVH, and 6% for open vein harvesting.

CONCLUSIONS

Our study demonstrates that harvesting techniques affect the integrity of different vein layers, albeit only slightly. Secondary outcomes suggest that histological findings do not directly contribute to major adverse cardiac event outcomes. Gains in health status were observed, and cost-effectiveness was better with closed tunnel EVH. High-level experience with endoscopic harvesting performed by a dedicated specialist practitioner gives optimal results comparable to those of open vein harvesting.

CLINICAL TRIAL REGISTRATION

URL: https://www.isrctn.com. International Standard Randomised Controlled Trial Registry Number: 91485426.