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Harvesting vein grafts endoscopically during coronary artery bypass graft (CABG) surgery, rather than with an open procedure, did not increase the risk of death or other adverse cardiac outcomes, researchers found.

Comparing the two forms of vein-grafting showed they were not significantly different from each other with regard to risks of long-term mortality (P>0.99) or composite death, myocardial infarction, or revascularization (P=0.34), according to Peter Smith, MD, of Duke University Medical Center, and colleagues.

The study also found that patients receiving endoscopic vein-graft harvest had significantly fewer harvest-site wound complications than those receiving open vein-graft harvest, at an adjusted hazard ratio of 0.83 (95% CI 0.77 to 0.89, P<0.001), Smith and co-authors wrote in the Aug. 1 issue of the Journal of the American Medical Association.

Although most CABG surgeries in the U.S. today use endoscopic vein-graft harvest because of perceived advantages to the patient, an observational study of the issue was requested by the FDA in response to a 2009 study of 3,000 patients by Lopes and colleagues.

The Lopes study "raised the concern that, compared with open vein-graft harvesting, endoscopic harvesting was associated with a 50% increase in mortality and a composite 22% increase in death, myocardial infarction, and revascularization" after 3 years of follow-up, wrote Lawrence Dacey, MD, of Dartmouth-Hitchcock Medical Center in Lebanon, N.H., in a related editorial.

The present study enrolled 235,394 Medicare patients undergoing CABG at 934 surgical sites across the U.S. from 2003 to 2008. Over half (52%) received endoscopic vein-graft harvesting, while the rest received open vein-graft harvesting. Patients were followed for a median of 3 years.

Outcomes included all-cause mortality, wound complications, and the composite of death, MI, and revascularization. Wound complication was defined as having one or more of the following:

• Opened wound with excision of tissue
• Positive culture
• Treated with antibiotics
• Complication developing within the first postoperative month and after hospital discharge
• Systemic sepsis within the first postoperative month and after discharge

Patient characteristics were mostly balanced at baseline between the endoscopic and open procedure groups, including:

• Age: mean of 74 for both groups
• BMI: 28.5 in the endoscopic group versus 28.4 in the open-harvest group
• Prevalence of peripheral vascular disease: 17.9% versus 18.0%, respectively
• Active smoking: 13.9% versus 13.5%
• Diabetes mellitus requiring insulin: 10.1% versus 9.9%
• Urgent procedure status: 48.9% versus 49.2%

Year of surgery was imbalanced, with more open procedures performed in 2003 (9% of the entire study's endoscopic procedures were done that year, versus 24% of the open procedures), but the balance was tipped the other way by 2008 (21% versus 11%).

The risk-adjusted hazard ratios for endoscopic versus open vein-graft harvesting were not significant for long-term mortality (1.00, 95% CI 0.97 to 1.04, P>0.99) and composite of death, MI, or revascularization (1.0, 95% CI 0.98 to 1.05, P=0.34).

Rates of wound complications were significantly lower with endoscopic versus open vein-graft harvesting, with 3% of endoscopic treatments developing a wound complication within 30 days of surgery compared with 3.6% of open procedures (adjusted HR 0.83, 95% CI 0.77 to 0.89, P<0.001).

The results of the study were "more definitive than prior studies," Dacey wrote, particularly due to the "sheer size and statistical power," as well as the "more accurate picture of contemporary CABG surgery in the U.S. because it includes so many diverse sites with widely varying practice styles."

He added, "Patient satisfaction is markedly better with endoscopic vein-graft harvesting. Patients who have had both ... marvel at the difference in reduced pain and time of healing with endoscopic vein-graft harvesting."

The authors noted that their research was limited by inconsistent technique between surgeries, median follow-up of 3 years, no direct clinical identification of endoscopic treatment prior to 2008, and potential misclassification of endoscopic treatment through use of billing to identify endoscopic vein-graft harvesting prior to 2008.

From the American Heart Association:

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