麻豆传媒

CHICAGO -- Endoscopic vein-graft harvest for coronary artery bypass grafting (CABG) did not turn out to be more dangerous than open harvest in the hands of experienced operators, the REGROUP trial confirmed.

Combined rates of death, MI, and repeat revascularization over almost 3 years were similar between the two strategies, reaching 15.5% with open harvest and 13.9% with endoscopic harvest (HR 1.12, 95% CI 0.83-1.51), according to Marco Zenati, MD, of Veterans Affairs Boston Healthcare System. Broken down, each individual component was also comparable between groups:

• Death: 8.0% vs 6.4% (HR 1.25, 95% CI 0.81-1.92)
• MI: 5.9% vs 4.7% (HR 1.27, 95% CI 0.77-2.11)
• Revascularization: 6.1% vs 5.4% (HR 1.14, 95% CI 0.70-1.85)

Results stayed the same after multivariable adjustment in the REGROUP trial, which was presented here at the American Heart Association (AHA) annual meeting and published simultaneously online in the .

Endoscopic vein harvest is meant to reduce harvest-site complications and promote better healing. It is already used in more than 90% of CABG cases in the U.S., according to the investigators.

Indeed, they found numerically fewer leg wound complications with this strategy (1.4% vs 3.1% with open harvest, RR 2.26, 95% CI 0.99-5.15). After endoscopic vein-graft harvesting, patients were also less likely to resort to antibiotic use after CABG (4.6% vs 14.4%, RR 3.15, 95% CI 2.06-4.82).

Even in the hands of expert harvesters in the trial, however, patients randomized to endoscopic harvest had a 5.6% rate of conversion to open harvesting.

In 2009, the PREVENT IV trial had suggested that endoscopic vein harvest was linked to more graft failures. "Because less experienced harvesters were allowed to participate in the trial, the quality of the conduits could have been compromised, contributing to accelerated vein-graft failure and worse clinical outcomes," Zenati's group reasoned.

Now, their REGROUP trial -- allowing only expert endoscopic vein-graft harvesters who had at least 100 cases under their belt with <5% conversion to open harvesting over more than 2 years of experience -- seems to confirm that the safety signal was really a problem of proficiency.

"The learning curve for vein-graft harvesting is steep, and proficiency is required for good outcomes. Inexperienced operators may cause unnecessary stretching and trauma to the vein graft during harvesting, leading to endothelial injury and possible early vein-graft failure," according to the authors.

"In my opinion, the best approach to vein harvesting is to have the same person do this all the time. My belief is that this should be a technician or operations room nurse with experience and not a trainee," said Steven Goldman, MD, of University of Arizona Sarver Heart Center in Tucson, who was part of the planning committee for the trial.

However, there are also studies (in both valve replacement and CABG) where there are no mortality differences whether a trainee or attending surgeon is the primary surgeon or the first assistant, he told 麻豆传媒.

"At Duke, we employ endoscopic vein harvesting for coronary bypass procedures in all patients. In our experience, almost all trainees become adept and independent with proper education and supervision. The 'learning curve' is no different than that of any surgical procedure and, with graded advancement and supervision in training, has no impact on patient outcomes," commented Peter Smith, MD, of Duke University Hospital in Durham, North Carolina.

REGROUP was conducted at 16 VA cardiac surgery centers. Patients undergoing elective or urgent (but not emergency) CABG were randomized to one of the two vein-graft harvesting modalities (n=1,150) and were followed out to a median of 2.78 years. Investigators excluded patients getting off-pump CABG and those with moderate or severe valve disease.

Groups were well-balanced at baseline. The study population was virtually all men.

Although the safety of endoscopic vein harvesting was called into question almost 10 years ago, subsequent observational studies along with this randomized trial confirm its safety and efficacy. "Endoscopic harvesting will now be considered the standard of care, unequivocally, as it is safe, reduces wound complications and is preferred by patients," according to Smith.

Zenati and colleagues have performed a "definitive trial" that says that endovascular vein-graft harvest is just as good as open harvest for the prevention of major adverse cardiovascular events, concluded AHA discussant Marc Ruel, MD, MPH, of University of Ottawa Heart Institute in Ontario.

"Is this the last trial? I think so," he stated.

As for REGROUP's weaknesses, however, "I would argue that perhaps these centers have become EVH [endovascular vein-graft harvesting] centers," Ruel commented, noting their potential loss in open harvesting proficiency. He added that the new technique of pedicled no-touch open vein-graft harvesting -- linked to better patency and improved outcomes -- was not studied in the trial.

Finally, Goldman pointed out that graft patency was not assessed by the investigators. "That is important because it will help determine if the harvesting technique altered the quality of the vein graft," he said.

Comment