'Debate closed': JAMA study finds endoscopic vein harvesting safe
The findings were published in the Aug. 1 issue of the Journal of the American Medical Association.
Smith, chief of cardiovascular and thoracic surgery at Duke University Medical Center in Durham, N.C., and colleagues conducted the analysis at the request of the FDA. The agency sought to clarify the long-term safety of the endoscopic method after a 2009 study concluded that patients who received the endoscopic procedure had a higher three-year mortality than those receiving the open vein-graft harvesting technique (N Engl J Med 2009;361:235-244).
A subsequent study countered that the endoscopic method was safe (Circulation 2011;123:147-153). Both studies were hampered by sampling sizes that could not adequately tackle the question of mortality.
Smith et al assessed the use of the endoscopic vein-graft harvesting technique in CABG surgery and the risk of death, heart attack and repeat revascularization. They included 235,394 Medicare patients undergoing isolated CABG surgery between 2003 and 2008 at 934 surgical centers participating in the Society of Thoracic Surgeons (STS) national database. The STS records were linked to Medicare files to allow longitudinal assessment (median three-year follow-up) through Dec. 31, 2008.
Based on Medicare Part B coding, 52 percent of patients received endoscopic vein-graft harvesting during CABG surgery. The researchers found no significant differences between the cumulative incidence rate for mortality through three years for the endoscopic (13.2 percent) and open (13.4 percent) vein-graft harvest groups. There were also no significant differences between the cumulative incidence through three years for the composite of death, heart attack or revascularization among the endoscopic vs. open vein-graft harvest groups (19.5 percent vs. 19.7 percent).
Endoscopic vein-graft harvesting was associated with lower harvest site wound complications relative to open vein-graft harvesting (3 percent vs. 3.6 percent). The wound complications results were in keeping with previous randomized comparison studies.
The findings likely will allay safety concerns from patients, providers and payers. For instance, the 2009 findings prompted the U.K.’s the National Institute for Health and Clinical Excellence to recommend endoscopic vein-graft harvesting only be used “with special arrangements,” according to the authors.
“Any agency that restricted its use will probably rethink its position,” Smith said. “Patients who have had endoscopic vein harvesting already performed—which are hundreds of thousands of patients—will be reassured, and patients and physicians will now be able to make a decision regarding the type of vein harvest without concern about any mortality hazard or differential.”
The analysis found that the endoscopic procedure was used in 70 percent of the CABG cases in 2008. In an accompanying editorial, Lawrence J. Dacey, MD, of the Dartmouth-Hitchcock Medical Center in Lebanon, N.H., wrote that Smith et al presented a more contemporary view for CABG surgery.
“Physician assistants typically perform vein harvesting in CABG surgery procedures,” Dacey wrote. “As more centers have adopted endoscopic vein-graft harvesting, the skill at performing open vein-graft harvesting has diminished. Indeed, many recent physician assistant graduates have no experience at open harvest and can only harvest veins endoscopically. Thus, endoscopic vein graft harvesting will become even more dominant in the future.”
Dacey praised the work by Smith et al for providing evidence that the short-term benefits of endoscopic vein-graft harvesting such as greater comfort and faster healing times are not negated by an increased risk of adverse long-term outcomes. “And that is something to be thankful for,” he concluded.
Smith added that the methodology shows a pathway for researchers to tap STS and federal resources for post-marketing surveillance on devices and possibly drugs. But he said the impact on patients provides the greatest gratification. “The thing that is most pleasing to me is that patients who already had this procedure don’t need to worry anymore,” he said.
The study authors listed some limitations with their observational study. The data did not let them assess factors such as the experience of the harvester or specifics about techniques or devices. Nor could they discern if a surgeon switched from an endoscopic harvest to an open harvest during a procedure.
Smith pointed to the size and comprehensiveness of the study as a major strength. “It is completely generalizable,” he said. “It is highly unlikely if this were replicated that a different result would occur. Short of an impractical randomized trial, this is close as we will get to ‘the truth.’”