'On-Pump' Heart Surgery Gets High Marks
Study Prompts New Debate Over Bypass Surgery With and Without Heart-Lung Machine
Nov. 4, 2009 -- Coronary artery bypass surgery performed on a beating heart without the aid of a heart-lung machine proved no more effective than traditional bypass surgery, a study comparing the two procedures shows.
Roughly 1,000 patients treated at 18 Veterans Administration hospitals across the country received beating heart, or "off-pump" bypass surgery. A similar number received "on-pump" surgery, performed while their hearts were stopped.
The two treatment groups had similar outcomes with regard to survival and medical complications within 30 days of surgery.
But composite outcomes a year later appeared to favor the on-pump procedure; the off-pump surgery offered no advantage in terms of neurological outcomes, such as memory loss and concentration.
The study appears in the Nov. 5 issue of TheNew England Journal of Medicine.
These days, about one in five coronary artery bypass graft (CABG) patients in the U.S. get the off-pump surgery.
Cardiovascular surgeon and study co-researcher Frederick Grover, MD, of the University of Colorado, Denver, tells WebMD that he doesn't expect this number to drop drastically as a result of the findings.
"I would expect surgeons who are expert at performing the [off-pump] procedure and who are getting excellent results to keep doing it," he says. "But I imagine that at some institutions, fewer of them will be done."
Beating Heart Bypass
First performed a little over a decade ago, the beating-heart CABG procedure became popular because it was widely believed to be associated with fewer postsurgical physical and cognitive complications.
With CABG, a blockage or area of severe narrowing in a coronary artery is bypassed with a piece of vein or artery called a graft. The graft is connected above and below the blocked area so that blood flow is restored.
Usually patients needing bypass surgery will have more than one blood vessel that requires a graft. The process of re-establishing blood flow in blocked or severely narrowed vessels is referred to as revascularization.
Bypass has been linked to complications such as memory loss, muddled thinking, and concentration problems lasting weeks to months after surgery. Placement on a heart-lung machine has been implicated, but not proven, as a possible contributor to this cognitive impairment.