When surgery requires the heart to be stopped, a heart-lung machine takes over, keeping blood flowing, adding oxygen and removing carbon dioxide. A perfusionist is the person who selects the equipment, sets it up and operates the machine.

During surgery, the perfusionist closely monitors the circulatory process and keeps the surgeon advised. Perfusionists typically work for hospitals, surgeons or independent contractors that supply their services to hospitals. They must be available to be on-call. The surgeries that require their expertise include coronary bypass, valve replacement, aortic replacement, and repairs of tears in the aorta or in a valve.

Demand ebbs and flows

With the evolution of products such as stents to open blocked arteries and decisions by some surgeons to perform bypass operations without a heart-lung machine, perfusionists aren't in as much demand. But Leonard Dolentz, a perfusionist for 27 years, believes that the aging of baby boomers and questions about the efficacy of stents may yield a renewed call for their services.

"Some of them will end up in the cath labs with stents, but a lot of them will end up in surgery," he predicts of the aging boomers.

Dolentz works for Nashville-based Hospital Clinical Services Group, which has a contract with Allina Hospitals & Clinics. One of about 25 perfusionists in the Twin Cities, he works primarily at United and St. Joseph's hospitals in St. Paul and sometimes at Abbott Northwestern in Minneapolis.

Equipment used by perfusionists has evolved over the years, as have the educational requirements to become a perfusionist. A student who wants to be certified as a perfusionist may need a bachelor's degree. Requirements for the certificate may be incorporated into a degree program or taken later.

Education options

The University of Minnesota used to offer a perfusion program, but no longer does. The Milwaukee (Wis.) School of Engineering offers an 18-24-month master's degree program in perfusion. The University of Iowa Hospitals and Clinics in Iowa City offer a 21-month certificate program. The American Board of Cardiovascular Perfusion administers the certification exam.

A recent graduate can expect to earn $60,000 to $75,000 a year, while those with 10 years' experience may earn $100,000. Perfusionists must do continuing education and work on at least 40 open-heart surgery cases a year to maintain their certificate. "It's becoming a very critical situation in smaller hospitals because perfusionists there can't get 40 cases a year," Dolentz says. "Here in the metropolitan area it's not a problem."

For more information about perfusion, visit the websites of the American Society of ExtraCorporeal Technology (www.AmSECT.org) and the American Academy of Cardiovascular Perfusion (www.TheAACP.com).

Nancy Crotti is a freelance writer who lives in St. Paul.