March 6, 2009

Rare valve procedure a first for heart team

Featured Image

Michael Petracek, M.D., left, and Steven Hoff, M.D., perform a cardiac procedure. (photo by Susan Urmy)

Rare valve procedure a first for heart team

With 37 years and 8,000 cardiac surgeries under his belt, Michael Petracek, M.D., still gets a kick out of doing a procedure for the first time.

He and colleague Steven Hoff, M.D., recently had the opportunity to collaborate on a technically challenging, rarely performed operation to bypass a diseased heart valve in a patient who was considered inoperable.

“It was fun,” Petracek said of the procedure known as apicoaortic conduit surgery.

A recent article in Circulation suggests that there are just more than 100 reported cases of this operation, the fundamentals of which have been used for years. The technique and equipment have evolved to the point where it is now a viable option to standard valve replacement in high-risk patients.

“There have not been a lot of them done across the country,” said Petracek, professor of Clinical Cardiac Surgery. “It's a unique operation for a very special subset of patients.”

Apicoaortic conduit surgery, sometimes referred to as aortic valve bypass (AVB), is reserved for patients with severe aortic stenosis, a narrowing or obstruction of the heart's aortic valve, which prevents it from opening properly and blocks the flow of blood from the left ventricle into the aorta and out to the rest of the body.

When a 77-year-old female patient who had two previous aortic valve surgeries and extreme aortic stenosis came to Vanderbilt Heart & Vascular Institute for help, Petracek knew she was an ideal candidate for AVB.

“She had severe shortness of breath, and her life expectancy was diminished because of aortic stenosis,” Petracek said.

Petracek, who specializes in valve repair and replacement, called upon Hoff, who has experience in heart transplantation and mechanical assist devices, to help him in the operating room. Both brought skills needed to ensure the success of the operation.
AVB is done through a small thoracotomy, which is less invasive than standard open heart surgery.

The surgeons used a graft conduit to bypass the diseased aortic valve to redirect blood flow out of the apex of the left ventricle and into a different location in the descending thoracic aorta.

They placed an artificial tissue valve at the midway point in the conduit, which keeps the blood flowing in one direction.

“The outflow conduit is exactly the same conduit we put in left ventricular assist device patients. Using it to bypass the aortic valve is pretty unconventional,” said Hoff, assistant professor of Cardiac Surgery.

The surgeons took the innovative approach of performing the operation off-pump, or without the aid of a heart-lung bypass machine, which decreases the risk of stroke, bleeding and infection, mobilizes the patient quicker and allows for a shorter healing time.

“It went very smoothly and the patient did quite well,” Petracek said, adding that he and Hoff hope to collaborate again soon.

“We got a great kick out of doing this operation for her,” Hoff said. “We're eager to do another one, but clearly it's for a highly select group. It's really only appropriate in a minority of patients.”