Virtual Valve Repair
Date: October 15, 2009
Mitral valve repair has no mercy. If it doesn’t work the first time, cardiac surgeons usually have no other option but to put in a prosthetic valve. And that adds complication to existing complexity. What’s been missing is a viable way to practice the procedure to get it as close to perfection as possible.
But cardiac surgeon David Yuh believes he’s found part of that answer—virtually speaking.
For the past year, Yuh has teamed up with engineers from the Johns Hopkins Applied Physics Laboratory and Department of Biomedical Engineering to develop a better way to understand and plan these reconstructive operations.
“The mitral valve is a complex entity,” says Yuh, who compares working on the valve, which is flat and flaccid when emptied of blood, to working on a deflated parachute. “It’s like trying to cut up a parachute on the floor and then hoping it will deploy properly.”
With NIH funding, Yuh and his team have found a way to combine real-time three-dimensional transesophageal echocardiographic (TEE) imaging with computational models of the mitral valve. Until now, two-dimensional TEE imaging has dominated as the gold standard for assessing valvular dysfunction and planning for repair. Yuh explains that adding computational modeling enhances predictive value.
“Three-dimensional echocardiography allows us to more accurately describe to our patients the likelihood of repair and why,” he says.
More importantly, he notes, it helps surgeons plan more accurate repairs. The combined technology allows them to image the patient’s own mitral valve and then navigate through the repair surgery. It provides a tool for trying and testing different surgical approaches, and then viewing the outcome on a computer monitor long before entering the operating room.
Yuh is quick to point out the challenges of working on the heart in general and the mitral valve in particular. But, modeling like this is useful, and his hope is that it will become applicable to other reconstructive heart operations such as aortic root replacement and aneurysm repairs, and ventricular remodeling operations.