Mayo Magazine

The Beat Goes On and On
A Less Invasive Way to Repair the Heart's Mitral Valve

Likened to a parachute, the mitral valve has tendons called chordae, which are attached to the heart muscle. If one of the chordae breaks, the valve will not close properly, making the heart pump less efficiently.

A mitral-valve repair replaces the broken chordae. Now, thanks to a new method and a new surgical instrument, this repair can be done without opening the heart, making the procedure less invasive.

Mitral valve leaflet with the artificial chordae in place

Some say it comes from experience, others say certain people are born with it. Either way, Richard C. Daly, M.D., and Giovanni Speziali, M.D., have it — a passion for innovation. These cardiac surgeons join a long legacy of Mayo physician-inventors ensuring that the "beat goes on" for patient care innovation at Mayo Clinic.

Their idea started in early 2000 when Dr. Speziali, who's now at the University of Pittsburgh Medical Center, came to Mayo Clinic to study surgical procedures. "Dr. Speziali had the idea of designing a surgical instrument that could improve heart surgery — specifically the method of performing mitral-valve repair," says Dr. Daly.

A mitral-valve repair is a procedure to fix the heart's valve rather than replace it with a mechanical or tissue valve. The mitral valve is the "inflow valve" for the main pumping chamber of the heart — the left ventricle. Blood flows from the lungs, across the open mitral valve, into the left ventricle. When the heart squeezes, the two leaflets of the mitral valve close to prevent the blood from going backward (to the lungs) and to direct the blood out of the heart (to the body).

Sometimes likened to a parachute, a mitral valve has "strings" or tendons called chordae, which are attached to the heart muscle. If one of the chordae breaks, the valve will flip back on itself and will not close completely. The heart, therefore, does not pump efficiently. A mitral-valve repair fixes or replaces the broken chordae and adjusts the valve to close properly.

"Closed" Heart Surgery

It was Dr. Speziali's idea to develop a surgical instrument to repair the mitral valve by placing sutures inside the closed heart. "Traditionally we have had to put the patient on bypass, open the heart, place the sutures down in the heart muscles and estimate how long to leave those sutures that act as artificial chordae," says Dr. Daly. "With this innovative instrument, we do not have to open the heart. Instead, we go through the heart at the apex, or point, and use the instrument to place the suture to the valve leaflet. Using echo guidance, we then adjust the new chordae length to be just right," he says.

"The instrument facilitates the current surgical procedure because it can be used on a beating heart. The suturing technology of the instrument inside the heart is revolutionary. It allows us to think of cardiac surgery in a different way," says Dr. Daly. "We believe this instrument and method have potential to initiate a platform of instruments that will move cardiac surgery toward minimally invasive surgery."

With a small amount of funding from Mayo Clinic's Division of Cardiovascular Surgery, Drs. Daly and Speziali, along with echocardiographer Charles J. Bruce, M.D., and anesthesiologist Mark H. Ereth, M.D., took a model of the instrument to the Division of Engineering at Mayo Clinic. Kevin Bennet, chair of the division, describes this area as a "one-of-a-kind resource with the charge of providing clinicians and researchers with innovative devices to help Mayo provide the best care for patients." Drs. Daly and Speziali were paired with engineers and technicians from the division: Steve Corner, Steve Deick, Shaun Herring and Ray Phelps. This team took the initial ideas generated by the cardiac surgeons, refined those ideas through several prototypes and developed the instrument envisioned by the cardiac surgeons.

Lab testing was the next necessary step. Cardiac surgeons needed lab time to further understand the usefulness of the instrument and become skilled in using it. This is an expensive step, so Drs. Daly and Speziali approached industry to request funding. Not unexpectedly, the funding proposal was turned down. Because the path from idea to safe patient application is long, industry commonly rejects funding at this phase of innovation. It can take up to two decades of research and refinement before an idea can safely be put into routine clinical practice. That's why many innovations never make it off the drawing board. The mitral-valve repair instrument might have met that same fate if not for a helping hand from inside Mayo Clinic.

Bankrolling Innovation

In 2005, Mayo Clinic established a fund to support translation of Mayo innovation in research, practice and education to patient care. The fund applies institutional and philanthropic money to support discoveries of Mayo Clinic investigators in an effort to improve patient care. The fund is separate from Mayo's core research budget. It's designed to support projects that will enhance clinical practice and generate revenue through licensing and commercial opportunities. Income generated is reinvested in the fund and supplemented by philanthropic sources to become a self-sustaining means of financial support for future innovations.

Last year, four projects were funded from a pool of 72 applications. Dr. Daly and his colleagues received one of these awards for the mitral-valve repair instrument. Bolstered by the funding award, they successfully completed many animal trials and have recently performed the first successful surgery on a human patient.

At Mayo Clinic, it's common practice for diverse professionals to work together toward a common goal. In this collaborative environment, ideas cross-fertilize, enthusiasm builds and breakthrough advances happen. Still, even in this system, translating new ideas into practical improvements in patient care is one of the most challenging phases of the research process.