Cardiac surgeons typically repair rather than replace failing mitral valves. The reason stems from the difficulty of completing such a technique and an initial resistance from the medical community to focus on repair.

But med-tech giant Medtronic (Minneapolis) is offering a solution that it says will significantly reduce the difficulty of valve repair and lead to more repair procedures in the future.

Earlier this week, the company reported the launch of this solution, the Profile 3-D Annuloplasty Ring, which is used to repair failing mitral valves. The device was given FDA approval in mid-March, the company said. CE-mark approval is pending.

Part of the easiness stems from the design of the surgically implanted device, which is based on the geometry of human mitral annulus. The annulus is a ring-like tissue on the heart valve where the leaflets of the valve are anchored.

"It's saddle-shaped," Daniel Beach, a spokesman for Medtronic, told Medical Device Daily. "By mimicking the natural shape of the annulus, it allows for the seamless repair of the heart valve. When it was designed it was designed to mimic the physiology of the annulus. The saddle shape has a strong mechanical benefit. Specifically, leaflet stress can be related to saddle height, which could change long-term durability of the repair."

When functioning normally, the dome-shaped mitral valve controls blood flow from the lungs, closing tightly under the pressure of freshly oxygenated blood when the heart contracts, then opening when the heart relaxes. Blood then flows into the left ventricle, the heart's main pumping chamber, where it is pumped throughout the body's circulatory system with the next heartbeat. Fatigue and shortness of breath are common symptoms of mitral valve insufficiency.

During mitral valve repair, the surgeon seeks to restore, or "remodel" a narrowed, prolapsed or leaking valve to a more-normal shape and leaflet alignment, thus restoring its functionality.

To do this, the device is placed around the valve to bring the leaflets into contact with each other.

"We're seeking to ensure that patients receive the best possible treatment," said Michael Acker, MD, chief of the cardiac surgery division of the Hospitals of the University of Pennsylvania (Philadelphia).

"Mitral valve repair has been found to be superior to valve replacement in the majority of patients but we're a long way from ensuring that all surgeons have the skills and experience necessary to perform these repairs," he said. "A physiologically-designed advance like the Profile 3-D Ring holds instinctive appeal for cardiac surgeons, driving interest in mitral repair as an essential skill and ultimately helping ensure that more patients benefit from the most appropriate procedure."

Twenty patients at six clinical sites have had the device implanted.

The attitude toward repair over replace is gradually changing with more surgeons opting to repair damaged or degenerated mitral valves rather than replacing them with prosthetic devices.

In a July 2005 report, Health Research International estimated the growth of mitral valve repair in the U.S. at a combined annual growth rate of 8.6% and estimated that 36,400 mitral repair procedures would take place this year, accounting for about 40% of mitral valve procedures.

Revised guidelines for the management of patients with valvular heart disease, published by the American College of Cardiology (Washington) and the American Heart Association (AHA; Dallas) in 2006, advised, "When possible, (mitral valve) repair is the treatment of choice for degenerative valve disease" because patients whose heart rhythm is normal do not need strong anticoagulant medication, the risk of clots or infection is low, functionality is good, ventricular function is unaffected, and "the long-term survival rate is favorable compared with mitral valve replacement." The guidelines followed publication of earlier studies supporting mitral valve repair in which it was credited for shorter hospital stays and lowered mortality rates.

However, Medtronic isn't the only company to have a device geared toward in mitral valve repair.

The Sorin Group (Milan, Italy), received FDA approval for its MEMO 3D Semirigid Annuloplasty Ring late last year.

"Due to its innovative core structure, the MEMO 3-D ring restores the natural mitral annulus' 3-D motility during the cardiac cycle" said Franco Vallana, chief scientific officer for Sorin, in a press release. "Mitral valve repair has become the therapy of choice for mitral valve disease and we believe that the MEMO 3-D provides a unique solution for surgeons worldwide."

According to the AHA's 2006 Statistical Update, 95,000 persons underwent heart valve surgery in U.S. hospitals during 2003.