Evolving concepts and technologies in mitral valve repair.

Over the past few decades, it has become apparent that mitral valve repair is preferable to mitral valve replacement for the majority of patients undergoing surgery for mitral regurgitation (MR). The advantages of mitral valve repair include low rates of thromboembolism, resistance to endocarditis, excellent late durability reported for as long as 25 years, and no need for anticoagulation in the majority of patients.1–5 Because of these advantages of repair over replacement, the threshold for performing mitral valve repair has been lowered to include patients with MR who have early symptoms or even those who are asymptomatic, assuming that the chance of successful repair is 90% according to the latest American College of Cardiology/American Heart Association guidelines.6,7 Recently, surgeons have evaluated new techniques to further improve mitral valve repair, and cardiologists and surgeons are increasingly interested in the potential for percutaneous approaches to mitral valve repair.8 Myxomatous MR affects 1% to 2% of the population and therefore is a common pathology for mitral valve surgery, but the complexity of the operation may be difficult, which leads to generally low rates of repair. In a recent review, only 44.3% of patients in the United States who required mitral valve surgery for MR received a mitral valve repair,9 and in the Euro Heart Survey, repair rates were similarly low (46.5%).10 The goals of mitral repair are to maintain leaflet mobility, remodel the annulus, and allow normal coaptation of the anterior and posterior leaflets. Recent advances in techniques and new concepts for mitral repair are important to cardiologists and other clinicians interested in the management of patients with mitral valve disease. Accordingly, an improved understanding of these concepts will aid in the development of innovative techniques to create safe, durable, reliable, and reproducible mitral valve repair techniques, both by open and by less invasive surgical methods. Many of these concepts may be applicable with novel percutaneous approaches.11–14 We aim to clarify these concepts and techniques in this review.