Die perkutane Mitralklappenintervention bei Mitralklappeninsuffizienz – eine Alternative zur konventionellen Herzchirurgie?

Abstract

Standard therapy of advanced mitral valve regurgitation currently consists of mitral valve reconstruction through heart surgery including heart-lung machine employment. Typically, a ring is implanted and a leaflet reduced, if necessary, to approximate the posterior and anterior mitral valve leaflets to each other. Because of high comorbidity among this patient population, new and less burdening catheter-based techniques have been developed. Clinical etiology of mitral valve regurgitation is divided into two categories: "structural" versus "functional". The MONARC system of the Edwards Lifesciences company consists of three components--distal stent, bridge with bioabsorbing coating, proximal stent--and is implanted into the coronary sinus. The underlying principle is an indirect annuloplasty of the mitral valve annulus resulting from resorption of the bridge coating and leading to a reduction and indirect tightening of the mitral valve annulus. The EVOLUTION I (EV I) study in patients suffering from functional mitral regurgitation to a degree between 2+ and 4+ revealed--12 months after the MONARC implantation--a mitral valve regurgitation reduction from 2.48 to 1.78. The EV I study found interaction of the foreshortening bridge with the coronary arteries in some patients. This problem is most widely excluded by previous computed tomographic or angiographic examinations in the ongoing follow-up study EV II. Direct annuloplasty is made possible in case of functional mitral regurgitation by using the Mitralign Percutaneous Annuloplasty System (MPAS) of the Mitralign company. In doing so, an improved coadaptation of the mitral valve leaflet is achieved by inserting three sutures into the posterior mitral valve annulus and subsequent plicating.The MitraClip of the Evalve company uses the principle of the edge-to-edge technique. In doing so, the posterior and anterior leaflets are joined by implanting a clip, resulting in a reduction of mitral regurgitation with two diastolic orifices. In contrast to strukthe other two procedures, the MitraClip can be used for both functional and structural mitral valve regurgitation. The EVEREST I study and the EVEREST II study, as far as it has already been published, show that this procedure is secure and its results are very positive. The previous results of all three procedures show that catheter-based techniques for treating high-risk patients suffering from mitral valve regurgitation arrive at positive results in part, so that possibly a real alternative to conventional heart surgery will be available in the future.