Response to Letter Regarding Article, “Initial Results of Posterior Leaflet Extension for Severe Type IIIb Ischemic Mitral Regurgitation”
As Dr Messas et al point out in their letter about our article,1 surgeons should attempt to restore function when addressing mitral regurgitation. The mitral valve is complex, and more than 1 cause of mitral regurgitation can be present at any one time. Carpentier’s classification was revolutionary because it was the first functional classification that truly allowed surgeons to identify and use repair techniques that would render the valve competent independently from the pathogenesis of the regurgitation.
Carpentier trained multiple surgeons and always made the point of performing a systematic segmental analysis of the entire valve. In this analysis, the valve is divided into 8 segments, for each of which the motion must be characterized as to whether it is normal or abnormal and, if the latter, whether the segment prolapsed or its motion is restricted. Moreover, sufficient expansion of the mitral annulus will produce mitral regurgitation without any abnormal motion of the leaflets. In any patient with mitral regurgitation, any 1 or more of these abnormalities may be present. The key to a good repair depends on the proper prior intraoperative characterization of each segment.
It is therefore essential that echocardiographers and surgeons view the mitral valve as an entity composed of 8 different segments and understand that the resultant regurgitation can be caused by 1 or many segments with various leaflet motion anomalies that need separate solutions to render the valve competent. For example, the most common lesion that surgeons have to correct is P2 prolapse from fibroelastic deficiency. Most people would call this type II Carpentier valve regurgitation, but one must not forget that the addition of a remodeling annuloplasty ring is essential because, although the other segments of the valve have normal leaflet motion, the annulus is almost always dilated. In fact, this valve should be identified as types I and II.
The point of our article was to describe the promising initial clinical results with a new surgical approach to the treatment of ischemic mitral regurgitation due to the combination of Carpentier I and IIIb mitral valve dysfunction: posterior leaflet extension with a patch of bovine pericardium combined with remodeling annuloplasty, each surgical element directed to the correction of a distinct and critical cause of mitral regurgitation. We believe the successful outcomes in our patients validate the conceptual and practical approach to mitral valve repair advocated by Carpentier.