Following the exposure of the mitral valve, the entire mitral valve apparatus is carefully examined. A detailed surgical valve analysis is performed to determine the functional type and the segmental localization. Valvular analysis will enable the surgeon to establish a comprehensive inventory of the lesions and the operative road map.
The presence of endocardial thickening or jet lesions is assessed. Jet lesions indicate a leaflet prolapse opposite to the side of the jet or a restricted leaflet motion on the side of the jet. The mitral valve annulus is examined to detect any annular dilatation and to assess its severity. The presence and the extent of annular calcification is carefully noted.
Mitral valve leaflets are examined using two nerve hooks to proceed to a functional analysis of all valvular segments. Leaflets motion is assessed using Carpentier's reference point technique. The free edge of P1 commonly serves as the reference point, as this segment is rarely affected by abnormal leaflet motion. This finding is particularly verifiable in patients with degenerative mitral valve disease. In this scenario, we first confirm the normal leaflet motion of P1 by pulling its free edge upward with a nerve hook. The free edge of P1 segment should not be prolapsing (it should not override the plane of the mitral annulus) nor be restricted. Using a second hook, other valve segments are examined in a systematic manner and compared to P1 to verify if they present with any abnormal leaflet motion. In the setting of type II dysfunction, the free edge of the prolapsing segment would be higher in the left atrium compared to the free edge of P1. In type III dysfunction, the mobility of the affected segment would be significantly reduced compared to P1. It is important to emphasize that type III dysfunction often affects all three segments of the posterior leaflet. Therefore, during intraoperative valve analysis the surgeon should compare the mobility of the posterior leaflet to that of the anterior leaflet. Echocardiographic valve analysis is of critical importance in patients with type III dysfunction.
The video shown below, with the voice of Professor Alain Carpentier, demonstrates surgical valve analysis applying the reference point technique in a patient with degenerative mitral valve disease.