Excess height (figure1 α 2)
Excess height is the most common lesion of P2 and sometimes of P1 and P3. In a normal Mitral Valve (MV), P2 is only slightly higher than P1 and P3, if not at the same height. The excess height going along with billowing is the result of the pathological process. The good closure line should not be in the middle of the mitral orifice but divided at 2/3 for the anterior leaflet and 1/3 for the posterior leaflet, if not 3/4 and 1/4, and it should be regular. To achieve these goals, one has to reduce P2 height. The aim is to reduce the height by performing a resection of P2. Resection location takes place at the level of the pathological process, either at the free edge when chordae are ruptured or elongated, or at the annular level in case of billowing without prolapse or in case of annular calcification . Resection can be of various shapes: it can be triangular; it can be at the free edge transversally; it can follow a resection close to the annulus at the hinge of the leaflet which is then reattached after a regular or an irregular resection creating a sort of sliding plasty, or it can be very symmetrical using a resection and a double sliding such as in the “butterfly technique”. By doing a transverse resection (wrongly called “hair cut technique” [2] ), only the excess height is being addressed. Some techniques, such as the sliding plasties or the butterfly technique [3] , can address both the excess height and some excess width at the same time. Similarly, the triangular resection may, in limited and favorable pathologies, take care of both the excess height and the excess width.
If the free edge does not show any pathological process (no prolapse, no elongated or ruptured chordae but most often in such instances a billowing of P2), we then address the issue of leaflet height by reducing it at the annular level. We detach the leaflet from the annulus, resect some leaflet tissue and re attach the leaflet to the annulus without any transverse displacement. This is what we call a “false sliding”. We also use this maneuver in case of a pathological process at the annular level such as a calcified annulus which requires decalcification (Figure 2) .