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) .