Intraoperative Application
The presence of IMR has a negative impact on survival rate, and there is
a significantly graded relationship between IMR severity and reduced
survival. The use of undersized ring annuloplasty for MV repair has
become the preferred treatment strategy for
IMR[48,49]. Although general consensus has been
reached on coronary artery bypass grafting (CABG) and MV surgery for
patients with severe MR, clinical dilemma exists in patients with mild
to moderate MR[50]. Govindan Set al.reported that there was no significant change in the MV nonplanarity
angle in patients with mild or moderate IMR who underwent
revascularization alone when they received 2D, 3D TEE and MV assessment
before and immediately after the CABG (n=20)[51].
These patients who undergo CABG surgery alone may leave them with
obvious residual disease, while the inclusion of MV surgery in the CABG
surgery will increase the perioperative risks[52].
A growing body of literature indicates an unacceptably high risk of
persistent or recurrent IMR after reduction
annuloplasty[7,53]; however, in patients without
recurrent IMR, MV repair may be more beneficial than valve replacement,
especially in terms of LV remodeling and function. Reduction
annuloplasty is an effective treatment for annular dilatation, but it
can make the posterior leaflet move forward and intensify the leaflet
tethering[54,55]. Vergnat Met al. had made
comparisons of 3D TEE data before and after a flat (n=9) or a saddle
annuloplasty (n=9) was implanted in patients with severe IMR. They found
that the shape of the ring affects
the curvature of the leaflet.
Implantation of a saddle ring kept
annular nonplanarity and showed higher 3D leaflet curvature across the
MV surface, whereas flat rings reduced annular nonplanarity and
flattened leaflet significantly in all but the P1
region[56]. This strongly demonstrates that an
imaging strategy that can reliably determine the risk of annuloplasty
failure and predict recurrence preoperatively would be considered during
surgical decision-making, so as to improve the surgical results.