Discussion
The cause of IMR is the remodeling of the left ventricle (LV), a change
in the LV from an oval to a spherical shape, and the subsequent
displacement of the papillary muscles, causing leaflet tethering and
coaptation mismatch without structural valve lesions.2Therefore, additional subvalvular or ventricular procedures are needed
to treat IMR.
Liel-Cohen et al.3 reported that the plication of the
sheep’s LV infero-posterior wall in an MI site shortens the distance
between both the papillary muscle and annular and bilateral papillary
muscles, leading to reduced tethering. Matsui et al.4reported integrated overlapping ventriculoplasty combined with papillary
muscle plication using 3 stitches with small felt strips to plicate the
bilateral papillary muscle. According to these reports, plication of
both the LV infarction site and papillary muscle is a useful method for
IMR surgery. However, these methods require left ventriculotomy. The
Surgical Treatment for Ischemic Heart Failure trial5showed that LV plasty with left ventriculotomy for IMR did not improve
patients’ prognosis. Moreover, LV plasty with left ventriculotomy poses
a risk of postoperative bleeding, dangerous arrhythmia, and cutting the
normal myocardium, causing cardiac dysfunction.
We have performed LVPWP through a left atriotomy over the MV without
left ventriculotomy for many cases with IMR, and the long-term outcomes
have been relatively favorable. The plication site is ususally
determined through preoperative echocardiography, which helps visualize
the site of wall thinning and hypokinesis. The trabeculae carneae are
then sutured with a horizontal mattress to lightly plicate only the
endocardial side. We think performing LVPWP changes the LV from a
spherical to an oval shape, restores the position of papillary muscles,
improves leaflet tethering, and prevents further LV remodeling.
Additionally, this method is advantageous in terms of anatomical
limitation and postoperative cardiac expandability compared to LV plasty
with left ventriculotomy.
In the present case, our approach improved leaflet tethering and
prevented further LV remodeling, enabling the patient to be off
mechanical support and a respiratory ventilator. MR was controlled to a
trivial level and no heart failure symptoms recurred.