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.