Abstract 11038: Echocardiography After Resect-Plicate-Release for Obstructive Hypertrophic Cardiomyopathy
Background: Anatomic features in hypertrophic cardiomyopathy (HCM) causing LV outflow obstruction are septal hypertrophy, elongated mitral leaflets and anteriorly displaced papillary muscles. The novel Resect-Plicate-Release (RPR) operation addresses each abnormality as detected by pre-op echocardiography and direct surgical inspection. In RPR, besides the myectomy resection, horizontal plication of the anterior leaflet and release of the papillary muscles are performed as needed.
Methods: 76 pts with obstruction had echo before and 9±11 mos. after RPR repair between 2003-2013. Anterior mitral leaflet (AML) length was measured in diastole from tip to non-coronary aortic cusp. Protrusion height (PH) was measured from the coapted leaflet tip to the mitral annular plane. Residual length (RL) was non-coapted distal protruding leaflet.
Results: All 76 pts had myectomy, 49 had anterior leaflet plication, 49 had papillary muscle release, 35 had papillary muscle resection and 18 had papillary muscle thinning. Surgery abolished resting gradients. There was one out-of-hospital death. Those who had plication had longer AML than those not plicated 3.2±0.4 vs. 2.8±0.4, p<0.01 and higher PH 2.5±0.6 vs. 2.3±0.4, p<0.05. After RPR, pts who underwent plication had decreased AML, PH and RL. After RPR pts who had any papillary muscle procedure had a decrease in the mitral coaptation point to posterior wall.
Conclusion: RPR operation successfully separates the inflow and outflow portions of the LV. Decreasing the length of AML decreases its protrusion into the LV cavity, stiffens it, and decreases its slack. Papillary muscle release, resection or thinning drops the coaptation point of the mitral leaflets posteriorly, further from the flow stream. Elongated AML ≥ 3 cm should be considered for plication. At surgery, after septal resection, direct inspection of papillary muscle abnormalities that contribute to anterior displacement is recommended, with targeted release.
- © 2013 by American Heart Association, Inc.