Right ventricular papillary muscle approximation as a novel technique of valve repair for functional tricuspid regurgitation in an ex vivo porcine model

Objectives Annuloplasty for functional tricuspid regurgitation may sometimes be ineffective because of chamber dilation and valve tethering. This study compared a novel technique, right ventricle (RV)–papillary muscle approximation, with annuloplasty in experimentally-produced tricuspid regurgitation. Methods RVs of isolated porcine hearts (n = 10) were statically pressurized, which led to RV dilation and central tricuspid regurgitation. Regurgitant flow was measured with a saline solution–filled column. The head of the anterior papillary muscle was approximated to 4 points on the ventricular septum. Next, a prosthetic ring was implanted, and then RV–papillary muscle approximation was combined. Tricuspid annular dimension, RV geometry, and tricuspid valve tethering were analyzed with 3-dimensional echocardiography. Results Tricuspid regurgitation (2270 ± 186 mL/min) was reduced by RV–papillary muscle approximation alone (214 ± 45 mL/min; P P P P P P Conclusions This ex vivo study suggests that RV–papillary muscle approximation potentially repairs tricuspid regurgitation better than annuloplasty by improving ventricular sphericity and valve tethering as well as annular dimension.