Reconstructive operations on subvalvular structures of the mitral valve during remodelling of the left ventricle. Papillary muscle interventions

The optimal treatment strategy for secondary mitral regurgitation of type IIIb (A. Carpentier classification) remains debatable. The use of a standard surgical technique for treating secondary mitral regurgitation and undersized ring annuloplasty demonstrates suboptimal results in several patients (about 30% of the patients exhibit postoperative hemodynamically significant mitral regurgitation with the absence of effective reverse remodelling of the left ventricle). Such suboptimal results are associated with the unification of only the mitral valve reconstruction technique, irrespective of the state of the left ventricle (degree of dysfunction, dilatation, tethering/tenting, and papillary muscle displacement); this is not entirely justified because of the disease complexity (valve and ventricular), and it is crucial to influence both the components of the disease. Particularly, modern researchers are inclined toward the need of using additional reconstructive interventions on the subvalvular structures that contribute to a more effective reverse remodelling of the left ventricle. Here, we present a review of recent studies on the surgical treatment of functional mitral insufficiency of type IIIb (A. Carpentier classification) with effects on the subvalvular structures (pupillary muscle relocation and approximation). Revised 19 April 2020. Revised 5 May 2020. Accepted 28 May 2020. Funding: The study did not have sponsorship. Conflict of interest: Authors declare no conflict of interest.