Erratum for a missing eComment 'Left ventricular rupture after mitral valve replacement: the most dreaded complication'

Abstract

Erratum for a missing eComment to ‘Preservation versus non-preservation of mitral valve apparatus during mitral valve replacement: a meta-analysis of 3835 patients’ [Interact CardioVasc Thorac Surg 2012;15:1033–1039]† The publisher regrets having failed to include the following eComment related to the article by Sa et al. [1]. We express our sincere apologies to the author of this eComment. eComment. Left ventricular rupture after mitral valve replacement: the most dreaded complication Author: Ovidio A. Garcia-Villarreal Department of Cardiac Surgery, Hospital of Cardiovascular Disease No. 34, IMSS, Monterrey, Mexico. E-mail: moc.liamtoh@vgoidivo. doi:10.1093/icvts/ivs467 © The Author 2012. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved. I have read with great interest the article by Sa et al [1]. This meta-analysis addresses a very important topic in surgery for mitral valve disease, that is, the preservation of subvalvular structures during mitral valve replacement (MVR) and its inherent consequences. As the authors note, after the analysis of 3835 patients (1918 for MVR with subvalvular preservation and 1917 for MVR with non-preservation) the odds ratio for early mortality (0.418, p <0.001), postoperative low cardiac output syndrome (0.299, p <0.001) and 5-year mortality (0.380, p <0.001) were in favour of MVR with subvalvular preservation. Unfortunately, this meta-analysis is not specific for anterior, posterior or bileaflet preservation. Many cardiac surgeons are reluctant to preserve the anterior mitral subvalvular complex due to the risk of left ventricular (LV) outflow tract obstruction. At the same time, there are no papers that conclusively prove the role of anterior subvalvular mitral structures in the concern discussed here. With regard to posterior subvalvular preservation, this is a common and easy procedure to perform in the real world. Particular care should be taken in rheumatic cases because of leaflet calcification and chordae thickening. But perhaps we have overlooked the relationship between the section of the posterior subvalvular apparatus and the LV rupture after MVR. This is a rare but dreaded and potentially lethal complication of mitral valve surgery, with an incidence of up to 1% and an associated mortality of up to 85% [2]. Treasure et al. [3] described type I and type II left ventricular ruptures as those located in the posterior atrioventricular groove, and the area overlying the papillary muscles, respectively. Type III cited by Miller et al. [4] is in an intermediate zone between the base of the papillary and the left atrioventricular sulcus, which is directly related to untethered loop hypothesis proposed by Cobbs et al. [5]. The supporting structures of the posterior LV wall form a loop. The outer portion is composed of longitudinal muscle fibres in the LV wall, and the inner portion consists of the papillary muscles with the chordae attached to the annulus of the posterior leaflet. Thus, the surgical division of the posterior leaflet chordae can seriously weaken the posterior LV wall. In rheumatic cases with advanced alteration of the valvular structures, such as chordae thickening and shortening, and leaflet thickening and calcification, preservation of the second and third order chordae tendinae of the posterior mitral leaflet may be enough to avoid this catastrophe. Conflict of interest: none declared