Preservation of the mitral valve apparatus: evidence synthesis and critical reappraisal of surgical techniques

Abstract

Sub-valvular apparatus preservation after mitral valve replacement is not a new concept, yet to date there has been no quantification of its clinical effectiveness as a procedure and no consensus as to which surgical preservation technique should be adopted to achieve the best immediate and midterm clinical outcomes. This systematic review of current available literature aims to use an evidence synthesis and meta-analytic approach to compare outcomes following replacement of the mitral valve with (MVR-P) or without preservation (MVR-NP) of its apparatus. It considers all the relevant anatomical, experimental, echocardiographic, and clinical studies published in the literature and appraises all reported mitral valve sub-valvular apparatus preservation techniques. The results of this review strongly suggest that MVR-P is superior to MVR-NP with regards to the incidence of early postoperative low-cardiac output requiring inotropic support, and early or mid-term survival. They also suggest that the operative decision should be individualised based on patient's anatomy, pathology and ventricular function and therefore surgeons should be familiar with more than one surgical preservation technique. Finally, this paper highlights the need for further high quality research focusing particularly on the long-term assessment of quality of life and health utility following MVR-P.

MitraClip for severe symptomatic mitral regurgitation in patients at high surgical risk

“…In fact, differing surgical approaches using right thoracotomy or minimally invasive approach for MVS have been shown to improve safety and efficacy endpoints [47]. MVR has been advocated over MVRP, but routine sparing of the sub-valvular apparatus has resulted in reproducible reductions in operative mortality after MVRP [48]. Many patient groups do not appear to benefit from MVR over MVRP, particularly patients with a greater burden of comorbidities [49,50].…”

Papillary Muscle Repositioning as a Subvalvular Apparatus Preservation Technique in Mitral Stenosis Patients with Normal Left Ventricular Systolic Function

“…16,24 In an experimental study, Hansen and associates 25 proposed that the apparatus of the anterior leaf let is more important than that of the posterior leaf let; however, another experimental study found no substantial difference between anterior and posterior chordal-sparing techniques. 8 Athanasiou and coauthors 26 published a meta-analysis that compared the outcomes of MVR with and without subvalvular-apparatus preservation (1,603 patients and 1,330 patients, respectively). This analysis suggested that preservation is superior to nonpreservation in regard to the perioperative mortality rate and the 1-and 5-year survival rates; further, it found no significant difference, in any of the outcomes of interest, between bileaflet and posterior leaflet preservation groups.…”

“…13,16 Use of a preservation technique that is simple, reproducible, and appropriate for the patient's individual anatomy, pathologic condition, and LV function is paramount. 26 Therefore, patients with a severely diseased subvalvular apparatus could benefit from decalcification of valve tissue, 27,28 use of artificial chordae, 13 or PMR. Chordal-sparing MVR (by use of artificial chordate) can be performed regardless of the severity of the subvalvular disease; however, determination of the optimal length of the artificial chordae is an important aspect of this technique.…”

Features of rheumatic mitral valves and a grading system to identify suitable repair cases in China

“…This may eventually lead to arrhythmias such as atrial fibrillation, or heart failure, where the heart is unable to pump enough blood to meet the body's needs (12). Considering its many advantages such as subvalvular apparatus preservation, protection of left ventricular systolic function (13,14), and avoiding risks of thromboembolism and bleeding resulting from warfarin (15,16), MVP has been acknowledged to be superior to replacement (15,(17)(18)(19). Several cardiac centres in Asian countries have performed rMVP for decades (20), and have gained a considerable amount of experience (3,4).…”