Impact of Subvalvular Procedure for Ischemic Mitral Regurgitation on Leaflet Configuration, Mobility, and Recurrence

Abstract

schemic mitral regurgitation (IMR) is currently believed to mostly originate not from leaflet pathology but rather from problems with the subvalvular apparatus, including the left ventricle. Mitral annuloplasty (MAP) using an undersized ring represents the gold standard for IMR, with favorable early and intermediate postoperative outcomes. 1 However, it is still controversial whether MAP alone is enough to control mitral regurgitation (MR) at late follow-up, because of progressive left ventricular (LV) dilatation and displacement of the subvalvular apparatus. [2][3][4] In contrast to MAP, which mainly increases the coaptation zone and reduces MR at the annular level, subvalvular procedures are an etiology-based strategy to correct the subvalvular anatomical changes in IMR and thus reduce the tethering force on the mitral leaflets. Subvalvular procedures are roughly classified by their target site of the pathological subvalvular apparatus: chordal cutting, 5,6 papillary muscle approximation, 7,8 and relocation of displaced papillary muscles. [9][10][11][12] In this study, we investigated the impact of supplemental subvalvular procedures on mitral valve conCirculation Journal Vol.72, November 2008 figuration and mobility, as evaluated by leaflet angles, and on MR at mid-term follow-up. Methods PatientsFifty-nine consecutive patients with IMR who underwent surgical intervention in the past 6 years were included in this study. The patients were divided into 3 groups according to the operative procedure: MAP (M group, n=27), MAP+LV reconstruction (LV group, n=18), and MAP+ LVR+subvalvular procedure (S group, n=14). Mid-term postoperative echocardiography was completed in 26, 16, and 12 patients in the M, LV, and S groups, respectively. Our current surgical strategy for patients with ischemic heart disease is as follows.Step 1: When the patients have even a single episode of more than moderate MR, MAP with coronary artery bypass grafting (CABG) is indicated. Otherwise, the patients undergo isolated CABG.Step 2: When patients undergoing MAP have a history of previous heart failure, a LV end-diastolic volume index >90 ml/m 2 , and LV ejection fraction (EF) <40%, LVR is indicated.Step 3: When patients undergoing LVR are diagnosed as having a great contribution of the subvalvular apparatus to the increased tethering force and consequent "sea-gull" deformity of the anterior mitral leaflet (AML) on echocardiography, 1 or 2 of the subvalvular procedures are indicated.The study was approved by the institution's review board and informed consent was given by all patients. Methods and ResultsFifty-nine patients with IMR were divided into 3 groups: mitral annuloplasty (MAP) (M group, n=27), MAP+left ventricular reconstruction (LVR) (LV group, n=18), and MAP+LVR+subvalvular procedure (S group, n=14). Tenting height and area, angle between the annular line and the line connecting leaflet base to the bending-or tip-point of either the anterior or posterior leaflet, and leaflet mobility were measured echocardiographically preope...

Impact of Papillary Muscle Approximation on Mitral Valve Configuration in the Surgical Correction of Ischemic Mitral Regurgitation

“…[9][10][11] However, the efficacy of this method in reducing valve tethering has not been examined. We compared the effect of RMAP alone and PMA in addition to RMAP on mitral valve configuration.…”

“…Papillary muscle approximation (PMA) is one such simple procedure used to correct valve tethering by directing the deviated papillary muscle toward a central position [9][10][11] ; however, the impact of this procedure on mitral valve configuration has not been elucidated. Hence, the purpose of this study was to verify the efficacy of PMA by Keywords ► echocardiography ► heart failure ► ischemic heart disease ► angina ► mitral valve surgery Abstract Background Efficacy of papillary muscle approximation (PMA) has not been well defined.…”

Surgical Treatment for Functional Mitral Regurgitation

“…[48][49][50][51][52][53][54] When the LV is too dilated or compromised, CABG alone 55 or CABG with MAP alone often is not effective enough to improve the patient outcome. 51,52,56 For these patients, LVR might be indicated.…”

“…54,57 A combination of LVR with subvalvular/valvular apparati seems more efficient to stabilize the valve. 33,43,53 Care should also should be taken to decrease ischemic time or cardiopulmonary bypass time because the patients in this category have poor LV and/or have a poor general condition.…”

Papillary Muscle Suspension Concomitant With Approximation for Functional Mitral Regurgitation

“…1 Understanding of the tethering mechanism provided both annular and subvalvular targets for therapy and several procedures have been reported. 2,3 Since 2003, we developed mitral complex reconstruction, which consists of mitral annuloplasty with a semi-rigid total ring and PM approximation (PMA), and since 2005 PM suspension (PMS), and we have aggressively applied this procedure in cases of heart failure. 4,5 We previously reported that PMA is a safe procedure and has more efficacy on mitral tethering than left ventriculoplasty.…”