Papillary Muscle Suspension Concomitant With Approximation for Functional Mitral Regurgitation

Abstract

unctional mitral regurgitation (MR) is a major contributing factor in heart failure and hospitalization of patients with nonischemic or ischemic dilated cardiomyopathy (DCM). The limitation of an undersized mitral annuloplasty has been recognized. Recurrent late MR is associated with continued left ventricular (LV) remodeling and enhanced papillary muscle (PM) displacement outside the posterior ring after mitral annuloplasty. 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. 4 Here we report our new additional procedure of PMS (posterior and anterior direction) for prevention of future mitral tethering because of LV remodeling. It is possible that PMS causes LV diastolic dysfunction by fixing the distance between the approximated PM heads and the mitral annulus, so we evaluated its early effects on LV systolic and diastolic mitral tethering and cardiac function. Otsuji et al reported "diastolic mitral tethering" that coincides with systolic mitral tethering in patients with LV dysfunction and incomplete mitral leaflet closure. 6 Therefore, it is important that for patients with LV dysfunction both systolic and diastolic mitral tethering are considered. Methods Study PopulationSubjects were 22 patients who underwent PMA with or without PMS for functional MR and an echocardiographic study of the submitral apparatus before and after operation, between November 2004 and August 2008. The mean age was 64±10 (range 39-85) years; 9 patients had nonischemic and 13 had ischemic pathology. The nonischemic cases were diagnosed by the preoperative clinical course, echocardiography, and pathological examination of intraoperative specimens. Functional MR of the ischemic patients was defined as stenosis of ≥75% in at least 1 coronary vessel, a corresponding regional wall motion abnormality, and type IIIb mitral leaflet dysfunction, based on Carpentier's classification, with or without myocardial infarction. Patients with degenerative etiology were excluded from this study. Patient characteristics are shown in Table 1. The New York Heart Association functional class was 3.1±0.5: II in 1 (5%), III in 17 (77%) and IV in 4 (18%). Two patients (9%) were dependent on intravenous catecholamine infusion. The mean age was 64±10 (range 39-85) years. The submitral apparatus geometry was measured by echocardiography. PM and mitral inflow angles in the anterior-directional suspension group were significantly larger than those in the posterior-directional suspension group (57±7° vs 46±9°, P=0.017 and 78±9° vs 60±6°, P<0.001, respectively), which were comparable to ...

Effects of Surgical Ventricular Reconstruction and Mitral Complex Reconstruction on Cardiac Oxidative Metabolism and Efficiency in Nonischemic and Ischemic Dilated Cardiomyopathy

“…and maintaining the elliptical LV shape (4,5,12). We previously demonstrated that OLVP and MCR improved NYHA functional class, and the 1-and 3-year actuarial survival rates were 91% and 87%, respectively.…”

“…Three patients had diabetes mellitus and were effectively treated with sulfonylurea (n ϭ 2) and acarbose (n ϭ 1). ␤-blockers were discontinued to avoid the worsening of heart failure during the perioperative period (for 1 month), as previously described (12). Other medical therapy except ␤-blockers was adjusted by physicians according to the patients' volume status and blood pressure.…”

“…This procedure has advantages such as preserving cardiac muscle and the circumflex coronary artery without resection of the left ventricle compared with traditional SVR. More importantly, this technique can alter the dilated spherical left ventricle to the appropriate elliptical shape (4,5,12).…”

“…1B). Papillary muscle approximation has been already proven to be an effective procedure to reduce the tethering of the mitral leaflets and to suspend the tips of papillary muscles from mitral annulus, helping to prevent future deterioration of tethering (4,5,12). Measurement of oxidative metabolism by 11 Cacetate PET and echocardiographic studies were performed in all patients before and 1 month after surgery.…”

Quantification of mitral valve apparatus by three-dimensional transesophageal echocardiography: in vitro validation study comparing two different analysis systems

“…3). With Real View Ò , both the mitral annulus and leaflets are reconstructed in 18 cross-sectional radial planes spaced 10°apart [19,[24][25][26][27]. With MVQ Ò , the annulus is marked in radial planes as with Real View Ò , and leaflets are traced on sections parallel to the anterior-posterior axis of the annulus.…”