Flexible or rigid ring in mitral annuloplasty-do the results differ?

INTRODUCTION: Mitral valve annuloplasty has evolved over the decades since its introduction and Carpentier played a major role in developing the technique. Mitral valve repair is preferred over replacement for severe primary mitral regurgitation, as it restores normal life expectancy when successful and does not require lifelong anticoagulation. There is an ongoing debate regarding the choice of ring for mitral valve annuloplasty-rigid or flexible. At present, the choice of ring is based on the availability of the ring and left to the surgeon's discretion.
METHODOLOGY: This is a retrospective study conducted at a tertiary referral centre. AIM: To compare the outcomes of mitral valve repair annuloplasty with flexible and rigid rings. The hospital records of 112 patients who underwent mitral valve annuloplasty between January 2010 and December 2014 at our hospital were studied. All patients were followed up for 5 years. The rigid and flexible groups were compared for left ventricular (LV) size regression and the presence of mitral regurgitation (MR).
RESULTS: One hundred and eight patients had no progression of mitral regurgitation at 5-year follow-up, compared with the immediate postoperative period. The choice of the ring (rigid and flexible) did not affect the recurrence of mitral regurgitation. At 5-year follow-up, three patients (2 patients in the rigid group and 1 patient in the flexible group) had 3+ MR. One of the two patients in the rigid group had poor functional status and underwent mitral valve replacement (MVR). The other two patients (one in the rigid group and one in the flexible group) with 3+ MR had class II NYHA symptoms and were on medical follow-up. The left ventricular internal diameter diastolic (LVIDD) measured 59.1 mm in the flexible ring group and 56.76 mm in the rigid group preoperatively and these values reduced to 48.4 mm and 47.3 mm, at 5-year follow-up respectively. The mean left ventricular internal diameter systolic (LVIDS) size regression at 5 years was 4.5 ± 6.09 mm in the flexible ring group and 3.2 ± 7.17 mm in the rigid ring group and the difference is not statistically significant (p value 0.314). The mean LVIDD size regression at 5 years was 10.62 ± 6.57 mm in the flexible ring group and 9.38 ± 9.29 mm in the rigid ring group and the difference is not statistically significant (p value 0.408).
CONCLUSION: The choice of rigid or flexible ring did not have a marked difference on the outcome of mitral valve annuloplasty at midterm follow-up. © Indian Association of Cardiovascular-Thoracic Surgeons 2020.