The double-orifice technique for mitral valve reconstruction: predictors of postoperative outcome.

Objective: The 'double-orifice' (DO) technique has been recently proposed as an additional option in mitral valve repair (MVR). However, little is known regarding the long-term postoperative outcome and the predictors of DO results. Therefore, the aim of this study was to evaluate our clinical series and to identify prognostic factors of DO repair.

Methods: From 1992, 75 patients underwent DO procedure because of severe mitral regurgitation. The study population consisted of 48 male and 27 female patients with a mean age of 58+/-13 years (range 16-80 years). The aetiology of mitral incompetence was Barlow disease in 30 cases, rheumatic disease in 18 cases, acute or healed endocarditis in 16 cases and other causes in 11 cases. Carpentier rigid ring was used in 38 patients, whereas autologous pericardium was used in 24 patients. Thirteen patients had no annuloplasty procedure. Statistical analysis included univariate and multivariate Cox proportional models to evaluate the predictors of the DO failure.

Results: There were four hospital and three late deaths with a survival rate of 92% at 8 years. Mean follow-up was 42+/-24 months (range 1-93 months). Twelve patients underwent reoperation (five cases of early failure) and had valve replacement, leading to 80% freedom from reoperation at 8 years. At follow-up, 13 patients had no mitral regurgitation, 36 patients had trivial or mild mitral incompetence, whereas eight patients had moderate or severe mitral insufficiency at transthoracic echocardiography. Preoperative low left ventricular ejection faction, pulmonary arterial hypertension and marked left atrial enlargement were predictors (P<0.05) of DO failure at univariate analysis. Pericardial annuloplasty was also a risk factor (P<0.05) for unsuccessful DO repair at long term. Cox proportional multivariate analysis confirmed left atrial dilatation, pulmonary hypertension and pericardial annuloplasty as independent predictors of unfavourable postoperative results.

Conclusions: This study suggests that preoperative factors, like pulmonary hypertension and severe left atrial dilatation, may predict late DO failure. Our findings also indicate that pericardial annuloplasty may negatively influence mitral valve reconstruction at long term when DO is employed in MVR.