Mid-Term Results of the Cox Maze III Procedure Combined With Open Mitral Commissurotomy for the Treatment of Rheumatic Mitral Stenosis

BACKGROUND: The purpose of the present study was to evaluate the mid-term results of the Cox maze III procedure (CM-III) combined with open mitral commissurotomy (OMC) for the treatment of rheumatic mitral stenosis (MS) associated with persistent atrial fibrillation (AF). METHODS AND RESULTS: Cardiac rhythm was determined before and after surgery in 50 patients with MS presenting with AF who underwent OMC with modified CM-III using cryoablation between May 2001 and April 2009. At late follow up among 50 patients, 45 patients (90%) maintained sinus rhythm (SR) for 6-97 months after surgery. The maintenance rates of SR were 91.7%, 89.2%, and 89.2% at 1, 3, and 5 years after surgery, respectively. Preoperative left atrial dimension (P=0.016) and AF or junctional rhythm at discharge (P<0.001) were found to significantly influence the maintenance of SR after CM-III. Late follow-up echocardiography performed after a mean interval of 28.7 months (range, 1-85 months) showed mitral valve areas ranging from 1.20 to 2.60 cm and pressure gradients across the mitral valve ranging from 1.80 to 7.0 mmHg. There were 2 late deaths, but no early death, and no reoperation was required during the follow-up period. CONCLUSIONS: The addition of CM-III to OMC was safe and effective for selected patients. A preoperative large left atrial size was found to be significantly associated with AF treatment failure.