Modified maze during endoscopic mitral valve surgery: the OLV Clinic experience.

BACKGROUND: The use of radiofrequency ablation to perform the mini-maze procedure (pulmonary veins isolation) has been reported with good results. The aim of this study was to evaluate our practice with the association of the mini-maze procedure, done with the use of the Cardioblade pen, and minimally invasive mitral valve surgery.

METHODS: From January 1999 to November 2004, 103 patients underwent a minimally invasive mitral valve surgery with a concomitant pulmonary veins isolation (modified maze procedure) done with unipolar radiofrequency. All files were reviewed retrospectively.

RESULTS: In our group of patients, 41.2% were known to have intermittent atrial fibrillation and 58.8%, continuous atrial fibrillation; 67.7% of the patients were in atrial fibrillation at the time of surgery. Precise time of duration of atrial fibrillation was known in 47.6% (mean time, 30.3 +/- 28.9 months), but 47.7% were also known to have atrial fibrillation for many years. Mitral surgery included mitral valve repair in 71.8% and mitral valve replacement in 26.2%; 22 patients also received tricuspid annuloplasty. Major complications were mortality in 1%, myocardial infarction in 1%, stroke or transient ischemic attack in 1.9% and permanent pacemaker placement in 5.9%. At the time of discharge, 71.9% of patients were in sinus rhythm, 21.9% in atrial fibrillation, 1% in atrial flutter, and 5.2% in paced rhythm. Seventy-six and a half percent of the patients left the hospital with an antiarrhythmic drug (amiodarone 56.9%, sotalol 15.7%). At the time of follow-up, 99 patients were still alive with a mean follow-up time of 17.4 +/- 14.1 months; 69.7% of patients were in sinus rhythm, 28.3% in atrial fibrillation, and 2% were pacemaker-dependent. Patients received antiarrhythmic medication in 81.2% of cases (amiodarone 46.4%, sotalol 17.9%, beta-blocker 39.3%, digoxine 7.1%). Eleven new pacemakers were implanted (11.1%).

CONCLUSIONS: The use of unipolar radiofrequency ablation to perform a mini-maze during minimally invasive mitral valve surgery is a safe procedure and is associated with good early results.