Cox maze operation without cryoablation for the treatment of chronic atrial fibrillation

Background. From August 1993 to May 1994, 20 patients (mean age, 43 years) with atrial fibrillation underwent the maze operation without cryoablation. Ten patients had mitral stenosis, 5 had mitral insufficiency, and 5 had a mixed mitral lesion. The mean left atrial diameter as measured on echocardiograms was 6.1 cm. The cause was rheumatic in 17 patients (85%) and degenerative in 3 (15%). Seven patients had had previous episodes of thromboembolism. Methods. Mitral valvuloplasty was performed on 7 patients, mitral commissurotomy on 4, and mitral valve replacement on 9. Thrombi were found in the left atrium of 7 patients and also in the right atrium in 2. The mean cross-clamp time was 73 minutes (range, 52 to 108 minutes). Results. Patients were discharged from the hospital in good condition. Hemodynamic studies and Doppler echocardiograms showed significant reduction in the left atrial diameter (mean diameter, 4.9 cm; p < 0.01) in 18 patients. The two-channel Holter monitor showed sinus rhythm in 15 patients, atrial ectopic rhythm in 4, and atrial fibrillation in 1. Eleven patients (55%) experienced atrial fibrillation (9 in the first 3 months postoperatively), which was reversed with quinidine. Ninety percent of patients had development of an effective, synchronous, atrial systole. Six to 15 months postoperatively (average follow-up, 10 months), all patients were in functional class I, and 18 were not on a regimen of antiarrhythmic medication. Conclusions. This simplification of the maze operation has been demonstrated to be an effective alternative for the treatment of chronic atrial fibrillation.