Initial experience with a modified left atrial maze procedure concomitant to cardiac surgery.

Background: The excellent results of the Cox-Maze-III operation showed that a surgical treatment of atrial fibrillation is possible. The maze operation is surgically demanding and time-consuming. This fact led to the development of simplified modifications. Due to the good results of an exclusive left atrial maze procedure in combination with mitral valve surgery and new technologies of ablation, it seems reasonable to perform these techniques concomitant to cardiac surgery on a large number of patients.¶   
Methods: From November 1999 until June 2000 a modified maze procedure concomitant to a cardiac surgical intervention was performed on 42 patients, with a mean age of 62.2 years, suffering from chronic or intermittent atrial fibrillation. Primary cardiac disease was mainly cardiac valve disease (mitral valve disease 19 patients, aortic valve disease 10 patients) or coronary heart disease (8 patients). After left atriotomy and with the use of the Thermaline probe (Boston Scientific, Corporation, San Jose, California, USA) a bilateral pulmonary veins isolation was carried out by radiofrequency ablation. An additional ablation line was directed from the left pulmonary veins to the posterior mitral valve anulus. Finally, the left atrial appendage was resected. An evaluation of the therapeutic success was carried out in the immediate postoperative course and 3 months after surgery, at that point of time operation-related influences on the refractory period of the atrial myocardium were negligible.¶   
Results: At the time of discharge 32 patients (76.2%) showed a regular supraventricular rhythm. Twenty-one patients have already undergone the 3-month follow-up examination. At the time of discharge 13 out of these 21 patients (61.9%) were in sinus rhythm and at 3 months after surgery 18 out of these 21 patients (85.7%) showed a sinus rhythm with a restoration of atrial transport function echocardiographically determined. Three patients were still receiving antiarrhythmic medication.¶   
Conclusion: The modified maze procedure in combination with cardiac surgical interventions proved to be easy, quick and reliable to perform. The early results suggest a high success rate of this technique. The long-term results have to be verified with further, regular follow-up examinations of the patients.