Microwave ablation for the surgical treatment of permanent atrial fibrillation--a single centre experience.

OBJECTIVE

Microwave ablation (MW) has been established as a safe and efficient procedure for the treatment of permanent atrial fibrillation (pAF) resulting in conversion to sinus rhythm (SR). For further improvement of clinical results, a new ablation line concept has been introduced. We present the first clinical results using this new concept in comparison with the results of previous ablation line concepts.

METHODS

Ablation lines were performed using microwave energy (Flex 2 and Flex 4 device). We compared two groups, including patients (pts) with mitral valve disease (MVD), coronary artery disease (CAD), and aortic valve disease (AVD). Group A included 137 patients, age 68.4+/-7.8, with ejection fraction 32-80%, left atrial diameter 52.6+/-9.6 mm, suffering from MVD (n=87), CAD (n=59) or AVD (n=36) with pAF for 6.5+/-9.2 years using the original ablation line concept. Group B included 112 patients, age 68.1+/-8.0, ejection fraction 20-83%, left atrial diameter 53.1+/-8.7 mm with pAF for 6.8+/-7.0 years suffering from MVD (n=72), CAD (n=33) or AVD (n=36) performing a modified ablation line.

RESULTS

Survival rate of group A was 98.5% and 97.3% in group B. In the 6-month follow-up for group A, 62% of patients with MVD, 68% with CAD and 78% with AVD were in SR. For group B, 88% of patients with MVD, 78% with CAD and 85% with AVD were in SR.

CONCLUSIONS

MW has become an efficient option with an excellent benefit/risk ratio for the treatment of pAF in patients with other cardio surgical disease. The modified ablation line concept in association with the introduction of a new ablation catheter resulted in a 10% higher success rate. Therefore we have established this new lesion line concept as our standard for microwave ablation.