Is there an evidence of pulmonary vein stenosis following epicardial microwave ablation of atrial fibrillation?

BACKGROUND

Surgical ablation techniques using microwave energy are an alternative to catheter based ablation therapy in the treatment of atrial fibrillation (AF). However, little is known about potential procedure-related complications. We investigate, whether there is evidence of pulmonary vein stenosis (PVST) in patients with atrial fibrillation undergoing epicardial microwave ablation.

METHODS

14 patients (ten males and four females) with AF and structural heart disease underwent cardiac surgery for the underlying disease and concomitant ablation of AF using microwave energy. In these patients with a mean age of 71 +/- 8 years microwave energy was applied epicardially on the beating heart. Ablation was implemented using a flexible microwave tool with a 40 mm long tip to create isolation of the pulmonary veins. Each application was performed with 65 watt for 90 s. Follow-up was performed twice at a mean of 207 +/- 73 days and 395 +/- 102 days. Patients were evaluated by 12-lead-ECG and echocardiography. Multidetector helical computer tomographic (MDCT) imaging was done in seven patients to show morphology of the pulmonary veins.

RESULTS

On second follow-up 11 patients were seen. ECG showed sinus rhythm in six patients (55 %) and atrial fibrillation in five patients (45%). MDCT showed a moderate pulmonary vein stenosis (50-70%) in one patient. The patient did not suffer from palpitations, dyspnea, angina or syncope.

CONCLUSIONS

Epicardial microwave ablation is an accepted treatment of atrial fibrillation. The procedure can be done off-pump on the beating heart. Nevertheless, pulmonary vein stenosis is a possible complication of this procedure, which should be kept in mind and evaluated during the follow-up.