Cryoablation of accessory pathways in children.

BACKGROUND

Cryoablation is utilized for septal tachycardia substrates due its safety. Considering the recent studies which reveal coronary artery stenosis related to radiofrequency ablation (RFA) in children, cryoablation may offer advantages for nonseptal accessory pathways (APs) as well. The aim of this study was to investigate the efficacy and safety of cryoablation of APs in children.

METHODS

A total of 39 patients (median age = 9.3 years, range 4.8 to 17.2 years) underwent cryoablation of APs. A three-dimensional, surface electrode-based navigation system (EnSite NavX, St. Jude Medical Inc., St. Paul, MN, USA) is used to decrease the fluoroscopy exposure.

RESULTS

A total of 45 APs were identified. Of these APs, 23 were septal (anteroseptal, midseptal, posteroseptal) and 22 were nonseptal. Acute success rate with cryoablation was 73%. RFA was used when cryoablation failed and overall acute success rate was 84%. To assess for the effect of institutional experience, the initial 23 APs were compared to the recent 22 APs and acute success rate revealed significant improvement (57% vs. 91%). Recurrence rate was 24% during a median follow-up of 282 days.

CONCLUSION

Cryoablation of APs is safe and yields to high acute success rates in children. It can potentially be used as the first ablation option for all APs in children. However, recurrence rate is higher compared to the RFA and there is a need for prospective comparative studies.