Efficacy and Safety of Cryoablation of Parahissian Accessory Pathways in Children: A Single Institution Study

BACKGROUND: Catheter cryoablation of supraventricular tachycardias involving the perinodal regions is considered to be a safer alternative compared to radiofrequency ablation. Limited information is available for efficacy, midterm outcomes, and complications regarding the ablation of parahissian accessory pathways (APs) in pediatric patients. METHODS: A retrospective review of all pediatric patients who underwent cryoablation for treatment of a parahissian AP was performed. RESULTS: Twenty-five patients (median age 13 years and weight 45.6 kg) underwent cryoablation of a parahissian AP. Median number of cryolesions applied was four (range: 3-6). Initial procedural success was achieved in 23 patients (23/25, 92%). Transient third-degree atrioventricular (AV) block was noted in two patients. There was no permanent AV block. Transient right bundle branch block (RBBB) was observed in one patient and permanent RBBB occurred in two patients. Of the patients successfully ablated with cryo, there was only one recurrence (1/23, 4.3%) over a follow-up of 17.5 months (range 6-34 months). CONCLUSION: Cryoablation of parahissian APs is both safe and effective with a low risk of recurrence in pediatric patients.