CT-scan-guided-irrigated trans-catheter ablation of epicardial accessory pathways in the coronary sinus: safety and feasibility in pediatric patients.

Background: The most common site of epicardial APs is posterior-septal, and ablation from the coronary sinus (CS) or its main tributaries is needed. However, particularly in children, it can carry a considerable risk of complications, such as coronary artery (CA) injury, CS damage, and perforation. This study aims to assess the efficacy and safety of computed tomography (CT)-scan-guided-irrigated trans-catheter (TC) ablation of epicardial APs through the CS in children.

Methods: Twenty-four children (19 males; mean age 13.8 ± 2.6) with posterior-septal and left posterior epicardial APs who underwent an endocavitary electrophysiological study (EPS) and TC ablation from the CS were enrolled in this study. All patients underwent a CT scan to visualize the CS and its branches and their proximity to the CAs before the ablation. Clinical, electrophysiological and follow-up data were collected.

Results: Acute success rate was 87.5% (21 out of 24 procedures). No complications occurred. In 16 (66.7%) patients, the ablation site was detected at the proximal CS, in two (8.3%) patients in the mid-proximal CS and in six (25%) in the middle cardiac vein (MCV). Ablation was achieved using an irrigated radiofrequency (RF) catheter in all patients and without the use of fluoroscopy in 20 patients (83.3%). Over a median follow-up of 15.1 months (IQR 2.5-32.3), no recurrences or complications occurred.

Conclusion: Epicardial posterior-septal and left posterior APs, in the area of CS or MCV, can be definitively eliminated in most children using CT-scan-guided electro-anatomical mapping and transvenous irrigated RF ablation.