Abstract
AIMS: Transseptal puncture (TSP) for left atrial (LA) access during catheter ablation poses technical challenges in patients with an atrial septal occluder (ASO) device because of altered septal anatomy and device coverage. However, detailed procedural techniques remain insufficiently described. This study aimed to describe a practical, case-based approach to TSP in patients with ASO devices and to evaluate procedural outcomes. METHODS: Between March 2005 and September 2025, a total of 1550 patients underwent ASO device implantation at our institution. Among them, 28 consecutive patients who later underwent atrial fibrillation (AF) ablation between March 2017 and September 2025 were retrospectively analysed. A representative clinical case illustrates the procedural workflow. RESULTS: Transseptal access was successfully achieved in 27 of 28 patients (96.4%). TSP was performed through the native septum in 17 patients and through the ASO device in 11 patients. Balloon dilation was frequently required in device puncture cases. Pulmonary vein isolation and adjunctive ablation were successfully completed in all patients without major complications. Small residual interatrial shunts observed immediately after the procedure resolved spontaneously during follow-up. CONCLUSION: TSP and AF ablation can be performed safely and effectively in patients with ASO devices. A case-based procedural approach with appropriate imaging guidance enables reliable LA access even in the presence of an ASO device.