Clinical application of the transseptal puncture technique using a biplane positioning method with left atrial 3D-CT

Introduction Traditional transseptal puncture (TSP) relies on x-ray imaging and anatomical landmarks, which poses challenges in patients with atrial structural variations or overweight. Furthermore, emerging interventional techniques demand precise puncture site localization. This feasibility study evaluates the safety and efficacy of a novel biplane positioning method guided by left atrial (LA) 3D-CT reconstruction for TSP. Methods A retrospective analysis included 100 atrial fibrillation patients undergoing radiofrequency catheter ablation (RFCA) between July 2023 and March 2024. Preoperative LA-enhanced CT scans were performed to reconstruct 3D models. Key measurements included vertebral height (H), horizontal distance (X) from the target puncture point (O) to the anterior spine edge at 45° right anterior oblique (RAO) view, and vertical distance (Y) between O and the great cardiac vein. Intraoperative biplane localization integrated CT-derived ratios (X/H, Y/H) with fluoroscopy. Statistical analyses compared outcomes across LA size subgroups. Results All patients achieved successful TSP without complications (e.g., cardiac tamponade, thromboembolism). The mean X/H and Y/H ratios were 0.8 ± 0.2 and 0.5 ± 0.1, respectively. Patients with larger LA diameters (≥50 mm) exhibited significantly greater X values (16.8 ± 3.3 mm vs. 13.6 ± 4.2 mm, P = 0.034). In 17 patients with unclear LA posterior borders on fluoroscopy (mean BMI 27.2 ± 3.5 vs. 24.9 ± 3.2 in others, P = 0.009), the method ensured safe puncture. The mean distance from the puncture site to the right inferior pulmonary vein was 24.2 ± 5.5 mm. Discussion The LA 3D-CT-guided biplane positioning method demonstrates feasibility, accuracy, and safety for TSP in atrial fibrillation patients, including those with enlarged atria, structural anomalies, or overweight. The protocol is feasible within a limited, single-center cohort.