Localization of fossa ovalis and Brockenbrough needle prior to left atrial ablation using three-dimensional mapping with EnSite Fusion™

Background: Transseptal catheterization of the interatrial septum has traditionally been performed under the guidance of fluoroscopy, echocardiography, and hemodynamic pressure monitoring. We hypothesized that the fossa ovalis could be identified on pre-ablation chest computerized tomography (CT) scan utilizing EnSite Verismo™ and Fusion™ software thereby permitting its real-time visualization during transseptal puncture. Objective: The purpose of this study is to generate multi-center data demonstrating the feasibility of the identification of the fossa ovalis and visualization of the transseptal needle tip using EnSite Verismo™ segmentation and EnSite Fusion™ prior to transseptal puncture. Methods: Patients scheduled to undergo transseptal puncture for ablation were enrolled. Pre-ablation CT scans were performed in all patients. The Verismo™ software tool was used to import and segmentally manipulate a three-dimensional CT image on the EnSite™ system workstation. EnSite Fusion™ registration was used to register the right atrial image and label and confirm the fossa ovalis' location prior to transseptal puncture. Results: Analysis of the pre-ablation CT scan using EnSite Fusion™ successfully allowed assessment of the anatomy and location of the fossa ovalis. Additionally, the transseptal needle tip location was located within the CT scan designated fossa ovalis location in 96% of cases. Conclusion: It is possible to visualize the fossa ovalis on pre-ablation CT and localize the transseptal needle accurately within the margins of the fossa ovalis utilizing EnSite Fusion™ and Verismo™ software.