Immersive 3D Virtual Reality-Based Clip Sizing for Thoracoscopic Left Atrial Appendage Closure.

Objective: Surgical left atrial appendage (LAA) closure using epicardial clips has become popular in stroke prevention in patients with atrial fibrillation. Optimal placement of the clip is essential to achieve complete LAA occlusion and to prevent complications due to compression of the circumflex artery. We determine the added value of immersive virtual reality (VR) in accurately assessing LAA base size and selection of an appropriately sized clip. Methods: We studied the feasibility of measuring the LAA base using VR and conventional computed tomography (CT). A retrospective analysis was performed of LAA base measurements in 15 patients who had undergone thoracoscopic LAA clipping. Subsequently, we compared the placed clip size with imaging-acquired LAA base size to retrospectively evaluate intraprocedural sizing. Results: We successfully applied a VR platform to measure LAA base size. The median LAA base size measured in CT (23.8 mm, interquartile range [IQR] 22.3 to 26.4 mm) and intracardial virtual reality (23.4 mm, IQR 21.6 to 25.5 mm) did not differ significantly (P = 0.416). VR measurements of the LAA base in surgeon's view (25.7 mm, IQR 24.2 to 29.2) were significantly higher than those of 2-dimensional CT (P = 0.037) and intracardial 3-dimensional (3D) VR (P < 0.05) measurements. All measurements differed significantly with placed clip sizes (P < 0.05). There were no clip malpositioning-related events. Conclusions: Immersive VR is a feasible method for obtaining anatomical information on LAA base size. In this retrospective analysis, CT and VR-based measurements of LAA base size differed significantly from intraoperatively placed LAA clips, indicating potential oversizing when measured intraoperatively. Using intuitive 3D VR-based imaging might be a useful method to assist in accurate preprocedural sizing of LAA base and can potentially prevent oversizing.