A novel image fusion technique to improve transseptal puncture during percutaneous mitral valve repair

Background Percutaneous mitral valve repair (PMVR) using the MitraClip (Abbott Vascular), has gained popularity to treat mitral regurgitation (MR) in high risk patients. Accurate transseptal puncture (TSP) is a crucial step to achieve optimal guiding catheter position during the procedure. Purpose The aim of this study was to determine whether a planned optimal TSP site, using a novel computed tomography (CT) and echo image fusion methodology, corresponded with the actual TSP site, and if this was related to procedure time and outcome. Methods The mitral annulus and inter atrial septum were segmented in 26 patients (mean age 75 years, 50% female) undergoing PMVR. The optimal transseptal puncture (TSP) site was based on (1) perpendicular distance of 35–45mm from the TSP site to the mitral annulus, and (2) posterior position relative to the aorta. Optimal TSP was planned using a cardiac CT scan and 3Mensio software (Pie Medical imaging). The CT scan was exported to a Vivid E95 ultrasound system (GE Healthcare). After alignment with the three-dimensional echo image, the coordinates of the actual TSP site were determined. The distance between the optimal and actual TSP site was measured as (1) difference in height above the mitral annulus, and (2) absolute distance to the actual TSP site. Comparisons were made on procedure time, which was measured from the TSP to the achievement of optimal MitraClip position. Results The distance between the optimal and actual TSP site showed to be more than 5mm in 85% of the cases. The mean difference in height above the mitral annulus was 6.9mm. The mean procedure time was 21% longer when the absolute distance was more than 10mm. However, this did not reach statistical significance yet (p=0.4), likely due to small sample size. Conclusion CT-echo image fusion is an applicable method to plan TSP. This ongoing study suggests that image fusion based guiding may improve TSP site, reduce PMVR procedure time and potentially lead to more effective reduction of MR. Bar chart of optimal and actual TSP site Funding Acknowledgement Type of funding source: Other. Main funding source(s): Abbott