Siddiqui, Uzma D.

Abstract Background/Introduction Multielectrode mapping catheters enhance the speed and accuracy of 3-dimensional data collection. However, with variable catheter configurations, data acquisition and efficiency may differ. We sought to compare the HD Grid X mapping catheter to a multi linear 8-spline catheter (spline catheter) with respect to chamber modeling speed and accuracy in in-vivo and bench setups. Methods In-vivo: In 6 pigs, 4 physicians used each catheter in a randomized order to create unedited models of the left atrium and ventricle (LA and LV) during coronary sinus atrial pacing. A sensor-enabled ablation catheter marked five locations per chamber while applying 10-15g of force. These markers, which denoted the ‘true’ location of the endocardial surface, were compared to the nearest surface location defined by each mapping catheter. Bench: In a tank setup designed to emulate an LA to pulmonary vein (PV) transition, chamber models were created during robotic manipulation of each mapping catheter. Resulting models were compared to a "gold-standard" model generated using robotic manipulation of sensor-enabled ablation catheters. Additionally, a static shape analysis was performed with each catheter held by a fixture in a deformed (HD Grid X catheter-bent 90o degrees; spline catheter-3 splines bunched) and undeformed state. Images of the physical catheters were captured to determine the true catheter shape and were compared to the renderings from the respective electroanatomical mapping systems (EnSite X v3.1 and Carto v7.2). Results In-Vivo: The mean error between the ablation catheter generated points and the models for HD Grid X trended lower than for the spline catheter by 11.7% (p=0.63; 2.57mm, 2.91mm) in the LA. In the LV, the mean error for HD Grid X was 34.4% (p=0.04; 2.04 mm, 3.67mm) less than for the spline catheter. In the LA, time for model creation for HD Grid X trended higher than for the spline catheter by 14.0% (p=0.34; 524s, 451s). However, in the LV, modeling time for HD Grid X was 22.9% (p=0.05; 368s, 478s) less than for the spline catheter. Bench: Compared to the ablation catheter created models, HD Grid X had a median bloat of 1.70mm (5.91mm max) while the spline catheter had 2.53mm (11.45mm max). The RMS error (mm) for the static shape analysis of electrode positions in an undeformed state was 0.60 for HD Grid X and 2.26 for the spline catheter. In a deformed state, the error was 0.82 for HD Grid X and 2.07 for the spline catheter. Conclusion In this translational model, the HD Grid X catheter created faster and more accurate unedited LV model geometry than the spline catheter, with no statistically significant difference noted in the LA. Bench data further supports the enhanced geometry accuracy seen in-vivo with HD Grid X, which may result in superior anatomical delineation, and faster mapping data acquisition times.

SUMMARY Volumetric laser endomicroscopy (VLE) uses optical coherence tomography (OCT) for real-time, microscopic cross-sectional imaging. A US-based multi-center registry was constructed to prospectively collect data on patients undergoing upper endoscopy during which a VLE scan was performed. The objective of this registry was to determine usage patterns of VLE in clinical practice and to estimate quantitative and qualitative performance metrics as they are applied to Barrett's esophagus (BE) management. All procedures utilized the NvisionVLE Imaging System (NinePoint Medical, Bedford, MA) which was used by investigators to identify the tissue types present, along with focal areas of concern. Following the VLE procedure, investigators were asked to answer six key questions regarding how VLE impacted each case. Statistical analyses including neoplasia diagnostic yield improvement using VLE was performed. One thousand patients were enrolled across 18 US trial sites from August 2014 through April 2016. In patients with previously diagnosed or suspected BE (894/1000), investigators used VLE and identified areas of concern not seen on white light endoscopy (WLE) in 59% of the procedures. VLE imaging also guided tissue acquisition and treatment in 71% and 54% of procedures, respectively. VLE as an adjunct modality improved the neoplasia diagnostic yield by 55% beyond the standard of care practice. In patients with no prior history of therapy, and without visual findings from other technologies, VLE-guided tissue acquisition increased neoplasia detection over random biopsies by 700%. Registry investigators reported that VLE improved the BE management process when used as an adjunct tissue acquisition and treatment guidance tool. The ability of VLE to image large segments of the esophagus with microscopic cross-sectional detail may provide additional benefits including higher yield biopsies and more efficient tissue acquisition. Clinicaltrials.gov NCT02215291