Clinical Trials Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Cardiol. Oct 26, 2016; 8(10): 606-614
Published online Oct 26, 2016. doi: 10.4330/wjc.v8.i10.606
Optimal C-arm angulation during transcatheter aortic valve replacement: Accuracy of a rotational C-arm computed tomography based three dimensional heart model
Verena Veulemans, Sabine Mollus, Axel Saalbach, Max Pietsch, Katharina Hellhammer, Tobias Zeus, Ralf Westenfeld, Jürgen Weese, Malte Kelm, Jan Balzer
Verena Veulemans, Katharina Hellhammer, Tobias Zeus, Ralf Westenfeld, Malte Kelm, Jan Balzer, Department of Medicine, Division of Cardiology, Pulmonary Diseases, Vascular Medicine, University Hospital Düsseldorf, 40225 Düsseldorf, Germany
Sabine Mollus, Axel Saalbach, Max Pietsch, Jürgen Weese, Philips Research Europe, Philips GmbH Innovative Technologies, Research Laboratories, 22335 Hamburg instead of Eindhoven, 5656 AE Eindhoven, The Netherlands
Author contributions: Veulemans V, Mollus S contributed equally to this study as primary authors; Veulemans V, Mollus S and Balzer J designed the study, analyzed and interpreted data and wrote the manuscript; Saalbach A, Pietsch M, Hellhammer K, Zeus T, Westenfeld F, Weese J and Kelm M supervised the study and revised the manuscript.
Institutional review board statement: The study conformed to the Declaration of Helsinki and was accepted by the University of Düsseldorf Ethics Committee.
Clinical trial registration statement: This registration policy applies to registry trials. https://clinicaltrials.gov/ct2/show/NCT01805739.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment, titled “Multi Modal Cardiac Imaging Prior Transcatheter Aortic Valve Implantation”.
Conflict-of-interest statement: Tobias Z and Verena V receive honoraria from St. Jude Medical for lectures. Philips Healthcare and the University Hospital Duesseldorf have a master research agreement. All authors take responsibility for all aspects of the reliability and freedom from bias of the data presented and their discussed interpretation.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Verena Veulemans, MD, Department of Medicine, Division of Cardiology, Pulmonary Diseases, Vascular Medicine, University Hospital Düsseldorf, Moorenstraße 5, 40225 Düsseldorf, Germany. verena.veulemanns@med.uni-duesseldorf.de
Telephone: +49-211-8118800 Fax: +49-211-8119520
Received: May 8, 2016
Peer-review started: May 9, 2016
First decision: June 13, 2016
Revised: July 23, 2016
Accepted: August 30, 2016
Article in press: August 31, 2016
Published online: October 26, 2016
Processing time: 171 Days and 19.9 Hours
Abstract
AIM

To investigate the accuracy of a rotational C-arm CT-based 3D heart model to predict an optimal C-arm configuration during transcatheter aortic valve replacement (TAVR).

METHODS

Rotational C-arm CT (RCT) under rapid ventricular pacing was performed in 57 consecutive patients with severe aortic stenosis as part of the pre-procedural cardiac catheterization. With prototype software each RCT data set was segmented using a 3D heart model. From that the line of perpendicularity curve was obtained that generates a perpendicular view of the aortic annulus according to the right-cusp rule. To evaluate the accuracy of a model-based overlay we compared model- and expert-derived aortic root diameters.

RESULTS

For all 57 patients in the RCT cohort diameter measurements were obtained from two independent operators and were compared to the model-based measurements. The inter-observer variability was measured to be in the range of 0°-12.96° of angular C-arm displacement for two independent operators. The model-to-operator agreement was 0°-13.82°. The model-based and expert measurements of aortic root diameters evaluated at the aortic annulus (r = 0.79, P < 0.01), the aortic sinus (r = 0.93, P < 0.01) and the sino-tubular junction (r = 0.92, P < 0.01) correlated on a high level and the Bland-Altman analysis showed good agreement. The interobserver measurements did not show a significant bias.

CONCLUSION

Automatic segmentation of the aortic root using an anatomical model can accurately predict an optimal C-arm configuration, potentially simplifying current clinical workflows before and during TAVR.

Keywords: Aortic stenosis; Imaging modalities; Degenerative valve disease; Transcatheter aortic valve replacement

Core tip: We were able to demonstrate the accuracy of a rotational C-arm CT (RCT) based 3D heart model to predict an optimal C-arm configuration and to provide anatomical context information during transcatheter aortic valve replacement (TAVR). Established and upcoming complex cardiac interventions require detailed anatomical information for procedure planning and intra-procedural guidance. According to our experience, RCT can be smoothly integrated into the clinical workflow, providing three-dimensional information of the relevant anatomical structures in the catheterization lab prior and as part of the TAVR intervention.