Realistic Vascular Replicator for TAVR Procedures

Cardiovasc Eng Technol. 2018 Sep;9(3):339-350. doi: 10.1007/s13239-018-0356-z. Epub 2018 Apr 13.

Abstract

Transcatheter aortic valve replacement (TAVR) is an over-the-wire procedure for treatment of severe aortic stenosis (AS). TAVR valves are conventionally tested using simplified left heart simulators (LHS). While those provide baseline performance reliably, their aortic root geometries are far from the anatomical in situ configuration, often overestimating the valves' performance. We report on a novel benchtop patient-specific arterial replicator designed for testing TAVR and training interventional cardiologists in the procedure. The Replicator is an accurate model of the human upper body vasculature for training physicians in percutaneous interventions. It comprises of fully-automated Windkessel mechanism to recreate physiological flow conditions. Calcified aortic valve models were fabricated and incorporated into the Replicator, then tested for performing TAVR procedure by an experienced cardiologist using the Inovare valve. EOA, pressures, and angiograms were monitored pre- and post-TAVR. A St. Jude mechanical valve was tested as a reference that is less affected by the AS anatomy. Results in the Replicator of both valves were compared to the performance in a commercial ISO-compliant LHS. The AS anatomy in the Replicator resulted in a significant decrease of the TAVR valve performance relative to the simplified LHS, with EOA and transvalvular pressures comparable to clinical data. Minor change was seen in the mechanical valve performance. The Replicator showed to be an effective platform for TAVR testing. Unlike a simplified geometric anatomy LHS, it conservatively provides clinically-relevant outcomes and complement it. The Replicator can be most valuable for testing new valves under challenging patient anatomies, physicians training, and procedural planning.

Keywords: 3D printing; Aortic stenosis; Aortic valve; Mitral valve; Prosthetic valve; TAVI.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Aorta / diagnostic imaging
  • Aorta / physiopathology
  • Aorta / surgery*
  • Aortic Valve / diagnostic imaging
  • Aortic Valve / pathology*
  • Aortic Valve / physiopathology
  • Aortic Valve / surgery*
  • Aortic Valve Insufficiency / etiology
  • Aortic Valve Insufficiency / physiopathology
  • Aortic Valve Stenosis / diagnostic imaging
  • Aortic Valve Stenosis / physiopathology
  • Aortic Valve Stenosis / surgery*
  • Aortography / methods
  • Calcinosis / diagnostic imaging
  • Calcinosis / physiopathology
  • Calcinosis / surgery*
  • Cardiologists / education
  • Computed Tomography Angiography
  • Education, Medical, Graduate / methods
  • Heart Valve Prosthesis*
  • Hemodynamics
  • Humans
  • Iliac Artery / diagnostic imaging
  • Materials Testing / methods*
  • Models, Anatomic*
  • Models, Cardiovascular*
  • Patient-Specific Modeling
  • Printing, Three-Dimensional
  • Prosthesis Design
  • Simulation Training / methods
  • Transcatheter Aortic Valve Replacement / adverse effects
  • Transcatheter Aortic Valve Replacement / education
  • Transcatheter Aortic Valve Replacement / instrumentation*

Supplementary concepts

  • Aortic Valve, Calcification of