Quantitative Prediction of Paravalvular Leak in Transcatheter Aortic Valve Replacement Based on Tissue-Mimicking 3D Printing

JACC Cardiovasc Imaging. 2017 Jul;10(7):719-731. doi: 10.1016/j.jcmg.2017.04.005.

Abstract

Objectives: This study aimed to develop a procedure simulation platform for in vitro transcatheter aortic valve replacement (TAVR) using patient-specific 3-dimensional (3D) printed tissue-mimicking phantoms. We investigated the feasibility of using these 3D printed phantoms to quantitatively predict the occurrence, severity, and location of any degree of post-TAVR paravalvular leaks (PVL).

Background: We have previously shown that metamaterial 3D printing technique can be used to create patient-specific phantoms that mimic the mechanical properties of biological tissue. This may have applications in procedural planning for cardiovascular interventions.

Methods: This retrospective study looked at 18 patients who underwent TAVR. Patient-specific aortic root phantoms were created using the tissue-mimicking 3D printing technique using pre-TAVR computed tomography. The CoreValve (self-expanding valve) prostheses were deployed in the phantoms to simulate the TAVR procedure, from which post-TAVR aortic root strain was quantified in vitro. A novel index, the annular bulge index, was measured to assess the post-TAVR annular strain unevenness in the phantoms. We tested the comparative predictive value of the bulge index and other known predictors of post-TAVR PVL.

Results: The maximum annular bulge index was significantly different among patient subgroups that had no PVL, trace-to-mild PVL, and moderate-to-severe PVL (p = 0.001). Compared with other known PVL predictors, bulge index was the only significant predictor of moderate-severe PVL (area under the curve = 95%; p < 0.0001). Also, in 12 patients with post-TAVR PVL, the annular bulge index predicted the major PVL location in 9 patients (accuracy = 75%).

Conclusions: In this proof-of-concept study, we have demonstrated the feasibility of using 3D printed tissue-mimicking phantoms to quantitatively assess the post-TAVR aortic root strain in vitro. A novel indicator of the post-TAVR annular strain unevenness, the annular bulge index, outperformed the other established variables and achieved a high level of accuracy in predicting post-TAVR PVL, in terms of its occurrence, severity, and location.

Keywords: annular bulge index; aortic valve calcification; balloon post-dilation; computed tomography; echocardiography; strain.

Publication types

  • Observational Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aortic Valve / diagnostic imaging
  • Aortic Valve / physiopathology
  • Aortic Valve / surgery*
  • Aortic Valve Insufficiency / diagnostic imaging
  • Aortic Valve Insufficiency / etiology*
  • Aortic Valve Insufficiency / physiopathology
  • Aortic Valve Stenosis / diagnostic imaging
  • Aortic Valve Stenosis / physiopathology
  • Aortic Valve Stenosis / surgery*
  • Feasibility Studies
  • Female
  • Heart Valve Prosthesis
  • Hemodynamics
  • Humans
  • Male
  • Models, Cardiovascular*
  • Patient-Specific Modeling*
  • Phantoms, Imaging
  • Predictive Value of Tests
  • Printing, Three-Dimensional*
  • Proof of Concept Study
  • Prosthesis Design
  • Radiographic Image Interpretation, Computer-Assisted
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Stress, Mechanical
  • Tomography, X-Ray Computed* / instrumentation
  • Transcatheter Aortic Valve Replacement / adverse effects*
  • Transcatheter Aortic Valve Replacement / instrumentation
  • Treatment Outcome