Comparison of radial deformability of stent posts of different aortic bioprostheses

Martins Kalejs, Romans Lacis, Vladimir Kasyanov, Iveta Ozolanta, Philippe Abdel Sayed, Peteris Stradins, Ludwig Karl Von Segesser

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


Objectives Little is known about the stent deformability required for optimal stented heart valve bioprosthesis design. Therefore, two bioprosthetic valves with known good long-term clinical Results were tested. The strain in the radial direction of the stent posts of these valves was compared with contemporary bioprosthetic valves and a native porcine aortic root. Methods Medtronic Intact and Carpentier-Edwards Standard (CES), and four contemporary bioprostheses, including one self-expanding prosthesis, were tested with three sonomicrometry probes per valve fixed at commissure attachment points. The mean values from 2400 data points from three measurements of the interprobe distances were used to calculate the radius of the circle circumscribed around the three probes. Changes in the radius of the aortic root at pressures 70-90 and 120-140 mmHg (pressure during diastole and systole) and that of the stent posts at 70-90 and 0-10 mmHg (transvalvular pressure gradient during diastole and systole) were compared. Results An increase in radius by 7.3 ± 2.6, 8.7 ± 0.0 and 3.9 ± 0.0% for the porcine aortic root, CES and Intact valves, respectively, was observed during transition from diastolic to systolic pressure and less for contemporary bioprostheses-mean 2.5 ± 0.9%, lowest 1.2 ± 0.0. Conclusions The Results indicate that the radial deformability of bioprosthetic valve stent posts can be as low as 1.2% for xenoaortic and 3.0% for xenopericardial prostheses with no compromise of valve durability. Although these Results suggest that valve stent post-deformability might not be of critical importance, a concrete answer to the question of the significance of stent deformability for valve durability can be obtained only by acquiring long-term follow-up Results for valve prostheses with rigid stents.

Original languageEnglish
Pages (from-to)129-133
Number of pages5
JournalInteractive Cardiovascular and Thoracic Surgery
Issue number2
Publication statusPublished - Feb 2013


  • Deformation
  • Heart valve
  • Mechanical properties
  • Prosthesis
  • Stent

Field of Science*

  • 3.2 Clinical medicine
  • 2.6 Medical engineering

Publication Type*

  • 1.1. Scientific article indexed in Web of Science and/or Scopus database


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