Physiological Function of Stentless Aortic Valves Is Altered by Trimming and Removal of Aortic Wall Components

Interact Cardiovasc Thorac Surg. 2007 Apr;6(2):182-7. doi: 10.1510/icvts.2006.142562. Epub 2007 Jan 25.

Abstract

Various techniques of stentless aortic valve implantation with or without wall components exist. We investigated the in-vitro performance of stentless valves without or with aortic wall removal mimicking root versus subcoronary implantation. Glutaraldehyde-preserved stentless aortic valves (gpSVG), cryo-preserved human homografts (cpHG), cryo-preserved xenografts (cpXG), and fresh xenografts (fXG) were used. Valves were mounted as full roots or trimmed in a mock circuit. Mean transvalvular gradient (MTVG, mmHg) was measured. Distensibility was quantified using post-systolic backflow volume (BV, ml) - after valve closure. Function was visualized by means of a high-speed camera. Glutaraldehyde-preserved valves exhibited higher MTVG than cryo-preserved or fresh substitutes. After trimming, cpHG, cpXG, and fXG demonstrated marked reduction of MTVG (cpHG: 7.6-5.2 mmHg; cpXG: 6.7-4.9 mmHg; fXG: 8.4-5.2 mmHg). In contrast, after trimming gpSVG exhibited a significant increase of MTVG (7.1-9.2 mmHg). BV remained constant. Visualization indicated maintained distension of all valves and types of all sizes after trimming. In fresh and cryo-preserved grafts, aortic wall trimming resulted in significantly improved systolic performance while glutaraldehyde-preserved stentless valves demonstrated systolic impairment after wall resection. Subcoronary implantation of fresh or cryo-preserved aortic valves may therefore be preferred. In contrast, glutaraldehyde-preserved valves are dependent on wall suspension and may therefore be implanted as a root.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Aorta / surgery*
  • Aortic Valve / physiology*
  • Aortic Valve / surgery
  • Bioprosthesis*
  • Cryopreservation
  • Elasticity
  • Fixatives
  • Glutaral
  • Heart Valve Prosthesis Implantation / instrumentation*
  • Heart Valve Prosthesis*
  • Humans
  • In Vitro Techniques
  • Pressure
  • Prosthesis Design
  • Research Design
  • Swine
  • Tissue Fixation / methods
  • Transplantation, Heterologous
  • Transplantation, Homologous

Substances

  • Fixatives
  • Glutaral