Physiological function of stentless aortic valves is altered by trimming and removal of aortic wall components

• Published in: Interactive cardiovascular and thoracic surgery 2007-04, Vol.6 (2), p.182-187
• Main Authors: Kuehnel, Ralf-U, Stock, Ullrich A, Wendt, Max O, Degenkolbe, Ilka, Jainski, Ute, Hartrumpf, Martin, Pohl, Manfred, Albes, Johannes M
• Format: Article
• Language: English
• Subjects: Animals; Aorta - surgery; Aortic Valve - physiology; Aortic Valve - surgery; Bioprosthesis; Cryopreservation; Elasticity; Fixatives; Glutaral; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation - instrumentation; Humans; In Vitro Techniques; Pressure; Prosthesis Design; Research Design; Swine; Tissue Fixation - methods; Transplantation, Heterologous; Transplantation, Homologous
• ISSN: 1569-9293; 1569-9285
• DOI: 10.1510/icvts.2006.142562

a Department of Cardiovascular Surgery, Heart Center Brandenburg, Bernau, Germany b Institute of Medical Physics and Biophysics, Charite, Berlin, Germany *Corresponding author. Herzchirurgie, Herzzentrum Brandenburg, Ladeburger Strasse 17, 16321 Bernau, Germany. Tel.: [phone]; fax: [phone]. E-mail address : r.kuehnel{at}immanuel.de (R.-U. Kuehnel). 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. Key Words: Aortic valve; Biological valve replacement; Stentless bioprostheses hemodynamics; Hydrodynamic performance index