A new self-expanding aortic stent valve with annular fixation: in vitro haemodynamic assessment.

Abstract

OBJECTIVE:

Balloon-expandable stent valves require flow reduction during implantation (rapid pacing). The present study was designed to compare a self-expanding stent valve with annular fixation versus a balloon-expandable stent valve.

METHODS:

Implantation of a new self-expanding stent valve with annular fixation (Symetis, Lausanne, Switzerland) was assessed versus balloon-expandable stent valve, in a modified Dynatek Dalta pulse duplicator (sealed port access to the ventricle for transapical route simulation), interfaced with a computer for digital readout, carrying a 25 mm porcine aortic valve. The cardiovascular simulator was programmed to mimic an elderly woman with aortic stenosis: 120/85 mmHg aortic pressure, 60 strokes/min (66.5 ml), 35% systole (2.8 l/min).

RESULTS:

A total of 450 cardiac cycles was analysed. Stepwise expansion of the self-expanding stent valve with annular fixation (balloon-expandable stent valve) resulted in systolic ventricular increase from 120 to 121 mmHg (126 to 830+/-76 mmHg)*, and left ventricular outflow obstruction with mean transvalvular gradient of 11+/-1.5 mmHg (366+/-202 mmHg)*, systolic aortic pressure dropped distal to the valve from 121 to 64.5+/-2 mmHg (123 to 55+/-30 mmHg) N.S., and output collapsed to 1.9+/-0.06 l/min (0.71+/-0.37 l/min* (before complete obstruction)). No valve migration occurred in either group. (*=p<0.05).

CONCLUSIONS:

Implantation of this new self-expanding stent valve with annular fixation has little impact on haemodynamics and has the potential for working heart implantation in vivo. Flow reduction (rapid pacing) is not necessary.

• Authors: Mathieu Vergnat, Roland Henaine, Martins Kalejs, Sandra Bommeli, Enrico Ferrari, Jean-Francois Obadia, Ludwig Karl Von Segesser
• Journal: European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery (Eur J Cardiothorac Surg) Vol. 35 Issue 6 Pg. 970-5; discussion 975-6 (Jun 2009) ISSN: 1873-734X [Electronic] Germany
• PMID: 19409805 (Publication Type: Journal Article)

Topics

• Aortic Valve (surgery)
• Blood Pressure (physiology)
• Heart Valve Prosthesis
• Heart Valve Prosthesis Implantation
• Hemodynamics (physiology)
• Humans
• Minimally Invasive Surgical Procedures (methods)
• Models, Cardiovascular
• Prosthesis Design
• Stents
• Ventricular Pressure (physiology)