ON-X bileaflet valve in aortic position--early experience shows an improved hemodynamic profile

Thorac Cardiovasc Surg. 1998 Oct;46(5):293-7. doi: 10.1055/s-2007-1010241.


Background: Despite considerable progress during the last decades, mechanical heart valves still have significant disadvantages in performance compared to native valves. To optimize the hemodynamic profile, a new mechanical bileaflet valve (ON-X) was developed and introduced in 1997. It was the aim of this study to assess the feasibility, safety, and the early postoperative hemodynamics with this new valve in vivo.

Methods: We analyzed 19 patients (11 male, 8 female; 63.2 +/- 8.2 years; aortic stenosis: n = 13; aortic incompetence: n = 2; combined aortic lesion: n = 2), undergoing aortic valve replacement with this prosthesis (valve size 19 mm: n = 1; 21 mm: n = 6; 23 mm: n = 8; 25 mm: n = 4; additional CABG: n = 4). In addition to intraoperative pressure gradient measurements, echocardiography was performed early postoperatively and after 3 months, evaluating pressure loss, effective orifice area, and regression of left-ventricular hypertrophy.

Results: No major perioperative complications were observed. The echocardiographic evaluation demonstrated a significantly increased effective orifice area and lower transvalvular gradients in all valve sizes compared with literature values for the St. Jude Medical prosthesis. Effective regression of left-ventricular hypertrophy (-23.6%) was observed over the first three months.

Conclusions: These preliminary data confirm the favorable hemodynamic characteristics of the ON-X valve as compared to standard bileaflet designs. Implantation was feasible and safe, and no major postoperative complications such as thrombembolic events were observed.

Publication types

  • Comparative Study

MeSH terms

  • Aortic Valve
  • Aortic Valve Insufficiency / physiopathology
  • Aortic Valve Insufficiency / surgery*
  • Aortic Valve Stenosis / physiopathology
  • Aortic Valve Stenosis / surgery*
  • Echocardiography
  • Feasibility Studies
  • Female
  • Heart Valve Prosthesis Implantation*
  • Heart Valve Prosthesis*
  • Hemodynamics / physiology
  • Humans
  • Hypertrophy, Left Ventricular / prevention & control
  • Male
  • Middle Aged
  • Prosthesis Design