Résultats à court et long terme du remplacement valvulaire mitral par prothèse mécanique à bille et à ailettes (à propos d’une série de 236 patients consécutifs avec un suivi moyen de 11 ans)

Objectives

To study the early and late results of mitral valve replacement (MVR) by Starr-Edwards caged-ball and bileaflet mechanical prosthesis.

Material and methods

We retrospectively analyzed 236 MVR performed in 236 patients: 127 by Starr-Edwards prosthesis (group 1) and 109 by bileaflet prosthesis (group 2).

Results

During the early period (30 days), the mortality rate was higher in group 1 (6.3 % vs 1.8 %; p = 0.0001), while hemorrhagic, thromboembolic and infectious complications were comparable in the two groups. In the late period (> 30 days) and with an average follow-up of 11.5 ± 5.7 years, mortality was higher in group 1 (9.4 % vs 4.6 %; p < 0.0001). The same was true for thromboembolic complications (20.8 % vs 6.4 %; p < 0.0001), hemorrhagic complications (13.4 % vs 7.3 %; p = 0.02), infectious complications (3.1 % vs 0.9 %; p = 0.02) and cardiac complications that were not due to the prosthesis (32.3 % vs 14.7 %; p = 0.02). The hemodynamic profile of the bileaflet prostheses was better than that of the Starr-Edwards prostheses (average functional prosthetic surface area was 2.37 ± 0.44 cm² and average pressure gradient was 5.6 ± 1.1 mmHg vs 2.04 ± 0.52 cm² and 7.6 ± 4.9 mmHg).

Conclusion

Our work confirms the superiority of bileaflet mechanical prostheses, with rates of early and late mortality, thromboembolic and hemorrhagic complications lower than those of the Starr-Edwards prostheses in more than 11 years of follow-up. However, one should not forget that the prevention of infective endocarditis, good observance of oral anticoagulant treatment and early surgery before left ventricular dysfunction occurs remain the best guarantee a good result of the MVR.