title: Clinical and hemodynamic results of cardiac valve replacement with the Monostrut Björk-Shiley prosthesis.
abstract: Between May 1983 and April 1986, 318 patients underwent cardiac valve replacement with the Monostrut Björk-Shiley prosthesis. There were 136 aortic valve replacements, 128 mitral valve replacements, and 54 multiple replacements. A total of 373 valves were implanted. Associated procedures were done in 79 (25%) of the patients. Hospital (30-day) mortality rate was 5.6% (18 patients): 2.9% (n = 4) after aortic, 7.8% (n = 10) after mitrals and 7.4% (n = 4) after multiple valve replacement. Follow-up was obtained in all 300 operative survivors, for a total of 500 patient-years (mean 18 months). Actuarial survival rate, excluding operative deaths, at 4 years was 94.7% +/- 1.5% (mean +/- standard error of the mean). There were 16 thromboembolic episodes (3.2/100 patient-years). Freedom from all valve-related complications was 87% +/- 2.4% at 3 1/2 years. Neither valve thrombosis nor structural failure has been observed. Eighty percent of the patients are in New York Heart Association functional class I. Forty-two patients (26 with aortic and 16 with mitral valve replacement) underwent cardiac catheterization a mean of 6 1/2 months after the operation. In the aortic position, peak gradients were an average of 6.9 +/- 1.2 mm Hg. Mean systolic gradients were 12.4 +/- 6.3 mm Hg and did not increase with exercise. In the mitral position, end-diastolic gradients were an average of 2.1 +/- 2 mm Hg and mean gradients, 5.9 +/- 2 mm Hg. Discharge coefficient (estimated orifice area/geometric area) was 0.63 +/- 0.2 for the aortic and 0.53 +/- 0.2 for the mitral prostheses. Disc opening was maximal in most patients. These results indicate that the Monostrut prosthesis has a low rate of thromboembolic events, no structural failures or thrombotic obstructions and excellent hemodynamic performance, especially in the small aortic sizes (discharge coefficient for 19 and 21 mm valves, 0.77).
authors.affiliation: Cardiac Surgery Unit, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Aris
authors.forename: J M
authors.initials: JM
authors.lastname: Padró
authors.forename: M L
authors.initials: ML
authors.lastname: Cámara
authors.forename: C
authors.initials: C
authors.lastname: Crexells
authors.forename: J M
authors.initials: JM
authors.lastname: Augé
authors.forename: J M
authors.initials: JM
authors.lastname: Caralps
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001021:Aortic Valve; D002648:Child; D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000401:mortality / Q000601:surgery*; D006350:Heart Valve Prosthesis / Q000009:adverse effects / Q000401:mortality; D006439:Hemodynamics; D006801:Humans; D008875:Middle Aged; D008943:Mitral Valve; D012086:Reoperation