An eighteen-year evaluation of the Bjork-Shiley valve prosthesis

We evaluated the long-term (18 years) results of 356 patients undergoing valve replacement with Bj?rk-Shiley valve prosthesis (aortic, 212; mitral 120; double valve, 24) between 1970 and 1988. Actuarial survival rates were 90% (18 years) for AVR, 80% 'years) for MVR and 90% (8 years) for DVR. Actuarial rates of thromboembolism were 99% (18 years) for AVR, 98% (8 years) for MVR and 94% (8 years) for DVR. Actuarial rates of freedom from events (including valve failure, thromboembolism, reoperation and prosthetic valve endocarditis) were 82% (18 years) for AVR, 95% (8 years) and 94% (8 years) for DVR. There were no differences in these results among spherical disc, convexo-concave disc and monostrut valve. In conclusion, this study demonstrated that Bj?rk-Shiley valve showed a low incidence of postoperative events. These results endorse our choice of the Bj?rk-Shiley.     

Ten years experience with the St. Jude Medical valve prosthesis for mitral valve replacement

During the 10-year period between 1980 and December 1989, isolated mitral valve replacement (MVR) with the St. Jude Medical (SJM) valve prosthesis was performed on 404 patients at our hospital, and a long-term postoperative follow-up was conducted. There were 161 males and 243 females ranged in age from 1 year to 73 years. Early operative mortality was 5.2%. Follow-up period for 383 patients who discharged from the hospital was 1970.7 patient-years. Twenty of these patients died during the follow-up period, and a late mortality rate was 5.2%. During 10 years, thromboembolic event occurred in 8 patients. Four patients had anticoagulant-related bleeding, 4 had paravalvular leak, and 5 underwent re-operations. There was neither structural valve failure nor prosthetic valve endocarditis. Therefore, the actuarial survival rate and the valve-related death-free rate at 10 years were 83.2%, and 96.8%. Of the patients who survived, New York Heart Association class improved significantly (93% in classes II and III preoperatively and 71% in class I postoperatively). Linearized rates for thromboembolism, anticoagulant-related bleeding, and hemolysis were 0.41%, 0.20% and 0.36%/100 patient-years, respectively. The actuarial estimate of incidence free from all complications was 92.0% at 10 years. On the basis of this 10 years' experience, we believe that the SJM valve prosthesis is an excellent mechanical prosthesis for mitral valve replacement, in terms of hemodynamic performance and low thrombogenicity in patients receiving anticoagulants.     

Clinical experience with an improved mitral valve prosthesis

More than five years ago a Dacron velour-covered Teflon-disc mitral valve prosthesis was introduced in an effort to decrease thromboembolic complications of mitral valve replacement. Numerous reports have demonstrated an extremely low incidence of thromboembolic complications with this prosthesis. Efforts toward improving the prosthesis have been aimed at using more durable materials, and a Dacron velour-covered mitral prosthesis using Pyrolite carbon for both the disc and the cage legs now is available. Animal investigations with scanning electron microscopical wear analysis predicted 140 years of wear prior to penetration of the Pyrolite carbon coating. Clinical trials then were begun, and combined experience with this prosthesis in three centers now includes 175 cases. There have been no deaths related to the prosthesis, and only four thromboembolic episodes have occurred; the only fatal one was an embolus from the left atrial appendage that occluded the prosthesis. This improved prosthesis appears to offer significant advantages.     

MKCh-25 ball prosthesis in correction of isolated defect of the mitral valve

The article analyses the immediate and late-term results of mitral valve replacement by a MK4-25 ball prosthesis in 605 patients with mitral valvular disease. Operative lethality for the last 100 operations was 6%. The late-term results of valve replacement were studied in 381 patients in follow-up periods of 6 months to 17 years. 17-year survival was 69% among patients who underwent operation in functional class III and 48.8% among those operated on in class IV. The survival of patients and the late-term functional results depended on the duration of the disease and the degree of circulatory insufficiency before the operation. Timely implantation of a ball prosthesis corrects the hemodynamic disorders satisfactorily and improves the survival of patients.     

Thrombosis of mechanical mitral valve prosthesis

Obstruction of mechanical valve prostheses is a rare but potentially lethal complication following valve replacement surgery. Identifying the etiology and differentiation between thrombus, pannus, and vegetation obstructing the valve prosthesis can pose a diagnostic challenge. We report a patient who had an acute cerebral hemorrhage, developed a progressive mass lesion obstructing his mechanical mitral valve, and discuss contemporary diagnostic and management strategies.     

Clinical experience with the Lillehei-Kaster valve prosthesis.

The Lillehei-Kaster valve was used in 215 patients over a 7-year period. The aortic valve was replaced in 81 of them. Hospital mortality was 21% (17 patients). Ten patients were lost to follow-up and long-term mortality was 5% (3 patients). The incidence of thromboembolism was 2.6 per 100 patient-years, and actuarial survival was 96% at 5 and 87% at 7 years. Mitral valve replacement was performed in 108 patients. Hospital mortality was 20% (22 patients), 24 patients were lost to follow-up, and long-term mortality was 13% (11 patients). The combined incidence of thromboembolism was 5.0 per 100 patient-years, and actuarial survival was 81% at 5 years and 75% at 7 years. In both groups, the majority of patients improved clinically. Fifteen patients had double-valve replacement, and 11 had coronary revascularization in addition to valve replacement.     

Isolated replacement of the mitral valve with the Starr-Edwards prosthesis.

Isolated mitral valve replacement with the Starr-Edwards prosthesis has been performed on 657 patients at the Mayo Clinic during the 11 year period ending January, 1972. The most recent subset of that series comprised patients who received the Model 6120 prosthesis. In this group, the operative mortality rate was 9 per cent and the actuarial late death rate at 5 years was 20 per cent. This survival rate is a significant improvement over the natural history of severe mitral valve disease. Factors associated with operative deaths are large left artrial size, advanced functional class, and previous heart surgery. Variables associated with higher incidence of late deaths are large left atrial size, patient age at operation, and multivalve disease. Risk of thromboembolism is increased with large left atrial size, presence of left atrial thrombus, and inadequate anticoagulant therapy.