Small aortic annulus: The hydrodynamic performances of 5 commercially available bileaflet mechanical valves

AbstractObjectiveHemodynamic performances of mechanical valve prostheses in patients with aortic valve stenosis and a small aortic annulus are crucial. We analyzed the in vitro hydrodynamics of 5 currently available bileaflet mechanical prostheses that fitted a 21-mm-diameter valve holder of a Sheffield pulse duplicator.MethodsThree samples of 5 high-performance production-quality prostheses, including the sewing ring cuffs, were tested in the aortic chamber of a Sheffield pulse duplicator. Sizes of the prostheses fitting the 21-mm valve holder were as follows: 18-mm ATS, 19-mm SJM Regent, 19-mm Sorin Bicarbon Slimline, 19-mm On-X, and 21-mm Carbomedics Top Hat. The tests were carried out at a fixed pulse rate (70 beats/min) and at increasing cardiac outputs of 2, 4, 5, and 7 L/min. Each valve was tested 10 times for each different cardiac output. This resulted in a total of 40 tests for each valve and 120 tests for each valve model. The aortic pressure was set at 120/80 mm Hg (mean pressure, 100 mm Hg) throughout the experiment for all cardiac outputs. Forward flow pressure decrease, total regurgitant volume, closing and leakage volumes, effective orifice area, and stroke work loss were recorded while the valve operated under each cardiac output.ResultsThe SJM Regent valve and the Sorin Bicarbon Slimline prosthesis showed the lowest mean and peak gradients at increasing cardiac outputs. The closure volume was higher for the SJM Regent and Sorin Bicarbon Slimline prostheses, unlike with the ATS prosthesis at 7 L/min of cardiac output. The ATS and SJM Regent prostheses showed the largest regurgitant volume, whereas the Sorin Bicarbon Slimline prosthesis showed the lowest regurgitant volume. The calculated effective orifice area and stroke work loss were significantly better with the SJM Regent and Sorin Bicarbon Slimline prostheses.ConclusionAssuming that the 21-mm valve holder in which all the tested prostheses were accommodated is comparable with a defined aortic valve size, this hydrodynamic evaluation model allowed us to compare the efficiency of currently available valve prostheses, and among these, the SJM Regent and the Sorin Bicarbon Slimline exhibited the best performances

Intracoronary artery shunt: An assessment of possible coronary artery wall damage

AbstractJ Thorac Cardiovasc Surg 2003;125:1160-

repair of congenital mitral valve dysplasia in infants and children is it always possible

Objectives: Surgical management of congenital malformation of the mitral valve (MV) in the pediatric age group remains a therapeutic challenge for the wide spectrum of the morphological abnormalities and the high incidence of associated cardiac anomalies. We reviewed our experience so as to assess whether MV conservative surgery is always advisable and its results are superior to MV replacement. Methods: Thirty-four consecutive children (20 male and 14 female) with a mean age of 5.9 years (range 45 days‐18 years) treated surgically for congenital MV disease between January 1987 and June 1999. Four patients (11.7%) were under 12 months of age, while 21 patients (62%) were younger than 5 years. Twenty-two patients presented with MV incompetence (or prevalent incompetence), while 12 presented with stenosis (or prevalent stenosis). Associated cardiac lesions were present in 22 patients (62.8%). Results: Mitral valve reconstruction was possible in all. There were no operative deaths. Three patients required reoperation for MV restenosis (a re-repair in one and MV replacement with mechanical prosthesis in two) 4 months, 27 months and 5.6 years after repair with no operative deaths. There was only one late death for prosthetic valve thrombosis. Follow-up data reveal that the 33 surviving patients are asymptomatic and well 4 months‐12 years (mean 72 months) after surgery. At 12 years, actuarial survival and freedom from reoperation are 96.8 and 85.9%, respectively. Echocardiography performed in all of them shows no or mild incompetence or stenosis in 26 (78%), while residual moderate MV incompetence persists in six. Conclusions: Our experience indicates that MV reconstructive procedures in infants and children with congenital MV dysplasia may be effective and reliable with low mortality and low incidence of reoperation rate. Mitral valve repair should always be attempted, especially in infants, despite the frequent severity of MV dysplasia, to avoid the drawbacks of the currently available prostheses. q 2000 Elsevier Science B.V. All rights reserved

Mechanics of cryopreserved aortic and pulmonary homografts

BACKGROUND AND AIM OF THE STUDY: The surgical placement of pulmonary valve grafts into the aortic position (the Ross procedure) has been performed for three decades. Cryopreserved pulmonary valves have had mixed clinical results, however. The objectives of this study were to compare the mechanics of cryopreserved human aortic and pulmonary valve cusps and roots to determine if the pulmonary root can withstand the greater pressures of the aortic position. METHODS: Six aortic and six pulmonary valve roots were obtained from the Oxford Valve Bank. They were harvested during cardiac transplantation from hearts explanted for dilated cardiomyopathy (mean patient age 68 years). The whole roots were initially stored frozen at -186 degrees C, then shipped packed on dry ice. After complete thawing, the roots were pressurized whole; test strips were then cut from the valve cusps, roots and sinuses and tested for stress/strain, stress relaxation, and ultimate failure strength. RESULTS: The pulmonary roots were more distensible (30% versus 20% strain to lock-up) and less compliant when loaded to aortic pressures. The pulmonary valve cusp and root tissue also showed greater extensibility and greater stiffness (lower compliance) when subjected to the same loads. CONCLUSION: We conclude that mechanical differences between aortic and pulmonary valve tissues are minimal. The pulmonary root should withstand the forces imposed on it when placed in the aortic position. However, if implanted whole, the pulmonary root will distend about 30% more than the aortic root when subjected to aortic pressures. These geometric changes may affect valve function in the long term and should be appreciated when implanting a pulmonary valve graft

Wear tested pulmonary porcine valve: mechanical properties and ultrastructural findings.

none4noneGEROSA G.; DAVID H.; VALENTE M.; D. CASAROTTOGerosa, Gino; David, H.; Valente, Marialuisa; Casarotto, Din

Unusual left ventricular mass.

Impact Factor 10,51

Mid-term follow-up in patients with Biocor porcine bioprostheses.

IF 0.87

Long-term results (from 5 to 7 years) with the Hancock S-G-P bioprosthesis.

This communication is concerned with the long-term results of the first 113 patients who underwent single or multiple heart valve replacement with the Hancock-SGP bioprosthesis at the Department of Cardiovascular Surgery, University of Padova Medical School, in a two years period (March 1970-March 1972). Hospital mortality was 18.5%; of the 92 survivors, whose follow-up is now 5 to more than 7 years, the authors report the clinical reevaluation, the complications and the causes of late death. Hemodynamic reevaluation has been performed so far in 26 patients and the prostheses have shown to function properly both in the mitral and the aortic position. The data available to date indicate that the glutaraldehyde preserved porcine valve is durable and its use is warranted in any valvular position