The aim of our study was to evaluate the impact of stentless aortic bioprosthesis implantation on early and late postoperative results and hemodynamic changes.
Material and methods: Study group consisted of 66 patients, who received stentless aortic bioprosthesis in 1999-2003, and control group of 38 patients, randomly selected for data analysis out of 203 patients, who received mechanical aortic valve substitute during the same period at the Heart Center of Kaunas University of Medicine. Study protocol included clinical data, patients functional status and echocardiographic data pre and postoperatively up to 2 years.
Results: Within a stentless bioprosthesis group clinically more severe forms of aortic valve disease were present (NYHA f. cl. 3.47 vs 3.0), with concomitant ischemic heart disease (51.5% vs 36.8%), and mitral valve insufficiency (51.5% vs 21.1%). Subsequently coronary artery bypass grafting was performed in 50% of patients within a stentless bioprosthesis group vs 28.9% in a mechanical valve group, and mitral valve repair in 30.49% vs 10.5%. Aortic cross clamp time in a stentless bioprosthesis group was 89.1+/-21.3 min, compared to 74.6+/-39.5 min in a "mechanical" group. Data analysis of valve/body surface area match was in favor of stentless valves: patients with the same body surface area received one size larger stentless valves. Mortality in a "stentless" group was 4.54 vs 7.3% in mechanical group. Mean transvalvular gradients after 2 years were statistically significantly lower in a "stentless" group: 9.4+/-3.1 mmHg vs 11.1+/-4.1 mmHg. Also there was significant decrease of left ventricular mass and mass index in both groups, however it was more pronounced in the "stentless" valve group.
Conclusions: Despite more advanced patient age, stages of aortic valve disease, complexity of operations including more demanding stentless bioprosthesis implantation techniques, early and late postoperative results are in favor of stentless bioprosthesis. Low and acceptable postoperative mortality, lower transvalvular gradients, optimal matching of valve and body surface area, could be achieved, which warrants more pronounced positive postoperative left ventricular remodeling: reduction of left ventricle mass and left ventricle mass index with improved pts survival.