Abstract
Surgical countermeasures for predictable regurgitation through an aortic stentless prosthesis, especially when the freehand method is employed, were investigated experimentally. Regurgitant flow at 100mmHg was measured under certain conditions using a porcine ascending aorta which included the valve. When one aortic cusp was injured, aortic regurgitation occured (160±18mL/min). Cusp enlargement and decreasing the size of the sinotubular junction (STJ) worsened the regurgitation. However annuloplasty eliminated the regurgitation when annular size was decreased by 30.7±6.9%. When the STJ was enlarged with three patches until it reached a size of 35.9±2.2mm (annular size;21.7±0.7mm), central regurgitation occured (54±18mL/min). When the STJ size was decreased by 22.0±6.0%, no regurgitation was observed. From this experiment, we concluded that annuloplasty and correction of the STJ size are effective countermeasures to decrease slight regurgitation through a soft aortic stentless prosthesis.
