Doppler echocardiographic findings in tissue engineered aortic valve in a sheep model

Background: Heart valve diseases are considered a common disease in human and animals, and valve replacement is an option for treatment of valvular diseases. Objectives: In this study efficacy of a tissue engineered valve in thoracic aorta was evaluated with transthoracic echocardiography. Methods: This study was undertaken on 6 male sheep. Echocardiography was performed on all sheep 24 hours before surgery and repeated 24 hours (D1), 2 weeks (W2) and 4 weeks (W4) after surgery. Right parasternal long axis view of left ventricular outflow tract (LVOT) was used to assess hemodynamic across new valve. Results: Velocity time integral (VTI) significantly decreased from 18.98±2.88 before surgery to 12.55±2.48 one day after surgery (D1) (p<0.05). Mean Velocity (Vmean) decreased significantly from 52.56±12.01 to 39.72±12.30 at D1 (p<0.05). But maximum velocity (Vmax) was constant during study. There was not any statistical difference between mean Pressure gradient (Pgmean) or maximum pressure gradient (Pgmax) in comparison with pre-surgery and D1, W2 and W4. At D1, W2 and W4, time to peak (TTP) differed significantly from previous time. Conclusions: Our results demonstrated that this tissue engineered aortic valve (TEAV) could change some hemodynamic parameters, but heart could compensate some of them. Valve movement remained normal but the major complication was aneurism which seems to be the result of poor scaffold.