本文介绍了由细菌纤维素(BC)制成的无支架人主动脉生物假体(HAB)的体外实验研究结果。设计并测试了基本模型的三个变体,以识别具有最佳性能参数的瓣膜假体。修改后的模型是由BC制成的,和心包的基本模型。
将每个模型(命名为V1、V2和V3)植入90mm猪主动脉中。有效孔口面积(EOA),确定快速阀门打开时间(RVOT)和快速阀门关闭时间(RVCT)。模拟心脏收缩期间每个生物假体模型的流动阻力,即,测量在全阀打开时的平均压差(ΔP)。所有实验样本均暴露于90.5±2.3mmHg的平均血压(MBP)。
V3模型表现出最佳性能。对于模型V1,V2和V3,定义收缩期生物假体最大开度的指数分别为2.67±0.59、2.04±0.23和2.85±0.59cm2。通过V3阀的平均流速为5.7±1,6.9±0.7和8.9±1.4l/min,每搏体积(SV)为65,90和110mL,分别。模型V1,V2和V3的立即打开和关闭阶段为循环持续时间的8%,7%和5%,分别。模型的平均流动阻力为:4.07±2.1,4.28±2.51和5.6±2.32mmHg。
主动脉瓣假体的V3模型是最有效的。建议使用BC作为该模型的结构材料进行体内测试。V3模型对改变的工作条件的响应时间与健康人类心脏的响应时间相当。该模型在体外条件下用作主动脉瓣假体。
The paper present findings from an in vitro experimental
study of a stentless human aortic bioprosthesis (HAB) made of bacterial cellulose (BC). Three variants of the basic model were designed and tested to identify the valve prosthesis with the best performance parameters. The modified models were made of BC, and the basic model of pericardium.
Each model (named V1, V2 and V3) was implanted into a 90 mm porcine aorta. Effective Orifice Area (EOA), rapid valve opening time (RVOT) and rapid valve closing time (RVCT) were determined. The flow resistance of each bioprosthesis model during the simulated heart systole, i.e. for the mean differential pressure (ΔP) at the time of full valve opening was measured. All experimental specimens were exposed to a mean blood pressure (MBP) of 90.5 ± 2.3 mmHg.
The V3 model demonstrated the best performance. The index defining the maximum opening of the bioprosthesis during systole for models V1, V2 and V3 was 2.67 ± 0.59, 2.04 ± 0.23 and 2.85 ± 0.59 cm2, respectively. The mean flow rate through the V3 valve was 5.7 ± 1, 6.9 ± 0.7 and 8.9 ± 1.4 l/min for stroke volume (SV) of 65, 90 and 110 mL, respectively. The phase of immediate opening and closure for models V1, V2 and V3 was 8, 7 and 5% of the cycle duration, respectively. The mean flow resistance of the models was: 4.07 ± 2.1, 4.28 ± 2.51 and 5.6 ± 2.32 mmHg.
The V3 model of the aortic valve prosthesis is the most effective. In vivo tests using BC as a structural material for this model are recommended. The response time of the V3 model to changed work conditions is comparable to that of a healthy human heart. The model functions as an aortic valve prosthesis in in vitro conditions.