Medical Engineering Division, Maritime Advanced Research Centre, Szczecińska 65, 80-392, Gdańsk, Poland.
Cardiac and Vascular Surgery Department, Medical University of Gdańsk, Dębinki 7, 80-211, Gdańsk, Poland.
Cardiovasc Eng Technol. 2020 Dec;11(6):646-654. doi: 10.1007/s13239-020-00500-z. Epub 2020 Nov 17.
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 V, V and V) 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 V model demonstrated the best performance. The index defining the maximum opening of the bioprosthesis during systole for models V, V and V was 2.67 ± 0.59, 2.04 ± 0.23 and 2.85 ± 0.59 cm, respectively. The mean flow rate through the V 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 V, V and V 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 V 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 V 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.
本文介绍了一种由细菌纤维素（BC）制成的无支架人工主动脉生物瓣（HAB）的体外实验研究结果。设计并测试了三种基本模型的变体，以确定性能参数最佳的瓣膜假体。改良模型由 BC 和心包制成，基本模型由心包制成。
将每个模型（分别命名为 V、V 和 V）植入 90mm 猪主动脉。确定有效瓣口面积（EOA）、快速瓣膜开启时间（RVOT）和快速瓣膜关闭时间（RVCT）。测量每个生物假体模型在模拟心脏收缩期间的流动阻力，即在瓣膜完全打开时的平均压差（ΔP）。所有实验标本均暴露于平均血压（MBP）90.5±2.3mmHg。
V 型模型表现最佳。模型 V、V 和 V 的最大瓣膜开启指数定义为 2.67±0.59、2.04±0.23 和 2.85±0.59cm。V 型瓣膜的平均流量为 5.7±1、6.9±0.7 和 8.9±1.4l/min，对于 65、90 和 110ml 的每搏量（SV）。模型 V、V 和 V 的立即开启和关闭相位分别为周期持续时间的 8%、7%和 5%。模型的平均流动阻力分别为：4.07±2.1、4.28±2.51 和 5.6±2.32mmHg。
V 型主动脉瓣假体最有效。建议使用 BC 作为该模型的结构材料进行体内测试。V 型模型对工作条件变化的响应时间与健康人心脏相当。该模型在体外条件下作为主动脉瓣假体起作用。
