Throckmorton Amy L, Ballman Kimberly K, Myers Cynthia D, Litwak Kenneth N, Frankel Steven H, Rodefeld Mark D
Department of Surgery, Section of Cardiothoracic Surgery, Indiana University School of Medicine, Indianapolis, Indiana [corrected] USA.
ASAIO J. 2007 Nov-Dec;53(6):734-41. doi: 10.1097/MAT.0b013e318159d14b.
A blood pump specifically designed to operate in the unique anatomic and physiologic conditions of a cavopulmonary connection has never been developed. Mechanical augmentation of cavopulmonary blood flow in a univentricular circulation would reduce systemic venous pressure, increase preload to the single ventricle, and temporarily reproduce a scenario analogous to the normal two-ventricle circulation. We hypothesize that a folding propeller blood pump would function optimally in this cavopulmonary circulation. The hydraulic performance of a two-bladed propeller prototype was characterized in an experimental flow loop using a blood analog fluid for 0.5-3.5 lpm at rotational speeds of 3,600-4,000 rpm. We also created five distinctive blood pump designs and evaluated their hydraulic performance using computational fluid dynamics (CFD). The two-bladed prototype performed well over the design range of 0.5-3.5 lpm, producing physiologic pressure rises of 5-18 mm Hg. Building upon this proof-of-concept testing, the CFD analysis of the five numerical models predicted a physiologic pressure range of 5-40 mm Hg over 0.5-4 lpm for rotational speeds of 3,000-7,000 rpm. These preliminary propeller designs and the two-bladed prototype achieved the expected hydraulic performance. Optimization of these configurations will reduce fluid stress levels, remove regions of recirculation, and improve the hydraulic performance of the folding propeller. This propeller design produces the physiologic pressures and flows that are in the ideal range to mechanically support the cavopulmonary circulation and represents an exciting new therapeutic option for the support of a univentricular Fontan circulation.
一种专门设计用于在腔肺连接独特的解剖和生理条件下运行的血泵尚未研发出来。在单心室循环中机械增强腔肺血流会降低体静脉压力，增加单心室的前负荷，并暂时重现类似于正常双心室循环的情况。我们假设折叠式螺旋桨血泵在这种腔肺循环中能发挥最佳功能。使用血液模拟液在实验流路中对两叶螺旋桨原型的水力性能进行了表征，流量范围为0.5 - 3.5升/分钟，转速为3600 - 4000转/分钟。我们还创建了五种独特的血泵设计，并使用计算流体动力学（CFD）评估了它们的水力性能。两叶原型在0.5 - 3.5升/分钟的设计流量范围内表现良好，产生的生理压力升高为5 - 18毫米汞柱。基于这一概念验证测试，对五个数值模型的CFD分析预测，在转速为3000 - 7000转/分钟时，流量范围为0.5 - 4升/分钟的生理压力范围为5 - 40毫米汞柱。这些初步的螺旋桨设计和两叶原型达到了预期的水力性能。对这些配置进行优化将降低流体应力水平，消除再循环区域，并改善折叠式螺旋桨的水力性能。这种螺旋桨设计产生的生理压力和流量处于理想范围内，能够机械支持腔肺循环，为单心室Fontan循环的支持提供了一种令人兴奋的新治疗选择。
