Department of Pediatric Surgery, The University of Texas Medical School at Houston, Houston, Texas, USA.
ASAIO J. 2010 Jan-Feb;56(1):73-6. doi: 10.1097/MAT.0b013e3181c83965.
The ratio of pulmonary:systemic blood flow (Qp:Qs) remains problematic after single ventricle reconstruction. The adjustable systemic-pulmonary artery shunt (AS) was created as a solution for this problem. Prototype ASs were created using a screw-plunger mechanism as a variable resistor. A stepper motor controls plunger displacement. Six adult dogs underwent placement of a 4-mm AS in the femoral position to test its ability to control flow. Shunts were placed as arteriovenous fistulae to simulate the continuous flow of systemic-pulmonary AS. The 3.5-mm control shunts (CS) were placed on the contralateral side. The stepper motor was rotated from fully open to 3.4 mm of plunger depression for six complete cycles. Flow in the fully open AS was 687.9 +/- 28.7 cc/min* vs. 578.7 +/- 26.8 cc/min in the CS (flow +/- standard error, *p < 0.005 vs. CS). Standard deviation of flow was similar between the AS and CS, implying hysteresis in resistor function did not contribute to flow variability. Peak torque requirement to turn the resistor was 2.4 mNm. The AS offers excellent control of flow in vivo. Control of Qp:Qs may lead to improved outcomes for single ventricle reconstructions.
单心室重建后，肺循环与体循环血流量的比值（Qp:Qs）仍然存在问题。可调式体肺动脉分流（AS）的出现解决了这个问题。原型 AS 采用螺旋柱塞机构作为可变电阻器。步进电机控制柱塞的位移。六只成年狗在股动脉位置植入 4mm 的 AS 以测试其控制流量的能力。AS 被安置为动静脉瘘以模拟体肺 AS 的连续血流。3.5mm 的对照分流（CS）被放置在对侧。步进电机从完全打开到柱塞压下 3.4mm 旋转六个完整的周期。完全打开的 AS 中的流量为 687.9 +/- 28.7 cc/min*，而 CS 中的流量为 578.7 +/- 26.8 cc/min（流量 +/- 标准误差，*p < 0.005 与 CS 相比）。AS 和 CS 之间的流量标准差相似，这意味着电阻器功能的滞后不会导致流量变化。转动电阻器所需的峰值扭矩为 2.4 mNm。AS 可在体内实现对流量的出色控制。对 Qp:Qs 的控制可能会改善单心室重建的结果。
