Extracorporeal Life Support Laboratory, Department of Surgery, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
J Thorac Cardiovasc Surg. 2011 Feb;141(2):537-42, 542.e1. doi: 10.1016/j.jtcvs.2010.08.092.
This study evaluated the effectiveness of an atrial septostomy with veno-venous extracorporeal membrane oxygenation in alleviating high afterload right ventricular dysfunction while providing respiratory support. This technique could be applied as a bridge to lung transplantation.
Sheep (56±3 kg) underwent a clamshell thoracotomy and hemodynamic instrumentation, including right ventricular pressure and cardiac output. Sheep with and without tricuspid insufficiency (n=5 each) were examined. While sheep were on extracorporeal membrane oxygenation, right ventricular failure was established by banding the pulmonary artery until cardiac output was 40% to 60% of baseline. An extracardiac atrial shunt was created with modified vascular grafts to examine the effect of shunt flow on hemodynamics. Hemodynamic data were thus collected at baseline, during right ventricular failure, and for 1 hour at 100% (fully open), 70%, 50%, and 30% of baseline shunt flow.
Cardiac output was returned to baseline values (tricuspid insufficiency: 5.2±0.2 L/min, without tricuspid insufficiency: 5.3±1.2 L/min) with 100% shunt flow (tricuspid insufficiency: 4.8±1.1 L/min, without tricuspid insufficiency: 4.8±1.0 L/min; P=.15) but remained significantly lower than baseline at 70% to 30% shunt flow. At 100% shunt flow, tricuspid insufficiency shunt flow was 1.4±0.8 L/min and without tricuspid insufficiency shunt flow was 1.7±0.2 L/min. Right ventricular pressure was significantly elevated over baseline values at all shunt flows (P<.001). In the group without tricuspid insufficiency, all sheep died beginning at the 70% shunt condition, whereas all animals with tricuspid insufficiency survived the entire experiment. Normal arterial blood gases were maintained under all conditions.
An atrial septostomy accompanied by veno-venous extracorporeal membrane oxygenation is capable of eliminating right ventricular failure while maintaining normal arterial blood gases if sufficient shunt flows are achieved. The presence of tricuspid insufficiency improves the efficacy of the shunt.
本研究评估了在提供呼吸支持的同时，通过房间隔造口术联合静脉-静脉体外膜肺氧合减轻高后负荷右心功能障碍的效果。该技术可作为肺移植的桥梁。
绵羊（56±3kg）接受了蛤壳式开胸术和血流动力学仪器检查，包括右心室压力和心输出量。检查了有和没有三尖瓣关闭不全的绵羊（每组各 5 只）。当绵羊在体外膜肺氧合时，通过捆绑肺动脉使右心室衰竭，直到心输出量降至基线的 40%至 60%。使用改良的血管移植物创建心外房间隔分流，以检查分流流量对血流动力学的影响。因此，在基线、右心室衰竭期间以及在分流流量为 100%（完全开放）、70%、50%和 30%的情况下 1 小时内收集血流动力学数据。
在 100%的分流流量下，心输出量恢复到基线值（三尖瓣关闭不全：5.2±0.2L/min，无三尖瓣关闭不全：5.3±1.2L/min）（三尖瓣关闭不全：4.8±1.1L/min，无三尖瓣关闭不全：4.8±1.0L/min；P=.15），但仍明显低于分流流量为 70%至 30%时的基线值。在 100%的分流流量下，三尖瓣关闭不全的分流流量为 1.4±0.8L/min，无三尖瓣关闭不全的分流流量为 1.7±0.2L/min。在所有分流流量下，右心室压力均明显高于基线值（P<.001）。在无三尖瓣关闭不全的组中，所有绵羊在 70%的分流条件下开始死亡，而所有有三尖瓣关闭不全的动物都完成了整个实验。在所有条件下均保持正常的动脉血气。
如果达到足够的分流流量，房间隔造口术联合静脉-静脉体外膜肺氧合可消除右心衰竭并维持正常的动脉血气。三尖瓣关闭不全的存在可提高分流的效果。
