Wang Dongfang, Lick Scott D, Zhou Xiaoqin, Liu Xiaojun, Benkowski Robert J, Zwischenberger Joseph B
Department of Surgery, University of Kentucky College of Medicine, Lexington, Kentucky 40536-0298, USA.
Ann Thorac Surg. 2007 Nov;84(5):1699-703. doi: 10.1016/j.athoracsur.2007.03.068.
Our goal is ambulatory total respiratory and right heart assistance allowing a bridge to lung transplant. To that end, we have coupled a compact paracorporeal gas exchange device with a right ventricular assist device (RVAD) to create an "OxyRVAD."
Through a limited left thoracotomy, the main pulmonary artery (PA) and right atrium (RA) were exposed in 5 anesthetized sheep. After a systemic heparin bolus, a 12-mm outer diameter crimped graft glued to tubing was anastomosed (end to side) to the main PA and a VAD atrial cannula was placed through the RA appendage. The chest was drained and closed, then the PA graft flowed at 1 to 2 L/min as a shunt to the RA overnight. The next day, the animal was reanticoagulated, and the shunt cannulae clamped and divided. The OxyRVAD unit, consisting of commercially available components including an axial flow pump and low-resistance cardiopulmonary bypass gas exchange device, was interposed. Pumping from RA to PA was maintained at 3 L/min.
Five consecutive sheep survived the implant, and stood and ate normally after initiation of the OxyRVAD. Three survived the full 2-week study, and a fourth was sacrificed on day 13 owing to a storm-related power failure. For these 4 sheep, pump flow was stable at 3 L/min. Carbon dioxide removal was constant and total during the experiment at 200 +/- 19 mL/min. Oxygen transfer was 144 +/- 44 mL/min. One sheep had progressive thrombocytopenia and was sacrificed on day 5 after implant.
Our ambulatory OxyRVAD can provide total assistance for the right heart and lungs in normal awake sheep for 14 days.
我们的目标是实现门诊全呼吸及右心辅助，以作为肺移植的过渡。为此，我们将一个紧凑型体外气体交换装置与一个右心室辅助装置（RVAD）相结合，打造出了“OxyRVAD”。
在5只麻醉的绵羊身上，通过有限的左胸廓切开术暴露主肺动脉（PA）和右心房（RA）。给予全身肝素推注后，将一根外径12毫米、压接在管道上并胶合的移植物（端侧）吻合至主PA，并通过RA心耳置入一个VAD心房插管。胸腔引流并关闭，然后PA移植物以1至2升/分钟的流量作为分流至RA，持续过夜。次日，动物再次抗凝，分流插管夹闭并切断。置入由包括轴流泵和低阻力体外循环气体交换装置等商用组件组成的OxyRVAD单元。从RA到PA的泵血维持在3升/分钟。
连续5只绵羊在植入后存活，并在启动OxyRVAD后正常站立和进食。3只绵羊存活至完整的2周研究结束，第4只因暴风雨相关的停电在第13天被处死。对于这4只绵羊，泵流量稳定在3升/分钟。实验期间二氧化碳清除恒定且总量为200±19毫升/分钟。氧输送为144±44毫升/分钟。1只绵羊出现进行性血小板减少，并在植入后第5天被处死。
我们研发的可门诊使用的OxyRVAD能够在正常清醒的绵羊中为右心和肺提供14天的全辅助。
