Ordies Sofie, Orlitova Michaela, Heigl Tobias, Sacreas Annelore, Van Herck Anke, Kaes Janne, Saez Berta, Vanstapel Arno, Ceulemans Laurens, Vanaudenaerde Bart M, Vos Robin, Verschakelen Johny, Verleden Geert M, Verleden Stijn E, Van Raemdonck Dirk E, Neyrinck Arne P
Unit of Anesthesiology and Algology, Department of Cardiovascular Sciences, Katholieke Universiteit Leuven, Leuven, Belgium.
Department of Anesthesiology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.
Intensive Care Med Exp. 2020 Nov 25;8(1):70. doi: 10.1186/s40635-020-00360-w.
Ex vivo lung perfusion (EVLP) is a widespread accepted platform for preservation and evaluation of donor lungs prior to lung transplantation (LTx). Standard lungs are ventilated using volume-controlled ventilation (VCV). We investigated the effects of flow-controlled ventilation (FCV) in a large animal EVLP model. Fourteen porcine lungs were mounted on EVLP after a warm ischemic interval of 2 h and randomized in two groups (n = 7/group). In VCV, 7 grafts were conventionally ventilated and in FCV, 7 grafts were ventilated by flow-controlled ventilation. EVLP physiologic parameters (compliance, pulmonary vascular resistance and oxygenation) were recorded hourly. After 6 h of EVLP, broncho-alveolar lavage (BAL) was performed and biopsies for wet-to-dry weight (W/D) ratio and histology were taken. The left lung was inflated, frozen in liquid nitrogen vapors and scanned with computed tomography (CT) to assess regional distribution of Hounsfield units (HU).
All lungs endured 6 h of EVLP. Oxygenation was better in FCV compared to VCV (p = 0.01) and the decrease in lung compliance was less in FCV (p = 0.03). W/D ratio, pathology and BAL samples did not differ between both groups (p = 0.16, p = 0.55 and p = 0.62). Overall, CT densities tended to be less pronounced in FCV (p = 0.05). Distribution of CT densities revealed a higher proportion of well-aerated lung parts in FCV compared to VCV (p = 0.01).
FCV in pulmonary grafts mounted on EVLP is feasible and leads to improved oxygenation and alveolar recruitment. This ventilation strategy might prolong EVLP over time, with less risk for volutrauma and atelectrauma.
体外肺灌注（EVLP）是肺移植（LTx）前供肺保存和评估广泛接受的平台。标准肺采用容量控制通气（VCV）进行通气。我们在大型动物EVLP模型中研究了流量控制通气（FCV）的效果。14只猪肺在2小时热缺血间隔后安装在EVLP上，并随机分为两组（每组n = 7）。在VCV组，7个移植物采用传统通气，在FCV组，7个移植物采用流量控制通气。每小时记录EVLP生理参数（顺应性、肺血管阻力和氧合）。EVLP 6小时后，进行支气管肺泡灌洗（BAL），并取活检组织测定湿干重（W/D）比和组织学检查。左肺充气，在液氮蒸汽中冷冻，并用计算机断层扫描（CT）扫描以评估亨氏单位（HU）的区域分布。
所有肺均耐受6小时的EVLP。与VCV相比，FCV组的氧合更好（p = 0.01），FCV组肺顺应性的下降更少（p = 0.03）。两组之间的W/D比、病理学和BAL样本无差异（p = 0.16、p = 0.55和p = 0.62）。总体而言，FCV组的CT密度倾向于不那么明显（p = 0.05）。CT密度分布显示，与VCV相比，FCV组通气良好的肺部分比例更高（p = 0.01）。
安装在EVLP上的肺移植物采用FCV是可行的，并可改善氧合和肺泡复张。这种通气策略可能会随着时间的推移延长EVLP，降低容积伤和肺不张伤的风险。
