Ikeyama K, Sakai H, Omasa M, Nakamura T, Hamakawa H, Fujinaga T, Fukuse T, Wada H
Department of Thoracic Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Eur Surg Res. 2005 Mar-Apr;37(2):85-91. doi: 10.1159/000084538.
In lung transplantation, cold preservation is an important process. However, the mechanical changes in the airway and tissue during cold preservation, especially before reperfusion, are unknown. To test the hypothesis that the mechanical changes in the airway and lung parenchyma start during cold preservation, we investigated the mechanical properties of the rat lung as a whole organ and in excised lung strips. In the 0 h group, the lungs were not preserved. In the 9 and 24 h group, the lungs were preserved for 9 and 24 h at 4 degrees C. After preservation, we evaluated the static compliance (Csta) of the whole lung as obtained from the pressure volume curves (n=5 in each group). Also, we measured the input impedance taken by a computer-controlled small-animal ventilator (n=9 in each group). All data were analyzed using a homogeneous linear model, which includes airway resistance (Raw), tissue elastance (H), and tissue resistance (G). Hysteresivity (eta) was calculated as G/H. Moreover, the tissue elasticity (Eqs) obtained from the quasi-static stress-strain curves was compared. There was no significant difference in Csta among the three groups. Raw was significantly lower in the 24 h group than in the 0 h group (p<0.01). Eqs was significantly higher in the preserved groups than in the 0 h group (p<0.01). These results demonstrated that the changes in the three mechanical properties of the airway and the tissue started within 9 h of preservation.
在肺移植中，冷保存是一个重要过程。然而，冷保存期间气道和组织的力学变化，尤其是在再灌注前，尚不清楚。为了验证气道和肺实质的力学变化始于冷保存的假说，我们研究了大鼠肺作为一个完整器官以及离体肺条的力学特性。在0小时组，肺未进行保存。在9小时和24小时组，肺在4℃下保存9小时和24小时。保存后，我们根据压力-容积曲线评估了全肺的静态顺应性（Csta）（每组n = 5）。此外，我们测量了由计算机控制的小动物呼吸机获取的输入阻抗（每组n = 9）。所有数据均使用包含气道阻力（Raw）、组织弹性（H）和组织阻力（G）的齐次线性模型进行分析。滞后率（η）计算为G/H。此外，还比较了从准静态应力-应变曲线获得的组织弹性（Eqs）。三组之间Csta无显著差异。24小时组的Raw显著低于0小时组（p<0.01）。保存组的Eqs显著高于0小时组（p<0.01）。这些结果表明，气道和组织的三种力学特性的变化在保存9小时内就已开始。
