改良EC液低温灌注犬肺离体肺组织形态学变化的研究

Morphological changes in canine lungs perfused with modified Euro-Collins solution

目的观察犬肺移植中供体离体保存后肺组织随时间延长而产生的结构变化。方法4℃改进型EC液灌注6只健康成年杂种犬肺,灌注结束后离体保存30、60、120、180、240 min。取材制作组织标本,观察不同时间点肺组织结构变化,以灌注前作为对照组。结果0 min时肺组织结构清晰完整,肺泡上皮细胞线粒体轻微肿胀;30 min时肺泡壁、血管周围组织轻微水肿;60 min时肺泡壁结构轻度破损,肺泡上皮细胞肿胀,线粒体肿胀较明显;120 min时部分肺泡壁断裂,肺泡腔融合;180 min时肺泡壁断裂,肺泡腔融合形成少量肺大泡;240 min时肺泡壁断裂,肺泡腔融合形成多个肺大泡,肺泡上皮细胞泡浆空泡变,Ⅱ型肺泡细胞板层小体模糊不清, 空泡变明显,微绒毛已消失。结论改进型EC液离体保存4 h内对离体保存肺组织细胞无明显损伤,4 h后肺损伤较为严重。

Objective To investigate the structural changes in canine lungs perfused with modified Euro-Collins solution (mECS), thus providing insight into the preservation of the donor lung tissue for transplantation. Methods Six dogs were anesthetized and pulmonary perfusion with mECS (4 ℃) was performed before the lungs were isolated thereafter and stored at 4 to 8 ℃for 30, 60, 120, 180, 240 min respectively, after which tissue samples of the donor lung were taken for morphological observation with both light and transmission electron microscope. Results Immediately after reperfusion, the pulmonary tissues exhibited clear and intact structures,showing that mitochondrion swelled slightly in the alveolar epithelial cells (AECs). Mild edema occurred in the alveolar wall and the tissues around the veins at 30 min after preservation, which exacerbated to dilapidation of the alveolar wall and obvious tumefaction of the mitochondrion in the AECs at 60 min. At 180 min, rupture of alveolar wall and mergence of the alveolus was observed at 120 min, and a few pulmonary bullae were formed, the AECs (I) of which presented vacuolar changes in the cytoplasma and mitochondrion, with disappearance of the tiny villus of the AECs (II) at 240 min. Conclusion Within 4 h of preservation in mECS, the pulmonary tissues do not undergo obvious changes as signs of injury, which, however, may not be the case after longer preservation.