Experimental study of mature pulmonary lobar allo-transplantation in puppies.

背景：使用缩小大小的成人肺移植可以帮助解决严重的儿科供肺短缺问题。然而，成熟移植物的充分长期功能需要与受者的发育成比例的增长。方法：取成年比格犬6只(平均体重12 kg)左肺下叶，移植给6只3个月龄、平均体重5 kg的幼犬，行左肺切除术(ID)。对照组(MD)：成年犬5只，接受同种异体肺叶移植。移植后12个月或以上在Fi02-1机械通气下进行右肺动脉阻断试验。分别于结扎前、结扎后5、10、15、30min测心输出量、肺动脉压(PAP)、股动脉血气分析(PaOA、PaCOA)，计算AaDO2。移植物被取出并进行组织学检查。结果：ID组有5只犬存活，3只犬耐受右肺动脉阻断试验。在MD中，有三只狗存活并耐受了闭塞试验。ID组和MD组的平均PAP升高差异无统计学意义。动脉血氧分压(PaO2)、二氧化碳分压(PaCO2)、动脉血氧分压(AaDO)在结扎前和结扎后30min的变化无差异。组织学检查显示，肺实质结构正常，但在ID和MD移植物中均可观察到肺泡扩大。结论：在本实验犬成熟肺叶移植模型中，成熟肺叶的肺泡结构接近正常外观或肺气肿，并保持了成熟肺叶的长期功能。

Back ground : The use of reduced-size adult lung transplantation could help solve the profound pediatric donor lung shortage. However, adequate long-term function of mature grafts requires growth in proportion to the recipient's development. Methods : Six mature left lower lobes from adult beagles (mean body weight : 12kg) were harvested and transplanted to six immature beagles (age : 3 months, mean body weight : 5kg) that underwent left pneumonectmy (ID). The control group (MD) was 5 adult dogs that underwent mature pulmonary lobar allotransplantation. Right pulmonary arterial occlusion test was performed under mechanical ventilation with Fi02 1 in 12 months or more after transplantation. Cardiac output and pulmonary arterial pressure (PAP) were measured, femoral arterial blood gas analysis (PaOa and PaCOa) was performed, and AaDO2 was calculated before and after occlusion at 5, 10, 15, and 30 minutes. The grafts were removed and examined histologically. Results : In ID, five dogs survived and three dogs tolerated the right pulmonary arterial occlusion test. In MD, three dogs survived and tolerated the occlusion test. There was no significant difference in mean PAP elevation between ID and MD. There were no differences in changes in Pa02, PaCO2 and AaDO before and 30 minutes after occlusion. Histological studies showed normal architecture of lung parenchyma but alveolar enlargement was observed in both ID and MD grafts.Conclusion : We conclude that in this experimental model of mature lobar transplantation in puppies, the alveolar architecture of a mature lobe is almost normal appearance or emphysema, and the long term function of a mature lobe is maintained well.