Experimental Sutdies for Application of the Heterogeneous Lung as Oxygenator

为了开发一种保留了体内肺的优点、更耐用且无抗原性的天然呼吸机，进行了以下研究。1.切除游离肺功能评价装置的开发：开发了通过用含氧血灌注与用静脉血间歇灌注来保存切除肺的装置，并在不同时间点同时评价气道阻力、肺动脉压和气体交换能力。2.保存肺的功能评价：用上述装置连续监测保存切除肺的气体交换能力，并评价最佳保存条件。单纯浸泡保存的兔肺功能在48小时内保持良好，但72小时后明显降低。3.固定肺的气体交换能力：评价最大限度保留肺功能的固定方法。是 ...更多信息 在10%福尔马林、0.625%戊二醛、4%多聚甲醛+0.325%戊二醛三组中，多聚甲醛与戊二醛混合液的气体交换能力最好，与新鲜肺相当。4.具有异质血液和气体交换能力的灌注：检查了天然肺是否可以用作跨物种的氧合器。犬肺对兔血有较好的气体交换能力。5.通过^1H-MRI对肺进行成像研究：作为开发异种肺移植物的基本步骤，通过MRI对肺功能进行研究。根据MR图像评价肺内水的动力学，这决定了肺的气体交换能力。保存兔肺各项参数的计算值随肺含水量指标湿/干重比的变化而变化，表明在适当条件下固定的离体肺仍具有与新鲜肺相当的气体交换能力，异质肺也具有气体交换能力，肺的气体交换能力由于水肿变化导致的气-血屏障增厚而降低，并且MRI可用于这些变化的非侵入性检测。期望改进用于固定肺的方法，并且为此目的，需要开发不会留下甚至痕量的固定剂的技术或用于物理固定的技术。少

The following studies were carried out for the purpose of developing a natural ventilator which retains the merits of the in vivo lung,is more durable,and has no antigenicity. 1.The development of an apparatus for functional evaluation of the resected free lung: An apparatus to preserve the resected lung by perfusion with oxygenated blood with intermittent perfusion with venous blood was developed,and airway resistance,pulmonary artery pressure,and gas exchange ability were evaluated simultaneously at various time points. 2.functional evaluation of the preserved lung: The gas exchange ability of the preserved resected lung was serially monitored with the above apparatus,and optimal conditions of preservation were evaluated. The function of the rabbit lung preserved by simple immersion was well maintained for 48 hours but was significantly reduced after 72 hours. 3.Gas exchange ability of the fixed lung: The fixation method for maximum preservation of the lung function was evaluated. Am … More ong 10% formalin,0.625% glutaraldehyde,4% paraformaldehyde + 0.325% glutaraldehyde,the mixture of paraformaldehyde and glutaraldehyde was the best and showed a gas exchange ability comparable to the fresh lung. 4.Perfusion with heterogeneous blood and gas exchange ability: Whether the natural lung can be used as an oxygenator across the species was examined. The resected dog lung showed sufficient gas exchange ability for rabbit blood. 5.Imaging studies of the lung by ^1H-MRI: As a basic step for the development of a heterogeneous lung graft,the lung function was studied by MRI. The dynamics of the water in the lung,which determines its gas exchange ability,was evaluated according to MR images. The values of various parameters calculated in the preserved rabbit lung changed with the wet/dry weight ratio,which is an index of the water content of the lung.These findings suggest that the resected lung retains gas exchange ability comparable to that of the fresh lung if it has been fixed under appropriate conditions,that heterogeneous lungs show a gas exchange ability,that the gas exchange ability of the lung is reduced by thickening of the air-blood barrier due to edematous changes,and that MRI is useful for noninvasive detection of these changes. Improvements in the method for fixation of the lung are desired,and,for this purpose,the development of techniques that do not leave even a trace amount of the fixative or techniques for physical fixation is needed. Less