Experimental Studies for Application of the Fixed Lung as an Oxygenator

下面的研究是为了从动物肺中开发出一种更耐用、抗原性更低的人工肺。用机械缺氧机灌注系统评价固定肺的气体交换能力：研制了一种用缺氧血持续灌注保存切除肺的装置。用多聚甲醛-戊二醛混合物（4%多聚甲醛+ 0.25%戊二醛）固定游离兔肺，评价其气体交换能力。5个肺中有2个在5小时的评估期间能够评估。评估5 h时D-PO2（进出血差）分别为28和40 torr (FiO2= 0.21).2。用体内灌注模型评价固定肺的气体交换能力：犬左全肺用同一固定物原位固定。在双侧通气（I组）和左单肺通气（II组）下评估气体交换能力。第一组（n=3），所有犬分别于评估后2、3、4小时死亡。第一次评估时D-PO2（动、静脉血差值）分别为190,212和321 torr （FiO2=1.0）。而在第二组（n=3）， 3只狗中有2只在右肺结扎后死亡，只有1只狗能存活2小时。第一次评估时D-PO2为158 torr。这些结果表明，切除的肺在适当的条件下固定后仍保持与新鲜肺相当的气体交换能力，但很难将固定物从肺中完全冲洗出来。需要改进固定肺的方法，为此目的，需要完全的。需要改进肺部固定方法，为此，需要开发不留下任何固定物的技术或物理固定技术。

The following studies were carried out for the purpose of developing an artificial lung from animal lung which has more durability and less antigenicity.1.Evaluation of gas exchange ability of fixed lung using a perfusion system with mechanical deoxygenator : An apparatus to preserve the resected lung by continuous perfusion with deoxygenated blood was developed. Free rabbit lungs which were fixed by the mixture of paraformaldehyde and glutaraldehyde (4% paraform-aldehyde+0.325% glutaraldehyde) were evaluated its gas exchange ability using this system. Two of 5 lungs were able to evaluate during 5 hour assessment period. D-PO2 (the difference of in-and out-flowing blood) were 28 and 40 torr at 5 hour of assessment (FiO2=O.21).2.Evaluation of gas exchange ability of fixed lung using an in vivo perfusion model : The left whole lung of canine was fixed by the same fixative in site. Gas exchange ability was evaluated under bilateral ventilation (Group I) and left single lungventilation (Group II). In Group I (n=3), all dogs were died at 2,3 and 4 hours of assessmsnt respectively. D-PO2 (the difference of arterial and venous blood) were 190,212 and 321 torr at the first assessment (FiO2=1.0). While, in Group II (n=3), 2 of 3 dogs were died just after ligation of right lung, and only one dog could be alive for 2 hour. D-PO2 at the first assessment was 158 torr.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, but it is very difficult to flush out fixative from lung completely. Improvements in the method for fixation of the lung are desired, and, for this purpose, the completely. 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.