摘要
以往的研究证明由左心房逆行灌注冲洗肺,在短期肺保存中获得良好效果。但此法是否适用于长时间的肺保存,至今尚无资料。也有资料表明:由于肺静脉端较低的血管阻力,常规用于顺行肺灌注—肺保存中的血管扩张素一前列腺素E_1可能不必用于逆行灌注—肺保存。本研究旨在估价逆行灌注和前列腺素E_1(PGE_1)在24h肺保存中的作用。实验狗分为两组,University of Wisconsin保存液(UW液)作为冲洗和保存液。在A组(n=7),250μg PGE_1在进行灌注之前注入供体的肺动脉,另外250μg混合在UW液中。B组为对照组,不用PGE_1。在4℃下保存22～25h后,作同种异体左肺移植。在肺移植之前和之后的10—,30—,60—,120—min测试血流动力学指标、血气分析、呼吸道阻力和肺顺应性。结果表明,经120 min的在体再灌注后,氧和二氧化碳分压(kPa)分别为85.52±3.20和4.93±0.40(A组);79.80±3.87和4.93±0.40(B组)。血流动力学指标(kPa,A组对B组):肺动脉压2.67±0.13对3.73±0.27(P<0.05);右房压0.53±0.13对1.07±0.13(P<0.05);肺血管阻力(dyne·s·cm^(-5))1109±51对1525±133(P<0.05)。气道阻力(kPa/L·s)2.16±0.10对2.35±0.10(P=NS);肺顺应性(CC╱cm)30±1对26±1(P<0.05)。在B组,经2h的再灌注后,气道阻力显著高于实验前的基值(19±1)(P<0.05)。电子显微镜观察表明:除组织间隙水肿外,Ⅰ型肺上皮细胞、毛细血管内皮和微细支气管上皮均现正常。Ⅱ型肺上皮细胞的板层小体内容物减少或消失。上述改变在两组间无明显差别。结论:用UW液逆灌保存犬肺24h是可行的。PGE_1有助于减小肺血管阻力、气道阻力和改善肺顺应性。
Our previous study showed that retrograde flush through the left atrium is better than antegrade flush in 6-- hour lung preservation. It is still not clear whether retrograde flush is feasible in long term lung preservation. Several studies suggested that prostaglandin E 1 may not be necessary in retrograde flush because of the low vascular resistance on the venous side. This study is to evaluate the effects of retrograde flush and prostaglandin E 1 in 24—hour lung preservation. Canine donor lungs were retrograde flushed with University of Wisconsin solution. In group A(n= 7), 250μg prostaglandin was injected into the pulmonary artery before flush and another 250μg was mixd with University of Wisconsin solution. No prostaglandin E1 was used in group B(n=7). After flush and cold immersion stroage in the University of Wisconsin solution at 4℃ for 22～25 hours, left lung allotransplantation was performed. To test the left lung function, measurements were taken while the right pulmonary artery was occluded. After transplantation and 120 minutes of reperfusion ,the oxygen tension and carbon dioxide tension(in kPa)were 85.52±3.20 and 4. 93±0. 40 in group A,and 79.80±3. 87 and 4.93±0.40 in group B Respectively(P=NS). Pulmonary artery pressure (in kPa,group A versus group B)was 2.67±0. 13 versus 3.73±0. 27 (P<0. 01);right atrium pressure: 0. 5±0. 13 versus 1.07±0. 13(P<0. 01); left pulmonary vascular resistance(in dyne. sec. cm^(-5)): 1109±51 versus 1525±133(P<0.05)Fairway resistance(in kPa/L .s) 2. 164±0.01 versus 2.35±0. 01 (P=NS); lung dynamic compliance(in cc/cm) : 30±1 versus 26±1 (P<0. 05), respectively. As compared with the baseline (19±1), airway resistance was significantly increased after 2 hours of reperfusion in group B(P<0.05). Electorn microscopic studies revealed that type Ⅰ pneumocyte, capillary endothelial cells and epithelial cells of bronchia were normal ,except for interstitial edema and there were no differences between the two groups. The contents of lamellar bodies of type Ⅱ cells were reduced or disappeared in both groups. In conclusions, retrograde flush and cold storage using University of Wisconsin solution is feasible in 24—hour lung preservation as evidenced by oxygenation. Pretreatment with prostaglandin E1 is helpful in reducing pulmonary vascular resistance, airway resistance and improving lung dynamic compliance. Efforts still have to be made to improve lung compliance in long term lung preservation.
