Aoe M, Okabayashi K, Cooper J D, Patterson G A
Division of Cardiothoracic Surgery, Department of Surgery, Barnes Hospital, St. Louis, MO, USA.
J Thorac Cardiovasc Surg. 1996 Jul;112(1):94-102. doi: 10.1016/s0022-5223(96)70182-4.
The optimal state of inflation for lung allografts during preservation is not known. We previously showed that hyperinflation of canine lung allografts during storage improved posttransplant graft function as measured during 10 minutes of contralateral pulmonary artery occlusion. However, we have also shown that hyperinflation during storage increases pulmonary capillary permeability. It is possible that short-term total cardiac perfusion through the transplanted left lung (for assessment) may not adequately reproduce the clinical situation. The purpose of this study was to assess the effects of hyperinflation during storage in a canine left single-lung transplantation model in which all perfusion was continuously directed to the graft after implantation. Twenty canine left single-lung transplants were done. The lungs of donor animals were ventilated at a tidal volume of 750 ml and an inspired oxygen fraction of 100%. Donor lungs were flushed with modified Euro-Collins solution and the trachea occluded at end inspiration. For donors in groups I and III, the trachea was sealed at that postinflation volume. In groups II and IV, 200 cc of air was withdrawn from the endotracheal tube under positive pressure and the trachea sealed at the lower tidal volume. Lungs were then extracted and stored at 1 degree C for 12 hours. After the preservation period, left lung transplants were performed. After implantation in all groups, the right pulmonary artery was ligated. In groups I and II, the right bronchus was ligated and in groups III and IV the right bronchus was kept open. Subsequent allograft gas exchange and hemodynamics were assessed during a 6-hour period of reperfusion. After assessment, both lungs were excised, wet/dry lung weight ratio was calculated, and histologic examination was done. During the 6-hour assessment, lungs stored in a state of hyperinflation (groups I and III) showed rapid deterioration of gas exchange. At the final assessment, arterial oxygen tension and alveolar-arterial oxygen gradient of groups I and III were significantly worse than those of groups II and IV (group I versus group II: arterial oxygen tension 87.5 +/- 15.0 versus 373.8 +/- 65.5 mm Hg, alveolar-arterial oxygen gradient 564.4 +/- 13.2 versus 298.6 +/- 69.3 mm Hg, p < 0.05; group III versus group IV: arterial oxygen tension 245.4 +/- 33.0 versus 543.6 +/- 41.8 mm Hg, alveolar-arterial oxygen gradient 392.5 +/- 35.6 versus 120.5 +/- 34.7 mm Hg, p < 0.01). We conclude that donor lung hyperinflation during storage does not provide better posttransplant allograft function when perfusion is limited only to the allograft.
肺移植保存期间的最佳充气状态尚不清楚。我们之前表明，犬肺移植在储存期间的过度充气可改善移植后移植物功能，这在对侧肺动脉闭塞10分钟期间进行了测量。然而，我们还表明，储存期间的过度充气会增加肺毛细血管通透性。通过移植的左肺进行短期全心灌注（用于评估）可能无法充分重现临床情况。本研究的目的是评估在犬左单肺移植模型中储存期间过度充气的影响，在该模型中，植入后所有灌注均持续导向移植物。进行了20例犬左单肺移植。供体动物的肺以750 ml潮气量和100%吸入氧分数进行通气。供体肺用改良的Euro-Collins溶液冲洗，并在吸气末阻塞气管。对于I组和III组的供体，气管在该过度充气体积处密封。在II组和IV组中，在正压下从气管内导管抽出200 cc空气，并在较低潮气量处密封气管。然后取出肺并在1℃下储存12小时。保存期过后，进行左肺移植。所有组植入后，结扎右肺动脉。在I组和II组中，结扎右支气管，在III组和IV组中，右支气管保持开放。在再灌注6小时期间评估随后的移植物气体交换和血流动力学。评估后，切除双肺，计算湿/干肺重量比，并进行组织学检查。在6小时评估期间，处于过度充气状态储存的肺（I组和III组）显示气体交换迅速恶化。在最终评估时，I组和III组的动脉血氧张力和肺泡-动脉血氧梯度明显低于II组和IV组（I组与II组比较：动脉血氧张力87.5±15.0对373.8±65.5 mmHg，肺泡-动脉血氧梯度564.4±13.2对298.6±69.3 mmHg，p<0.05；III组与IV组比较：动脉血氧张力245.4±33.0对543.6±41.8 mmHg，肺泡-动脉血氧梯度392.5±35.6对120.5±34.7 mmHg，p<0.01）。我们得出结论，当灌注仅局限于移植物时，储存期间供体肺过度充气并不能提供更好的移植后移植物功能。
