Pancreas oxygenation is limited during preservation with the two-layer method
Pancreas oxygenation is limited during preservation with the two-layer method
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DOI：
10.1016/j.transproceed.2005.09.085
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发表时间：
2005-10-01
影响因子：
0.9
通讯作者：
Avgoustiniatos, ES
中科院分区：
文献类型：
--
作者：
Papas, KK;Hering, BJ;Avgoustiniatos, ES
背景据报道，用于胰腺保存的双层方法（TLM）相对于先前的方法提高了胰岛产量和移植结果。ATP浓度的增加支持了这样的假设，即这些改善与全氟化碳溶液的更好的氧化有关。然而，用TLM保存的胰腺中氧分压（pO（2））的直接测量有限。理论预测，人类胰腺只有一小部分可以在外部充氧。在本报告中，我们使用理论和直接pO（2）测量来检查TLM的胰腺氧合作用。方法。用扩散-反应模型计算了不同温度下柱状胰腺的pO（2）分布。在100%氧饱和的介质中，使用光纤传感器测量用TLM保存的猪胰腺组织核心中的pO（2）。该模型预测，在8摄氏度，即使在没有外部pO（2）梯度，氧渗透深度约为1毫米，胰腺直径不敏感，而氧合体积分数约为15%的2.5厘米直径的胰腺。实验测量证实，在用TLM保存的1cm厚胰腺片的核心中，pO（2）几乎为零。溶液在传感器周围的渗透可能是观察到的滞后和先前报告的非零pO（2）测量值的原因。热处理组织的复氧需要几个小时。TLM仅能包裹人胰腺的一小部分体积。应探索通过天然血管系统的胰腺氧合，以进一步提高活胰岛的产量。
Background. The two-layer method (TLM) for pancreas preservation reportedly improves islet yield and transplantation outcome relative to previous methods. Increased ATP concentrations support the hypothesis that these improvements are related to better oxygenation from the perfluorocarbon solution. However, there are limited direct measurements of oxygen partial pressure, (pO(2)) in pancreata preserved with the TLM. Theory predicts that only a small fraction of a human pancreas can be oxygenated externally. In this report we examine pancreas oxygenation with the TLM using theory and direct pO(2) measurements.Methods. pO(2) profiles in cylindrical pancreata were calculated at various temperatures with a diffusion-reaction model. The pO(2) was measured using fiber optic sensors in the core of porcine pancreatic tissue preserved with the TLM in media saturated with 100% oxygen.Results. The model predicts that at 8 degrees C even in the absence of an external pO(2) gradient, oxygen penetration depth is about 1 mm and insensitive to pancreas diameter, while the oxygenated volume fraction is about 15% for a 2.5-cm-diameter pancreas. Experimental measurements verified that pO(2) is virtually zero in the core of a 1-cm-thick pancreatic piece preserved with the TLM. Penetration of solution around the sensor may be responsible for the observed lag and for the previously reported nonzero pO(2) measurements. Reoxygenation of heat-treated tissue took several hours.Conclusions. The TLM can oxygenate only a small volume fraction of a human pancreas. Pancreas oxygenation through the native vasculature should be explored to further improve yield of viable islets.