Significance: Real-time information about oxygen delivery to the hepatic graft is important to direct care and diagnose vascular compromise in the immediate post-transplant period. Aim: The current study was designed to determine the utility of visible diffuse reflectance spectroscopy (vis-DRS) for measuring liver tissue saturation in vivo. Approach: A custom-built vis-DRS probe was calibrated using phantoms with hemoglobin (Hb) and polystyrene microspheres. Ex vivo (extracorporeal circulation) and in vivo protocols were used in a swine model (n = 15) with validation via blood gas analysis. Results:In vivo absorption and scattering measured by vis-DRS with and without biliverdin correction correlated closely between analyses. Lin’s concordance correlation coefficients are 0.991 for μa and 0.959 for μs ′ . Hb measured by blood test and vis-DRS with (R2 = 0.81) and without (R2 = 0.85) biliverdin correction were compared. Vis-DRS data obtained from the ex vivo protocol plotted against the PO2 derived from blood gas analysis showed a good fit for a Hill coefficient of 1.67 and P50 = 34 mmHg (R2 = 0.81). A conversion formula was developed to account for the systematic deviation, which resulted in a goodness-of-fit R2 = 0.76 with the expected oxygen dissociation curve. Conclusions: We show that vis-DRS allows for real-time measurement of liver tissue saturation, an indicator for liver perfusion and oxygen delivery.

中文翻译：

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肝组织中可见漫反射光谱的评估：使用体外循环验证组织饱和度

意义：关于向肝移植物输送氧气的实时信息对于在移植后即刻指导护理和诊断血管损害非常重要。目的：本研究旨在确定可见漫反射光谱 (vis-DRS) 在体内测量肝组织饱和度的效用。方法：使用带有血红蛋白 (Hb) 和聚苯乙烯微球的体模校准定制的 vis-DRS 探针。体外（体外循环）和体内方案用于猪模型（n = 15），并通过血气分析进行验证。结果：在有和没有胆绿素校正的情况下，通过 vis-DRS 测量的体内吸收和散射在分析之间密切相关。Lin 的一致性相关系数对于 μa 为 0.991，对于 μs ' 为 0.959。比较了通过血液测试和 vis-DRS 测量的 Hb（R2 = 0.81）和没有（R2 = 0.85）胆绿素校正。从离体协议中获得的 Vis-DRS 数据针对从血气分析得出的 PO2 绘制，表明非常适合希尔系数为 1.67 和 P50 = 34 mmHg（R2 = 0.81）。开发了一个转换公式来解释系统偏差，这导致与预期的氧解离曲线的拟合优度 R2 = 0.76。结论：我们表明 vis-DRS 允许实时测量肝组织饱和度，这是肝脏灌注和氧气输送的指标。67 和 P50 = 34 mmHg (R2 = 0.81)。开发了一个转换公式来解释系统偏差，这导致与预期的氧解离曲线的拟合优度 R2 = 0.76。结论：我们表明 vis-DRS 允许实时测量肝组织饱和度，这是肝脏灌注和氧气输送的指标。67 和 P50 = 34 mmHg (R2 = 0.81)。开发了一个转换公式来解释系统偏差，这导致与预期的氧解离曲线的拟合优度 R2 = 0.76。结论：我们表明 vis-DRS 允许实时测量肝组织饱和度，这是肝脏灌注和氧气输送的指标。