Department of Surgery, Division of HPB and Transplant Surgery, Transplant Institute, Erasmus Medical Center, Rotterdam, the Netherlands.
Department of Biomechanical Engineering, Delft University of Technology, Delft, the Netherlands.
Lasers Surg Med. 2023 Oct;55(8):784-793. doi: 10.1002/lsm.23715. Epub 2023 Aug 9.
Normothermic machine perfusion (NMP) provides a platform for pre-transplant kidney quality assessment that is essential for the use of marginal donor kidneys. Laser speckle contrast imaging (LSCI) presents distinct advantages as a real-time and noncontact imaging technique for measuring microcirculation. In this study, we aimed to assess the value of LSCI in visualizing renal cortical perfusion and investigate the additional value of dual-side LSCI measurements compared to single aspect measurement during NMP.
Porcine kidneys were obtained from a slaughterhouse and then underwent NMP. LSCI was used to measure one-sided cortical perfusion in the first 100 min of NMP. Thereafter, the inferior renal artery branch was occluded to induce partial ischemia and LSCI measurements on both ventral and dorsal sides were performed.
LSCI fluxes correlated linearly with the renal blood flow (R = 0.90, p < 0.001). After renal artery branch occlusion, absence of renal cortical perfusion could be visualized and semiquantified by LSCI. The overall ischemic area percentage of the ventral and dorsal sides was comparable (median interquartile range [IQR], 38 [24-43]% vs. 29 [17-46]%, p = 0.43), but heterogenous patterns between the two aspects were observed. There was a significant difference in oxygen consumption (mean ± standard deviation [SD], 2.57 ± 0.63 vs. 1.83 ± 0.49 mLO /min/100 g, p < 0.001), urine output (median [IQR], 1.3 [1.1-1.7] vs. 0.8 [0.6-1.3] mL/min, p < 0.05), lactate dehydrogenase (mean ± SD, 768 ± 370 vs. 905 ± 401 U/L, p < 0.05) and AST (mean ± SD, 352 ± 285 vs. 462 ± 383 U/L, p < 0.01) before and after renal artery occlusion, while no significant difference was found in creatinine clearance, fractional excretion of sodium, total sodium reabsorption and histological damage.
LSCI fluxes correlated linearly with renal blood flow during NMP. Renal cortical microcirculation and absent perfusion can be visualized and semiquantified by LSCI. It provides a relative understanding of perfusion levels, allowing for a qualitative comparison between regions in the kidney. Dual-side LSCI measurements are of added value compared to single aspect measurement and renal function markers.
体温非停搏机器灌流（NMP）为移植前肾脏质量评估提供了一个平台，这对于使用边缘供体肾脏至关重要。激光散斑对比成像（LSCI）作为一种实时、非接触式的微循环测量技术具有明显的优势。本研究旨在评估 LSCI 可视化肾皮质灌注的价值，并探讨在 NMP 期间与单侧测量相比，双侧 LSCI 测量的附加价值。
从屠宰场获得猪肾，然后进行 NMP。在 NMP 的前 100 分钟内，使用 LSCI 测量单侧皮质灌注。此后，闭塞肾动脉分支以诱导部分缺血，并进行腹侧和背侧的 LSCI 测量。
LSCI 通量与肾血流量呈线性相关（R=0.90，p<0.001）。肾动脉分支闭塞后，LSCI 可可视化和半定量显示肾皮质无灌注。腹侧和背侧的整体缺血面积百分比相当（中位数[四分位距（IQR）]，38[24-43]% vs. 29[17-46]%，p=0.43），但两个方面的模式存在异质性。耗氧量（均值±标准差[SD]，2.57±0.63 vs. 1.83±0.49 mLO / min / 100 g，p<0.001）、尿量（中位数[IQR]，1.3[1.1-1.7] vs. 0.8[0.6-1.3]mL/min，p<0.05）、乳酸脱氢酶（均值±SD，768±370 vs. 905±401 U/L，p<0.05）和 AST（均值±SD，352±285 vs. 462±383 U/L，p<0.01）在肾动脉闭塞前后存在显著差异，而肌酐清除率、钠排泄分数、总钠重吸收和组织学损伤无显著差异。
LSCI 通量与 NMP 期间的肾血流量呈线性相关。LSCI 可可视化和半定量评估肾皮质微循环和无灌注。它提供了对灌注水平的相对了解，允许对肾脏区域之间进行定性比较。与单侧测量相比，双侧 LSCI 测量具有附加价值，并且与肾功能标志物相关。
