Fluorescence Spectroscopy in Renal Ischemia and Reperfusion: Noninvasive Evaluation of Organ Viability

Abstract Background Damage provoked by ischemia in renal transplants is difficult to quantify. To determine whether a donated organ is fit for transplantation. We sought to correlate the findings of fluorescence spectroscopy (FS) with histologic evidence of ischemic injury and organ viability. Methods Kidneys of 33 rats were submitted to FS of the upper and lower poles as well as the middle third. Excitation was generated by the laser's wavelengths of 408, 442, and 532 nm. Rats were randomized into groups with the 30, 60, and 120 minutes warm ischemia before analysis by FS, that was repeated at 5 minutes after reperfusion. Results FS results in the reperfusion phase correlated with ischemia time and degree of histologic injury. After 60 or 120 minutes of ischemia, the excitation lasers of 532 and 442 nm resented a significant negative correlation coefficient with the histological grade ( r = −0.61 and r = −0.73, respectively). Conclusions There was a strong correlation between FS and histologic changes only in the reperfusion phase after renal ischemia. The method was thus unable to assess the viability of organs before transplantation.