Evaluation by Fluorescence Spectroscopy of the Most Appropriate Renal Region for Obtaining Biopsies: A Study in the Rat

Abstract Introduction Renal puncture biopsies are directed at the lower poles of the organ to decrease the risk of hemorrhage and complications. Objectives To evaluate by fluorescence spectroscopy (FS) the most appropriate renal region (in terms of metabolic changes) to obtain a biopsy. Materials and methods The kidneys of 33 Rattus norvegicus rats were submitted to FS detection in the upper and lower poles and in the middle third. Excitations were generated with lasers at wavelengths of 408, 442, and 532 nm. Animals were divided at random into groups of warm ischemia (30, 60, and 120 minutes), whose kidneys were again analyzed by FS, as well as after 5 minutes of reperfusion using the same excitation beams in the same renal regions. Then the kidneys underwent histologic preparation and examination. Results The middle third area of the rat's kidneys proved to be significantly more sensitive to ischemic and reperfusion changes than the renal poles, as determined by FS ( P < .001). Conclusions The middle third of the kidney was the most appropriate site for a renal biopsy to monitor a transplanted organ.