Dynamic renal scintigraphic estimation of deceased donor kidneys in a rat model.

At present a large number of the renal transplantations are being performed from the deceased donors. The success of these transplantations depends on the viability of the deceased donor kidneys. The aim of this study was to investigate the reliability of scintigraphic estimation of function of deceased donor kidneys by comparing the histopathologic and scintigraphic findings. Ten rats were included in the study (2-3 months old, 250-300 g, all male). Control scintigraphy was performed to all the rats by injection of 37 MBq Tc-99m DTPA from the tail vein in a dynamic manner. Brain death of the rats was achieved by inflation of a Fogartys catheter in the cranial cavity. Immediately, after brain death confirmation, dynamic renal scintigraphy was performed with the same parameters of control scintigraphy. In the comparison of scintigraphies obtained in the before and just after brain death period, there was impairment of tubular functions, concentration and excretion functions in the postbrain death period. In the immediate postbrain death period, there was a significant elevation in the glomerular filtration rate and time to maximum concentration values. In the histopathological evaluation of the kidney samples in the postbrain death period, there were definitive findings of tubular impairment. Dynamic renal scintigraphy also demonstrated definite impairment of tubular system and tubular functions in the deceased donor kidneys. This could explain the reason of the increased frequency of acute tubular necrosis seen among deceased donor kidneys.

Brain death scintigraphy and pathology results in a rat model.

OBJECTIVES: Brain scintigraphy with Tc-99m-labeled diethylenetriaminopenta-acetic acid is a sensitive diagnostic method showing loss of cerebral blood flow that occurs after brain death. Cerebral blood flow can be quantitatively estimated by this method. The aim of this study was to compare histopathologic changes occurring with the decrease of cerebral blood flow (as shown by Tc-99m-labeled diethylenetriaminopenta-acetic acid brain death scintigraphy) after brain death in an experimental model. MATERIALS AND METHODS: The study included examination of cerebral blood flow by Tc-99m-labeled diethylenetriaminopenta-acetic acid brain scintigraphy in the 20 rats, 1 day before brain death, after producing brain death in 11 surviving rats. Tc-99m-labeled diethylenetriaminopenta-acetic acid brain scintigraphy was performed under intubation and monitored. The Mann-Whitney U test was performed to compare groups (scintigraphic quantification results before and after brain death). RESULTS: In the time activity curves generated from the analysis of the scintigraphies, decreases in counts in the brain death group were obtained in the arterial phase (P < .01). Decreases of the cerebral blood flow between the first and the sixth minutes were statistically significant (P < .05). Common principal histopathologic changes of the brain death (ie, autolysis and color loss in the nerve cells, diffuse edema, petechial hemorrhage in the brain tissues) were observed in all subjects. CONCLUSIONS: Quantitative findings of the brain scintigraphy by Tc-99m-labeled diethylenetriaminopenta-acetic acid was related with the histopathologic findings seen during the early brain death, with significant decreases of the cerebral blood flow. Quantification of Tc-99m-labeled diethylenetriaminopenta-acetic acid brain death scintigraphy as an easier and less-expensive scintigraphic method of cerebral blood flow might indicate a definite diagnosis of brain death and thus, potential donors can be determined earlier, leaving to increased transplant rates.