Assessing the reliability of rapid frozen tissue sections from pre-transplant kidney biopsies in DCD donors and correlations with clinico-pathological data: a pilot study

Compared to donations after brain death, donations after circulatory death present a series of difficulties: the acquisition of the family's consent, the need for qualified personnel and specific resources, death assessment, assessment of the organ, and graft care (pre- and post-transplant). These are all time-related factors that negatively impact the organ, resulting in increased tubular, glomerular, and vascular damage. The evaluation of the organ, as per today's standards, requires three hours for the preparation and processing of formalin-fixed paraffin-embedded (FFPE) samples. An alternative to this is the use of the extemporaneous frozen biopsy. However, frozen samples are considered a second choice in the decision-making process. This retrospective study investigates the reliability of the frozen samples in identifying a series of morphological alterations compared to the more accepted results from FFPE samples. Additionally, two important clinical data, terminal serum creatinine levels and warm ischemia time, were correlated to the presence of some morphological alterations in an attempt to find effective and fast strategies to predict the kidney transplant outcome.