Short-term storage of human testicular tissue: effect of storage temperature and tissue size

During short-term storage, before cryopreservation, testicular tissue quality can be affected by storage medium, duration, temperature and tissue size. We previously established the best storage medium and time for short-term maintenance of tissue. In this study, three different storage temperatures (4°C, room temperature, 37°C) and four tissue sizes (~6 mm3; ~ 15 mm3; ~ 50 mm3 or ~80 mm3) were assessed over the course of a fixed period of 3 days. Storing human testicular tissue at 37°C caused a significant increase in the number of apoptotic cells per tubule (P = 0.002), compared with fresh control, but this was not the case at 4°C or room temperature. Temperature did not affect viability, tissue morphology or number of spermatogonia in samples. The morphology of the testicular tissue was optimally preserved when stored as large fragments (~50 mm3: P = 0.018; ~ 80 mm3: P = 0.018). Tissue size did not significantly affect viability, number of spermatogonia or apoptotic cells. Adult human testicular tissue can be preserved at 4°C or room temperature without altering tissue morphology, Sertoli cell morphology, number of spermatogonia or number of apoptotic cells. The tissue does not need to be extensively dissected as tissue morphology is better maintained in larger fragments.