Evaluation of the scrotal testis before and after orchidopexy in experimental unilateral cryptorchidism.

Unilateral cryptorchidism was induced in newborn Wistar rats. With standard histological techniques, no abnormality was found in the scrotal testis at any age. Using DNA flow cytometry to measure the proportion of cells in the haploid phase in the testis, secondary degenerative changes were noted at 40 days of age. Orchidopexy carried out at 30 days of age prevented these changes appearing; at 50 days reversed the abnormality already present; and at 90 days failed to reverse the degeneration of the scrotal testis. These data would suggest that although early orchidopexy can prevent secondary changes in the scrotal testis, operation up to puberty will allow these changes to be reversed.