Temporary intraabdominal cryptorchidism in the weanling rat leads to irreversible azoospermia.

To study surgical reversibility of intraabdominal cryptorchidism, a study in which weanling rats were made artificially cryptorchid was undertaken. At the same time both sperm ducts were anastomosed into the urine bladder (vasocystostomy) to enable sperm output measurements, which were performed by putting the animals in metabolic cages for 24 hr. Group I animals were reoperated on 2 weeks after the initial cryptorchidism operation to reverse this intervention by an orchiopexy operation; in Group II orchiopexy was carried out after 4 weeks, in Group III after 8 weeks. In Group IV, a control group in which only the vasocystostomy operation was performed, the rats were sham operated. The animals were followed for 3 months after orchiopexy. All control animals showed sperm output between 20 and 30 million of spermatozoa per 24 hr from the age of 13 weeks on. However, experimental animals that had been de facto cryptorchid did not show any sperm output. Three out of 4 animals in which spontaneous descent of one or both testes had taken place showed sperm output from 6 to 8 weeks after orchiopexy. The results show that, notwithstanding the short periods of cryptorchidism, certain irreversible changes had already developed.