Epididymal-testicular fusion anomalies in cryptorchidism are associated with proximal location of the undescended testis and with a widely patent processus vaginalis.

Past studies documented the presence of epididymal/testicular fusion anomalies and persistence of a patent processus vaginalis in a small case-series of cryptorchid and/or hydrocele patients. The primary aim of this study was to determine the prevalence of the epididymal/testicular anomalies in a series of more than 1000 cryptorchid patients compared with controls. Secondary aims were: (i) to investigate the association between the cryptorchidism and the patency of p. vaginalis; and (ii) to correlate the epididymal/testicular fusion anomalies with the position of the testis and with the patency of the p. vaginalis. The clinical and surgical data of 1002 cryptorchid patients and 230 controls were retrospectively retrieved and analysed. Epididymal/testicular fusion anomalies were classified as: (i) normal anatomy; (ii) minor anomalies; and (iii) major anomalies. Statistical analysis was performed using the Student's t-test and Chi-square tests. The prevalence of the epididymal/testicular fusion anomalies was higher in the cryptorchid group compared with that of the control group (minor and major anomalies in cryptorchids vs. controls, respectively: 42.2 vs. 5.6\% and 9.3 vs. 1.6\%, P < 0.0001). Moreover, we documented a correlation of these anomalies with a more proximal localization of the testis (minor and major anomalies in proximal vs. distal location of the testis, respectively: 62.5 vs. 34.8\% and 19.1 vs. 6.3\%, P < 0.0001) and with the persistence of a widely patent p. vaginalis (minor and major anomalies in widely patent p. vaginalis vs. narrow duct, respectively: 51.7 vs. 42.2 and 11.9\% vs. 7.8\%, P < 0.001). In conclusion, the epididymal/testicular fusion anomalies were strongly associated with cryptorchidism and the persistence of a widely patent peritoneal vaginal duct. Although it remains unclear whether these anomalies cause non-descent of the testis or, conversely, result from the cryptorchidism or from the persistence of a widely patent duct, our data re-enforce this association.