INTRODUCTION: For more than 50 years vasectomy reversal is a routinely performed procedure in the field of urology. However, there is no scientific agreement about morphological changes of the testes caused by vasectomy. The existing evidence for reduced fertility rates following vasectomy reversal demands a clear statement regarding potential histological changes and impaired spermatogenesis following vasectomy. Thus far there is little knowledge about potential histological changes of the testis caused by vasectomy. MATERIAL AND METHODS: 330 consecutive patients who underwent vasectomy reversal had bilateral testicular biopsies which were evaluated utilising semi-thin sections. The number of mature spermatids per seminiferous tubule was considered the variable of interest as it represents an objective and reproducible parameter of spermatogenesis. The number of mature spermatids per tubule was correlated with patient age, obstructive interval and the presence or absence of sperm granulomas via the chi-square test. RESULTS: Overall, 570 sections of 285 patients were eligible for evaluation. The mean patient age was 41.2 years (range 27-63 years, SD +/- 6.5 years) with a mean obstructive interval of 105.9 months (range 12-328, SD +/- 66.1). 56 patients (19.6 %) had a sperm granuloma on the right and 22 (11.6 %) on the left ductus deferens. There was no statistically significant correlation between the presence of a sperm granuloma with the number of mature spermatids per tubule (p = 0.717). Furthermore, there was neither an association of obstructive interval (p = 0.144) nor patient age (p = 0.168) with spermatogenesis. CONCLUSION: Regular spermatogenetic activity in all examined samples with development of mature spermatids was shown. Furthermore, for the first time we were able to demonstrate in a large cohort of patients that neither patient age nor obstructive interval nor sperm granuloma have a significant impact on spermatogenesis.
