Quantitative testicular biopsy in spinal cord injured men: comparison to fertile controls.

Spermatogenic abnormalities have been reported in the majority of spinal cord injured men on routine testicular biopsy. However, given the interim advances in their urological and rehabilitative care, a quantitative assessment of the germinal epithelium after spinal cord injury and comparison of these parameters to normal controls are warranted. Incisional testicular biopsy was performed in 14 spinal cord injured men. Quantitative micrometric techniques were applied to assess spermatogenesis and the results were compared to a normative data base of testicular biopsies previously obtained from a group of 15 fertile volunteers. From a minimum of 10 randomly selected round seminiferous tubules per subject the mean number of Sertoli cells, mature spermatids, tubular diameter and tubular wall thickness were determined in both groups and statistically analyzed. In the spinal cord injury group the mean number of spermatids per tubule was significantly lower and the mean number of Sertoli cells per tubule was significantly higher than in fertile controls (p less than 0.05). Moreover, the mean Sertoli cell-to-spermatid ratio per seminiferous tubule was significantly higher in the spinal cord injury group and discriminated between spinal cord injured men and controls, with a sensitivity of 93% and specificity of 100% (p less than 0.0001). Half of the spinal cord injury group showed a mean tubular spermatid density of less than 10. Compared to the fertile population, spinal cord injured men show significant differences in quantitative parameters of the germinal epithelium that may contribute to the reproductive dysfunction.