Injury to the pre-pubertal vas deferens. I. Histological analysis of pre-pubertal human vas.

There is very little information in the literature on the development of the human vas deferens. Therefore, the age at which the pre- or para-pubertal vas deferens becomes large enough for a vasovasostomy to be technically feasible is unknown. To determine the age or degree of sexual maturity at which a microscopic vasovasostomy is technically feasible, we collected surgical or autopsy vasa from 34 young males over a three year period, and correlated vasal size to age and Tanner stage (degree of sexual maturity ranging from 1-childhood to 5-adult). The specimens were embedded and sectioned transversely in glycol methacrylate. Using image analysis, the total transverse area and diameter, and luminal area and diameter was determined for each specimen. Surprisingly, there was no change in vasal size from birth up through 11 years. From age 15 years and on, the vas was adult in size. The vas develops to adult size between Tanner stages 2 and 3. The average external and luminal diameters of pre-midpuberty specimens (Tanner stages 1 and 2) were 1.0 and 0.19 (mm.) and the diameters of post-midpuberty specimens were 2.1 and 0.43 (mm.), respectively. These results suggest that, in the event of a recognized iatrogenic injury to the vas deferens after midpuberty, a repair by a traditional microsurgical vasovasostomy is possible. If the vas is injured before midpuberty it may be technically difficult to repair by traditional microsurgical methods.