Alloplastic spermatocele: diffusion across the allograft material and survival of spermatozoa in vitro and in vivo.

Alloplastic spermatoceles have not proved to be a very successful method for acquiring fertile spermatozoa from patients with obstructive azoospermia. Many basic aspects of spermatocele function have apparently not yet been considered; therefore, we performed experiments to determine the motility survival of rat spermatozoa in spermatoceles in vivo and in vitro, and of human spermatozoa in spermatoceles in vitro. Also, net diffusion of Na+, K+, 3H-H2O, 3H-inulin and 3H-polyethyleneglycol from alloplastic spermatoceles was determined in vitro. Spermatoceles were constructed from expanded polytetrafluoroethylene. In general, neither rat nor human spermatozoa motility survived 24 hr. incubation in alloplastic spermatoceles in vitro or in vivo. Na+ and K+ diffused from alloplastic spermatoceles, demonstrating that specific intraluminal electrolyte concentrations cannot be maintained in polytetrafluorethylene spermatoceles. 3H-H2O diffused freely across the spermatocele wall, demonstrating that fluids can enter or exit the spermatocele lumen and potentially effect sperm survival. 3H-inulin (m.w. 5000) and 3H-polyethyleneglycol (m.w. 4000) were largely retained in the spermatocele lumen over the 3-day experimental period. It is recommended that other basic aspects of spermatocele design be worked out experimentally before perhaps premature designs are installed in human patients.