Quantitative (stereological) and qualitative study of rat epididymis after vasectomy and percutaneous epididymal...

We investigated whether viable spermatozoa could be obtained from the rat epididymis after vasectomy by up to 5 percutaneous epididymal sperm aspiration punctures. We analyzed the inflammatory and scar forming histological alterations to the epididymis due to these punctures. Epididymal smooth muscle fiber and collagen density were also analyzed.

A total of 50 rats that underwent bilateral vasectomy were divided into 5 groups of 10 each. Groups 1 to 5 underwent 1 to 5 right transscrotal percutaneous epididymal sperm aspiration punctures, respectively. Sperm quantification, and histological and stereological analyses were done on the punctured epididymides.

A mean of 48.78 x 10(6), 37.55 x 10(6), 26.33 x 10(6), 33.90 x 10(6) and 41.34 x 10(6)/ml spermatozoa were recovered in groups 1 to 5, respectively. A cumulative effect of the punctures was only observed in the variables of lymphoplasmacytic infiltrate and fibrosis, thus, showing that groups 1 and 2 differed significantly from groups 3 to 5. Stereological analysis revealed that conjunctive tissue volumetric density was 21.56%, 27.60%, 35.67%, 37.56%, 38.60% and 22.30% on the punctured side in groups 1 to 5 and controls, respectively (p <0.05).

Spermatozoa were obtained from all groups. All animals showed significant histological alterations in the epididymides from the second puncture and thereafter except with regard to necrosis. The cumulative effect of percutaneous epididymal sperm aspiration was only shown by lymphoplasmacytic infiltrate and fibrosis. Stereological analysis showed increased conjunctive tissue volumetric density from the second puncture and thereafter.