Bilateral histological evaluation of exocrine testicular function in men with obstructive azoospermia: condition of spermatogenesis and andrological implications?

BACKGROUND The aim of this study was to investigate whether there is a need for diagnostic biopsies in men with obstructive azoospermia (OA). METHODS Sixty-three adult men with OA due to vasectomy, bilateral inflammation or bilateral aplasia of the vas deferens were included in the study. We determined testicular volume, sexual hormone levels and testicular histologies of right and left testes (236 biopsies from 118 testes) during diagnostic and therapeutic infertility surgery (microsurgical vasal reconstruction or testicular/epididymal sperm extraction). Spermatogenesis was histologically classified according to the Holstein score from 0 (Sertoli cell-only, complete absence of germ cells) to 10 (100% of tubules with elongated spermatids). RESULTS All patients (mean age 34 ± 5 years) had low glucosidase levels (5.4 ± 4.2 mU/ejaculate), normal serum FSH levels (4.6 ± 2.5 mU/ml) and normal testicular volumes (right 21 ± 8 ml; left 19 ± 6 ml). Median histological score for right and left testis was 9. There were eight patients with score differences ≥ 3 between right and left testis (14% of men), showing that even in men with OA, there may be differences in spermatogenic activity between both sides. In all of these patients, normal spermatogenesis was found in the larger testis. Testicular histology (spermatogenesis score) was positively correlated with testicular volume and negatively correlated with FSH levels. CONCLUSIONS Patients with OA may not need to be biopsied for diagnostic purposes. Our data support the use of unilateral therapeutic biopsy in men with OA and that the larger testicle should be operated on when there is a significant difference in size.