Predictive factors of successful sperm retrieval on microdissection testicular sperm extraction in Japanese men.

Purpose: To evaluate retrospectively the outcomes of microdissection testicular sperm extraction (micro-TESE) in men with nonobstructive azoospermia (NOA) and to identify the parameters predicting successful sperm retrieval in this cohort of patients. Methods: After excluding patients with normal testicular volume and serum follicle-stimulating hormone (FSH) level who received conventional TESE, this study included 329 consecutive NOA patients undergoing micro-TESE at our institution. The significance of several factors, including age, testicular volume, etiology and serum levels of FSH, luteinizing hormone (LH) and serum testosterone (T), as predictors of successful sperm retrieval, was evaluated. Results: Of the 329 men included in this series, 246 (74.8 %), 40 (12.2 %), and 43 (13.1 %) were pathologically diagnosed with Sertoli cell only, maturation arrest, and hypospermatogenesis, respectively. Spermatozoa were retrieved in 97 (29.5 %) of these 329 men by micro-TESE. Older age and non-idiopathic etiology were significantly associated with the probability of successful sperm retrieval; however, there were no significant effects of testicular volume as well as serum levels of FSH, LH, and T on sperm retrieval outcome. Furthermore, Johnsen score of the micro-TESE specimen showed a significant association with whether spermatozoa were successfully retrieved. Univariate analysis of preoperative parameters identified older age and non-idiopathic etiology as significant predictors of successful sperm retrieval, of which only etiology appeared to be independently related to successful sperm retrieval on multivariate analysis. Conclusions: Spermatozoa are significantly less likely to be successfully retrieved by micro-TESE in men with idiopathic azoospermia.