Predictive factors of successful salvage microdissection testicular sperm extraction (mTESE) after failed mTESE in patients with non-obstructive azoospermia: Long-term experience at a single institute

Objective: To observe the clinical practice of salvage microdissection testicular sperm extraction (mTESE) in patients with non-obstructive azoospermia (NOA) and to determine the factors that may predict the presence of spermatozoa in preoperative salvage mTESE. Methods: We retrospectively reviewed the medical records of 445 patients with the diagnosis of NOA, who had undergone the mTESE operation consecutively in our institution between the dates of March 2008 and June 2017. The study included a total of 49 patients with failure to detect spermatozoa in the first mTESE and who had then undergone salvage mTESE. In order to investigate the factors that predict the result of salvage mTESE, the patients were classified into two groups according to the outcome of salvage mTESE, as those with and without spermatozoa retrieval. Patients in these two groups were compared with regard to age, body mass index, history of varicocele, history of cryptorchidism, duration of infertility, outcomes of genetic analysis, results of hormone profiles and the testicular histopathology results of the first mTESE. Results: The sperm retrieval rate following salvage mTESE was observed to be 42.8%. Statistically a significant difference was determined between the mean follicle stimulating hormone (FSH) values of the groups (p = 0.013). No significant difference was observed between the groups with regard to the remaining parameters. Conclusion: It was observed that among the factors that predict the success of sperm retrieval in salvage mTESE in patients with NOA and previous unsuccessful sperm retrieval in mTESE operation, only the pre-operative FSH level was observed to significantly correlate with the success in salvage mTESE.