The testicular histopathology as a predictive factor of sperm retrieval in patients with non-obstructive azoospermia (NOA)

Study question: The purpose was to investigate the sperm retrieval rate and sperm recovery time after testicular biopsy, and clinical outcomes according to five different testicular histopathologies. Summary answer: Testicular histopathology is predictive of research time needed for sperm retrieval. No difference was found in clinical outcomes in ICSI cycles performed with testicular sperm. What is known already: Azoospermia occurs in 10–15% of infertile male population. Non-obstructive azoospermia (NOA) is caused by testicular failures and represents 60% of azoospermia. It is due to testicular or pre-testicular damages, such as hypothalamus pituitary dysfunctions. Surgical retrieval of spermatozoa in order to perform an ICSI cycle, is the only possibility of fathering a child in patients suffering for NOA. Some studies show that testicular histology is the best predictor of success in sperm retrieval from testicular biopsy, such as Testicular Sperm Extraction (TESE). Study design, size, duration: This retrospective study was performed from March 2005 to November 2015 on 518 patients. Patients were divided in five different groups, based on different testicular histopathology: Sertoli-cell-only (A), maturation arrest (B), severe hypo-spermatogenesis (C), normal spermatogenesis (D), Sclerohyalinosis (E). Sperm recovery time (SRT), fertilization rate (FR), clinical pregnancy (CPR) and live birth rates (LBR) for each enrolled groups, were analyzed. Statistical analyses were performed using student T-test and Fisher’s exact test (P value < 0.05). Participants/materials, setting, methods: If spermatozoa were not retrieved in one testis, the biopsy was performed on the other one. In each surgery, a small tissue sample was histologically analyzed. For each Group the same observation time, from few minutes to almost 12 hours, was applied. Recovered spermatozoa were used for fresh ICSI of partner's oocytes or cryopreserved for future use. There were no differences in male and female mean ages among the five groups. Main results and the role of chance: Patients who underwent conventional TESE were 518: 200, 94, 73, 140, 11 in groups A-B-C-D-E, respectively. Spermatozoa were recovered in 348 patients (67.2%): 64 (32%), 77 (81.9%), 63 (86.3%), 135 (96.4%), 9 (81.8%) in groups A-B-C-D-E, respectively. Statistical difference in sperm retrieval rate, was observed in group A compared to all other groups (p≤0.0001) and in group D compared with groups B, C, E (p≤0.002). For each group, the mean of SRT was considered: 3.4, 2.7, 2.5, 1.0, 3.3 hours in groups A-B-C-D-E, respectively. Statistical significant difference in SRT was found only among group-D compared to all the other groups (p≤0.02). A total of 336 (A-64, B-77, C-63, D-123, E-9) patients with positive spermatozoa retrieval performed an ICSI cycle, 119 using fresh and 217 frozen spermatozoa. Injected oocytes were 2027. FR was 58.3% (224/384), 54.3% (266/490), 61.5% (221/359), 67.3% (504/749), 48.9% (22/45) in groups A-B-C-D-E, respectively and a statistical difference was found in group-D compared with A, E and B (p≤0.01) and in group-B compared with C (p=0.03).CPR was 36.9% (17/46), 32.8% (20/61), 30.6% (15/49), 34.1% (31/91), 25% (1/4) in groups A-B-C-D-E, respectively(NS). LBR was 14.3% (15/105), 10.6% (15/142), 9.2% (11/120), 19.4% (41/211), 10% (1/10) in groups A-B-C-D-E, respectively (NS). Limitations, reasons for caution: Clinical data are not complete since many patients with positive spermatozoa retrieval didn’t undergo an ICSI cycle. Sperm recovery time is strictly related to the number of biologists involved in the research and to the laboratory equipment. Performing a multiple-TESE or a micro-dissection TESE could shorten sperm recovery time.