Testicular sperm extraction with intracytoplasmic sperm injection is successful for the treatment of nonobstructive azoospermia associated with cryptorchidism

[Testicular and epididymal sperm extraction surgery]

BACKGROUND

Testicular and epididymal sperm extraction surgery is a frequent procedure. However, to date, there has been no French consensus on the technique to be preferred in the various situations of male infertility and on the best way to perform them. We therefore decided to proceed with a formalized expert consensus, using the method recommended by the French National Authority for Health. The aim was to provide the French urology community with practical advice on how best to perform these procedures.

METHODS

Twenty-six international experts met online for the consensus. A research committee carried out a comprehensive literature review and prepared the 55 statements submitted to the rating group. After 2 rounds of scoring, 50 recommendations were validated in March 2023, having achieved a consensus of more than 85% among the experts.

RESULTS

The consensus covered (1) preparation for sperm extraction surgery, (2) the different sperm extraction surgery techniques (Microsurgical epididymal sperm aspiration [MESA], Percutaneous epididymal sperm aspiration [PESA], Conventional Testicular Sperm Extraction [TESE], Microsurgical Testicular Sperm Extraction [micro-TESE]), (3) advice to be given to the patient concerning the postoperative period, before presenting the results of the sperm extraction surgeries.

CONCLUSIONS

The expert consensus meeting on the performance of sperm extraction surgery presented a set of clinical guidelines based on the available literature and expert opinion. These guidelines should have a favourable effect on the development of this activity in France.

Microdissection Testicular Sperm Extraction

Nonobstructive azoospermia (NOA) is among the most common causes of male infertility. For men with NOA seeking fertility treatment, microdissection testicular sperm extraction (microTESE) is the best option for retrieving sperm, which can be used with in vitro fertilization-intracytoplasmic sperm injection to achieve pregnancy in their partner. With the aid of the operating microscope, microTESE allows for thorough evaluation of the testis tissue and selection of seminiferous tubules that appear most capable of sperm production. Rates of success with microTESE vary depending on the underlying cause of NOA and the center at which the procedure is performed. Not all patients are candidates for microTESE, and those who are candidates should be counseled on the likelihood of sperm retrieval and the potential for changes in postoperative testis function.

Comparison of unilateral and bilateral microdissection testicular sperm extraction (MD-TESE) in patients with non-obstructive azoospermia: a prospective study

OBJECTIVE

To compare sperm retrieval rates between unilateral and bilateral microdissection testicular sperm extraction (MD-TESE) procedures in patients with non-obstructive azoospermia and to contribute to the literature by comparing them with literature data.

METHODS

This prospective study included 84 males with primary infertility who had azoospermic NOA, who had been married for at least one year, and whose female partners did not have a history of infertility. The study was conducted between January 2019 and January 2020. MD-TESE was applied bilaterally to 48% (n:41) (Group 1) and unilaterally to 52% (n:43) (Group 2) of the patients, and sperm retrieval rates were compared.

RESULTS

There was no statistically significant difference between Group 1 patients and Group 2 patients in terms of sperm availability (61%, 56.5%, p=0.495, respectively). In addition, while no complications were observed in unilateral MD-TESEs, 3 complications were observed in bilateral MD-TESEs.

CONCLUSIONS

In our study, it was determined that there was no significant difference between the groups in terms of sperm availability in patients with NOA. Considering the operative time and complication rates of bilateral MD-TESE in patients diagnosed with NOA and the possible MD-TESE procedures that may be performed later, we believe that unilateral MD TESE is a more preferable procedure for the patient and surgeon in this patient group.

Stepwise mini-incision microdissection testicular sperm extraction in NOA patients with a history of cryptorchidism: a case-control study

BACKGROUND

Although the orchiopexy is recommended for cryptorchidism to preserve male fertility, non-obstructive azoospermia (NOA) may occur in adulthood. Fortunately, a great many of azoospermic men may obtain sperm by microdissection testicular sperm extraction (mTESE). Due to the potential injuries caused by testicular diagnostic biopsy and vascular damage at the time of orchidopexy, minimal invasiveness is particularly important during mTESE, aims to reduce the surgical damage and avoids secondary testicular failure. This comparative study aims to investigate the efficacy of stepwise mini-incision mTESE technique by comparison with standard mTESE in the treatment of NOA patients with a history of cryptorchidism.

RESULTS

A total of 73 mTESE procedures were divided into two groups: Group 1 included 37 cases performed by stepwise mini-incision mTESE, while Group 2 included 36 cases with standard mTESE. The overall sperm retrieval rate (SRR) in the two groups was 68.5% (50/73), with no significant difference in SRR between Group 1 (78.4%, 29/37) and Group 2 (58.3%, 21/36) (P = 0.1). In addition, 46.0% of the patients (17/37) obtained sperm in the first mini-incision step in Group 1, which was also equal to an overall SRR in Group 2 (58.3%, 21/36) (P = 0.3). The operation time in Group 1 (72.6 ± 33.9 min) was significantly shorter than that in Group 2 (90.4 ± 36.4 min) (P = 0.04). Patients with an orchidopexy age no more than 10 years old had a higher SRR (79.5%, 31/39) than others (55.9%, 19/34) (P = 0.03). There were no postoperative complications including wound infection, scrotal hematoma, persistent pain, and testicular atrophy during a follow-up period of at least 6 months.

CONCLUSIONS

In conclusion, our study suggests that the stepwise mini-incision mTESE could be a promising approach for sperm retrieval in NOA men with a history of cryptorchidism. While the technique may potentially reduce operation time and surgical invasiveness, further research is needed to validate these findings on a larger scale. The results also suggest that age at orchidopexy may affect SRR and have important implications for the management of cryptorchidism.

A Machine Learning Approach for the Prediction of Testicular Sperm Extraction in Nonobstructive Azoospermia: Algorithm Development and Validation Study

BACKGROUND

Testicular sperm extraction (TESE) is an essential therapeutic tool for the management of male infertility. However, it is an invasive procedure with a success rate up to 50%. To date, no model based on clinical and laboratory parameters is sufficiently powerful to accurately predict the success of sperm retrieval in TESE.

OBJECTIVE

The aim of this study is to compare a wide range of predictive models under similar conditions for TESE outcomes in patients with nonobstructive azoospermia (NOA) to identify the correct mathematical approach to apply, most appropriate study size, and relevance of the input biomarkers.

METHODS

We analyzed 201 patients who underwent TESE at Tenon Hospital (Assistance Publique-Hôpitaux de Paris, Sorbonne University, Paris), distributed in a retrospective training cohort of 175 patients (January 2012 to April 2021) and a prospective testing cohort (May 2021 to December 2021) of 26 patients. Preoperative data (according to the French standard exploration of male infertility, 16 variables) including urogenital history, hormonal data, genetic data, and TESE outcomes (representing the target variable) were collected. A TESE was considered positive if we obtained sufficient spermatozoa for intracytoplasmic sperm injection. After preprocessing the raw data, 8 machine learning (ML) models were trained and optimized on the retrospective training cohort data set: The hyperparameter tuning was performed by random search. Finally, the prospective testing cohort data set was used for the model evaluation. The metrics used to evaluate and compare the models were the following: sensitivity, specificity, area under the receiver operating characteristic curve (AUC-ROC), and accuracy. The importance of each variable in the model was assessed using the permutation feature importance technique, and the optimal number of patients to include in the study was assessed using the learning curve.

RESULTS

The ensemble models, based on decision trees, showed the best performance, especially the random forest model, which yielded the following results: AUC=0.90, sensitivity=100%, and specificity=69.2%. Furthermore, a study size of 120 patients seemed sufficient to properly exploit the preoperative data in the modeling process, since increasing the number of patients beyond 120 during model training did not bring any performance improvement. Furthermore, inhibin B and a history of varicoceles exhibited the highest predictive capacity.

CONCLUSIONS

An ML algorithm based on an appropriate approach can predict successful sperm retrieval in men with NOA undergoing TESE, with promising performance. However, although this study is consistent with the first step of this process, a subsequent formal prospective multicentric validation study should be undertaken before any clinical applications. As future work, we consider the use of recent and clinically relevant data sets (including seminal plasma biomarkers, especially noncoding RNAs, as markers of residual spermatogenesis in NOA patients) to improve our results even more.

DDX58 expression promotes inflammation and growth arrest in Sertoli cells by stabilizing p65 mRNA in patients with Sertoli cell-only syndrome

Sertoli cell -only syndrome (SCOS) is a type of testicular pathological failure that causes male infertility and no effective treatment strategy, is available for this condition. Moreover, the molecular mechanism underlying its development remains unknown. We identified DExD/H-Box helicase 58 (DDX58) as a key gene in SCOS based on four datasets of testicular tissue samples obtained from the Gene Expression Synthesis database. DDX58 was significantly upregulated in SCOS testicular Sertoli cells. Moreover, high expression of DDX58 was positively correlated with the expression of several testicular inflammatory factors, such as IL -1β, IL-18, and IL-6. Interestingly, DDX58 could be induced in the D-galactose (D-gal)-stimulated TM4 cell injury model. Whereas silencing of DDX58 inhibited D-gal -mediated p65 expression, inflammatory cytokine release, and growth arrest. Mechanistically, we found that DDX58 acts as an RNA-binding protein, which enhances p65 expression by promoting mRNA stability. Furthermore, p65 gene silencing decreased the expression of inflammatory cytokines and inhibition of cell growth in D-gal-induced cells. In conclusion, our findings demonstrate that DDX58 promotes inflammatory responses and growth arrest in SCOS Sertoli cells by stabilizing p65 mRNA. Accordingly, the DDX58/p65 regulatory axis might be a therapeutic target for SCOS.

Azoospermic Men with a History of Cryptorchidism Treated by Orchiopexy Have Favorable Outcomes after Testicular Sperm Extraction: A Systematic Review and Meta-Analysis

PURPOSE

This systematic review and meta-analysis investigated the sperm retrieval rate (SRR) and pregnancy rate after testicular sperm extraction in men with azoospermia and those with a history of cryptorchidism treated by orchiopexy.

MATERIALS AND METHODS

The SRR and clinical pregnancy rate were investigated. We performed a sub-analysis that included factors such as bilaterality, age, and idiopathic non-obstructive azoospermia (iNOA). The analysis comprised 13 studies from January 1995 to July 2021. The data sources were PubMed/MEDLINE, Embase, and the Cochrane Library included "cryptorchidism", "orchidopexy", "azoospermia", and "testicular sperm extraction".

RESULTS

The overall mean SRR was 63.3% (95% confidence interval [CI], 57.6%-68.6%; I²=62.4%), and the overall mean clinical pregnancy rate was 30.1% (95% CI, 22.6%-38.8%; I²=69.9%). The meta-analysis comparing the SRR, there was no significant difference between patients with a history of bilateral and unilateral orchiopexy (relative risk [RR]=1.02; 95% CI, 0.89-1.16; p=0.79). Orchiopexy performed under the age of 10 years showed significantly increased SRR compared to the age of over 10 years (RR=1.25; 95% CI, 1.06-1.47; p=0.008). Azoospermic men with a history of cryptorchidism treated by orchiopexy had significantly higher SRR than iNOA (RR=1.90; 95% CI, 1.40-2.58; p<0.0001).

CONCLUSIONS

Men with azoospermia and a history of cryptorchidism treated by orchiopexy had significantly higher SRR than those with iNOA after testicular sperm extraction. Furthermore, patients who underwent orchiopexy before the age of ten years had significantly higher SRR than patients operated at an older than the age of ten years.

Aberrant Gene Expression Profiling in Men With Sertoli Cell-Only Syndrome

Sertoli cell-only syndrome (SCOS) is the most severe and common pathological type of non-obstructive azoospermia. The etiology of SCOS remains largely unknown to date despite a handful of studies reported in this area. According to the gene expression of testicular tissue samples in six datasets from the Gene Expression Omnibus, we detected 1441 differentially expressed genes (DEGs) between SCOS and obstructive azoospermia (OA) testicular tissue samples. Enriched GO terms and KEGG pathways for the downregulated genes included various terms and pathways related to cell cycle and reproduction, while the enrichment for the upregulated genes yielded many inflammation-related terms and pathways. In accordance with the protein-protein interaction (PPI) network, all genes in the most critical module belonged to the downregulated DEGs, and we obtained nine hub genes, including CCNB1, AURKA, CCNA2, BIRC5, TYMS, UBE2C, CDC20, TOP2A, and OIP5. Among these hub genes, six were also found in the most significant SCOS-specific module obtained from consensus module analysis. In addition, most of SCOS-specific modules did not have a consensus counterpart. Based on the downregulated genes, transcription factors (TFs) and kinases within the upstream regulatory network were predicted. Then, we compared the difference in infiltrating levels of immune cells between OA and SCOS samples and found a significantly higher degree of infiltration for most immune cells in SCOS than OA samples. Moreover, CD56bright natural killer cell was significantly associated with six hub genes. Enriched hallmark pathways in SCOS had remarkably more upregulated pathways than the downregulated ones. Collectively, we detected DEGs, significant modules, hub genes, upstream TFs and kinases, enriched downstream pathways, and infiltrated immune cells that might be specifically implicated in the pathogenesis of SCOS. These findings provide new insights into the pathogenesis of SCOS and fuel future advances in its theranostics.

Repeated microdissection testicular sperm extraction in patients with non-obstructive azoospermia: Outcome and predictive factors

Objective

To assess the feasibility of repeated sperm recovery in patients with non-obstructive azoospermia (NOA), as little is known about the extraction rate in repeated microdissection testicular sperm extraction (microTESE) in these patients.

Patients and Methods

A total of 134 men with NOA had their first sperm recovery between January 2013 and February 2020. Repeated microTESE had been done mostly for patients with a successful initial retrieval.

Results

In the 323 procedures performed on the 134 men with NOA, sperm could be retrieved in 236 procedures (73.1%). A total of 88, 61 and 40 men underwent two, three and four sperm retrievals, respectively. In these cycles, sperm could be extracted in 65 (73.9%), 53 (86.9%) and 37 (92.5%) men, respectively. During the first microTESE procedure, sperm could be extracted in 81 (60.4%) men with NOA. In all, the success rate was significantly different between subgroups, showing highest rate in hypospermatogenesis cases (95.6%), followed by maturation arrest (58.5%), and Sertoli cell-only syndrome (56.0%). However, this difference was not significant at the third and fourth repeated microTESE. The FSH levels and testicular volume were among the noticeable factors affecting success of sperm retrieval. The duration between the first and second biopsies significantly increased the success rate by a factor of 1.3-fold/month; however, afterwards, the duration did not play any role in the success of microTESE. The success of previous trial significantly increased the probability of success by 10.1-fold in the second trial, 5.6-fold in the third trial, and 16.5 folds in the fourth.

Conclusion

Repeated MD -TESE ensures a high sperm recovery rate in patients with NOA. These data also show that when no spermatozoa can be obtained after thawing cryopreserved testicular sperm for ICSI in NOA patients, a repeat microTESE procedure can be planned.

Abbreviations

ICSI: intracytoplasmic sperm injection; IVF: in vitro fertilisation; MA: maturation arrest; (N)OA: (non-)obstructive azoospermia; OR: odds ratio; SCOS, Sertoli cell-only syndrome; SRR: spermatozoa retrieval rate; (micro)TESE: (microdissection) testicular sperm extraction

Non-obstructive idiopathic azoospermia vs azoospermia with antecedents of cryptorchidism: ways and probabilities of becoming parents

Background

Non-obstructive azoospermia (NOA) with history of cryptorchidism and idiopathic NOA are the most common forms of NOA without genetic aetiology. Of all patients with one of these two types of NOA, only a few will have a positive TEsticular Sperm Extraction (TESE). Of those with positive extraction followed by sperm freezing, not all will have a child after TESE-ICSI. What are the ways and probabilities of taking home a baby for patients with NOA and a history of cryptorchidism compared with patients with idiopathic NOA?

Results

Patients with idiopathic NOA or NOA and a history of cryptorchidism who underwent their first TESE were included. The patients were divided into two groups: Group 1 was composed of 125 patients with idiopathic NOA and Group 2 of 55 patients with NOA and a history of surgically treated cryptorchidism. Our results showed that more than half of the NOA patients succeeded in becoming parents. The main way to fulfil their plans for parenthood is to use sperm or embryo donation (72%) for men with idiopathic NOA, whereas the majority of men with NOA and a history of cryptorchidism had a child after TESE-ICSI (58.8%).

Conclusions

In our centre, before considering TESE for a patient with NOA, we explain systematically TESE-ICSI alternatives (sperm donation, embryo donation or adoption). As a result, the couple can consider each solution to become parents.

Fertility of Cryptorchid Testis-An Unsolved Mistery

Cryptorchidism (undescended testis) is one of the most common diagnoses in the pediatric urologist office. Even in the modern era, there still are a lot of debates regarding the optimal time for surgery related to the expected results in relation with the testicular function, including fertility. The review below intends to clarify issues regarding the impact of cryptorchidism on testicular histology and function, semen analysis, the relation between hormonal and surgical treatment, future fertility, and paternity rate.

Predictive factors of successful testicular sperm extraction for non-obstructive azoospermia with a history of bilateral cryptorchidism and normal testosterone

This study aimed to assess the predictive factors of successful sperm retrieval in non-obstructive azoospermia with a history of bilateral cryptorchidism. This retrospective study included 103 patients with azoospermia who had micro-dissection testicular sperm extraction between January 2010 and January 2020. The median (range) age of the patients and their wives in the study group was 33 (21-44) and 24 (19-33) years, respectively. The patients with low testosterone level (<3 ng/dl) were prescribed with human chorionic gonadotropin 5,000 IU injection every 3 days for 3 months. Those with persistent low testosterone even after hormonal stimulation were excluded. Sperms were retrieved from 64 (62%) patients, whilst failed in 39 (38%) patients. On univariate analysis, the median testicular volume was significantly larger in the successful group versus the failed group (p < .001), serum FSH and serum LH were significantly lower in the successful group (p = .001), serum testosterone was significantly higher in the successful group compared to the failed group (p < .001) and the age of orchidopexy was lower in the successful group versus the failed group (p = .016). On multivariate analysis, the average testicular volume and the serum testosterone levels were independent factors for successful sperm retrieval.

Microdissection testicular sperm extraction (micro-TESE) in men with infertility due to nonobstructive azoospermia: summary of current literature

PURPOSE

Nonobstructive azoospermia (NOA) is associated with intrinsic testicular defects that severely impair sperm production. Although NOA invariably leads to infertility, focal sperm production may exist in the testicles of affected patients, which can be retrieved and used for intracytoplasmic sperm injection (ICSI) to generate healthy offspring. However, geographic locations of testicular sperm producing-areas are uncertain, making microsurgical-guided sperm retrieval (microdissection testicular sperm extraction; micro-TESE) an attractive method to identify and retrieve sperm in patients with NOA due to spermatogenic failure. Given the widespread use of micro-TESE, its effectiveness in harvesting sperm and related potential complications need to be clarified.

METHODS

We queried PubMed/MEDLINE for studies published in English, from inception to May 2021, concerning the effect of micro-TESE on sperm retrieval rate (SRR), complication rate and ICSI pregnancy rate-using retrieved testicular sperm in subfertile couples where the male had NOA.

RESULTS

We found 116 articles, including 70 original papers, 32 review articles, and 14 systematic reviews. The evidence accounted for 4895 patients. Micro-TESE retrieved sperm in 46.6% of men with NOA, but SRRs varied considerably (18.4-70.8%) and were mainly related to the treated population characteristics. Concerning the general population of NOA patients who have not undergone previous sperm retrieval (naïve population), the SRR by micro-TESE was 46.8% (1833 of 3914 patients; range 20-70.8%; 28 studies). In studies reporting SR by micro-TESE for men who had failed percutaneous testicular sperm aspiration or non-microsurgical testicular sperm extraction, the SRR was 39.1% (127 of 325 patients; range 18.4-57.1%; 4 studies). Data on adverse events indicated that micro-TESE was associated with low (~ 3%) short-term postoperative complication rates. The fertilizing ability of testicular sperm retrieved by micro-TESE and used for ICSI was adequate (~ 57%), whereas clinical pregnancy and live birth were obtained in 39% and 24% of couples who had an embryo transfer, respectively. The health of the resulting children seems reassuring, but the evidence is limited. The procedure increases sperm retrieval success compared to non-microsurgical retrieval methods, particularly in men with Sertoli cell-only testicular histopathology.

CONCLUSION

We concluded that micro-TESE is an effective and safe method to retrieve sperm from men with NOA-related infertility, with potential advantages over non-microsurgical methods. Nevertheless, high-quality, head-to-head comparative randomized controlled trials by sperm retrieval method, focusing on SRR, live birth rate and assessing long-term adverse events and health of children conceived using testicular sperm from NOA patients are lacking. Therefore, further research is required to determine the full clinical implications of micro-TESE in male infertility treatment.

Effect of vas ligation on testicular sperm extraction results in nonobstructive azoospermic rats: Shaeer's lock-in technique

This study evaluates the efficacy of vas ligation in enhancing sperm retrieval in nonobstructive azoospermia cases, by accumulating intratesticular spermatozoa. Fifty-six mature male rats with equally sized testes were included in this study. Forty-six were in the study group, and 10 were in the control group. Bilateral testicular fine needle aspiration was performed for all, to confirm presence of spermatozoa in all testes. Nonobstructive azoospermia was induced in all 56 rats, using Dienogest (40 mg/kg) + Testosterone Undecanoate (25 mg/kg) every month for three months. Monthly aspirations confirmed nonobstructive azoospermia from all rats, within the three months treatment. This was followed by unilateral vas ligation and was performed for 46 rats of the study group, with no ligation performed in the control group. After a further period of 90 days (2 spermatogenic cycles) with the same medical treatment maintained, bilateral testicular sperm extraction was performed. Sperm retrieval was evaluated, comparing the outcome of vas-ligated testicles to the nonligated. Upon evaluation, spermatozoa were found in 14/46 of the vas-ligated testes (30.4%), compared to none of the nonligated (0/66), p = .0005. Ligation of the vas deferens in rats with nonobstructive azoospermia may enhance the results of sperm retrieval via sperm accumulation.

Trace the profile and function of circular RNAs in Sertoli cell only syndrome

Studies increasingly show the involvement of circular RNAs (circRNAs) in several diseases. This study aims to explore the circRNA expression pattern in the testicular tissues of patients with Sertoli only cell syndrome (SCOS) and their potential functions. High throughput circRNA microarray analysis indicated that 399 circRNAs were upregulated and 1195 were down-regulated (fold change >2, P < 0.05) in SCOS relative to obstructive azoospermia (OA). The hsa_circRNA_101222, hsa_circRNA_001387, hsa_circRNA_001153, hsa_circRNA_101373 and hsa_circRNA_103864 were validated by qRT-PCR. Furthermore, the hosting genes of the differentially expressed circRNAs (DEcircRNAs) were enriched in biological processes related to cell cycle and intercellular communication. Also, the overlapping genes between the hosting genes of SCOS-related DEcircRNAs and those highly expressed in Sertoli cells of non-obstructive azoospermia (NOA) were enriched in immune cell development and cell communication. Taken together, aberrantly expressed circRNAs likely mediate SCOS development by regulating the function of Sertoli cells and the spermatogenic microenvironment.

Reproductive Chances of Men with Azoospermia Due to Spermatogenic Dysfunction

Non-obstructive azoospermia (NOA), or lack of sperm in the ejaculate due to spermatogenic dysfunction, is the most severe form of infertility. Men with this form of infertility should be evaluated prior to treatment, as there are various underlying etiologies for NOA. While a significant proportion of NOA men have idiopathic spermatogenic dysfunction, known etiologies including genetic disorders, hormonal anomalies, structural abnormalities, chemotherapy or radiation treatment, infection and inflammation may substantively affect the prognosis for successful treatment. Despite the underlying etiology for NOA, most of these infertile men are candidates for surgical sperm retrieval and subsequent use in intracytoplasmic sperm injection (ICSI). In this review, we describe common etiologies of NOA and clinical outcomes following surgical sperm retrieval and ICSI.

Two Decades from the Introduction of Microdissection Testicular Sperm Extraction: How This Surgical Technique Has Improved the Management of NOA

The treatment of men with non-obstructive azoospermia (NOA) has improved greatly over the past two decades. This is in part due to the discovery of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), but also significantly due to improvements in surgical sperm retrieval methods, namely the development of microdissection testicular sperm extraction (mTESE). This procedure has revolutionized the field by allowing for identification of favorable seminiferous tubules while simultaneously limiting the amount of testicular tissue removed. Improving sperm retrieval rates is imperative in this cohort of infertile men as there are a limited number of factors that are predictive of successful sperm retrieval. Currently, sperm retrieval in NOA men remains dependent on surgeon experience, preoperative patient optimization and teamwork with laboratory personnel. In this review, we discuss the evolution of surgical sperm retrieval methods, review predictors of sperm retrieval success, compare and contrast the data of conventional versus mTESE, share tips for optimizing sperm retrieval outcomes, and discuss the future of sperm retrieval in men with NOA.

Non-obstructive azoospermia: current and future perspectives

Infertility affects 1 in 6 couples, and male factor infertility has been implicated as a cause in 50% of cases. Azoospermia is defined as the absence of spermatozoa in the ejaculate and is considered the most extreme form of male factor infertility. Historically, these men were considered sterile but, with the advent of testicular sperm extraction and assisted reproductive technologies, men with azoospermia are able to biologically father their own children. Non-obstructive azoospermia (NOA) occurs when there is an impairment to spermatogenesis. This review describes the contemporary management of NOA and discusses the role of hormone stimulation therapy, surgical and embryological factors, and novel technologies such as proteomics, genomics, and artificial intelligence systems in the diagnosis and treatment of men with NOA. Moreover, we highlight that men with NOA represent a vulnerable population with an increased risk of developing cancer and cardiovascular comorbodities.

[Testicular sperm extraction in male infertility : Indications, success rates, practical implementation, and possible complications]

BACKGROUND

Unwanted childlessness is a burden on a couple's relationship. The therapeutic spectrum of male infertility has increased significantly in recent years so that even azoospermia patients can be given biological paternity by testicular sperm extraction (TESE).

OBJECTIVES

The indications, success rates, practical implementation, and possible complications of conventional and microscopic TESE in male infertility are presented in this review.

METHODS

A nonsystematic search of the relevant literature was carried out.

RESULTS

In obstructive azoospermia (OA), primarily desobstructive surgical procedures are used, while TESE is the surgical procedure of choice in nonobstructive azoospermia (NOA). In the latter, sperm extraction can be performed conventionally or microscopically (mTESE) assisted, whereby the latter offers an advantage in terms of sperm detection rate in the case of small testicular volumes (<12 ml), chemotherapy, Klinefelter's disease and AZFc microdeletions. The sperm detection rate of TESE is about 50%. Postoperative controls are useful because of the possible induction of symptomatic hypogonadism.

CONCLUSION

Before performing TESE, determining the hormone status and human genetic clarification are necessary. Any costs incurred and the possibility of missing sperm proof must be discussed. Close cooperation between andrologists, gynecologists, reproductive physicians, and human geneticists is necessary. All in all, TESE is a safe surgical procedure with a low complication rate.

Fertility potential in adult men treated for uncorrected bilateral cryptorchidism: A systematic literature review and analysis of case reports

OBJECTIVE

Reports of adult orchidopexy for bilateral undescended testicles (bUDT) are sparse, and fertility outcomes are not well established. Our aim was to determine prognosis for restoration of spermatogenesis among adult men (≥18 years) undergoing orchidopexy for bUDT.

METHODS

A systematic literature review, conforming to the PRISMA statement, was conducted using the PubMed/MEDLINE and EMBASE databases through March 2020 using search terms "adult" AND "bilateral orchidopexy" OR "bilateral cryptorchidism." Relevant referenced articles from non-indexed journal were identified by Google Scholar search and additionally included.

RESULTS

Fifty-seven publications including adult men with uncorrected bilateral UDTs were identified. Baseline semen analysis was reported in 157 men, all of whom demonstrated azoospermia. Testosterone values were reported in 82 cases and were normal in 89%. Germ cells could not be identified in 72.6% of histologic specimens from 62 testicles. Abdominal testicles more frequently lacked germ cells (90%, p = 0.038) on univariate analysis. Eleven cases identified ejaculated spermatozoa following adult bilateral orchidopexy (8 publications). Sperm extraction (TESE) during orchidopexy or orchiectomy was reported in 13 men without success. Delayed TESE (median 10 months) was performed in 22 persistently azoospermic men with success in 10 (45.5%), none of whom had abdominal testicles prior to orchidopexy. Six men experienced successful paternity via natural conception (3) or assisted reproduction (3).

CONCLUSION

Fertility is possible in adult men with inguinal bUDT following orchidopexy. Subsequent sperm retrieval may involve ejaculated specimens or delayed TESE. TESE performed prior to or at time of orchidopexy is unlikely to be of benefit.

Sperm retrieval rates and clinical outcomes for patients with different causes of azoospermia who undergo microdissection testicular sperm extraction-intracytoplasmic sperm injection

The aim of our study was to compare the sperm retrieval rates (SRRs) and clinical outcomes of patients with different causes of azoospermia who underwent microdissection testicular sperm extraction-intracytoplasmic sperm injection (micro-TESE-ICSI). We conducted a retrospective study at the Reproductive Medicine Center of Peking University Third Hospital in Beijing, China, from January 2014 to December 2017. This study examined 769 patients with nonobstructive azoospermia who underwent 347 cycles of micro-TESE-ICSI. Patients with azoospermia were classified into Group A (Klinefelter syndrome, n = 284, 125 cycles), Group B (azoospermia Y chromosome factor c [AZFc] microdeletion, n = 91, 64 cycles), Group C (cryptorchidism, n = 52, 39 cycles), Group D (previous mumps and bilateral orchitis, n = 23, 23 cycles), and Group E (idiopathic azoospermia, n = 319, 96 cycles). Clinical characteristics, SRR, embryonic development, and pregnancy outcomes of the patients were compared between all groups. Patients in Group D had the highest and most successful SRR. The average SRR for all patients was 46.0%. The rates of clinical pregnancy, implantation, and live birth in Group D were 78.3%, 65.0%, and 74.0%, respectively, which were higher than those in all other groups (P < 0.05). Group B patients had the lowest clinical pregnancy, implantation, and live birth rates of all groups (P < 0.05). No differences were found in the miscarriage rate or birth defects among the groups (P > 0.05). Patients with orchitis had the highest SRR and best clinical outcomes. Although AZFc microdeletion patients had a higher SRR, their clinical outcomes were worse.

Modified stepwise mini-incision microdissection testicular sperm extraction: a useful technique for patients with a history of orchidopexy affected by non-obstructive azoospermia

Non-obstructive azoospermia (NOA), which is defined as the absence of spermatozoa in the ejaculate secondary to impaired spermatogenesis within the testis, may be caused by a variety of etiologies, including varicocele-induced testicular damage, cryptorchidism, prior testicular torsion, post-pubertal mumps orchitis, gonadotoxic effects from medications, genetic abnormalities, chemotherapy/radiation, and other unknown causes currently classified as idiopathic (Cocuzza et al., 2013). The microdissection testicular sperm extraction (micro-TESE) technique involves a meticulous microsurgical exploration of the testicular parenchyma to identify and selectively extract larger seminiferous tubules that carry a higher probability of complete spermatogenesis (Schlegel, 1999). The Cornell group evaluated the efficacy of micro-TESE in 152 NOA patients with an associated history of cryptorchidism. In their series, spermatozoa were successfully retrieved in 116/181 attempts (64%), and the resulting pregnancy rate was 50% with a delivery rate of 38% (Dabaja and Schlegel, 2013). Franco et al. (2016) described a stepwise micro-TESE approach in NOA patients, which was considered to reduce the cost, time, and effort associated with the surgery. Alrabeeah et al. (2016) further reported that a mini-incision micro-TESE, carried through a 1-cm equatorial testicular incision, can be useful for micro-TESE candidates, particularly in patients with cryptozoospermia. We conducted a retrospective study of 20 consecutive NOA patients with a history of orchidopexy from May 2015 to March 2017.

Fertility outcomes and predictors for successful sperm retrieval and pregnancy in 327 azoospermic men with a history of cryptorchidism who underwent microdissection testicular sperm extraction

BACKGROUND

Although few studies have reported fertility outcomes, no study has reported risk factors that might predict sperm retrieval and pregnancy in azoospermic men with a history of cryptorchidism in a large series.

OBJECTIVES

To investigate fertility outcomes and predictors for successful sperm retrieval and pregnancy in azoospermic men with a history of cryptorchidism who underwent microdissection testicular sperm extraction (mTESE).

MATERIALS AND METHODS

This retrospective observational study included 327 azoospermic men with a history of cryptorchidism who underwent mTESE. Fertility outcomes including sperm retrieval, fertilization rate, number of transferred embryos, pregnancy, miscarriage, and live birth rates were recorded.

RESULTS

Sperm retrieval was observed in 172 (52.6%) of the patients. The mean fertilization, pregnancy, and live birth rates were 55.2%±20.5, 53.5%, and 44.8%, respectively. The sperm retrieval rate was significantly higher at the orchidopexy age of ≤ 9.5 years (70.8%) than the orchidopexy age of > 9.5 years (42.1%) (P = .000). Patients with total testicular volume of ≥ 13.75 mL had significantly higher sperm retrieval rate (65.2%) than the patients with total testicular volume of < 13.75 mL (45.5%) (P = .001). Patients with total testosterone level of ≥ 300.5 ng/dL had significantly higher sperm retrieval rate (65.6%) than the patients with total testosterone level of < 300.5 ng/dL (40.3%) (P = .000). Patients with follicle-stimulating hormone (FSH) level of ≤ 17.25 mIU/ml had significantly higher sperm retrieval rate (72.3%) than the patients with FSH level of > 17.25 mIU/mL (44.4%) (P = .000). Younger male and female ages, and higher fertilization rates were the parameters that might predict pregnancy.

CONCLUSIONS

Infertile azoospermic men with a history of cryptorchidism have high sperm retrieval rate with mTESE. Patients who had orchidopexy at the age of ≤ 9.5 years, and having total testicular volumes of ≥ 13.75 mL with total testosterone level of > 300.5 ng/dL and FSH level of ≤ 17.25 mIU/mL have higher success rate for sperm retrieval.

Bilateral versus unilateral cryptorchidism in nonobstructive azoospermia: Testicular sperm extraction outcomes

Cryptorchidism is one of the most frequent causes of nonobstructive azoospermia (NOA) in adulthood. Although it is well known that spermatogenesis is more impaired in bilateral than in unilateral cryptorchidism, previous studies have only described small cohorts or inhomogeneous population. Consequently, we analyzed a cohort of 225 men with only a history of cryptorchidism as sole etiopathogenetic factor for NOA, and compared testicular sperm extraction (TESE) outcomes between men with bilateral versus unilateral cryptorchidism. Our results show no difference in follicle-stimulating hormone (FSH) levels and testicular volumes between men with a history of bilateral cryptorchidism compared to unilateral cryptorchidism (median: 21.3 IU l⁻¹vs 19.3 IU l⁻¹, P = 0.306; and 7.2 ml vs 7.9 ml, P = 0.543, respectively). In addition, sperm retrieval rates were similar (66.2% vs 60.0%, P = 0.353). Using multivariate analysis, we have found that only a low inhibin B level (above the assay's detection limit) was positively associated with successful sperm retrieval (P < 0.05). Regarding intracytoplasmic sperm injection outcomes, we found that cumulative pregnancy rate and live birth rate per cycle were not statistically different between the two groups (17.4% vs 27.8%, P = 0.070; and 16.1% vs 26.4%, P = 0.067, respectively). Unexpectedly, there was no significant difference in hormonal profiles (FSH, luteinizing hormone [LH], testosterone, and inhibin B levels) and TESE outcomes between unilateral versus bilateral cryptorchidism. This suggests that a history of unilateral cryptorchidism could reflect a bilateral testicular impairment. Interestingly, inhibin B level might be a predictor of successful TESE.

Testicular volume in non-obstructive azoospermia with a history of bilateral cryptorchidism may predict successful sperm retrieval by testicular sperm extraction

Purpose

Cryptorchidism is one of the most common causes of non‐obstructive azoospermia (NOA) in adulthood. Even if early orchidopexy is performed to preserve fertility potential, some patients still suffer from azoospermia. Fertility potential is significantly lower in bilateral than unilateral cryptorchidism. The aims of this study were to identify clinical parameters that predict the likely success of sperm recovery by microscopic testicular sperm extraction (micro‐TESE) and also the likely outcome of intracytoplasmic sperm injection using sperm from NOA patients who submitted to bilateral orchidopexy.

Methods

Fifty‐two NOA patients with a history of bilateral cryptorchidism underwent micro‐TESE. The following clinical parameters were evaluated as predictive factors for successful sperm recovery: age at micro‐TESE; age at orchidopexy; period from orchidopexy to micro‐TESE; luteinizing hormone (LH); follicle‐stimulating hormone (FSH); testosterone; average testicular volume; and body mass index.

Results

In the successful sperm retrieval group, average testicular volume was significantly greater, while serum LH and FSH, and body mass index were significantly lower. In a multivariate analysis, average testicular volume was positively correlated with successful sperm recovery.

Conclusion

Our results indicate that testicular volume in NOA patients with bilateral cryptorchidism is a predictor for successful sperm recovery.

A risk prediction model of sperm retrieval failure with fine needle aspiration in males with non-obstructive azoospermia

STUDY QUESTION

Can we predict the risk of sperm retrieval failure among men with non-obstructive azoospermia (NOA) before they undergo fine needle aspiration (FNA)?

SUMMARY ANSWER

Our model, which includes FSH level, age and testicular volume as variables, can predict the risk of sperm retrieval failure with FNA.

WHAT IS KNOWN ALREADY

Combined with ICSI, testicular sperm aspiration (TESA) can enable patients with NOA to have their own genetic offspring. Nearly all reproductive medicine centres in China have applied FNA, but approximately half of patients with NOA experience testicular sperm retrieval failure. Nevertheless, the models developed to predict the likelihood of obtaining spermatozoa with testicular sperm extraction (TESE) cannot accurately predict sperm retrieval, and few of these models have been sufficiently validated.

STUDY DESIGN, SIZE, DURATION

This study involved three cohorts including 597 men with NOA. From 1 January 2015 to 31 July 2017, a retrospective cohort of 317 males with NOA who underwent FNA procedures at a university affiliated hospital were included to build a risk prediction model of sperm retrieval failure with FNA. Then, from 25 October 2017 to 31 March 2018, two prospective cohorts of 61 and 219 males with NOA from the same hospital and one other reproductive specialist hospital respectively, were recruited to validate the risk prediction model.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All men with NOA undergoing their first TESE procedure as part of a fertility treatment were included. The primary end-point was the presence of one or more spermatozoa (regardless of their motility) obtained with FNA. A binary multivariable logistic model was built to predict the risk of sperm retrieval failure after TESA using the dataset from the retrospective cohort. A cut-off value for risk was calculated with receiver operating characteristic (ROC) curve analysis. Two validation sets from the prospective cohort were used to validate the risk prediction model by measures including prediction accuracy and the true positive rate.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 327 (54.8%) males with NOA experienced sperm retrieval failure with FNA. FSH level, age and testicular volume were included in the prediction model for sperm retrieval failure risk. The model had an AUC of 82.3% (95% CI: 77.6–87.1%) and a cut-off value of 64.61% with a sensitivity of 0.677 and specificity of 0.863 for predicted risk. The predictive accuracies were 85.25 and 83.56% in the external validation sets from two centres. Specifically, 85.71 and 85.15% of NOA patients from two centres that experienced sperm retrieval failure were correctly identified using our model.

LIMITATIONS, REASONS FOR CAUTION

A small proportion of males with NOA in whom sperm were successfully retrieved with FNA were misclassified; therefore, TESA techniques with higher sperm retrieval rates may be attempted in patients with high predicted risks of sperm retrieval failure rather than terminating the efforts to produce a genetic offspring. In addition, the ability to achieve a live birth using sperm retrieved with FNA was not tested in this study.

WIDER IMPLICATIONS OF THE FINDINGS

We would recommend the use of micro-TESE for men with NOA and a high predicted risk of FNA failure.

STUDY FUNDING/COMPETING INTEREST(S)

This study was partly supported by National Key R&D Program of China (No. 2017YFC0907305), the National Natural Science Foundation of China (No.81803332), Sichuan Science & Technology Program (No. 2018SZ0144, 2016SZ0066, 2018SZ0284 and 2018FZ0043), Chengdu Science & Technology Bureau (No. 2018-YF05-01265-SN), Postdoctoral Research foundation of Sichuan University (No. 2018SCU12012) and West China Second University Hospital of Sichuan University (No. kx027). There are no competing interests related to this study.

TRIAL REGISTRATION NUMBER

Not applicable.

Predictors of surgical sperm retrieval in non-obstructive azoospermia: summary of current literature

Intracytoplasmic sperm injection (ICSI), combined with surgical sperm retrieval (SR) techniques, is the sole option for patients with non-obstructive azoospermia to achieve fertility; however, with suboptimal results. Given the variability in clinical presentation, the potential role of factors that can predict the likelihood of successful testicular SR needs to be clarified. This article summarizes the current evidence concerning the variables predicting SR success in non-obstructive azoospermic patients with spermatogenic failure. For this, we used 60 articles, including 46 original papers and six meta-analyses. Clinical and laboratory factors, as well as adjuvant therapies and surgical retrieval methods, were the factors most commonly investigated. We found that Klinefelter syndrome, Y chromosome microdeletions in regions AZFa/b, and Sertoli cell-only histopathology were associated with reduced SR success. By contrast, testis volume > 12.5 ml, history of cryptorchidism, use of micro-TESE as the sperm retrieval method, and adjuvant therapy were associated with improved SR success. None of the predictors, alone or combined, provide definitive information about the chances of harvesting sperm in men with non-obstructive azoospermia, except for Y chromosome microdeletions in regions AZFa/b. In the latter, SR success is virtually nil. We conclude that SR outcomes in men with non-obstructive azoospermia are difficult to predict based on the existing variables. Although several predictors can be used for patient counseling, their clinical value is limited to either ensure SR success or discourage reproductive urologists from recommending SR to men with non-obstructive azoospermia seeking fertility. A notable exception includes the deletions involving the regions AZFa and/or AZFb of the Y chromosome; the affected patients should be counseled against undergoing SR.

Blood plasma miR-20a-5p expression as a potential non-invasive diagnostic biomarker of male infertility: A pilot study

BACKGROUND

Recently, alterations in miRNAs expression profile in semen have been linked to damaged spermatogenesis, suggesting miRNAs could be used as potential infertility biomarkers. In previous animal studies, miR-20a-5p was found to be down-expressed in low motile spermatozoa, implying its potential target of genes associated with cell apoptosis.

OBJECTIVE

To investigate miR-20a-5p expression in blood plasma of patients suffering from non-obstructive azoospermia (NOA), compared to normozoospermic controls.

MATERIALS AND METHODS

Between January 2018 and December 2019, from 52 infertile couples eligible for the study, 24 couples were finally enrolled in this monocentric observational prospective pilot study. Patients were included into two groups: Group 1 comprised men with NOA (n = 14) and Group 2 fertile men partners of women with female tubal factor infertility (n = 10). All NOA patients underwent testicular sperm extraction. The expression of circulating miR-20a-5p in plasma samples was assessed by RT-qPCR. A relative quantification strategy was adopted using the 2^-ΔCq method to calculate the target miR-20a-5p expression with respect to miR-16-5p as endogenous control.

RESULTS

Median blood plasma miR-20a-5p was significantly higher in patients affected by NOA (0.16 2^-ΔCt , range: 0.05-0.79 2^-ΔCt ) than in fertile controls (0.06 2^-ΔCt , range: 0.04-0.10 2^-ΔCt ), P < .001. MiR-20a-5p was positively correlated with follicle-stimulating hormone (FSH) (r_rho  = -0.490, P = .015) and luteinizing hormone (LH) (r_rho  = -0.462, P = .023), and negatively correlated with serum total testosterone (TT) (r_rho  = -0.534, P = .007) and right and left testicular size (r_rho  = -0.473, P = .020 and r_rho  = -0.471, P = .020, respectively). Successful sperm retrieval (SR) rate was 50.0%. Median value of miR-20a-5p did not differ significantly among patients with successful SR and those with negative SR. Testicular histological examination showed: hypospermatogenesis in 6/14 (42.8%), maturation arrest in 4/14 (28.6%), sertoli cell-only syndrome in 4/14 (28.6%). No significant differences in miR-20a-5p were found between histopathological patterns (P > .05).

CONCLUSIONS

MiR-20a-5p could represent a novel non-invasive diagnostic biomarker of male infertility.

Prediction of microdissection testicular sperm extraction outcome in men with idiopathic nonobstruction azoospermia

The aim of the present study is to assess whether the preoperative clinical indicators have an impact on sperm retrieval rate (SRR) in men with idiopathic nonobstructive azoospermia (NOA).We retrospectively studied 241 consecutive men with NOA who underwent microdissection testicular sperm extraction from 2016 to 2019 in the Reproductive Medicine Center, including 154 patients diagnosed with idiopathic NOA. They were grouped according to preoperative indicators, including average testicular volume, follicle-stimulating hormone (FSH), luteinizing hormone, Testosterone (T), and pathology, respectively.The overall SRR was 20.0% (31/155). Men with testicular volume of ≤5 mL had significant higher SRR than men with testes 5 to 10 and ≥10 mL (35.6% vs 12.3%, P = .002; 35.6% vs 16.2, P = .049, respectively). The SRR in men with FSH ≥ 24.8 mIU/mL was significant higher, compared with FSH level of 12.4 to 24.8 mIU/mL (32.6% vs 15.8%, P = .033). Men with Sertoli cell-only had significantly lower SRR than other pathological type (8.1%). Men with an FSH ≥ 24.8 mIU/mL in testicular volume ≤5 mL group had a significantly higher SRR than FSH level of 12.4 to 24.8 mIU/mL in testicular volume of ≤5 to 10 mL group (44.0% vs 11.4%, P = .002). Men with a luteinizing hormone level of 8.6 to 17.2 mIU/mL in testicular volume of 5 to 10 mL group had a poor prognosis, with an SRR of only 6.5%.Severely reduced testicular volume (≤5 mL) and severely increased FSH level (≥24.8 mIU/mL) had the better sperm retrieval outcome, which can be used as independent predictors in men with idiopathic NOA. And a combination of testicular volume and the hormone seemed to be useful in further increase predictive value.

Comparison and outcomes of nonobstructive azoospermia patients with different etiology undergoing MicroTESE and ICSI treatments

Background

The purpose of the study was to compare clinical, laboratory, histological features, microdissection testicular sperm extraction (MicroTESE) and intracytoplasmic sperm injection (ICSI) treatment outcomes of nonobstructive azoospermia (NOA) patients of various etiologies, and to investigate ICSI outcomes using fresh and frozen thawed sperms from MicroTESE, so to explore an optimal MicroTESE-ICSI procedure for NOA couples.

Methods

A retrospective analysis was made in 595 NOA patients undergoing MicroTESE from January 2013 to December 2017. The men were classified into six groups based on etiology. Patients' age, history, hormone profile, testis volume, testicular histology, sperm retrieval, fertile and pregnancy outcomes of ICSI were included for analysis.

Results

A total of 595 NOA patients were included in this study, with 446 (75.0%) were idiopathic NOA, 66 (11.1%) were Klinefelter syndrome (KS), 34 (5.7%) with microdeletion of the AZFc, 33 (5.5%) cases had the history of cryptorchidism, 13 (2.2%) had a history of mumps orchitis, and 3 (0.5%) cases underwent chemotherapy. The overall sperm retrieval rate (SRR) was 40.3% (240/595), SRR of the cryptorchidism (84.8%, 28/33) and mumps orchitis (84.6%, 11/13) groups were much higher than that of other groups, the SRR of idiopathic group was the lowest (31.8%, 142/446). One hundred and ninety-eight ICSI cycles utilizing MicroTESE sperm were retrospectively analyzed, including 155 fresh MicroTESE ICSI cycles and 43 frozen-thawed MicroTESE ICSI cycles. Fertilization rate, cleavage rate, and clinical pregnancy rate of fresh sperm group were slightly higher than those in frozen thawed MicroTESE sperm group, but high qualified embryo rate of fresh sperm group was lower than frozen thawed group. The differences were of no statistical meaning.

Conclusions

Etiology may be an effective prognostic factor for SRR in NOA patients. NOA of definite etiology, such as cryptorchidism, has high SRR, while idiopathic NOA, the most common type of NOA, has the lowest SRR. Using of frozen thawed sperm from MicroTESE had similar pregnant outcome to that of fresh sperm, so cryopreservation of testicular sperm seems to be more suitable and of great benefit in these cases and good results can also be expected when oocyte retrieval and ICSI are not performed at the same time.

Step-by-step loupes-mTESE in non-obstructive azoospermic men, a retrospective study

Background

Men with non-obstructive azoospermia (NOA) may have sperm in their testes and a procedure of sperm retrieval and assisted reproduction is required in them to allow fertility. Standard procedures such as fine needle aspiration (FNA) and conventional testicular sperm extraction (cTESE) harvest random samples with a sperm retrieval rate (SRR) of 45%. Microdissection testicular sperm extraction (mTESE) is nowadays considered to be the most accurate technique to retrieve sperm in men with NOA. This procedure can identify dilated tubules that are more likely to contain viable sperm with a SRR of 60%.

Results

In our center, testicular biopsy was conducted in a standard fashion in 321 patients with NOA until March 2003. From then to December 2017, due to the lack of an operating microscope, we used 6 fold magnifying loupes to perform a step-by-step macro- mTESE in 1050 patients. Sperm was found in the first testis in 61% of the cases, leading to stop the procedure with less testicular damage. We increased our SRR from 43 to 51.8% in an acceptable operating time of 75mn for both sides.

Conclusions

In institutions where surgeons cannot afford an operating microscope, this modified mTESE technique using × 6 magnifying loupes is reliable, especially in patients with low testicular volumes and high FSH, in whom dilated tubules can be easily identified from the surrounding tissue.

miR-202-3p Regulates Sertoli Cell Proliferation, Synthesis Function, and Apoptosis by Targeting LRP6 and Cyclin D1 of Wnt/β-Catenin Signaling

MicroRNAs (miRNAs) play important roles in mammalian spermatogenesis, which is highly dependent on Sertoli cells. However, the functions and mechanisms of miRNAs in regulating human Sertoli cells remain largely unknown. Here, we report that hsa-miR-202-3p mediates the proliferation, apoptosis, and synthesis function of human Sertoli cells. miR-202-3p was upregulated in Sertoli cells of Sertoli cell-only syndrome (SCOS) patients compared with obstructive azoospermia (OA) patients with normal spermatogenesis. Overexpression of miR-202-3p induced Sertoli cell apoptosis and inhibited cell proliferation and synthesis, and the effects were opposite when miR-202-3p was knocked down. Lipoprotein receptor-related protein 6 (LRP6) and Cyclin D1 of the Wnt/β-catenin signaling pathway were identified as direct targets of miR-202-3p in Sertoli cells, which were validated by bioinformatics tools and dual-luciferase reporter assay. Differentially expressed LRP6 and Cyclin D1 between OA and SCOS Sertoli cells were also verified. LRP6 small interfering RNA (siRNA) interference not only mimicked the effects of miR-202-3p overexpression, but also antagonized the effects of miR-202-3p inhibition on Sertoli cells. Collectively, miR-202-3p controls the proliferation, apoptosis, and synthesis function of human Sertoli cells via targeting LRP6 and Cyclin D1 of the Wnt/β-catenin signaling pathway. This study thus provides a novel insight into fate determinations of human Sertoli cells and niche of human testis.

New insights into the morphological and hormonal characteristics of spermatogenic arrest

The reported sperm retrieval rate (SRR) in patients with nonobstructive azoospermia (NOA) due to spermatogenic arrest (SA) is highly variable in the literature. This discrepancy could be explained by the heterogeneity of testicular tissues. Surprisingly, even though inhibin B levels reflect directly Sertoli cell function; no studies have evaluated this parameter in SA. We aimed to clarify the morphological and biological profile in 158 men with SA. From the total population, patients whose seminiferous tubules diameter was below 165 µm have higher SRR (46.9% vs. 27.4%, p < 0.05), lower inhibin levels and a higher frequency of nonuniform SA (71.9% vs. 38.7%, p < 0.001). On multivariate analysis, patients with late SA and a history of cryptorchidism were positively associated with successful sperm extraction. Patients with successful SRR and uniform SA exhibited inhibin levels twofold lower than those with failed TESE (45 pg/ml vs. 95 pg/ml, p < 0.05), whereas FSH levels were similar in the two groups. In this study, we showed for the first time that the mean diameter of the seminiferous tubules may be of value in the diagnosis of SA. Our results suggest that inhibin levels could be useful in the management of NOA with SA, along with FSH levels and testicular volume.

Assessment of the use of contrast enhanced ultrasound in guiding microdissection testicular sperm extraction in nonobstructive azoospermia

BACKGROUND

The aim of this study is to assess the value of contrast-enhanced ultrasound (CEUS) as a new non-invasive approach to locate the testicular area in which spermatogenesis is most likely to be found in non-obstructive azoospermic testes and to evaluate the accuracy of CEUS as a predictor of successful sperm retrieval.

METHODS

CEUS was performed in 120 nonobstructive azoospermia (NOA) patients. Microdissection testicular sperm extraction (M-TESE) was performed on the best and poorest perfusion areas selected by CEUS and on conventional areas.

RESULTS

In the 187 testicles that underwent M-TESE, the sperm retrieval rates (SRRs) in the best perfusion area and poorest perfusion area over the maximal longitudinal section and conventional area were 63.1, 34.7 and 47.1%. According to receiver operating characteristic (ROC) analysis, the arrival times (AT) ≤27 s, time-to-peak intensity (TTP) ≤45 s, and peak intensity (PI) ≥11 dB were the best predictors of positive sperm retrieval. The location of the best perfusion area was able to guide M-TESE to improve the success rates.

CONCLUSIONS

Testicle CEUS is suggested to be performed in all patients with NOA. If AT≤27 s, TTP ≤ 45 s or PI≥11 dB are found in the best perfusion area, M-TESE is strongly recommended.

Distinct Expression Profiles and Novel Targets of MicroRNAs in Human Spermatogonia, Pachytene Spermatocytes, and Round Spermatids between OA Patients and NOA Patients

Human spermatogenesis includes three main stages, namely, the mitosis of spermatogonia, meiosis of spermatocytes, and spermiogenesis of spermatids, which are precisely regulated by epigenetic and genetic factors. Abnormality of epigenetic and genetic factors can result in aberrant spermatogenesis and eventual male infertility. However, epigenetic regulators in controlling each stage of normal and abnormal human spermatogenesis remain unknown. Here, we have revealed for the first time the distinct microRNA profiles in human spermatogonia, pachytene spermatocytes, and round spermatids between obstructive azoospermia (OA) patients and non-obstructive azoospermia (NOA) patients. Human spermatogonia, pachytene spermatocytes, and round spermatids from OA patients and NOA patients were isolated using STA-PUT velocity sedimentation and identified by numerous hallmarks for these cells. RNA deep sequencing showed that 396 microRNAs were differentially expressed in human spermatogonia between OA patients and NOA patients and 395 differentially expressed microRNAs were found in human pachytene spermatocytes between OA patients and NOA patients. Moreover, 378 microRNAs were differentially expressed in human round spermatids between OA patients and NOA patients. The differential expression of numerous microRNAs identified by RNA deep sequencing was verified by real-time PCR. Moreover, a number of novel targeting genes for microRNAs were predicted using various kinds of software and further verified by real-time PCR. This study thus sheds novel insights into epigenetic regulation of human normal spermatogenesis and the etiology of azoospermia, and it could offer new targets for molecular therapy to treat male infertility.

MiRNA-133b promotes the proliferation of human Sertoli cells through targeting GLI3

Sertoli cells play critical roles in regulating spermatogenesis and they can be reprogrammed to the cells of other lineages, highlighting that they have significant applications in reproductive and regenerative medicine. The fate determinations of Sertoli cells are regulated precisely by epigenetic factors. However, the expression, roles, and targets of microRNA (miRNA) in human Sertoli cells remain unknown. Here we have for the first time revealed that 174 miRNAs were distinctly expressed in human Sertoli cells between Sertoli-cell-only syndrome (SCOS) patients and obstructive azoospermia (OA) patients with normal spermatogenesis using miRNA microarrays and real time PCR, suggesting that these miRNAs may be associated with the pathogenesis of SCOS. MiR-133b is upregulated in Sertoli cells of SCOS patients compared to OA patients. Proliferation assays with miRNA mimics and inhibitors showed that miR-133b enhanced the proliferation of human Sertoli cells. Moreover, we demonstrated that GLI3 was a direct target of miR-133b and the expression of Cyclin B1 and Cyclin D1 was enhanced by miR-133b mimics but decreased by its inhibitors. Gene silencing of GLI3 using RNA inference stimulated the growth of human Sertoli cells. Collectively, miR-133b promoted the proliferation of human Sertoli cells by targeting GLI3. This study thus sheds novel insights into epigenetic regulation of human Sertoli cells and the etiology of azoospermia and offers new targets for treating male infertility

Clinical management of infertile men with nonobstructive azoospermia

The clinical management of men with nonobstructive azoospermia (NOA) seeking fertility has been a challenge for andrologists, urologists, and reproductive medicine specialists alike. This review presents a personal perspective on the clinical management of NOA, including the lessons learned over 15 years dealing with this male infertility condition. A five-consecutive-step algorithm is proposed to manage such patients. First, a differential diagnosis of azoospermia is made to confirm/establish that NOA is due to spermatogenic failure. Second, genetic testing is carried out not only to detect the males in whom NOA is caused by microdeletions of the long arm of the Y chromosome, but also to counsel the affected patients about their chances of having success in sperm retrieval. Third, it is determined whether any intervention prior to a surgical retrieval attempt may be used to increase sperm production. Fourth, the most effective and efficient retrieval method is selected to search for testicular sperm. Lastly, state-of-art laboratory techniques are applied in the handling of retrieved gametes and cultivating the embryos resulting from sperm injections. A coordinated multidisciplinary effort is key to offer the best possible chance of achieving a biological offspring to males with NOA.

Management of non-obstructive azoospermia

Non-obstructive azoospermia (NOA) is defined as no sperm in the ejaculate due to failure of spermatogenesis and is the most severe form of male infertility. The etiology of NOA is either intrinsic testicular impairment or inadequate gonadotropin production. Chromosomal or genetic abnormalities should be evaluated because there is a relatively high incidence compared with the normal population. Although rare, NOA due to inadequate gonadotropin production is a condition in which fertility can be improved by medical treatment. In contrast, there is no treatment that can restore spermatogenesis in the majority of NOA patients. Consequently, testicular extraction of sperm under an operating microscope (micro-TESE) has been the first-line treatment for these patients. Other treatment options include varicocelectomy for NOA patients with a palpable varicocele and orchidopexy if undescended testes are diagnosed after adulthood, although management of these patients remains controversial. Advances in retrieving spermatozoa more efficiently by micro-TESE have been made during the past decade. In addition, recent advances in biotechnology have raised the possibility of using germ cells produced from stem cells in the future. This review presents current knowledge about the etiology, diagnosis, and treatment of NOA.

Surgical management of nonobstructive azoospermia

Nonobstructive azoospermia (NOA) is characterized by the complete absence of sperm in the ejaculate due to testicular failure. The evaluation and management of patients with NOA offer a challenge to the reproductive urologist. In the era of in vitro fertilization with intracytoplasmic sperm injection, surgical sperm extraction techniques can afford men with NOA biologic paternity. To provide a comprehensive review of surgical sperm retrieval approaches in the patient with NOA emphasizing complications, success rates and outcome optimization, a Medline search was conducted querying surgical approaches used to manage NOA. Four sperm extraction techniques are described including: testicular sperm aspiration, testicular sperm extraction, fine needle aspiration mapping and microdissection testicular sperm extraction. In addition, the roles for pre-extraction varicocelectomy and sperm cryopreservation are discussed. The management of NOA continues to evolve as newer tools become available. Several modalities of sperm acquisition exist. An understanding of their complications and success rates is fundamental to the treatment of NOA.

Testicular histological and immunohistochemical aspects in a post-pubertal patient with 5 alpha-reductase type 2 deficiency: case report and review of the literature in a perspective of evaluation of potential fertility of these patients

BACKGROUND

Testicular morphology and immunohistochemical studies have never been reported in genetically documented adult patients with 5 alpha-reductase type 2 deficiency (5α-R2 deficiency).

CASE PRESENTATION

We describe the testicular histopathology of a 17-year-old XY subject with 5α-R2 deficiency caused by the recurrent homozygous Gly115Asp loss of function mutation of the SRD5A2 gene.We also performed an immunohistochemical analysis in order to further study the relationship between seminiferous tubules structure, Sertoli cell differentiation and androgenic signaling impairment in this case. We thus evaluated the testicular expression of the anti-Müllerian hormone (AMH), androgen receptor (AR) and 3β-hydroxysteroid dehydrogenase (3βHSD). Histological analysis revealed a heterogeneous aspect with a majority (92%) of seminiferous tubules (ST) presenting a mature aspect but containing only Sertoli cells and devoid of germ cells and spermatogenesis. Focal areas of immature ST (8%) were also found. Testicular AR and 3βHSD expression were detected in adult male control, 5α-R2 deficiency and CAIS subjects. However, AMH expression was heterogeneous (detectable only in few AR negative prepubertal ST, but otherwise repressed) in the 5α-R2 deficiency, conversely to normal adult testis in which AMH was uniformly repressed and to an adult CAIS testis in which AMH was uniformly and strongly expressed.

CONCLUSION

Intratesticular testosterone can repress AMH by itself, independently of its metabolism into dihydrotestosterone. We also compare our results to the few post pubertal cases of 5α-R2 deficiency with available histological testicular description, reported in the literature. We will discuss these histological findings, in the more general context of evaluating the fertility potential of these patients if they were raised as males and were azoospermic.