Enzymatic digestion plus mechanical searching improves testicular sperm retrieval in non-obstructive azoospermia cases

The changing landscape of nonobstructive azoospermia

PURPOSE OF REVIEW

This article aims to describe new developments in the field of nonobstructive azoospermia biology, diagnostics, biomarkers, and therapeutic strategies.

RECENT FINDINGS

Recent studies have investigated the molecular underpinnings of cellular dysfunction that is contributing to spermatogenic dysfunction and findings suggest abnormalities across both somatic and germ cells. Biomarkers to predict the chances of sperm retrieval are being explored utilizing cell free (cf) DNA and RNA from various body fluids, in addition to a full range of transcripts and epigenetics within seminal fluid. Various approaches are being explored to optimize sperm identification from surgical specimens including microfluidic and machine learning approaches. Finally, approaches to regenerating sperm production from males with nonobstructive azoospermia are evolving to include various 3-dimensional culture techniques with integration of computational modeling.

SUMMARY

The landscape of nonobstructive azoospermia biomarkers, molecular underpinnings, technological approaches to more reliably identify sperm and novel regenerative therapeutic strategies are likely to transform the field of male reproduction in years to come.

[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.

Enzymatic tissue processing after testicular biopsy in non-obstructive azoospermia enhances sperm retrieval

STUDY QUESTION

What is the added value of enzymatic processing of testicular biopsies on testicular sperm retrieval (SR) rates for patients with non-obstructive azoospermia (NOA)?

SUMMARY ANSWER

In addition to mechanical mincing, enzymatic digestion increased SR rates in testicular biopsies of NOA patients.

WHAT IS KNOWN ALREADY

Many studies focus on the surgical approach to optimize recovery of testicular sperm in NOA, and in spite of that, controversy still exists about whether the type of surgery makes any difference as long as multiple biopsies are taken. Few studies, however, focus on the role of the IVF laboratory and the benefit of additional lab procedures, e.g. enzymatic digestion, in order to optimize SR rates.

STUDY DESIGN SIZE DURATION

This retrospective single-center cohort study included all patients who underwent their first testicular sperm extraction (TESE) by open multiple-biopsy method between January 2004 and July 2022. Only patients with a normal karyotype, absence of Y-q deletions and a diagnosis of NOA based on histology were included. The primary outcome was SR rate after mincing and/or enzymes. The secondary outcome was cumulative live birth (CLB) after ICSI with fresh TESE and subsequent ICSI cycles with frozen TESE.

PARTICIPANTS/MATERIALS SETTING METHODS

Multiple biopsies were obtained from the testis, unilaterally or bilaterally, on the day of oocyte retrieval. Upon mechanical mincing, biopsies were investigated for 30 min; when no or insufficient numbers of spermatozoa were observed, enzymatic treatment was performed using Collagenase type IV. Multivariable regression analysis was performed to predict CLB per TESE by adjusting for the following confounding factors: male FSH level, female age, and requirement of enzymatic digestion to find sperm.

MAIN RESULTS AND THE ROLE OF CHANCE

We included 118 patients, of whom 72 (61.0%) had successful SR eventually. Spermatozoa were retrieved after mechanical mincing for 28 patients (23.7%; 28/118) or after additional enzymatic digestion for another 44 patients (37.2%; 44/118). Thus, of the 90 patients requiring enzymatic digestion, sperm were retrieved for 44 (48.9%). Male characteristics were not different between patients with SR after mincing or enzymatic digestion, in regard to mean age (34.5 vs 34.5 years), testis volume (10.2 vs 10.6 ml), FSH (17.8 vs 16.9 IU/l), cryptorchidism (21.4 vs 34.1%), varicocele (3.6 vs 4.6%), or histological diagnosis (Sertoli-cell only 53.6 vs 47.7%, maturation arrest 21.4 vs 38.6%, sclerosis/atrophy 25.0 vs 13.6%).Of the 72 patients with sperm available for ICSI, 23/72 (31.9%) achieved a live birth (LB) after the injection with fresh testicular sperm (and fresh or frozen embryo transfers). Of the remaining 49 patients without LB, 34 (69.4%) had supernumerary testicular sperm frozen. Of these 34 patients, 19 (55.9%) continued ICSI with frozen testicular sperm, and 9/19 (47.4%) had achieved an LB after ICSI with frozen testicular sperm. Thus, the total CLB was 32/118 (27.1%) per TESE or 32/72 (44.4%) per TESE with sperm retrieved.Of the female characteristics (couples with sperm available), only female age (30.3 vs 32.7 years; P = 0.042) was significantly lower in the group with a LB, compared to those without.The CLB with testicular sperm obtained after enzymatic digestion was 31.8% (14/44), while the CLB with sperm obtained after mincing alone was 64.3% (18/28). Multivariable logistic regression analysis showed that when enzymatic digestion was required, it was associated with a significant decrease in CLB per TESE (OR: 0.23 (0.08-0.7); P = 0.01).

LIMITATIONS REASONS FOR CAUTION

Limitations of the study are related to the retrospective design. However, the selection of only patients with NOA, and specific characteristics (normal karyotype and absence Y-q deletion) and having their first TESE, strengthens our findings.

WIDER IMPLICATIONS OF THE FINDINGS

Enzymatic processing increases the SR rate from testicular biopsies of NOA patients compared to mechanical mincing only, demonstrating the importance of an appropriate laboratory protocol. However, NOA patients should be counseled that when sperm have been found after enzymatic digestion, their chances to father a genetically own child may be lower compared to those not requiring enzymatic digestion.

STUDY FUNDING/COMPETING INTERESTS

None reported.

TRIAL REGISTRATION NUMBER

N/A.

Germplasm cryopreservation in bulls: Effects of gonadal tissue type, cryoprotectant agent, and freezing-thawing rates on sperm quality parameters

Germplasm preservation is crucial for reproductive programs involving farm and endangered species. This study describes the effects of slow-uncontrolled cryopreservation protocols on bovine sperm associated with testicular or epididymal tissues. Samples from the testis or epididymis (cauda) were cut into ∼0.5 or 1 cm³ fragments and cryopreserved using Me2SO (Dimethyl Sulfoxide) or glycerol-based cryoprotectants. Sperm were collected from testicular or epididymal tissue before and after freezing-thawing (38 °C or 40 °C) and kept at room temperature (RT) or 4 °C during handling. The parameters studied were viability, membrane integrity (HOS), motility, acrosome integrity, chromatin, and morphology. Pre-freezing parameters were lower in testicular sperm than epididymal: HOS+ and DNA integrity (P < 0.05). Normal-% pre-freezing testicular sperm morphology was lower than epididymal (43.3 ± 1.8% vs. 65.3 ± 14.8%). All testicular RT-kept sperm parameters decreased post-freezing, except for acrosome integrity, which remained constant (P > 0.05). There were no differences in Me2SO-frozen tissue sizes (P > 0.05). All epididymal RT-kept sperm parameters dropped post-freezing except for the constant DNA integrity (P > 0.05). 4^oC-kept sperm were fitter than those at RT (P < 0.05). 4^oC-kept testicular sperm viability, DNA, and membrane integrities declined after 38 °C or 40 °C thawing (P < 0.05). Acrosome integrity and motility remained unchanged after freezing (P > 0.05). 4^oC-kept epididymal sperm acrosome integrity, motility, and HOS+% severely dropped post-thawing (P < 0.05). Viability and DNA integrity were unchanged (38 °C vs. 40 °C; P > 0.05). Overall, post-freezing sperm morphology was unaffected (P > 0.05), but Dag defect was significantly lower in testicular samples (P < 0.05). Whole-epididymis parameters were maintained up to 24h at 4 °C (P > 0.05). In conclusion, testis-epididymis freezing protocols should use small tissue pieces, Me2SO-based cryoprotectants, and 4°C-kept samples to reduce sperm damage.

Co-Culture of Cryopreserved Healthy Sertoli Cells with Testicular Tissue of Non-Obstructive Azoospermia (NOA) Patients in Culture Media Containing Follicle-Stimulating Hormone (FSH)/Testosterone Has No Advantage in Germ Cell Maturation

Different cell culture conditions and techniques have been used to mature spermatogenic cells to increase the success of in vitro fertilization. Sertoli cells (SCs) are essential in maintaining spermatogenesis and FSH stimulation exerts its effect through direct or indirect actions on SCs. The effectiveness of FSH and testosterone added to the co-culture has been demonstrated in other studies to provide microenvironment conditions of the testicular niche and to contribute to the maturation and meiotic progression of spermatogonial stem cells (SSCs). In the present study, we investigated whether co-culture of healthy SCs with the patient's testicular tissue in the medium supplemented with FSH/testosterone provides an advantage in the differentiation and maturation of germ cells in NOA cases (N = 34). In men with obstructive azoospermia (N = 12), healthy SCs from testicular biopsies were identified and purified, then cryopreserved. The characterization of healthy SCs was done by flow cytometry (FC) and immunohistochemistry using antibodies specific for GATA4 and vimentin. FITC-conjugated annexin V/PI staining and the MTT assay were performed to compare the viability and proliferation of SCs before and after freezing. In annexin V staining, no difference was found in percentages of live and apoptotic SCs, and MTT showed that cryopreservation did not inhibit SC proliferation compared to the pre-freezing state. Then, tissue samples from NOA patients were processed in two separate environments containing FSH/testosterone and FSH/testosterone plus co-culture with thawed healthy SCs for 7 days. FC was used to measure 7th-day levels of specific markers expressed in spermatogonia (VASA), meiotic cells (CREM), and post-meiotic cells (protamine-2 and acrosin). VASA and acrosin basal levels were found to be lower in infertile patients compared to the OA group (8.2% vs. 30.6% and 12.8% vs. 30.5%, respectively; p < 0.05). Compared to pre-treatment measurements, on the 7th day in the FSH/testosterone environment, CREM levels increased by 58.8% and acrosin levels increased by 195.5% (p < 0.05). Similarly, in medium co-culture with healthy SCs, by day 7, CREM and acrosin levels increased to 92.2% and 204.8%, respectively (p < 0.05). Although VASA and protamine levels increased in both groups, they did not reach a significant level. No significant difference was found between the day 7 increase rates of CREM, VASA, acrosin and protamine-2 in either FSH/testosterone-containing medium or in medium additionally co-cultured with healthy SCs (58.8% vs. 92.2%, 120.6% vs. 79.4%, 195.5% vs. 204.8%, and 232.3% vs. 198.4%, respectively; p > 0.05). Our results suggest that the presence of the patient's own SCs for maturation of germ cells in the culture medium supplemented with FSH and testosterone is sufficient, and co-culture with healthy SCs does not have an additional advantage. In addition, the freezing-thawing process would not impair the viability and proliferation of SCs.

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.

Sperm Selection Procedures for Optimizing the Outcome of ICSI in Patients with NOA

Retrieving spermatozoa from the testicles has been a great hope for patients with non-obstructive azoospermia (NOA), but relevant methods have not yet been developed to the level necessary to provide resolutions for all cases of NOA. Although performing testicular sperm extraction under microscopic magnification has increased sperm retrieval rates, in vitro selection and processing of quality sperm plays an essential role in the success of in vitro fertilization. Moreover, sperm cryopreservation is widely used in assisted reproductive technologies, whether for therapeutic purposes or for future fertility preservation. In recent years, there have been new developments using advanced technologies to freeze and preserve even very small numbers of sperm for which conventional techniques are inadequate. The present review provides an up-to-date summary of current strategies for maximizing sperm recovery from surgically obtained testicular samples and, as an extension, optimization of in vitro sperm processing techniques in the management of NOA.

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.

Evaluating the quality of reported outcomes for microsurgical TESE in men with non-obstructive azoospermia: A methodological analysis

BACKGROUND

Publications of microsurgical testicular sperm extraction (mTESE) techniques and outcomes are heterogeneous, which may limit creation of best surgical practices.

OBJECTIVE

To study the quality and heterogeneity of published mTESE outcomes via a methodological analysis.

MATERIALS/METHODS

A systematic methodological analysis of all published literature on the use of mTESE in men with non-obstructive azoospermia from 1999 to the July 2020 was performed. PubMed and MEDLINE searches were performed using the search terms "microdissection TESE OR microsurgical TESE." Publications were evaluated on their reporting of pre-operative factors, intraoperative techniques, surgical and clinical outcomes, and adverse events.

RESULTS

Fifty-five studies met inclusion criteria. Surgical technique and sperm retrieval rates were the most reported criteria. Reporting on the presence of an embryologist intraoperatively was observed in approximately 30% of articles, while other procedural details including method of sperm quantification, quantity retrieved, and number of cryopreserved vials were observed in fewer than 10% of articles. Clinical outcomes, including pregnancy rates and live birth rates, were reported in fewer than 40% of the articles. Fetal outcomes including fetal and neonatal anomalies were rarely reported. Fetal growth restriction, preterm delivery, small or large for gestational age, and NICU admissions were never reported.

CONCLUSION

There are inconsistencies in reporting quality of mTESE outcomes, specifically a lack of information on the quantity and quality of sperm retrieved, the role of embryology intraoperatively, and clinical outcomes, such as live birth rate and fetal anomalies. These gaps may guide development of standardized reporting guidelines to better assess and compare clinical outcomes across institutions and maintain focus on couples-centric fertility outcomes in future mTESE studies.

Sperm recovery and ICSI outcomes in men with non-obstructive azoospermia: a systematic review and meta-analysis

BACKGROUND

Factor affecting sperm retrieval rate (SRR) or pregnancy rates (PR) after testicular sperm extraction (TESE) in patients with non-obstructive azoospermia (NOA) have not been systematically evaluated. In addition, although micro-TESE (mTESE) has been advocated as the gold standard for sperm retrieval in men with NOA, its superiority over conventional TESE (cTESE) remains conflicting.

OBJECTIVE AND RATIONALE

The objective was to perform a meta-analysis of the currently available studies comparing the techniques of sperm retrieval and to identify clinical and biochemical factors predicting SRR in men with NOA. In addition, PRs and live birth rates (LBRs), as derived from subjects with NOA post-ICSI, were also analysed as secondary outcomes.

SEARCH METHODS

An extensive Medline, Embase and Cochrane search was performed. All trials reporting SRR derived from cTESE or mTESE in patients with NOA and their specific determinants were included. Data derived from genetic causes of NOA or testicular sperm aspiration were excluded.

OUTCOMES

Out of 1236 studies, 117 studies met the inclusion criteria for this study, enrolling 21 404 patients with a mean age (± SD) of 35.0 ± 2.7 years. cTESE and mTESE were used in 56 and 43 studies, respectively. In addition, 10 studies used a mixed approach and 8 studies compared cTESE with mTESE approach. Overall, a SRR per TESE procedure of 47[45;49]% (mean percentage [95% CI]) was found. No differences were observed when mTESE was compared to cTESE (46[43;49]% for cTESE versus 46[42;49]% for mTESE). Meta-regression analysis demonstrated that SRR per cycle was independent of age and hormonal parameters at enrolment. However, the SRR increased as a function of testis volume. In particular, by applying ROC curve analysis, a mean testis volume higher than 12.5 ml predicted SRR >60% with an accuracy of 86.2% ± 0.01. In addition, SRR decreased as a function of the number of Klinefelter's syndrome cases included (S = -0.02[-0.04;-0.01]; P < 0.01. I = 0.12[-0.05;0.29]; P = 0.16). Information on fertility outcomes after ICSI was available in 42 studies. Overall, a total of 1096 biochemical pregnancies were reported (cumulative PR = 29[25;32]% per ICSI cycle). A similar rate was observed when LBR was analysed (569 live births with a cumulative LBR = 24[20;28]% per ICSI cycle). No influence of male and female age, mean testis volume or hormonal parameters on both PR and LBR per ICSI cycle was observed. Finally, a higher PR per ICSI cycle was observed when the use of fresh sperm was compared to cryopreserved sperm (PR = 35[30;40]%, versus 20[13;29]% respectively): however, this result was not confirmed when cumulative LBR per ICSI cycle was analysed (LBR = 30[20;41]% for fresh versus 20[12;31]% for cryopreserved sperm).

WIDER IMPLICATIONS

This analysis shows that cTESE/mTESE in subjects with NOA results in SRRs of up to 50%, with no differences when cTESE was compared to mTESE. Retrieved sperms resulted in a LBR of up to 28% ICSI cycle. Although no difference between techniques was found, to conclusively clarify if one technique is superior to the other, there is a need for a sufficiently powered and well-designed randomized controlled trial to compare mTESE to cTESE in men with NOA.

Enhanced efficiency in isolation and expansion of hAMSCs via dual enzyme digestion and micro-carrier

A two-stage method of obtaining viable human amniotic stem cells (hAMSCs) in large-scale is described. First, human amniotic stem cells are isolated via dual enzyme (collagenase II and DNAase I) digestion. Next, relying on a culture of the cells from porous chitosan-based microspheres in vitro, high purity hAMSCs are obtained in large-scale. Dual enzymatic (collagenase II and DNase I) digestion provides a primary cell culture and first subculture with a lower contamination rate, higher purity and a larger number of isolated cells. The obtained hAMSCs were seeded onto chitosan microspheres (CM), gelatin-chitosan microspheres (GCM) and collagen-chitosan microspheres (CCM) to produce large numbers of hAMSCs for clinical trials. Growth activity measurement and differentiation essays of hAMSCs were realized. Within 2 weeks of culturing, GCMs achieved over 1.28 ± 0.06 × 107 hAMSCs whereas CCMs and CMs achieved 7.86 ± 0.11 × 106 and 1.98 ± 0.86 × 106 respectively within this time. In conclusion, hAMSCs showed excellent attachment and viability on GCM-chitosan microspheres, matching the hAMSCs' normal culture medium. Therefore, dual enzyme (collagenase II and DNAase I) digestion may be a more useful isolation process and culture of hAMSCs on porous GCM in vitro as an ideal environment for the large-scale expansion of highly functional hAMSCs for eventual use in stem cell-based therapy.

Microdissection testicular sperm extraction: preoperative patient optimization, surgical technique, and tissue processing

Infertility due to nonobstructive azoospermia is treatable with the use of testicular sperm extraction and IVF. The optimal approach for sperm retrieval is microdissection testicular sperm extraction (mTESE). This systematic review summarizes and evaluates the literature pertaining to patient optimization before mTESE, mTESE technique, and post-mTESE testicular tissue processing. Preoperative patient optimization has been assessed in terms of adjuvant hormone therapy and varicocele repair. Limited data are available for adjuvant medical therapy, and although also limited, data for varicocele repair support increased sperm retrieval, pregnancy, and return of sperm to the ejaculate. Post-mTESE tissue processing has few comparative studies; however, most studies support the combination of mechanical mincing and use of type 4 collagenase for tissue disintegration along with pentoxifylline to assist in identifying motile and viable spermatozoa for intracytoplasmic sperm injection.

Predictive value of FSH, testicular volume, and histopathological findings for the sperm retrieval rate of microdissection TESE in nonobstructive azoospermia: a meta-analysis

We performed this meta-analysis to evaluate the predictive value of different parameters in the sperm retrieval rate (SRR) of microdissection testicular sperm extraction (TESE) in patients with nonobstructive azoospermia (NOA). All relevant studies were searched in PubMed, Web of Science, EMBASE, Cochrane Library, and EBSCO. We chose three parameters to perform the meta-analysis: follicle-stimulating hormone (FSH), testicular volume, and testicular histopathological findings which included three patterns: hypospermatogenesis (HS), maturation arrest (MA), and Sertoli-cell-only syndrome (SCOS). If there was a threshold effect, only the area under the summary receiver operating characteristic curve (AUSROC) was calculated. Otherwise, the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and the diagnostic odds ratio (DOR) were also calculated. Twenty-one articles were included in our study finally. There was a threshold effect among studies investigating FSH and SCOS. The AUSROCs of FSH, testicular volume, HS, MA, and SCOS were 0.6119, 0.6389, 0.6758, 0.5535, and 0.2763, respectively. The DORs of testicular volume, HS, and MA were 1.98, 16.49, and 1.26, respectively. The sensitivities of them were 0.80, 0.30, and 0.27, while the specificities of them were 0.35, 0.98, and 0.76, respectively. The PLRs of them were 1.49, 10.63, and 1.15, respectively. And NLRs were 0.73, 0.72, and 0.95, respectively. All the investigated factors in our study had limited predictive value. However, the histopathological findings were helpful to some extent. Most patients with HS could get sperm by microdissection TESE.

Effect of erythrocyte-sperm separation medium on nuclear, acrosomal, and membrane maturity parameters in human sperm

PURPOSE

The purpose of this study is to investigate whether erythrocyte-sperm separation medium (ESSM) has effects on human sperm motility, morphology, viability, membrane maturity, acrosome integrity, and nuclear attributes before and after cryopreservation.

METHODS

Semen samples from normozoospermic (n = 36) and oligozoospermic (n = 9) patients were analyzed. Samples from the same patient were divided into three aliquots: group 1 and group 2 were resuspended in sperm washing media and ESSM, respectively. Group 3 was resuspended in ESSM with blood sample to mimic the extensive number of erythrocytes in the testicular sperm extraction (TESE) material. All groups were evaluated for sperm concentration, motility, Kruger/Tygerberg strict morphology, viability by eosin-nigrosin staining, membrane maturity by hyaluronic acid-binding assay (HBA), acrosomal integrity by Pisum sativum lectin staining, chromatin maturity by aniline blue staining, and DNA integrity by TUNEL assay before and after cryopreservation.

RESULTS

No significant difference was determined between ESSM-treated and ESSM-untreated sperm samples for the sperm parameters tested (p > 0.05). After cryopreservation, total sperm motility and viability decreased regardless of ESSM used. The percentages of sperm with Tygerberg normal morphology, intact acrosome, and HA-bound sperm were found to be lower in oligozoospermic samples before cryopreservation in each group. However, no statistically significant differences were found between oligozoospermic and normozoospermic samples when all groups were compared. Thus, ESSM treatment did not cause a significant change on sperm motility, normal morphology, viability, HA-binding capacity, chromatin maturity, and DNA fragmentation.

CONCLUSION

ESSM can enhance the efficiency of sperm retrieval protocol and can also decrease the time required to collect spermatozoa while not affecting sperm morphogenetic properties.

Processing and selection of surgically-retrieved sperm for ICSI: a review

Although the technique of intracytoplasmic sperm injection (ICSI) has been a revolution in the alleviation of male infertility, the use of testicular sperm for ICSI was a formerly unseen breakthrough in the treatment of the azoospermic man with primary testicular failure. At the clinical level, different procedures of testicular sperm retrieval (conventional TESE, micro-TESE, FNA/TESA, MESA, PESA) are being performed, the choice is mainly based on the cause of azoospermia (obstructive versus non-obstructive) and the surgeon's skills. At the level of the IVF laboratory, mechanical procedures to harvest the sperm from the tissue may be combined with enzymatic treatment in order to increase the sperm recovery rates. A number of techniques have been developed for viable sperm selection in males with only immotile testicular sperm available. However, large, well-designed studies on the benefit and safety of one over the other technique are lacking. Despite all the available methods and combinations of laboratory procedures which have a common goal to maximize sperm recovery from testicular samples, a large proportion of NOA patients fail to father a genetically own child. Advanced technology application may improve recovery rates by detection of the testicular foci with active spermatogenesis and/or identification of the rare individual sperm in the testicular suspensions. On the other hand, in vitro spermatogenesis or sperm production from embryonic stem cells or induced pluripotent stem cells might be future options. The present review summarizes the available strategies which aim to maximize sperm recovery from surgically retrieved samples.

Novel concepts in male factor infertility: clinical and laboratory perspectives

In recent years, the management of male factor infertility has undergone important changes with the introduction of novel concepts, advanced testing, and therapeutic interventions. This review highlights some of these changes and discusses their impact to routine clinical practice. First, we discuss the recent changes in the World Health Organization (WHO) laboratory methods and reference values for the examination of human semen. Second, we examine the role of sperm chromatin integrity tests in light of increasing evidence of the detrimental effect of sperm DNA fragmentation on reproductive outcomes. Third, we summarize the main findings of varicocele-related infertility and the outcomes of microsurgical varicocele repair to different case scenarios. Lastly, we critically discuss the current management of men with nonobstructive azoospermia seeking fertility and the new opportunities that emerged to help these men achieve biological fatherhood.

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.

A laboratory modification to testicular sperm preparation technique improves spermatogenic cell yield

Testicular sperm extraction is a common procedure used to find spermatogenic cells in men with nonobstructive azoospermia. The laboratory processing of biopsied testicular tissues needs to be performed meticulously to acquire a high yield of cells. In this study, the effectiveness of mincing the tissues after testicular biopsy was assessed using histological evaluation, as was the possible adverse effect of residual tissue on the migration of spermatogenic cells during density gradient centrifugation. Our results indicate that testicular residual tissue, when laid on the density gradient medium along with the sperm wash, hinders the spermatogenic cells’ forming a pellet during centrifugation, and therefore impairs the intracytoplasmic sperm injection procedure. Whereas the mean number of recovered cells from the sperm wash medium (SWM) with residual tissue is 39.435 ± 24.849, it was notably higher (60.189 ± 28.214 cells) in the SWM without minced tissues. The remaining tissue contained no functional seminiferous tubules or spermatogenic cells in histological sections. In conclusion, the remaining residual tissue after mincing biopsied testicular tissue does not add any functional or cellular contribution to spermatogenic cell retrieval; in fact, it may block the cellular elements in the accompanying cell suspension from migrating through the gradient layers to form a pellet during centrifugation and cause loss of spermatogenic cells.

Testis sperm extraction

The last 20 years have produced developments in the treatment for patients with non-obstructive azoospermia (NOA) who were once considered to be infertile. The combination of intracytoplasmic sperm injection together with various testicular sperm retrieval techniques, including conventional testicular sperm extraction (TESE), microdissection TESE (micro-TESE) and fine needle aspiration (FNA), have revolutionized treatment for these men. In men with NOA, isolated regions of spermatogenesis within the testis are common. The goal for all types of sperm retrieval procedures is locating the focal region(s) of spermatogenesis, and harvesting the sperm for assisted reproduction. This review article explores the surgical management of men with NOA and describes all techniques that can be used for testicular sperm retrieval. A PubMed search was conducted using the key words: “sperm extraction”, “NOA”, “testicular FNA”, “testicular mapping”, “TESE”, and “testicular biopsy”. All articles were reviewed. Articles were included if they provided data on sperm retrieval rates. The methods for performing sperm retrieval rates and outcomes of the various techniques are outlined. Micro-TESE has a higher sperm retrieval rates with fewer postoperative complications and negative effects on testicular function compared with conventional TESE.

Microdissection testicular sperm extraction: an update

Patients with non-obstructive azoospermia (NOA) were once considered to be infertile with few treatment options due to the absence of sperm in the ejaculate. In the last two decades, the advent of intracytoplasmic sperm injection (ICSI), and the application of various testicular sperm retrieval techniques, including fine needle aspiration (FNA), conventional testicular sperm extraction (TESE) and microdissection testicular sperm extraction (micro-TESE) have revolutionized treatment in this group of men. Because most men with NOA will have isolated regions of spermatogenesis within the testis, studies have illustrated that sperm can be retrieved in most men with NOA, including Klinefelter's syndrome (KS), prior history of chemotherapy and cryptorchidism. Micro-TESE, when compared with conventional TESE has a higher sperm retrieval rate (SRR) with fewer postoperative complications and negative effects on testicular function. In this article, we will compare the efficacy of the different procedures of sperm extraction, discuss the medical treatment and the role of testosterone optimization in men with NOA and describe the micro-TESE surgical technique. Furthermore, we will update our overall experience to allow counseling on the prognosis of sperm retrieval for the specific subsets of NOA.

Recovery, isolation, identification, and preparation of spermatozoa from human testis

In some cases, human spermatozoa to be used for in vitro fertilization are processed from testicular or epididymal biopsies collected in the clinic or operating room. An appropriately equipped Andrology or Embryology Laboratory is required. Sterility must be maintained at all stages from collection and transport to identification and processing to insemination or cryopreservation. The technologist must be able to properly process and identify spermatozoa from aspirates, seminiferous tubules or pieces of testicular tissue. Recovery of undamaged spermatozoa from tubules or tissue requires mincing, squeezing, or vortexing the tissue, usually without the need of enzymatic digestion. A motility stimulant such as Pentoxifylline is commonly used to calculate the number of functionally competent spermatozoa. After recovery, spermatozoa may be used immediately for IVF-ICSI, incubated overnight prior to IVF-ICSI, or cryopreserved for future use. Methods for identifying, purifying, and determining the number and motility of spermatozoa during these processes are presented.

Sperm donation and its application in China: a 7-year multicenter retrospective study

Sperm donation in China is different from that in other countries due to cultural, social and political factors. This research presents the current status of sperm donation in Mainland China and highlights some problems. Between January 2003 and December 2009, 19 471 sperm donors were screened totally and 6467 donors (33.2%) were recruited. The primary reasons for non-recruitment were either inadequate semen parameters (55.0%) or positive results for sexually transmitted diseases (7.9%). There were 327 (1.7%) qualified donors who withdrew from the program because of frustration related to failed semen parameters, participation merely for free medical tests or job transfer. A questionnaire investigating donor intention, as well as other concerns associated with sperm donation, was distributed to 516 potential donors. All potential donors indicated their primary motivation as altruism, while 90.9% mentioned monetary reward as a second motivating factor. Approximately 93.4% of donors expressed some apprehension about the risk of consanguineous mating and the protection of their identity. Over the past 7 years, 488 389 vials of donors' semen have been cryopreserved. In 36 438 artificial insemination with donor sperm (AID) cycles, the clinical pregnancy rate was 23.9% and the live birth rate was 16.6%. In 7148 in vitro fertilization cycles, the clinical pregnancy rate was 45.8% and the live birth rate was 35.2%. Human sperm banks have been strictly monitored to ensure that each sperm donor can only impregnate five women nationwide. There is still a large gap between the supply and demand for sperm donation which may be solved by updated guidelines.

Fine needle aspiration vs. mTESE in non-obstructive azoospermia

This study was carried out on 100 patients with non-obstructive azoospermia (NOA) to compare between results and complications of fine needle aspiration (FNA) vs. microdissection testicular sperm extraction (mTESE) sperm retrieval. They underwent history taking, clinical examination, semen analysis, serum follicle stimulating hormone estimation and scrotal Duplex. One testis was subjected to FNA screening whereas the other testis was subjected to mTESE and histopathology. Follow-up was by ultrasonography at 1, 3 and 6 months. The overall sperm retrieval rate was 54% by mTESE and 10% by FNA. Spermatozoa were retrieved by mTESE from all cases with hypospermatogenesis, severe hypospermatogenesis, 30% of Sertoli cell only (SCO), 16.7% of germ cell arrest and in 28.6% of tubular hyalinization. Sperms were retrieved by FNA in 33.3% of hypospermatogenesis, 9% in severe hypospermatogenesis, 5% in SCO, 16.7% in germ cell arrest, while no sperms were retrieved in the tubular hyalinization group. The total complication rate following mTESE was 10% in the early phase and none in the long-term follow-up compared to 24% of FNA side. It is concluded that mTESE is superior to FNA as regards sperm retrieval rate and lower incidence of complications in NOA patients.

Outcome of repeated micro-surgical testicular sperm extraction in patients with non-obstructive azoospermia

AIM

To evaluate the outcome of repetitive micro-surgical testicular sperm extraction (mTESE) attempts in non-obstructive azoospermia (NOA) cases, in relation to patients' initial testicular histology results.

METHODS

A total of 68 patients with NOA in whom mTESE had been performed in previous intracytoplasmic sperm injection (ICSI) attempts were reviewed.

RESULTS

Among the 68 patients with NOA, the first mTESE yielded mature sperm for ICSI in 44 (64%) (Sp(+)), and failed in the remaining 24 (36%) (Sp(-)). Following their first trial, 24 patients decided to undergo a second mTESE. Of these 24 patients, no spermatozoa were obtained in 5 patients, and Sp(+) but no fertilization/pregnancy were achieved in 19. In these 24 cases, mTESE was successively repeated for two (n = 24), three (n = 4) and four (n = 1) times. The second attempt yielded mature sperm in 3/5 patients from the Sp- group and 16/19 patients from the Sp(+) group. At the third and fourth trials, 4/4 and 1/1 of the original Sp(+) patients were Sp(+) again, respectively. Distribution of main testicular histology included Sertoli cell-only syndrome (16%), maturation arrest (22%), hypospermatogenesis (21%) and focal spermatogenesis (41%). Overall, in repetitive mTESE, 24/29 (82%) of the attempts were finally Sp(+).

CONCLUSION

Repeated mTESE in patients with NOA is a feasible option, yielding considerably high sperm recovery rate. In patients with NOA, mTESE may safely be repeated one or more times to increase sperm retrieval rate, as well as to increase the chance of retrieving fresh spermatozoa to enable ICSI.