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.     

Microdissection testicular sperm extraction: Prediction, outcome, and complications

Testicular spermatozoa can be retrieved successfully by the testicular sperm extraction (TESE) procedure and used for intracytoplasmic sperm injection in cases of non-obstructive azoospermia (NOA). The successful application of TESE depends on the identification of seminiferous tubules containing spermatozoa; testicular tubules of patients with NOA are usually heterogeneous, and TESE may not always be successful in these patients. Microdissection TESE with an operative microscope is advantageous because larger, more opaque, and whitish tubules, presumably containing germ cells with active spermatogenesis, can be identified directly. This procedure is currently the best method for the certain identification of sperm, resulting in a high spermatozoa retrieval rate and minimal postoperative complications. The present review considers the surgical procedure, outcome, prediction for spermatozoa retrieval, and postoperative complications of microdissection TESE.     

Sperm Cells for Artificial Reproduction and Germ Cell Transplantation

Sperm retrieval for in vitro fertilization/intracytoplasmic sperm injection is the only medical procedure that enables a man with testicular azoospermia to father a child. In obstructive azoospermia after failed refertilization, microsurgical epididymal sperm aspiration is the gold standard, with retrieval rates up to 100%. In nonobstructive azoospermia (NOA), testicular spermatozoa (spermatids) can be recovered by testicular sperm extraction (TESE) in approximately half of the men. No parameters are available to definitively predict a successful recovery individually, but genetic factors, reduced testicular volume, and high serum follicle-stimulating hormone levels are associated with an unfavorable outcome. Retrieval surgery is well standardized, chiefly performed with microsurgical assistance and without severe local complications. Microsurgically assisted TESE (M-TESE) and TESE that is not microscopically supported in low-chance NOA patients may result in hypogonadism in the long term. In patients with Klinefelter syndrome, the outcome is worse with increasing age. For children before chemotherapy, M-TESE for stem cell preservation must be performed with minimal damage to the testicles.     

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.

     

Treatment of azoospermia: surgical sperm retrieval (MESA, TESE, micro-TESE)

The introduction of intracytoplasmic sperm injection (ICSI) into the spectrum of assisted reproductive technologies has offered men who suffer from severe disorders of spermatogenesis and azoospermia the possibility of fathering a child. Different surgical techniques can be used to extract spermatozoa from these men from either the epididymis and/or the testis. Surgical sperm retrieval offers a treatment for patients with testicular and/or obstructive azoospermia in cases where microsurgical refertilization is not an option or has already failed. Among surgical techniques that have been explored over the years, microsurgical epididymal sperm aspiration (MESA) and testicular sperm extraction (TESE) have become the most popular. Percutaneous techniques (such as TEFNA) are available but have disadvantages versus open surgical procedures. Together with cryopreservation of extracted spermatozoa, these techniques facilitate retrieval of spermatozoa for several ICSI attempts by a single surgical intervention.     

Operative Spermiengewinnung

The introduction of intracytoplasmic sperm injection (ICSI) into the catalogue of assisted reproductive technologies in the mid-nineties has, for the first time, offered men who suffer from severe disorders of spermatogenesis and azoospermia the possibility of fathering a child. Different surgical techniques can be used to extract spermatozoa from these men from either the epididymis and/or the testis for ICSI. Surgical sperm retrieval offers a treatment for both patients with testicular or obstructive azoospermia in cases where microsurgical refertilization is not an option or has already failed. Among surgical techniques that have been developed over the years, microsurgical epididymial sperm aspiration (MESA) and testicular sperm extraction (TESE) have become the most popular. By utilizing these techniques together with the cryopreservation of extracted spermatozoa, a single surgical intervention is able to provide spermatozoa for several ICSI attempts.     

Surgical sperm retrieval

The introduction of intracytoplasmic sperm injection (ICSI) into the catalogue of assisted reproductive technologies in the mid-nineties has, for the first time, offered men who suffer from severe disorders of spermatogenesis and azoospermia the possibility of fathering a child. Different surgical techniques can be used to extract spermatozoa from these men from either the epididymis and/or the testis for ICSI. Surgical sperm retrieval offers a treatment for both patients with testicular or obstructive azoospermia in cases where microsurgical refertilization is not an option or has already failed. Among surgical techniques that have been developed over the years, microsurgical epididymial sperm aspiration (MESA) and testicular sperm extraction (TESE) have become the most popular. By utilizing these techniques together with the cryopreservation of extracted spermatozoa, a single surgical intervention is able to provide spermatozoa for several ICSI attempts.     

睾丸精子获取和单精子卵胞浆内注射术治疗非梗阻性无精子症不育

目的　探讨非梗阻性无精子症患者外科获取睾丸精子的方法和意义。　方法　 4 9例非梗阻性无精子症患者行开放睾丸活检和诊断性睾丸精子获取术 (TESE) ,诊断性TESE有精子者至少 3个月后行单精子卵胞浆内注射 (ICSI)治疗。　结果　 12例 (2 4 .9% )诊断性TESE中发现精子 ,其中 3例为生精减少 ,2例为生精阻滞 ,7例为Sertoli细胞综合征。睾丸体积、血FSH水平和睾丸病理类型不能准确预测是否有精子。 8例行ICSI治疗 ,7例 (87.5 % )再次TESE获得睾丸精子行显微注射 ,3例获得临床妊娠。　结论　非梗阻性无精子症患者有必要行诊断性TESE确定睾丸内是否存在精子 ,获取睾丸精子结合ICSI可以有效治疗非梗阻性无精子症不育。     

Selection of individual testicular tubules from biopsied testicular tissue with a stereomicroscope improves sperm retrieval rate

The present study describes a new modification for testicular sperm extraction (TESE) with an intraoperative surgical loop, coupled with stereomicroscopic dissection in the laboratory, to identify sperm-containing tubules. The study included 116 consecutive patients with nonobstructive azoospermia (NOA) undergoing TESE and intracytoplasmic sperm injection. After dissection of testicular tissue under the stereomicroscope, patients were separated into 2 groups according to tubular diameter. In the first group (n = 72), all tubules were of the same diameter. In the second group (n = 44), tubules with variable diameters could be identified. In such cases, 1-2 of the most distended and opaque seminiferous tubules were selected and minced alone, then examined for the presence of spermatozoa. The rest of the testicular tissue suspension was minced and examined separately. In 11 (25%) cases, retrieved spermatozoa were found in the isolated distended tubules only. In 21 (47.7%) cases, spermatozoa were found in both the isolated distended tubules and the rest of the specimen. In 2 cases, spermatozoa were found only in the whole sample, not in the isolated tubules. In the remaining 10 cases, spermatozoa were not found in either the whole sample or the isolated tubules. The sperm recovery rate in the isolated tubules was significantly higher than that of the rest of the specimen (72.7% vs 52%, chi(2) = 3.93, P <.05), and larger numbers of spermatozoa could be easily retrieved in a shorter period of time. In conclusion, the selection and isolation of the most dilated and opaque seminiferous tubules by using the surgical loop, coupled with laboratory stereoscopic dissection, improves sperm retrieval for men with NOA. It is possible that surgical-loops TESE coupled with stereomicroscope may offer superior sperm retrieval when compared with conventional TESE and may also offer reduced operative time when compared with microdissection TESE.     

Intracytoplasmic sperm injection outcomes with cryopreserved testicular sperm aspiration samples

Intracytoplasmic sperm injection (ICSI) may be performed with testicular frozen–thawed spermatozoa in patients with nonobstructive azoospermia (NOA). Sperm retrieval can be performed in advance of oocyte aspiration, as it may avoid the possibility of no recovery of spermatozoa on the day of oocyte pickup. There are few studies available in the literature concerning the use of frozen–thawed spermatozoa obtained from testicular sperm aspiration (TESA). To evaluate the effects and the outcomes of ICSI with frozen–thawed spermatozoa obtained by TESA, we performed a retrospective analysis of 43 ICSI cycles using frozen–thawed TESA. We obtained acceptable results with a fertilisation rate of 67.9%, an implantation rate (IR) of 17.1%, and clinical and ongoing pregnancy rates of 41.9% and 37.2% respectively. The results of this study suggest that performing ICSI using cryopreserved frozen–thawed testicular spermatozoa with TESA as a first option is a viable, safe, economic and effective method for patients with NOA.     

Impact of testicular histopathology as a predictor of sperm retrieval and pregnancy outcome in patients with nonobstructive azoospermia: correlation with clinical and hormonal factors

In this study, our objective was to evaluate the impact of testicular histopathology on the outcome of intracytoplasmic sperm injection (ICSI) cycles of patients with nonobstructive azoospermia and correlate with clinical and hormonal parameters. For this purpose, 271 patients with nonobstructive azospermia (NOA) who underwent testicular sperm extraction (TESE) for ICSI cycles were retrospectively evaluated for sperm retrieval, fertilisation, embryo cleavage, clinical pregnancy and live birth rates among different testicular histology groups. We also correlated hormonal and clinical factors with histological findings. Sperm retrieval and fertilisation rates (FR) were found to be significantly different among all testicular histological groups of NOA except for embryo cleavage, clinical pregnancy and live birth rates. Furthermore, serum follicle stimulating hormone (FSH) level was the most significant variable to predict sperm recovery on TESE. Separate analyses within each testicular histological group revealed that higher FSH was also associated with lower pregnancy rates in only maturation arrest group. In conclusion, testicular histology significantly influences sperm retrieval and FRs but not pregnancy and live birth rates in nonobstructive azoospermia. However, FSH is the best predictor of a successful TESE.     

Intracytoplasmic sperm injection by testicular sperm in patients with aspermia or azoospermia after cancer treatment

The aim of this retrospective study was to evaluate the efficiency of testicular biopsy and intracytoplasmic sperm injection (ICSI) in patients with aspermia or non-obstructive azoospermia (NOA) after cancer treatment. From 1996 to 2003, 30 men with a history of cancer, affected by aspermia or NOA and without sperm cryopreserved before cytotoxic treatment underwent testicular sperm extraction (TESE). In these men, clinical, hormonal and histological characteristics were compared; 13 underwent 39 TESE-ICSI cycles using frozen-thawed testicular spermatozoa (TESE-ICSI group). In the same period, 31 ICSI cycles were performed in 20 men with aspermia or NOA using ejaculated sperm frozen before cancer treatment (ejaculated sperm-ICSI group). Fertilization, blastocyst development, pregnancy and miscarriage rates were compared between the groups. Testicular volume, serum follicle-stimulating hormone level and Johnsen score indicated complete although reduced spermatogenesis in men with aspermia and abnormal spermatogenesis in men with NOA. After TESE, sperm retrieval was positive in 92% of men with aspermia and 58% of men with NOA. In TESE-ICSI patients with NOA a significantly lower proportion of embryos developed to the blastocyst stage than in patients with aspermia and in those after ICSI with frozen-thawed ejaculated sperm (23% vs. 43% and 47%, p = 0.03 and p < 0.01 respectively). In all groups the miscarriage rates were high; in patients with aspermia and NOA, characterized by increased age, the miscarriage rate tended to be higher in spite of similar female age and female indications of infertility. In patients affected by aspermia or NOA after cancer treatment and without sperm cryopreserved before treatment, TESE-ICSI using testicular sperm provide a chance to father a child.     

Nonobstructive azoospermia

Nonobstructive azoospermia (NOA) remains a challenging condition in reproductive medicine to manage. The genetic basis of NOA related to partial deletions of the Y-chromosome has been intensely investigated. Such information is of prognostic value and allows more insightful genetic counseling of couples who opt for assisted reproductive technology. Testicular sperm extraction (TESE) combined with intracytoplasmic sperm injection has allowed many men with NOA to father their own biologic children. Although studies in the current literature support open testicular biopsy as the most reliable method to obtain testicular sperm, less invasive techniques such as testicular fine-needle aspiration and percutaneous needle biopsy are feasible alternatives in selected groups of patients. Measures to improve the efficacy of TESE, including the application of microsurgical techniques, are addressed. Other recent developments related to the management of NOA reviewed include processing of testicular tissue, cryopreservation of retrieved spermatozoa, in-vitro maturation of germ cells and microinjection of immature spermatogenic precursor cells.     

Comparison of intracytoplasmic sperm injection outcomes between spermatozoa retrieved from testicular biopsy and from ejaculation in cryptozoospermic men

The infrequent presence of spermatozoa in cryptozoospermic men ejaculate is a limiting factor in the treatment of them. Sometimes, this consideration impels us to apply meticulous microscopic search in ejaculate or testicular sperm extraction (TESE) method. The aim of this study was to assess putative effectiveness of sperm origin, ejaculated or testicular, in cryptozoospermia treatment. In this context, were evaluated intracytoplasmic sperm injection (ICSI) outcomes in two parameters including fertilisation rate (2PN) and embryo quality, independently. We compared the outcome in two groups: patients who underwent ejaculate/ICSI and ones who underwent TESE/ICSI process. Nineteen ICSI cycles performed with testicular spermatozoa and the rest of cycles (n = 208) carried out with ejaculated spermatozoa. Result analysis showed similar fertilisation rate between testicular and ejaculated spermatozoa (respectively, 60% versus 68%, P ≥ 0.05). Also, on the other hand, embryo quality did not show significant differences between two groups, except grade A with low significance. With regard to almost equal performance of both methods in results and being invasive of TESE as surgical sperm retrieval method, the use of ejaculated sperm more than testicular sperm should be recommended in patients with cryptozoospermia whenever possible.     

Operative sperm retrieval – the urological aspects

Summary Nowadays operative sperm retrieval in connection with assisted reproduction is a well established procedure in urological-gynecological co-working-groups. MESA (microsurgical epididymal sperm aspiration) and TESE (testicular sperm extraction) are the fundamental procedures in case of non-reconstructable obstructive azoospermia or testicular azoospermia. Percutaneous techniques as PESA (percutaneous epididymal sperm aspiration) or PTESE (percutaneous testicular sperm extraction), as they are often favorised in the anglo-american countries and the countries of Northern Europe have to be discussed to their efficacy (number of retrieved spermatozoa) and the possible testicular injury due to the blind or ultrasound-guided puncture.      

Outcome of testicular sperm extraction in nonmosaic Klinefelter syndrome patients: what is the best approach?

Klinefelter syndrome (KS) is the most common chromosomal disorder associated with male hypogonadism and infertility. Parenthood can be achieved in men with KS by intracytoplasmic sperm injection (ICSI) using testicular spermatozoon. The aim of this study was to evaluate surgical sperm retrieval (SSR) rate in patients with KS and to investigate the approach associated with the highest SSR. This is a retrospective study where all medical records of patients with KS who underwent SSR for ICSI, in our centre in the past 14 years, were reviewed. Forty‐three patients were included in this study. Twenty‐three underwent conventional testicular sperm extraction (TESE), while 20 patients underwent microsurgical TESE (Micro‐TESE). The SSR was significantly higher in the Micro‐TESE group when compared with the TESE group (30% versus 0% respectively). In the Micro‐TESE group, hormonal stimulation was given to 16 patients, while no treatment was given to four patients. SSR was only successful in hormonally treated patients (6/16). When the type of hormone stimulation was evaluated, SSR was higher in patients receiving aromatase inhibitors (27.8%). SSR in patients with KS is significantly higher when using hormonal stimulation by aromatase inhibitors followed by microsurgical testicular sperm extraction.     

非梗阻性无精子症患者睾丸活检组织细胞悬液检查与病理组织学检查精子检出率的差异性研究

目的:比较非梗阻性无精子症(NOA)患者睾丸活检组织细胞悬液检查与病理组织学检查精子检出率的差异,探讨两种检查方法结果不一致时获取精子的可靠性及临床治疗方案的选择。方法:1 112例NOA患者接受睾丸精子抽吸术(testicular sperm extraction,TESE),睾丸活检组织分别进行细胞悬液检查和病理组织学检查。结果:两种检查方法结果一致率为92.63%,一致精子检出率为41.82%,一致精子未检出率为50.81%。Kappa分析表明两种检查方法的一致性强度属于最强。25例进入辅助生殖周期的细胞悬液检查发现精子而组织学检查未发现精子患者中,24例患者取卵日成功获取精子(取精成功率为96.0%)并实施卵胞质内单精子注射(ICSI),其治疗结局为8例临床妊娠(33.33%)、4例流产(16.67%)、12例未妊娠(50.0%)。结论:实施诊断性TESE时,采用睾丸活检组织的细胞悬液检查与组织病理学检查双重评估精子检出率的方法,结果一致率高并且迅捷、准确、可靠,为NOA患者进入辅助生殖周期时成功取到精子提供了保障。当两种检查方法结果不一致时,细胞悬液检查对临床治疗方案的选择指导意义更大。     

Clinical analysis of patients with azoospermia factor deletions by microdissection testicular sperm extraction

Microdeletions of the azoospermia factor (AZF) locus on the Y chromosome have been implicated as a major genetic component of idiopathic male infertility, and the incidence of AZF deletions has been reported to be 15-20% in men with non-obstructive azoospermia (NOA). Numerous studies have described AZF deletion rates in patients with azoospermia; however, a clinical comparison of azoospermic patients with AZF deletion and those with no deletion has not been reported well. A new technique for testicular sperm extraction, microdissection testicular sperm extraction (TESE), has been used widely on NOA patients. Although testicular spermatozoa are reliably detected and retrieved from NOA patients by microdissection TESE, sperm retrieval rates for patients with AZF deletions are not well known. Therefore, characteristics of NOA patients with AZF deletion were investigated. Six of 60 patients (10%) who underwent microdissection TESE were found to have AZF deletions by genomic polymerase chain reaction. Testicular data, outcome of sperm retrieval and endocrinological profiles, were compared between patients with AZF deletions (n = 6) and those with no deletions (n = 54). Testicular size, varicocele rates and testicular histology were similar between the groups. Significant differences were not detected in the endocrinological profiles. Sperm retrieval rates were not significantly different between the groups. In conclusion, AZF deletions do not appear to confer specific characteristics to NOA patients.     

Testicular Sperm Retrieval in Azoospermic Men

ContextSperm retrieval in combination with IVF/ICSI is the only medical procedure for an azoospermic man to father a child. Different techniques, especially testicular sperm extraction (TESE), have evolved over time and have dramatically improved the outlook for men with testicular azoospermia. However sperm retrieval rates are associated not only with the operation proposed but especially with a distinct pattern of prognostic factors that must be effectively managed for all these infertile patients for their best benefit.ObjectivesTo review the etiology, clinical work-up including operative techniques, and prognostic factors for testicular sperm retrieval in azoospermic men to maximin clinical benefit by these procedures.Evidence AcquisitionData from basic and clinical studies with a defined, standardized approach pre- and postoperatively were analyzed.Evidence SynthesisDifferent standardized surgical techniques can be offered to extract spermatozoa of azoospermic men from either the epididymis and/or the testis for ICSI. Sperm retrieval offers a treatment for both patients with testicular azoospermia and men with obstructive azoospermia in cases where microsurgical refertilization is not an option or has already failed. Among surgical techniques testicular sperm extraction (TESE) and microsurgical epididymial sperm aspiration (MESA) have become the most popular techniques. However, also percutaneous techniques are employed due their easy feasibility and low costs. By utilizing these techniques together with kryopreservation of extracted spermatozoa a single surgical intervention is able to provide spermatozoa for several ICSI attempts. Extensive surgical interventions in the testis of azoospermic patients have raised concerns about the potential influence on the endocrine compartment of the testis, particularly in patients with small testes and low levels of testosterone.ConclusionsTesticular sperm retrieval is a feasible and successful procedure. Testicular spermatozoa can be retrieved from the testis in up to 70% of patients, even in cases with testicular azoospermia and severe disorders of spermatogenesis. However, surgical damage of the testis might also compromise the interstitial compartment of the testis with testosterone deficiency as a consequence. Conclusively, endocrine follow-up can be considered mandatory.