Azoospermia and Sertoli‐cell‐only syndrome: hypoxia in the sperm production site due to impairment in venous drainage of male reproductive system

Sertoli‐cell‐only (SCO) syndrome, or germ cell aplasia, is diagnosed on testicular biopsy when germ cells are seen to be absent without histological impairment of Sertoli or Leydig cells. It is considered a situation of irreversible infertility. Recent studies have shown that varicocele, a bilateral disease, causes hypoxia in the testicular microcirculation. Destruction of one‐way valves in the internal spermatic veins (ISV) elevates hydrostatic pressure in the testicular venules, exceeding the pressure in the arteriolar system. The positive pressure gradient between arterial and venous system is reversed, causing hypoxia in the sperm production site. Sperm production deteriorates gradually, progressing to azoospermia. Our prediction was that, if genetic problems are excluded, SCO may be the final stage of longstanding hypoxia which deteriorates sperm production in a progressive process over time. This would indicate that SCO is not always an independent disease entity, but may represent deterioration of the testicular parenchyma beyond azoospermia. Our prediction is confirmed by histology of the seminiferous tubules demonstrating that SCO is associated with extensive degenerative ischaemic changes and destruction of the normal architecture of the sperm production site. Adequate treatment of bilateral varicocele by microsurgery or by selective sclerotherapy of the ISV resumes, at least partially, the flow of oxygenated blood to the sperm production site and restored sperm production in 4 out of 10 patients. Based on our findings the following statements can be made: (i) SCO may be related in part of the cases to persistent, longstanding testicular parenchymal hypoxia; (ii) germ cells may still exist in other areas of the testicular parenchyma; and (iii) if genetic problems are excluded, adequate correction of the hypoxia may restore very limited sperm production in some patients.     

Histopathological mapping of open testicular biopsies in patients with unobstructive azoospermia.

OBJECTIVE: To evaluate, in patients with unobstructive azoospermia, the heterogeneity of spermatogenesis within the testes and thus whether there is any region of advanced spermatogenesis. Patients and methods Seventy infertile men (mean age 34 years, SD 5.01) with no varicoceles or testicular atrophy had bilateral open testicular biopsies taken from six different sites. For each biopsy specimen the number of seminiferous tubules and of tubules with sperm maturation were counted (by light microscopy at x 400). The ratio of tubules with active spermatogenesis to the total number was calculated for each biopsy sample. RESULTS: The mean (SD) right and left testicular volumes were 19.82 (7.8) and 18.84 (7.89) mL, respectively; the patients' follicle-stimulating hormone level was 8.34 (1.17) IU/mL. On sextant biopsy spermatozoa were detected in 42 of the 70 patients (60%). The mean (SD) ratio of tubules with spermatozoa was 5.23 (0.8)% for the right and 5.37 (0.76)% for the left testes. There was no statistically significant difference in the ratio of seminiferous tubules positive for spermatozoa at the different biopsy sites in either the right or left testis. Spermatozoa were identified in only one to three biopsy sites in almost half of those with maturation arrest; this ratio increased to 74% in patients diagnosed as having Sertoli-cell-only syndrome with focal spermatogenesis. Conclusion There is no region of the testis that is rich or advanced in spermatogenesis in patients with unobstructive azoospermia. Without multiple testicular biopsy it is possible to miss advanced spermatogenesis in some unobstructed patients. The sextant testis biopsy is a reliable method for detecting the presence and exact location of seminiferous tubules with spermatozoa in patients with unobstructive azoospermia.     

抑制素B βB亚单位在不同病理分型的无精子症患者睾丸组织中的表达

目的:探讨抑制素B(INH B)βB亚单位在不同生精功能状态的人睾丸组织中的表达情况。方法:对83例无精子症患者进行睾丸组织病理检查诊断,根据病理形态的不同分为:唯支持细胞综合征型(n=21);生精功能低下型(n=20);生精阻滞型(n=24);生精功能基本正常型(n=18)。选择上述各型结构完整的睾丸组织,分别应用免疫组化法(SP)对血清INH B βB亚单位在不同生精功能状态的睾丸组织,进行定位研究。结果:各型睾丸组织内均存在血清INH B βB的表达,其分布特点为:间质细胞(Leydig cell)和早期生精细胞多为强阳性表达,呈深棕黄色;支持细胞(Sertoli cell)多为阳性表达;而晚期精子细胞和成熟精子未见表达;生精小管管周类肌细胞呈弱阳性表达。结论:INH B可能是睾丸Sertoli细胞和早期生精细胞的一个联合产物。     

Successful testicular sperm extraction in an azoospermic man with postpubertal mumps orchitis

A 46-year-old man who has a child from a previous marriage without artificial reproductive technologies was referred to our hospital with a chief complaint of infertility. He had suffered from bilateral orchitis after parotitis six years ago. On physical examination, both testes were soft and 4 ml in size. Semen analysis showed azoospermia and the serum follicle stimulating hormone value was high (36.9 mIU/ml). Microdissection testicular sperm extraction was performed, and motile sperm were successfully retrieved. The histological examination showed increased thickness of the basement membrane and, peritubular fibrosis in most seminiferous tubules, with few focal areas of normal spermatogenesis.     

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.     

Unilateral or bilateral testicular biopsy in the era of intracytoplasmic sperm injection

PURPOSE: Intracytoplasmic sperm injection has significantly improved the treatment of male infertility. Since only single vital spermatozoa are required for successful fertilization, the value of unilateral or bilateral diagnostic testicular biopsies in patients with azoospermia is controversial. We evaluated differences in bilateral testicular biopsies in azoospermic patients with regard to testicular histology and focal spermatogenesis. MATERIALS AND METHODS: Histopathological results of 100 testicular biopsies from 50 patients (mean age 33.3 years) were reviewed. In all cases azoospermia was the indication for diagnostic testicular biopsy. Intra-individual differences of bilateral testicular biopsies were retrospectively reviewed by determining the latest stage of spermatogenesis. RESULTS: After bilateral biopsy a difference in testicular histology was found in 28% and identical histopathology was noted in 70% of patients. An unsuspected burned out seminoma with maturation arrest in the contralateral testis was seen in 2% of cases. Testicular symmetry determined by a Prader orchidometer was noted in 54.8% of patients whereas 45.2% had asymmetrical testis. The frequency of divergent histopathologies in relation to testicular symmetry was 21.7 and 26.3%, respectively. Spermatozoa were found in 42% of right and 44% of left testes (p >0.05), and spermatids as the latest stage of differentiation were detected in 14 and 16%, respectively (p >0.05). Differentiation of testicular histologies according to the side of biopsy revealed spermatozoa and/or spermatids in 56% of right and 58% of left testes (p >0.05). Bilateral biopsies increased the detection of focal spermatogenesis to 68%. If only unilateral diagnostic testicular biopsies had been performed, in 20% of patients focal spermatogenesis in the contralateral testis would have been missed. CONCLUSIONS: Bilateral testicular biopsies are superior to unilateral biopsies in the evaluation of patients with azoospermia. A 28% intra-individual difference in testicular pathology was seen after bilateral biopsies, and in 20% of patients focal spermatogenesis would have been missed after unilateral biopsy only. Due to the prognostic relevance of testicular biopsies for successful sperm retrieval before assisted reproduction, bilateral diagnostic testicular biopsies are recommended in the evaluation of patients with azoospermia.     

Long-term effect of vasectomy on spermatogenesis in men: a morphometric study

Spermatogenic damage may occur after vasectomy, and the damage is pressure mediated, occurring when the occluded reproductive tract is unable to accommodate additional sperm produced by the testis. This study aimed to determine the long-term effect of vasectomy on spermatogenesis in humans and clarify how the balance between sperm production in the testis and sperm storage in or removal from the tract might be maintained. During inguinal hernia repair, an open biopsy was performed to obtain testicular tissue blocks from 51 Chinese men (aged ≥50 years), of whom 25 (control group) had not undergone vasectomy and 26 (vasectomized group) had undergone bilateral vasectomy 22–42 years before. Methacrylate resin-embedded testicular sections were made, and morphometric studies were performed using light microscopy. In addition, sizes of the testis and epididymis were estimated with ultrasonography. The testicular tissue blocks obtained from one control and seven vasectomized men consisted almost completely of connective tissue. In the other 43 men, significant differences were not found between the two groups in the testicular or epididymal size, qualitative histology or quantitative parameters including the mean diameter or volume fraction of the seminiferous tubules. In conclusion, sperm production and sperm storage/removal reached a static equilibrium after vasectomy, likely due to spermatogenic degeneration or less sperm production as a result of aging or due to vasectomy-induced testicular (interstitial) fibrosis. Thus, complications that might occur in association with overproduction of sperm and distension of the tract would disappear or be relieved with time.     

Ultrastructure of the seminiferous tubules in oligoasthenoteratozoospermic men associated with varicocele

Varicocele is associated with venous reflux that may cause increased heat and interstitial pressure within the testes, with variable pathological effects on spermatogenesis. This study aimed to study the ultrastructural testicular changes in the seminiferous tubules of 20 infertile severe oligoasthenoteratozoospermia (OAT) men associated with varicocele and five patients with obstructive azoospermia without varicocele as controls. They were subjected to testicular biopsy which was evaluated by transmission electron microscopy. Ultrastructurally, the seminiferous epithelium in the testicular biopsies of infertile severe OAT men associated with varicocele was variably affected in the form of thickening of the peritubular connective tissue, vacuolation of Sertoli cell and germ cell cytoplasm, presence of degenerated and apoptotic cells among the germinal epithelium, altered spermatids and abnormal spermatozoa. It is concluded that varicocele in severe OAT men is associated with ultrastructural changes in the seminiferous tubule.     

无精子症患者睾丸组织病理分型与血清抑制素B关系的研究

目的:探讨无精子症患者睾丸组织病理分型与血清抑制素B(INH B)水平间的关系,了解血清INH B在评估无精子症患者睾丸生精功能状态的敏感性和特异性。方法:对83例无精子症患者进行睾丸活组织病理检查诊断,根据病理形态的不同分为:唯支持细胞综合征组(n=21)、生精功能低下组(n=20)、生精阻滞组(n=24)和生精功能基本正常组(n=18)。患者睾丸活检前分别测定其血清INH B、卵泡刺激素(FSH)、黄体生成素(LH)及睾酮(T)水平。结果:上述4组血清INH B水平分别为(20.85±18.78)、(67.25±40.98)、(73.63±25.54)和(149.48±27.92)ng/m l。INH B水平在生精阻滞组与生精功能低下组之间差异无显著性(P>0.05),其他各组间以及与上述两组血清INH B水平间差异均有极显著性(P<0.001);FSH水平在生精阻滞组与基本正常组间差异无显著性(P>0.05),其他各组间以及与上述两组血清FSH水平间差异均有显著性(P<0.05);4组血清LH及T水平之间无相关性。结论:血清INH B水平在生精小管生精功能受损时明显降低,唯支持细胞综合征者下降最为显著。血清INH B水平可直接反映睾丸生精功能的总体状态,是判断无精子症患者睾丸生精功能更有效的诊断指标。     

Use of Raman spectroscopy to identify active spermatogenesis and Sertoli‐cell‐only tubules in mice

Microdissection testicular sperm extraction (micro‐TESE) has become the first line therapy to harvest spermatozoa for men with nonobstructive azoospermia. However, the pitfall is that the selection of seminiferous tubules depends on subjective assessment of the colour and size of tubules, which cannot guarantee successful retrieval of spermatozoa. The aim of this study was to determine whether Raman spectroscopy (RS) could distinguish tubules with spermatogenesis from Sertoli‐cell‐only (SCO) tubules, and potentially serve as a useful tool to improve sperm retrieval rates. Fourteen male adult mice were divided into two groups: SCO group received a single intraperitoneal injection of busulfan (40 mg per kg body weight), and the control group received a placebo dose of 0.9% saline solution. Mice were sacrificed after 4 weeks, and the testicular tissue was assessed by RS and then confirmed with histopathology. The results indicated that tubules with spermatogenesis had intensified Raman peaks at 748, 1124, 1309, 1446 and 1658 cm^?1 compared to SCO tubules, except a decreased peak at 1582 cm^?1. RS was able to distinguish the two groups with a sensitivity of 91.2% and specificity of 82.9%. In conclusion, RS may serve as a useful diagnostic tool prior to sperm retrieval.     

Prediction of the extent of germ cell loss utilising a noninvasive spectroscopy method in rat testicular damage model

The aim of this study is to investigate the efficiency of elastic light single-scattering spectroscopy system, a noninvasive method, to acquire spectra during testicular biopsy from normal and damaged seminiferous tubules with various degrees of germ cell loss. Adult control rats and doxorubicin-injected rats to achieve seminiferous germ cell loss (for 10 days [10D], 20 days [D20], 30 days [D30], 40 days [D40], and 50 days [D50]) were used. Spectroscopic measurements were acquired utilising a single-fibre optical probe, and histopathology of the biopsied testicular tissue samples were compared. Time-dependent testicular damage comprising various degrees of seminiferous tubule degeneration after doxorubicin-administration was observed. In D30, D40 and D50 groups, where significant germ cell loss was identified, elastic light single-scattering spectroscopy system signals were well correlated with disturbed spermatogenesis where significant differences in spectral signals were obtained. Our findings indicate that the elastic light single-scattering spectroscopy system has the potential to enable instant imaging of spermatogenesis in rats and could also be useful in humans for clinical applications, such as to increase sperm recovery success during micro-TESE for men with nonobstructive azoospermia.     

Expression of endothelial nitric oxide synthase in the Sertoli cells of men with infertility of various causes

OBJECTIVE: To investigate how endothelial nitric oxide (eNOS) expression in the seminiferous tubules might be related to spermatogenesis, by examining eNOS expression in testicular tissue of patients infertile from various causes. PATIENTS AND METHODS: The study included five fertile men with a normal sperm concentration, nine patients with obstructive azoospermia, 20 with varicocele testes and eight with idiopathic azoospermia (Sertoli cell-only syndrome). Testicular biopsy specimens were examined by immunohistochemistry for eNOS protein expression, in addition to a routine pathological assessment. eNOS protein was detected using an eNOS monoclonal antibody. A Sertoli cell staining index (SSI) was defined as the ratio of stained Sertoli cells per total number of Sertoli cells, and was compared among the groups. RESULTS: eNOS was localized to Sertoli cells in the seminiferous tubules and Leydig cells in the interstium; although some degenerating germ cells stained, normal germ cells did not. The SSI was significantly lower in patients with Sertoli cell-only syndrome than in either fertile men or patients with obstructive azoospermia or varicocele. However, the SSI did not correlate significantly with the Johnsen score. CONCLUSION: The expression of eNOS in Sertoli cells may depend on the existence of germ cells and be associated with germ cell development.     

Attractin蛋白在不同病理分型无精子症患者睾丸组织中的表达

目的探讨Attractin蛋白在不同生精功能状态的人睾丸组织中的表达情况。方法对31例无精子症患者进行睾丸组织病理检查诊断,根据病理形态的不同分为:唯支持细胞综合征型(n=4),生精功能低下型(n=12),生精阻滞型(n=5),生精功能基本正常型(n=10)。选择上述各型结构完整的睾丸组织,分别应用免疫组化法(SP)观察Attractin蛋白在不同生精功能状态的睾丸组织中的表达。结果各组睾丸组织内均存在Attractin蛋白的表达,其分布特点为:睾丸生精小管和间质细胞、管周肌样细胞、支持细胞上均有Attractin蛋白的表达,主要表达于胞膜和胞质,胞膜表达强于胞质。Leydig细胞、Sertoli细胞、精原细胞、精母细胞及精子细胞均为阳性表达,呈棕黄色着染。Attractin的表达与生精功能有关,正常组表达明显高于其它组,唯支组表达明显低于其他组。结论 Attractin蛋白与男性生殖密切相关,但其具体作用环节尚有待进一步研究。     

High-magnification observation of seminiferous tubules through the tunica albuginea by two-photon laser scanning microscopy

Testicular sperm extraction is widely used in the treatment of male infertility in cases of non-obstructive azoospermia. Identifying spermatogenetic foci within the testes is critical for testicular sperm extraction. Two-photon laser scanning microscopy (TPLSM) is an autofluorescence-based microscopy technique that allows observation at a cellular level in the depth of fresh living tissues and does not require any histological processing (fixation or staining). The wavelengths previously used have shown no phototoxicity on sperm. We used TPLSM to detect spermatogenetic foci in fresh mouse testicular parenchyma without disrupting the tunica albuginea. Fresh surgically retrieved testes were observed using TPLSM within 1 h after extraction. Contralateral testes for each animal were observed using standard histology. Using TPLSM we were able to observe and measure the diameter of seminiferous tubules through the tunica albuginea, similar to the histological control. Structures within epithelial tubules were also observed, although their nature has yet to be identified. TPLSM is a real-time microscopy technique that could detect spermatogenetic foci.     

1例环状22号染色体综合征致无精子症并文献复习

目的:探讨1例患有环状22号染色体综合征的无精子症患者的临床表型和遗传学特征。方法:收集1例环状22号染色体综合征患者的临床信息,结合文献加以分析。结果:患者身材矮小,体检双侧睾丸小,质地软,精液检查示无精子症。染色体核型为46,XY,r(22)(p11,q25),性激素示睾酮低下,睾丸大体病理示组织脆、易拉断,病理镜检示生精小管内支持细胞及生殖细胞数量均减少,细胞层次变薄,生殖细胞均为精原细胞,未见精母细胞和精子细胞,完全无精子发生。部分生精小管的管壁可见间质轻度纤维化。结论:环状22号染色体综合征的临床表型基本正常,但这种遗传异常使患者的睾丸组织严重受损,生精过程被阻滞而导致了无精子症。     

Surgical recovery of sperm in non-obstructive azoospermia

The development of intracytoplasmic sperm injection (ICSI) opened a new era in the field of assisted reproduction and revolutionized the assisted reproductive technology protocols for couples with male factor infertility. Fertilisation and pregnancies can be achieved with spermatozoa recovered not only from the ejaculate but also from the seminiferous tubules. The most common methods for retrieving testicular sperm in non-obstructive azoospermia (NOA) are testicular sperm aspiration (TESA: needle/fine needle aspiration) and open testicular biopsy (testicular sperm extraction: TESE). The optimal technique for sperm extraction should be minimally invasive and avoid destruction of testicular function, without compromising the chance to retrieve adequate numbers of spermatozoa to perform ICSI. Microdissection TESE (micro-TESE), performed with an operative microscope, is widely considered to be the best method for sperm retrieval in NOA, as larger and opaque tubules, presumably with active spermatogenesis, can be directly identified, resulting in higher spermatozoa retrieval rates with minimal tissue loss and low postoperative complications. Micro-TESE, in combination with ICSI, is applicable in all cases of NOA, including Klinefelter syndrome (KS). The outcomes of surgical sperm retrieval, primarily in NOA patients with elevated serum follicle-stimulating hormone (FSH) (NOA including KS patients), are reviewed along with the phenotypic features. The predictive factors for surgical sperm retrieval and outcomes of treatment were analysed. Finally, the short- and long-term complications in micro-TESE in both 46XY males with NOA and KS patients are considered.     

Studies on relationship between testicular capsule and sperm transport in rat testis

Aim: In SD rats, histological changes in the testis were observed after bilateral capsulotomy (of the tunica albuginea) in order to investigate the physiological role of the testicular capsule on sperm transport. Methods: Bilateral longitudinal capsulotomy was devised to disrupt the capsular contractile function. With this technique, only the tunica vaginalis and tunlca albuginea were slit open, leaving the tunica vasculosa intact to embrace the underlying testicular parenchyma. After capsulotomy, the structural changes in the seminiferous tubules, the transitional distal seminiferous segment, and the rete testis were observed. Results: In the capsulotomized testis, there was sperm retention at the transitional seminiferous segment and progressive degenerative changes in seminiferous tubules. Conclusion: The results clearly indicated that an intact testicular capsule was required for normal sperm transport from the seminiferous tubules into the rete testis. This is the first attempt to study the physiological role of the testicular capsule in intact animals.     

Reevaluation of testicular biopsies of males with nonobstructive azoospermia in assisted reproductive technology

Spermatogenesis was investigated in seminiferous tubules of 100 males with nonobstructive azoospermia. Forty-four (44%) cases had Sertoli-cell-only syndrome, 23 (23%) had spermatogonium in the tubules, 17 (17%) had primary spermatocyte in the tubules, and 16 (16%) had round or late spermatid in the tubules. No cases showed secondary spermatocyte present in the tubules. The mean serum follicle-stimulating hormone (FSH) in males with nonobstructive azoospermia was significantly higher than that in males with obstructive azoospermia (p < .001). The mean concentrations of serum FSH in cases with Sertoli-cell-only syndrome and spermatogonium in the tubules were significantly higher than those in cases with primary spermatocyte and spermatid in the tubules (p < .05-.001). The results indicate that the evaluation of testicular histology using the type of germ cells present in seminiferous tubules is available for assisted reproductive technology.     

Immunohistochemical expression of cyclin A in testicular biopsies of fertile and infertile men: correlation with the morphometry of seminiferous tubules

Cyclin A is a member of the cyclin family of proteins, which are required for both the mitotic and meiotic divisions that characterise spermatogenesis in human and other mammalian species. The data on cyclin A expression in various human spermatogenic disorders and its relationship to the morphology of seminiferous tubules are not well clarified. This study aimed to evaluate the immunohistochemical expression of cyclin A in testicular biopsies of different spermatogenic disorders correlating with the morphology of seminiferous tubules using morphometry tools. Immunohistochemical evaluation of cyclin A was carried out on testicular biopsies obtained from 48 infertile males (nonobstructive azoospermia) and 15 normal subjects together with using semiautomatic morphometric analysis for evaluation of seminiferous tubules. Cyclin A is expressed in 100% of normal and hypospermatogenesis groups and in 80% of maturation arrest group, with complete absence in Sertoli cell only group. In positive cases, cyclin A stained the nuclei of spermatogonia and primary spermatocytes with a higher intensity of expression in normal cases compared with infertile group. Cyclin A expression was significantly associated with the different examined morphometric parameters. Cyclin A is involved in both mitosis and meiosis of human spermatogenesis as it is expressed in spermatogonia and primary spermatocytes. Morphometry of human testis is intimately correlated with the testicular histopathology.     

睾丸精曲小管精子发生功能量化评价法分析无精子症患者睾丸生精功能

目的 :分析无精子症患者临床和病理资料 ,研究病理学量化评价睾丸精曲小管精子发生功能的方法的临床意义。　方法 :无精子症患者 112例 ,年龄 2 2～ 4 6 (2 9.0± 4 .4 )岁 ,婚龄 2～ 12 (4 .0± 2 .8)年、病程 2～ 6 (2 .70±1.0 2 )年 ,其中原发性无精子症 96例 ,继发性无精子症 16例 ;梗阻性无精子症 7例。不育症患者精液常规检查 3次确认无精子症 ,检测性激素水平 ,常规消毒下睾丸活检病理检查 ,在高倍镜下计数每个精曲小管中各类生精细胞数 ,测定小管直径、生精上皮高度和固有层厚度 ,按制定的精曲小管精子发生功能 10分 5级分度法加以评分 ,进行统计学分析。　结果 :精曲小管生精上皮 10分分度法评分结果 ,1分 5例 (4 .5 % ) ,2分 38例 (33.9% ) ,3分 2例(1.8% ) ,4分 6例 (5 .4 % ) ,5分 2例 (1.8% ) ,6分 17例 (15 .2 % ) ,7分 6例 (5 .4 % ) ,8分 19例 (17% ) ,9分 10例(8.9% ) ,10分 7例 (6 .3% )。精曲小管精子发生功能 5级分度法结果 ,1级 5例 (4 .5 % ) ,2级 38例 (33.9% ) ,3级 33例 (2 9.5 % ) ,4级 2 9例 (2 5 .9% ) ,5级 7例 (6 .3% )。多元回归分析结果 ,精曲小管精子发生功能分级与生精上皮高度、固有层厚度、精曲小管直径和血清卵泡刺激素 (FSH)具有极显著相关性 (P <0 .0 1)。组合