Predictors of testicular sperm retrieval in patients with non-obstructive azoospermia: a review

Azoospermia is divided into two categories of obstructive azoospermia and non-obstructive azoospermia. Before 1995, couples with a male partner diagnosed with non-obstructive azoospermia had to choose sperm donation or adoption to have a child. Currently, testicular sperm aspiration or micro-dissection testicular sperm extraction combined with intracytoplasmic sperm injection allows patients with non-obstructive azoospermia to have biological offspring. The sperm retrieval rate is significantly higher in micro-dissection testicular sperm extraction compared with testicular sperm aspiration. Additionally, micro-dissection testicular sperm extraction has the advantages of minimal invasion, safety, limited disruption of testicular function, a low risk of postoperative intratesticular bleeding, and low serum testosterone concentrations. Failed micro-dissection testicular sperm extraction has significant emotional and financial implications on the involved couples. Testicular sperm aspiration and micro-dissection testicular sperm extraction have the possibility of failure. Therefore, predicting the sperm retrieval rate before surgery is important. This narrative review summarizes the existing data on testicular sperm aspiration and micro-dissection testicular sperm extraction to identify the possible factor(s) that can predict the presence of sperm to guide clinical practice. The predictors of surgical sperm retrieval in patients with non-obstructive azoospermia have been widely studied, but there is no consensus.

Clinical and seminal parameters associated with testicular microlithiasis and its severity in males from infertile couples

STUDY QUESTION

Is there an association of testicular microlithiasis (TM) and its severity with testicular dysfunction in men from infertile couples?

SUMMARY ANSWER

The presence of ≥5 testis microcalcifications per sonogram at the scrotal ultrasonography (US) of infertile males was associated with a more severe testicular dysfunction as compared to males with limited, or without, TM.

WHAT IS KNOWN ALREADY

TM, representing an incidental finding in the scrotal US, is associated with male infertility and a higher risk for testicular cancer as compared to that in infertile males without TM. Still, there are unresolved questions on the relation between TM severity and testicular dysfunction in infertile men, as well as on the identification of risk factors for TM.

STUDY DESIGN, SIZE, DURATION

This study was an observational, retrospective, case-control investigation involving males who underwent clinical evaluation, measurement of reproductive hormones, seminal analysis and scrotal US as part of diagnostic work-up for couple infertility at an andrology clinic, between January 2004 and December 2018. One hundred patients, out of the 2112 scored men, were found to have TM during the US evaluation. One hundred male partners from 100 infertile couples without TM, comprising the control group, were selected through a matched analysis by age and date of evaluation to reduce the confounding effect of both age and technique variability all along the long period of observation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

TM was defined as limited TM (LTM) or classical TM (CTM), when the maximum number of hyperecogenic spots per sonogram was <5 or ≥5, respectively. CTM, LTM and control groups were compared for clinical variables, serum levels of FSH, LH, and total testosterone, as well for semen parameters and scrotal US features.

MAIN RESULTS AND THE ROLE OF CHANCE

After the exclusion of cases with testicular nodules to eliminate the possible confounding effect of testis cancer on testicular dysfunction, cases with CTM showed a lower mean testis volume (P = 0.03) and a lower sperm concentration (P = 0.03) as compared to the other two groups. A higher FSH level was observed in the CTM group compared to the LTM group (P = 0.02) and in controls (P = 0.009). The multiple logistic regression analysis showed that only a smaller testicle volume exhibited an independent significant association with a higher odds of detecting CTM (odds ratio = 0.84, 95% CI: 0.75–0.94; P = 0.02). No significant differences were observed between groups in the prevalence of risk factors for testicular cancer, or in the prevalence of conditions associated with TM.

LIMITATIONS, REASONS FOR CAUTION

The retrospective design of the study did not allow conclusions to be drawn about the possible underlying links in the associations of TM with defective spermatogenesis.

WIDER IMPLICATIONS OF THE FINDINGS

Males from infertile couples who exhibit a reduced testicular volume should undergo scrotal US, independent of sperm parameters, to exclude CTM and, eventually, testis cancer, although the association of CTM and current or future testis cancer risk is not yet clear. Evidence is provided here demonstrating that the presence of LTM has no clinical relevance in males from infertile couples.

STUDY FUNDING/COMPETING INTEREST(S)

Investigation was funded by Ministero dell’Università e della Ricerca, PRIN 2018, Italy. The authors have not declared any competing interests.

TRIAL REGISTRATION NUMBER

N/A

Diagnostic value of transrectal combined scrotal ultrasonography in acquired obstructive azoospermia

OBJECTIVE

To investigate the transrectal and scrotal ultrasonographic features of acquired obstructive azoospermia and evaluate the role of ultrasonography in the location diagnosis of acquired obstructive azoospermia patients.

METHODS

Retrospectively analysis of 92 cases of acquired obstructive azoospermia in recent years. All the patients underwent transrectal and scrotal ultrasonography. The ultrasonographic features were observed of testis, epididymis, scrotal segment of vas deferens, seminal vesicle, ejaculatory duct and prostate. Eighty cases with normal semen were taken as control group.

RESULTS

Among the 92 cases of acquired obstructive azoospermia, 28 cases were prostate midline cyst, 32 cases were stone or calcification of the ejaculation duct and 21 cases were chronic seminal vesicle inflammation, which were found through transrectal ultrasonography; 27 cases were vas deferens dilation, 30 cases had abnormal mass of epididymis tail, 31 cases were epididymis thickness with reticular change, 8 cases were cystic dilatation of rete testis, which were found through scrotal ultrasonography. Compared with the control group, ultrasound examination increased the detection rate of distal seminal duct lesions and epididymal lesions in acquired obstructive azoospermia patients (p<.01). Comparison of testicular volume between case group and control group did not reveal significant difference (p>.05). The thickness of the head, body and tail of epididymis in case group was significantly bigger than that in control group (p<.01).

CONCLUSION

Transrectal and scrotal ultrasonography can find lesions in different parts of the seminal passage. Acquired obstructive azoospermia patients have increased rate of distal seminal duct lesions, epididymal lesions and epididymis volume. Transrectal and scrotum ultrasonography can provide reliable imaging evidence for the location diagnosis of acquired obstructive azoospermia.

Testosterone, level of the lesion and age are independently associated with prostate volume in men with chronic spinal cord injury

PURPOSE

Although men with spinal cord injury (SCI) exhibit a prostate volume significantly smaller compared to age-matched able-bodied men, the independent association of lower prostate volume with its putative determinants has never been analyzed in this population. This study was designed to identify variables independently associated with prostate volume in men with chronic SCI.

METHODS

In this cross-sectional study, prostate volume of 138 men with chronic (> 1 years) SCI, aged 54.5 (25th-75th percentile: 36.0-66.0) years, was evaluated with trans-rectal ultrasonography. All patients underwent a complete neurological exam, as well as biochemical and hormonal assessment, including total testosterone (TT) levels. Free testosterone levels were calculated (cFT) by the Vermeulen formula.

RESULTS

The median prostate volume was 23.4 mL. At the univariate analysis, a larger prostate volume was associated with higher TT (p = 0.00001) and cFT (p = 0.001), SCI level below T12 (p = 0.007), more advanced age (p = 0.04), lower body mass index (p = 0.04), higher functional independence score (p = 0.06), higher values of prostate-specific antigen (p = 0.12) and shorter duration of the injury (p = 0.21). However, at the multiple regression analyses, an independent and positive association only persisted between the prostate volume with either TT or cFT levels, and, to a lesser extent, with age and a level of spinal lesion below T12. A prostate volume below the median value was observed in 91.4% (32/35) of patients with both androgen deficiency (TT < 264 ng/dL) and spinal lesion level ≥ T12, but only in 16.5% (2/12) of patients with both normal androgen levels and spinal lesion level below T12 (p < 0.001).

CONCLUSIONS

Our data indicate that lower testosterone levels and, to a lesser extent, a younger age and a spinal lesion level ≥ T12 represent the only variables exhibiting an independent association with a smaller prostate volume in men with SCI.

5-Alfa reductase type 2 (SRD5A2) gene rs523349 polymorphism is not associated with non-obstructive azoospermia in Turkish patients

Spermatogenesis is an androgen-dependent event, and testosterone is the major androgen source. The enzyme 5-alpha reductase converts testosterone to dihydrotestosterone (DHT) in testicular and peripheral tissues. Polymorphisms in genes encoding 5-alpha reductase may be associated with impaired male fertility. The present study aimed to investigate the relationship between 5-alpha reductase type 2 (SRD5A2) gene rs523349 polymorphism and non-obstructive azoospermia (NOA) in Turkish patients. The study included 75 NOA patients and 43 fertile men from Turkey. No significant relationship was found between SRD5A2 gene rs523349 polymorphism and male infertility (P = 0.071). There was a statistically significant difference in total testosterone level and total testis volume between NOA patients and the control groups, however there was no significant difference between serum follicle-stimulating hormone and luteinizing hormone levels. Our results showed that SRD5A2 gene rs523349 polymorphism was not associated with NOA in Turkish patients.

In vivo biochemical investigation of spermatogenic status: 1H-MR spectroscopy of testes with nonobstructive azoospermia

OBJECTIVES

To evaluate the biochemical milieu in testes with nonobstructive azoospermia (NOA) by using proton MR spectroscopy (1H-MRS) in detecting differences in testicular metabolites between histological stages of NOA and in assessing the possible presence of spermatozoa before microdissection testicular sperm extraction (mTESE).

METHODS

Forty-nine NOA men and fifty age-matched controls were included in this prospective study. A single-voxel point-resolved spectroscopy sequence with TR/TE (2000/25 ms) was used. NOA testes were classified using the higher Johnsen score (hJS) (group 1, hJS ≥ 8; and group 2, hJS < 8). Nonparametric statistical tests were used to assess differences in normalized metabolite concentrations, defined as ratios of the metabolite concentrations versus creatine concentration between (a) NOA and controls, (b) NOA groups, and (c) NOA with positive and negative sperm retrieval.

RESULTS

Normalized concentrations of total choline (median 0.396 vs 1.09 mmol/kg, p = 0.002), myo-inositol (median 1.985 vs 3.19 mmol/kg, p = 0.002), and total lipids and macromolecules (TLM) resonating at 0.9 ppm (median 0.962 vs 2.43 mmol/kg, p = 0.024), 1.3 ppm (median 4.88 vs 10.7 mmol/kg, p = 0.043), and 2.0 ppm (median 2.33 vs 5.96 mmol/kg, p = 0.007) were reduced in NOA testes compared with controls. Decreased concentrations of TLM 2.0 (median 3.755 vs 0.436 mmol/kg, p = 0.043) were found in group 2 compared with group 1. Increased normalized concentrations of glutamate were observed in NOA testes with failed sperm retrieval (median 0.321 vs 0.000 mmol/kg, p = 0.028).

CONCLUSIONS

1H-MRS provides metabolic information about the testis in NOA patients and assesses spermatogenic status before mTESE.

KEY POINTS

• NOA testes differed from age-matched controls, in terms of reduced normalized concentrations of tChol, mI, and lipids. • TLM 2.0 peaks were found useful in the identification of NOA testes with the presence of foci of advanced spermatogenesis up to the haploid gamete stage. • Glu proved a reliable metabolic signature of spermatogenesis in NOA population by assessing the possible presence of sperm after mTESE.

Left spermatic vein reflux after varicocele repair predicts pregnancies and live births in subfertile couples

PURPOSE

Varicocele repair (VR) is proposed to improve fertility in subfertile couples with a poor semen quality. We explored whether the disappearance of a left continuous spermatic venous reflux (SVR) at scrotal colour-Doppler ultrasound (CDUS), an objective evidence for a VR, is predictive for improved fertility outcome in subfertile couples.

METHODS

VR was performed by left internal spermatic vein sclero-embolisation in 88 males seeking a consultation for subfertility. Semen analysis and scrotal CDUS were evaluated before and 6 months after VR. Serum levels of FSH and total testosterone (TT) were obtained at baseline. Telephone interview was used to obtain information about fertility outcome. Significant predictors of pregnancy and live births, selected by univariate analyses, were included into multiple logistic regression models to assess independent associations.

RESULTS

At the adjusted model, independent significant predictors of pregnancy after VR were a disappeared SVR at CDUS (OR = 5.5, 97.5% CI 2.01-15.4; p = 0.0009) and an improved sperm total motile count (TMC) (OR = 5.5, 97.5% CI 1.4-27.9; p = 0.02). Even live births were independently associated with both disappeared left SVR at CDUS (OR = 4.3, 97.5% CI = 1.6-11.8; p = 0.003) and improved TMC after VR (OR = 4.8, 97.5% CI 1.3-24.2; p = 0.02).

CONCLUSION

The still controversial effect of varicocele repair on fertility in subfertile couples may reside on the undefined objective methods to document a successful VR and its effect on couple fertility. The disappearance of a continuous left SVR at CDUS after VR was the objective best predictor for subsequent improved fertility in subfertile couples.

Infectious, inflammatory and 'autoimmune' male factor infertility: how do rodent models inform clinical practice?

BACKGROUND

Infection and inflammation of the reproductive tract are significant causes of male factor infertility. Ascending infections caused by sexually transmitted bacteria or urinary tract pathogens represent the most frequent aetiology of epididymo-orchitis, but viral, haematogenous dissemination is also a contributory factor. Limitations in adequate diagnosis and therapy reflect an obvious need for further understanding of human epididymal and testicular immunopathologies and their contribution to infertility. A major obstacle for advancing our knowledge is the limited access to suitable tissue samples. Similarly, the key events in the inflammatory or autoimmune pathologies affecting human male fertility are poorly amenable to close examination. Moreover, the disease processes generally have occurred long before the patient attends the clinic for fertility assessment. In this regard, data obtained from experimental animal models and respective comparative analyses have shown promise to overcome these restrictions in humans.

OBJECTIVE AND RATIONALE

This narrative review will focus on male fertility disturbances caused by infection and inflammation, and the usefulness of the most frequently applied animal models to study these conditions.

SEARCH METHODS

An extensive search in Medline database was performed without restrictions until January 2018 using the following search terms: 'infection' and/or 'inflammation' and 'testis' and/or 'epididymis', 'infection' and/or 'inflammation' and 'male genital tract', 'male infertility', 'orchitis', 'epididymitis', 'experimental autoimmune' and 'orchitis' or 'epididymitis' or 'epididymo-orchitis', antisperm antibodies', 'vasectomy'. In addition to that, reference lists of primary and review articles were reviewed for additional publications independently by each author. Selected articles were verified by each two separate authors and discrepancies discussed within the team.

OUTCOMES

There is clear evidence that models mimicking testicular and/or epididymal inflammation and infection have been instructive in a better understanding of the mechanisms of disease initiation and progression. In this regard, rodent models of acute bacterial epididymitis best reflect the clinical situation in terms of mimicking the infection pathway, pathogens selected and the damage, such as fibrotic transformation, observed. Similarly, animal models of acute testicular and epididymal inflammation using lipopolysaccharides show impairment of reproduction, endocrine function and histological tissue architecture, also seen in men. Autoimmune responses can be studied in models of experimental autoimmune orchitis (EAO) and vasectomy. In particular, the early stages of EAO development showing inflammatory responses in the form of peritubular lymphocytic infiltrates, thickening of the lamina propria of affected tubules, production of autoantibodies against testicular antigens or secretion of pro-inflammatory mediators, replicate observations in testicular sperm extraction samples of patients with 'mixed atrophy' of spermatogenesis. Vasectomy, in the form of sperm antibodies and chronic inflammation, can also be studied in animal models, providing valuable insights into the human response.

WIDER IMPLICATIONS

This is the first comprehensive review of rodent models of both infectious and autoimmune disease of testis/epididymis, and their clinical implications, i.e. their importance in understanding male infertility related to infectious and non-infectious/autoimmune disease of the reproductive organs.

Prospective evaluation of scrotal ultrasound and intratesticular perfusion by color-coded duplex sonography (CCDS) in TESE patients with azoospermia

PURPOSE

The objective of this study was to assess whether CCDS might improve the outcome of testicular sperm retrieval in patients with azoospermia. Furthermore, we evaluated potential sonographic alterations of the testis before and after trifocal and Micro-TESE.

METHODS

78 patients were enrolled prospectively: 24 with obstructive azoospermia (OA) and 54 with non-obstructive azoospermia (NOA). 31 of 54 patients in the NOA group had negative surgical sperm retrieval. Testicular volume, hormonal parameters and sonographical findings were compared before and after TESE. The spermatogenetic score was determined for all retrieval sites. CCDS was performed at the upper, middle and lower segment of the testis. Ultrasound parameters and peak systolic velocity (PSV) were measured pre- and post-operatively.

RESULTS

Testicular volume and epididymal head size were significantly increased in OA patients compared to NOA patients. Ultrasound parameters were comparable between NOA patients with and without successful sperm retrieval. A higher intratesticular PSV was significantly correlated with a better spermatogenic score in the corresponding sonographic position. However, after adjustment for other clinical confounders, PSV does not show a significant influence on the spermatogenic score. Testicular volume decreased significantly in all patients post-operatively after 6 weeks (p < 0.001). Finally, the PSV significantly increased in all patients 24 h after surgery and nearly returned to baseline levels after 6 weeks (p < 0.001).

CONCLUSIONS

A higher intratesticular PSV may be helpful as a pre-operative diagnostic parameter in mapping for better sperm retrieval, but CCDS does not help to predict successful testicular sperm retrieval after adjustment for other clinical confounders.

Activin and follistatin interactions in the male reproductive tract: activin expression and morphological abnormalities in mice lacking follistatin 288

Activin A is an important regulator of testicular and epididymal development and function, as well as inflammation and immunity. In the adult murine reproductive tract, activin A mRNA (Inhba) expression levels are highest in the caput epididymis and decrease progressively towards the distal vas deferens. The activin-binding protein, follistatin (FST), shows the opposite expression pattern, with exceptionally high levels of the Fst288 mRNA variant in the vas deferens. This unique pattern of expression suggests that activin A and follistatin, in particular FST288, play region-specific roles in regulating the epididymis and vas deferens. The cellular distribution of activin and follistatin and structural organization of the male reproductive tract was examined in wild-type and transgenic (TghFST315) mice lacking FST288. Compared to wild-type littermates, TghFST315 mice showed a 50% reduction in serum follistatin and a significant elevation of both activin A and B. Testicular, epididymal and seminal vesicle weights were reduced, but intra-testicular testosterone was normal. A decrease in the epididymal duct diameter in the corpus and thickening of the peritubular smooth muscle in the cauda, together with increased coiling of the proximal vas deferens, were observed in TghFST315 mice. No immune cell infiltrates were detected. Immunohistochemistry indicated that epithelial cells are the main source of activins and follistatin in the epididymis and vas deferens. Activin A, but not activin B, was also localized to sperm heads in the lumen of the epididymis and vas deferens. Expression of Inhba and another immunoregulatory gene, indoleamine-2,3-dioxygenase (Ido-1), was increased approximately twofold in the TghFST315 caput epididymis, but several other genes associated with immunoregulation, inflammation or fibrosis were unaffected. Our novel data indicate that disruption of follistatin expression has significant effects on the testis and epididymis, and suggest an association between activin A and indoleamine-2,3-dioxygenase in the caput epididymis, with implications for the epididymal immunoenvironment.