Varicocoele. Classification and pitfalls

The epigenetic approach of varicocele: a focus on sperm DNA and m6A-RNA methylation

BACKGROUND

Varicocele is an abnormal dilation and torsion of the pampiniform venous plexus in the scrotum due to venous reflux, primarily affecting the left side. It affects 15% of men and is a prevalent contributor to male infertility. Varicocele is a complex disorder influenced by genetic, epigenetic, and environmental factors. Epigenetic modifications, which regulate genome activity independently of DNA or RNA sequences, may contribute to the development and severity of varicocele. These include DNA methylation, histone modifications, and RNA modifications like N6-methyladenosine (m6A). Irregularities in DNA and m6A-RNA methylation during spermatogenesis can cause gene expression abnormalities, DNA damage, and decreased fertility in varicocele patients.

OBJECTIVE AND RATIONALE

The review aims to comprehensively understand the underlying mechanisms of varicocele, a condition that can significantly impact male fertility. By exploring the role of methylation modifications, specifically DNA and m6A-RNA methylation, the review aims to synthesize evidence from basic, preclinical, and clinical research to expand the existing knowledge on this subject. The ultimate goal is to identify potential avenues for developing targeted treatments that can effectively improve varicocele and ultimately increase sperm quality in affected individuals.

SEARCH METHODS

A thorough investigation of the scientific literature was conducted through searches in PubMed, Google Scholar, and Science Direct databases until May 2024. All studies investigating the relationship between DNA and m6A-RNA methylation and male infertility, particularly varicocele were reviewed, and the most pertinent reports were included. Keywords such as varicocele, epigenetics, DNA methylation, m6A-RNA methylation, hypermethylation, hypomethylation, spermatozoa, semen parameters, spermatogenesis, and male infertility were used during the literature search, either individually or in combination.

OUTCOMES

The sperm has a specialized morphology essential for successful fertilization, and its epigenome is unique, potentially playing a key role in embryogenesis. Sperm DNA and RNA methylation, major epigenetic marks, regulate the expression of testicular genes crucial for normal spermatogenesis. This review explores the role of DNA and m6A-RNA methylation, in responding to oxidative stress and how various nutrients influence their function in varicocele condition. Evidence suggests a potential link between varicocele and aberrant DNA/m6A-RNA methylation patterns, especially hypomethylation, but the body of evidence is still limited. Further studies are needed to understand how abnormal expression of DNA/m6A-RNA methylation regulators affects testicular gene expression. Thus, analyzing sperm DNA 5mC/5hmC levels and m6A-RNA methylation regulators may reveal spermatogenesis defects and predict reproductive outcomes.

WIDER IMPLICATIONS

Nutri-epigenomics is an emerging field that could enhance the knowledge and management of diseases with unpredictable risks and consequences, even among individuals with similar lifestyles, by elucidating the influence of nutrition on DNA/m6A-RNA methylation through one-carbon metabolism. However, the importance of one-carbon metabolism to varicocele is not well-recognized. Health status and diet influence one-carbon metabolism and its associated DNA/m6A-RNA methylation modification. Future research should identify optimal methylation patterns that promote health and investigate modulating one-carbon metabolism to achieve this. Furthermore, additional studies are necessary to develop personalized dietary strategies through clinical and longitudinal research. However, a research gap exists on dietary interventions utilizing epigenetics as a therapeutic method for treating varicocele.

REGISTRATION NUMBER

Not applicable.

The role of the radiologist in the evaluation of male infertility: recommendations of the European Society of Urogenital Radiology-Scrotal and Penile Imaging Working Group (ESUR-SPIWG) for scrotal imaging

OBJECTIVES

The Scrotal and Penile Imaging Working Group (SPIWG) of the European Society of Urogenital Radiology (ESUR) aimed to produce recommendations on the role of the radiologist in the evaluation of male infertility focused on scrotal imaging.

METHODS

The authors independently performed an extensive literature Medline search and a review of the clinical practice and consensus opinion of experts in the field.

RESULTS

Scrotal ultrasound (US) is useful in investigating male infertility. US abnormalities related to abnormal sperm parameters (sperm concentration, total count, motility, and morphology) are low testicular volume (TV), testicular inhomogeneity (TI), cryptorchidism, testicular microlithiasis (TML), high-grade varicocele, bilateral absence of vas deferens, bilateral dilation and echotexture abnormalities of the epididymis. The proposed ESUR-SPIWG recommendations for imaging in the evaluation of male infertility are therefore: to measure TV; investigate TI; perform annual (US) follow-ups up to age 55 in men with a history of cryptorchidism/orchidopexy and/or in men with TML plus "additional risk factors" or with "starry sky" TML; perform scrotal/inguinal US in men with nonpalpable testis; perform scrotal US in men with abnormal sperm parameters to investigate lesions suggestive of tumors; evaluate varicocele in a standardized way; evaluate the presence or absence of vas deferens; investigate the epididymis to detect indirect signs suggesting obstruction and/or inflammation.

CONCLUSIONS

The ESUR-SPIWG recommends investigating infertile men with scrotal US focusing on TV, inhomogeneity, localization, varicocele, vas deferens, and epididymal abnormalities. Cryptorchidism, TML, and lesions should be detected in relation to the risk of testicular tumors.

CLINICAL RELEVANCE STATEMENT

The ESUR-SPIWG recommendations on scrotal imaging in the assessment of male infertility are useful to standardize the US examination, focus on US abnormalities most associated with abnormal semen parameters in an evidence-based manner, and provide a standardized report to patients.

KEY POINTS

So far, ESUR-SPIWG recommendations on scrotal imaging in the assessment of male infertility were not available. The ESUR-SPIWG recommends investigating infertile men with scrotal US focusing on testicular volume, inhomogeneity, localization, varicocele, vas deferens and epididymal abnormalities, and assessing cryptorchidism, testicular microlithiasis and lesions in relation to the risk of testicular tumors. The ESUR-SPIWG recommendations on scrotal imaging in the assessment of male infertility are useful to standardize the US examination, focus on US abnormalities most associated with abnormal sperm parameters in an evidence-based manner, and provide a standardized report to patients.

"Management of andrological disorders from childhood and adolescence to transition age: guidelines from the Italian Society of Andrology and Sexual Medicine (SIAMS) in collaboration with the Italian Society for Pediatric Endocrinology and Diabetology (SIEDP)-Part-1"

PURPOSE

Andrological pathologies in the adulthood are often the results of conditions that originate during childhood and adolescence and sometimes even during gestation and neonatal period. Unfortunately, the reports in the literature concerning pediatric andrological diseases are scares and mainly concerning single issues. Furthermore, no shared position statement are so far available.

METHODS

The Italian Society of Andrology and Sexual Medicine (SIAMS) commissioned an expert task force involving the Italian Society of Pediatric Endocrinology and Diabetology (SIEDP) to provide an updated guideline on the diagnosis and management of andrological disorders from childhood and adolescence to transition age. Derived recommendations were based on the grading of recommendations, assessment, development, and evaluation (GRADE) system.

RESULTS

A literature search of articles in English for the term "varicoceles", "gynecomastia", "fertility preservation", "macroorchidism", "precocious puberty" and "pubertal delay" has been performed. Three major aspects for each considered disorder were assessed including diagnosis, clinical management, and treatment. Recommendations and suggestions have been provided for each of the mentioned andrological disorders.

CONCLUSIONS

These are the first guidelines based on a multidisciplinary approach that involves important societies related to the field of andrological medicine from pediatric to transition and adult ages. This fruitful discussion allowed for a general agreement on several recommendations and suggestions to be reached, which can support all stakeholders in improving andrological and general health of the transitional age.

Beyond the Incision: A Comparative Study of Suprainguinal and Inguinal Varicocele Surgeries

Background Varicocele, characterised by the abnormal dilation of the pampiniform plexus of scrotal veins, is a prevalent and treatable cause contributing to male infertility, affecting 40% of men experiencing primary infertility and 80% of those with secondary infertility. Often asymptomatic, it can lead to chronic scrotal pain or a feeling of heaviness. Surgical interventions such as open, laparoscopic, or microsurgical varicocelectomy aim to eliminate venous reflux into the scrotum. This study sought to assess and evaluate the surgical outcomes and postoperative complications of the suprainguinal and inguinal approaches to varicocelectomy, offering evidence-based insights to improve varicocele management. Methodology A total of 60 males diagnosed with grade II or III unilateral or bilateral varicocele were included in the study. Patients with subclinical or grade I varicocele, recurrent varicocele, or concomitant inguinoscrotal pathology (hydrocele, epididymal cyst, and inguinal hernia) were excluded. Participants were randomly assigned to one of two groups based on the surgical technique: Group A (suprainguinal approach) and Group B (inguinal approach). Surgical outcomes were assessed by evaluating operating time, postoperative pain, wound hematoma, wound infection, hydrocele development, testicular atrophy, and semen analysis, both pre- and postoperatively. Results The study included 60 patients with a mean age of 29.05±5.96 years and an age range of 18-40 years. The suprainguinal approach offers a significantly shorter operating time than the inguinal approach (33.1 vs. 40.8 minutes). Both surgical techniques resulted in similar postoperative pain levels. The incidence of complications, such as wound hematoma, wound infection, and hydrocele development, showed no significant differences between the two approaches. In Group A (suprainguinal approach), the rates were 3.3%, 6.6%, and 3.3%, respectively, while in Group B (inguinal approach), they were 6.6%, 13.3%, and 6.6%. Additionally, 75% of patients in the infertility group showed improvements in semen parameters, with 80% in Group A and 71.4% in Group B, with no significant difference between the surgical approaches. Conclusion The suprainguinal and inguinal approaches to varicocelectomy effectively manage varicoceles, with the suprainguinal approach offering a shorter operating time. Postoperative complications and improvements in semen parameters were comparable between the two methods.

The Effect of Varicocele Treatment on Fertility in Adults: A Systematic Review and Meta-analysis of Published Prospective Trials

CONTEXT

The benefits and harms of varicocele treatment versus observation in adult infertile males are still controversial.

OBJECTIVE

To systematically pool the evidence on outcomes of varicocele treatment (any surgical or radiological) versus observation in adult infertile men.

EVIDENCE ACQUISITION

A systematic review and meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Only prospective randomized and nonrandomized studies were included until November 2021. The primary outcome was pregnancy rate; the secondary outcomes were improvements in sperm concentration, normal morphology, and progressive sperm motility after treatment compared to baseline. Men ≥18 yr of age with any-grade varicoceles were included.

EVIDENCE SYNTHESIS

Of 557 articles identified, 12 were eligible for inclusion, involving 1357 patients. Varicoceles were treated surgically in ten and radiologically in four studies. Varicocele treatment improved pregnancy rates (odds ratio 1.29; 95% confidence interval [CI] 1.00-1.65; p = 0.048) and sperm concentration (mean difference 12.34 million/ml, 95% CI 3.49-21.18; p = 0.006) compared with observation. Proportions of spermatozoa with normal morphology and progressive motility were not statistically different from those with observation. However, considering treatment arm only, sperm concentration, progressive motility, and normal sperm morphology were improved compared with baseline. A subgroup analysis showed that the benefit of varicocele treatment is evident in men with an abnormal semen analysis. The main limitation is represented by the heterogeneity of the included studies, mostly in terms of study population, fertility of the partner, outcome evaluation, lack of long-term outcomes, and intermediate/high risk of bias.

CONCLUSIONS

Treatment of any-grade varicoceles may improve pregnancy rates and sperm concentration in adult infertile men, while benefits in sperm motility and normal morphology are less clear.

PATIENT SUMMARY

In this systematic review and meta-analysis of all published prospective trials on varicocele treatment, significant evidence emerged on its benefit in terms of improved pregnancy rates and sperm concentration, while benefits in sperm motility and morphology are less clear.

The European Academy of Andrology (EAA) ultrasound study on healthy, fertile men: An overview on male genital tract ultrasound reference ranges

BACKGROUND

So far, male genital tract color-Doppler ultrasound (MGT-CDUS) was not standardized. Recently, the European Academy of Andrology (EAA) published the results of a multicenter study assessing the CDUS characteristics of healthy-fertile men (HFM) to obtain normative parameters.

OBJECTIVES

To report the EAA US study (i) standard operating procedures (SOPs) for assessing MGT-CDUS, (ii) main MGT-CDUS normative parameters, and (iii) compare the EAA and previously published "normal" CDUS values.

METHODS

A cohort of 248 HFM (35.3 ± 5.9 years) was studied, evaluating MGT-CDUS before and after ejaculation following SOPs.

RESULTS

SOPs for MGT-CDUS assessment are summarized here. All subjects underwent scrotal CDUS and 188 men underwent transrectal ultrasound before and after ejaculation. The main CDUS reference ranges and characteristics of the HFM-MGT are reported here. The mean testicular volume was ∼17 mL. The lower limit for right and left testis was 12 and 11 mL, defining testicular hypotrophy. The upper limit for epididymal head, body, tail, and vas deferens was 11.5, 5, 6, and 4.5 mm, respectively. Testicular and epididymal arterial reference ranges are reported. The EAA varicocoele classification is reported. CDUS-varicocoele was detected in ∼37% of men. Prostate mean volume was ∼25 mL, while lower and upper limits were 15 and 35 mL, defining hypotrophy and enlargement, respectively. Prostate arterial reference ranges are reported. Prostate calcifications and inhomogeneity were frequent; midline prostatic cysts were rare and small. Ejaculatory duct abnormalities were absent. The upper limit for periprostatic venous plexus was 4.5 mm. Lower and upper limits of seminal vesicles (SV) anterior-posterior diameter were 6 and 16 mm, defining hypotrophy or dilation, respectively. Seminal vesicle volume and ejection fraction reference ranges are reported. SV-US abnormalities were rare. Deferential ampullas upper limit was 6 mm. A discussion on the EAA and previously published "normal" CDUS values is reported here.

CONCLUSIONS

The EAA findings will help in reproductive and general male health management.

Doppler Ultrasonography - An Important Tool in Managing Patients With Varicocele and Secondary Infertility

BACKGROUND/AIM

Doppler ultrasound was successfully implemented as part of the diagnostic plan of medical emergencies in scrotal pathology. This study aimed to investigate whether it could play an important role in managing not only varicocele, but patients with secondary infertility as well.

PATIENTS AND METHODS

The current study included 135 patients with varicocele and infertility. Surgery was performed in 18 cases with painful varicocele, 15 cases with testicular hypotrophy, and 48 cases with infertility.

RESULTS

Among cases with infertility who underwent surgery, aged between 19 and 36 years old, 80% showed a significant improvement in the spermogram after curing the varicocele. In patients over 36 years of age, only 42% had some improvement in the spermogram after surgery. In addition, after surgery, antispermatic antibodies showed a significant decrease in all patients.

CONCLUSION

Varicocele and secondary infertility are a well-known pathology. While the role of Doppler ultrasonography is established in varicocele diagnosis, we found an important pool of patients with secondary infertility and asymptomatic varicocele that would not have been diagnosed in the absence of Doppler ultrasound investigations. Since the best results in fertility were observed in patients younger than 36 years of age, we reiterate the importance of Doppler ultrasonography in addressing infertility.

Varicocele associated male infertility: cellular and molecular perspectives of pathophysiology

BACKGROUND

Varicocele is a common risk factor associated with reduced male fertility potential. The current understanding of varicocele pathophysiology does not completely explain the clinical manifestation of infertility. The present treatment options such as antioxidant supplementation and varicocelectomy only helps ∼35% of men to achieve spontaneous pregnancy.

OBJECTIVE

This review aims to summarize the available knowledge on cellular and molecular alterations implicated to varicocele associated male infertility and also highlights the new knowledge generated by 'Omics' technologies.

MATERIALS AND METHODS

PubMed, MEDLINE, Cochrane and Google Scholar databases are searched using different combinations of keywords (varicocele, infertile/fertile men with varicocele, cellular changes, molecular mechanisms, proteome, epigenome, transcriptome and metabolome). A total of 229 relevant human and animal studies published till 2021 were included in this review.

RESULTS

Current understanding advocates oxidative stress (OS) as a major contributory factor to the varicocele associated male infertility. Excessive OS causes alteration in testicular microenvironment and sperm DNA fragmentation which further contributes to infertility. Molecular and omics studies have identified several promising biomarkers such as AAMP, SPINT1, MKI67 (genetic markers), sperm quality and function related protein markers, global sperm DNA methylation level (epigenetic marker), Hspa2, Protamine, Gadd7, Dynlt1 and Beclin1 (mRNA markers), PRDX2, HSPA, APOA2, YKL40 (seminal protein markers), total choline and PHGDH (metabolic markers).

DISCUSSION

Mature spermatozoa harbours a plethora of molecular information in form of proteome, epigenome and transcriptome; which could provide very important clues regarding pathophysiology of varicocele associated infertility. Recent molecular and omics studies in infertile men with varicocele have identified several promising biomarkers. Upon further validation with larger and well-defined studies, some of these biomarkers could aid in varicocele management.

CONCLUSION

The present evidences suggest inclusion of OS and sperm DNA fragmentation tests could be useful to the diagnostic workup for men with varicocele. Furthermore, including precise molecular markers may assist in diagnostics and prognostics of varicocele associated male infertility. This article is protected by copyright. All rights reserved.