Effect of varicocelectomy on sperm deoxyribonucleic acid fragmentation rates in infertile men with clinical varicocele: a systematic review and meta-analysis

Lira et al., 2021 | Fertil Steril | Meta Analysis

Citation

Lira Neto Filipe Tenório, Roque Matheus, Esteves Sandro C. Effect of varicocelectomy on sperm deoxyribonucleic acid fragmentation rates in infertile men with clinical varicocele: a systematic review and meta-analysis. Fertil Steril. 2021-Sep;116(3):696-712. doi:10.1016/j.fertnstert.2021.04.003

Abstract

OBJECTIVE: To evaluate the effect of varicocelectomy on sperm deoxyribonucleic acid fragmentation (SDF) rates in infertile men with clinical varicocele. DESIGN: Systematic review and meta-analysis. SETTING: Not applicable. PATIENT(S): Infertile men with clinical varicocele subjected to varicocelectomy. INTERVENTION(S): Systematic search using PubMed/Medline, EMBASE, Cochrane's central database, Scielo, and Google Scholar to identify relevant studies published from inception until January 2021. We included studies comparing SDF rates before and after varicocelectomy in infertile men with clinical varicocele. MAIN OUTCOME MEASURE(S): The primary outcome was the difference between the SDF rates before and after varicocelectomy. A meta-analysis of weighted data using random-effects models was performed. Results were reported as weighted mean differences (WMD) with 95% confidence intervals (CIs). Subgroup analyses were performed on the basis of the SDF assay, varicocelectomy technique, preoperative SDF levels, varicocele grade, follow-up time, and study design. RESULT(S): Nineteen studies involving 1,070 patients provided SDF data. Varicocelectomy was associated with reduced postoperative SDF rates (WMD -7.23%; 95% CI: -8.86 to -5.59; I2 = 91%). The treatment effect size was moderate (Cohen's d = 0.68; 95% CI: 0.77 to 0.60). The pooled results were consistent for studies using sperm chromatin structure assay, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling, sperm chromatin dispersion test, and microsurgical varicocele repair. Subgroup analyses showed that the treatment effect was more pronounced in men with elevated vs. normal preoperative SDF levels, but the impact of varicocele grade remained equivocal. Meta-regression analysis demonstrated that SDF decreased after varicocelectomy as a function of preoperative SDF levels (coefficient: 0.23; 95% CI: 0.07 to 0.39). CONCLUSION(S): We concluded that pooled results from studies including infertile men with clinical varicocele indicated that varicocelectomy reduced the SDF rates. The treatment effect was greater in men with elevated (vs. normal) preoperative SDF levels. Further research is required to determine the full clinical implications of SDF reduction for these men.

Key Findings

Further research is required to determine the full clinical implications of SDF reduction for these men.

Outcomes Measured

• Requires manual extraction

Population

MeSH Terms

• Adult
• DNA Fragmentation
• Fertility
• Humans
• Infertility, Male
• Male
• Spermatozoa
• Treatment Outcome
• Urologic Surgical Procedures, Male
• Varicocele

Evidence Classification

• Level: Meta Analysis
• Publication Types: Journal Article, Meta-Analysis, Systematic Review
• Vertical: biotin

Provenance

• PMID: 33985792
• DOI: 10.1016/j.fertnstert.2021.04.003
• PMCID: Not in PMC
• Verified: 2026-04-09 via PubMed E-utilities API

Source extracted via PubMed E-utilities API on 2026-04-09