Effect of varicocele repair on sperm DNA fragmentation: a review

Varicocele, the leading cause of male infertility, can impair sperm quality and fertility via various oxidative stress mechanisms. An imbalance between excessive reactive oxygen species production and antioxidant protection causes alterations in nuclear and mitochondrial sperm DNA, thus rendering a subset of varicocele men less fertile. In particular, sperm DNA fragmentation is usually elevated in men with clinical varicocele in both abnormal and normal semen parameters by the current World Health Organization criteria. In this review, we discuss the evidence concerning the association between varicocele, oxidative stress, and SDF, and the possible mechanisms involved in infertility. Furthermore, we summarize the role of varicocele repair as a means of alleviating SDF and improving fertility. Lastly, we critically appraise the evidence-based algorithm recently issued by the Society for Translational Medicine aimed at guiding urologists on the use of SDF testing in men with varicocele seeking fertility. Current evidence based on careful review of published studies confirms the effectiveness of varicocelectomy as a means of both reducing oxidatively induced sperm DNA damage and potentially improving fertility. Varicocele repair should be offered as part of treatment option for male partners of infertile couples presenting with palpable varicoceles.