The effect of varicocele repair for sperm DNA fragmentation

Sperm DNA integrity has been considered as one of the important determinants of normal fertilization and embryonic development in natural and assisted pregnancy. It is difficult for men with high levels of sperm DNA fragmentation (SDF) in semen to conceive their partners naturally and assist in conception. The studies have found that the level of SDF in the semen of patients with varicocele (VC) was on the high side. In recent years, the effect of VC surgery on DNA fragmentation index has attracted the attention of researchers. In this study, we will evaluate the effectiveness of VC repair as a way to alleviate SDF and improve male fertility. Methods and analysis: Electronic databases including English databases (PubMed, MEDLINE, EMBASE, Web of Science, Cochrane Library) and Chinese databases (China National Knowledge Infrastructure, China Biology Medicine Database, Wanfang Database, VIP Database) will be searched from their inception to December 2020 to recognize related studies. All the randomized controlled trials of microsurgical varicocelectomy for the management of VC patients will be included. The potential outcome will include improvement in SDF, oxidative stress markers (reactive oxygen species, nitric oxide, and lipid peroxidation products), sperm chromatin compaction, other advanced sperm function characteristics, follow-up of fertility results. We will conduct this study strictly according to the Cochrane Handbook for Systematic Reviews of Interventions. Results: The study is a protocol for systematic review and meta-analysis without results, and data analysis will be carried out after the protocol. We will share our findings on April 5th of 2021. Conclusion: This systematic review will provide more evidence to assess whether varicocelectomy is an effective intervention for patients with SDF. The results will be published in a public issue journal and offer the urologists help to make clinical decisions. Ethics and dissemination: Formal ethical approval is not required in this protocol. We will collect and analyze data based on published research. Since this research does not involve patients, personal privacy will not be affected. The results of this review will be distributed to peer-reviewed journals or submitted to relevant conferences. Protocol registration number: INPLASY202070119