Relationship between varicocele and sperm DNA damage and the effect of varicocele repair: a meta-analysis

Abstract

Varicocele, a cause of male infertility, occurs in nearly 40% of infertile males. It has been postulated that varicoceles may cause sperm DNA damage. Sperm DNA integrity has been recognized as one of the important determinants of normal fertilization and embryo growth in natural and assisted conception. Eighty-three human studies were identified after an extensive literature search involving the role of varicoceles in sperm DNA damage. Of the 83 studies, 12 were selected that measured similar types of reactive sperm DNA damage. Seven studies determined the damage of sperm DNA in varicocele-associated patients and six studies evaluated the efficacy of varicocelectomy. One study was a duplicate because both outcomes were included. Data were analysed using RevMan software. The overall estimate showed that patients with varicoceles have significantly higher sperm DNA damage than controls, with a mean difference of 9.84% (95% CI 9.19 to 10.49; P<0.00001). A varicocelectomy can improve sperm DNA integrity, with a mean difference of -3.37% (95% CI -4.09 to -2.65; P<0.00001). In conclusion, there is increased sperm DNA damage in patients with varicoceles and varicocelectomy may be a possible treatment; however, more studies with appropriate controls are needed to confirm this finding. A varicocele is an important cause of male infertility and occurs in nearly 40% of infertile males. The recent understanding of the effect of varicoceles in male reproduction has led some researchers to postulate varicoceles as the possible cause of sperm DNA damage. Eighty-three human studies were identified after an extensive literature search involving the role of varicoceles in sperm DNA damage. Of the 83 studies, 12 were selected that measured similar types of reactive sperm DNA damage by a similar method. Seven studies determined the damage of sperm DNA in varicocele-associated patients and six studies evaluated the efficacy of varicocelectomy. One study was a duplicate because both outcomes were included. The data were then entered in the RevMan software for analysis. The overall estimate showed that patients with varicoceles have significantly higher sperm DNA damage than controls, with a mean difference of 9.84% (95% CI 9.19 to 10.49; P<0.00001). A varicocelectomy can improve sperm DNA integrity, with a mean difference of -3.37% (95% CI -4.09 to -2.65; P<0.00001). Based on the results, it can be concluded that there is increased sperm DNA damage in patients with varicoceles and that varicocelectomy may be a possible treatment; however, more studies with appropriate controls are needed to confirm this finding.

Comparison of reproductive outcome in oligozoospermic men with high sperm DNA fragmentation undergoing intracytoplasmic sperm injection with ejaculated and testicular sperm

“…The intake of oral antioxidants (6,7), varicocele repair (8), and the use of recurrent ejaculations before fertilization (9,10) alone or combined with micromanipulation-based sperm selection techniques such as magnetic cell sorting (11,12), physiological ICSI (13), or intracytoplasmic morphologically selected sperm injection (14)(15)(16) have been attempted with varying success rates to decrease SDF. Yet none of these interventions, alone or combined, have been unequivocally proven to be of clinical value to bypass the potential detrimental effect of abnormal SDF on assisted reproductive technology (ART) outcomes (5).…”

The Clinical Outcomes of Varicocelectomy and Assisted Reproductive Technology to Treat Men Infertility: A Meta-Analysis

“…The effect of varicocele repair using microsurgical techniques among men with azoospermia was predominant in this study largely promoted semen quality and clinical outcomes of couples who underwent ARTs. This result was previously demonstrated in some studies [23,25,[30][31][32]. Moreover, several studies reported the effectiveness of IUI or ICSI to increase clinical outcomes [30,33], however Baker et al [12] found that high DNA fragmentation index (>30) help to achieve spontaneous pregnancy.…”

“…This result was previously demonstrated in some studies [23,25,[30][31][32]. Moreover, several studies reported the effectiveness of IUI or ICSI to increase clinical outcomes [30,33], however Baker et al [12] found that high DNA fragmentation index (>30) help to achieve spontaneous pregnancy. Thoroughly, spontaneous pregnancy should remain the ultimate standard for evaluating the succeed management of male infertility due to varicocele treatment.…”

Varicocele and DNA Fragmentation in Senegalese Infertile Males—A Study of 95 Cases

“…In our study, DNA fragmentation is significantly more important in patients with varicocele. Wang meta-analysis [29] including 416 patients (240 varicocele and 176 controls) in seven studies showed the same tendency and there was a significant decrease after surgery. We find the same tendency in Kadioglu study [13] [36]) and even induction of spermatogenesis in case of azoospermia [37].…”

“…The new event is the fact that in that pathology DNA fragmentation is a reversible lesion after surgery ([13] [29]). This is as a new argument to support the clinical utility of this test.…”