New Insights into the Pathophysiology of Varicocele in Male Infertility

Varicocele is defined as an abnormal dilation and tortuosity of the veins of the pampiniform plexus with the presence of malfunctioning valves and is the most common correctable cause of male infertility. Varicocele affects nearly 15% of men in the general population and is diagnosed in up to 41% of men with primary infertility and 80% secondary infertility cases. Some fertile and some infertile men with varicoceles may have similar conventional semen parameters, many have diminished parameters which improve with varicocele repair, and there is a significant association between varicocele and male infertility. There are a number of mechanisms of testicular damage, which have been described in men with varicocele. Sperm DNA fragmentation assays and assays measuring seminal oxidative stress have been associated with male infertility and spermatogenic dysfunction. Oxidative stress levels are significantly higher in varicocele patients and significantly reduced following varicocele repair. Elevated sperm DNA fragmentation levels correlate with poor semen quality, impaired preimplantation development, and increased spontaneous pregnancy loss rates and have been shown to improve following varicocele repair.