Role of Colored Doppler Sonography in Evaluation of Testicular Perfusion Before and After Varicocelectomy in Patients With Infertility

Introduction Varicocele, an abnormal dilatation of the internal spermatic veins, is considered the major reversible cause of male infertility. It is observed in 35%-40% of all men with primary infertility and in up to 80% of those with secondary infertility.

The higher incidence of varicocele in men with secondary infertility suggests its progressive nature, which might be explained by a progressive testicular dysfunction involving both spermatogenesis and steroidogenesis. The negative impact of varicocele on spermatogenesis has been documented by a progressive reduction in the size of testicle ipsilateral to the varicocele.

Semen parameters improvement after varicocele treatment were first reported by Tulloch in the mid-20th century, who performed high surgical ligation of varicose veins in 30 patients with infertility. The author showed a marked improvement in postoperative seminal parameters in 66% of the treated subjects.

Several theories have been formulated to explain the testicular impairment caused by varicocele, including hypoxia, autoimmunity, elevated testicular temperature, reflux of catecholamine, and increased oxidative stress. However, none of them can completely explain the variable modulating effect of varicocele on male fertility. Recently, the oxidative stress theory has emerged as an important contributory factor due to findings of an association between elevated reactive oxygen species and impaired sperm function in men with varicocele. Additionally, reduction of oxidative stress markers has been noted after varicocele repair.

It is hypothesized that impaired venous drainage causes an increase in venous stasis and a decrease in arterial blood flow, thus inducing hypoxia and deficiency in testicular microcirculation . Also, it is thought that this hypoxia could be responsible for defective energy metabolism at mitochondrial levels, causing dysfunction of both Leydig and germinal cells.