Coban S, et al. - In this study with 61 patients with varicocele, researchers assessed the dynamic thiol–disulphide homeostasis as an oxidative stress marker in the spermatic vein of infertility secondary to varicocele. Prior to the separation of spermatic vein during surgery, blood was extracted from the median cubital vein and the testicular venous return side. In the samples obtained from spermatic venous blood, significantly lower albumin, native thiol and total thiol values and the native thiol/total thiol ratio were detected, as well significantly higher ischaemia modified albumin value and the disulphide/native thiol and disulphide/total thiol ratios. In the spermatic vein vs the peripheral vein, they found thiol–disulphide balance had deteriorated towards disulphide formation. Findings are suggestive of a possible role of abnormal thiol–disulphide balance as an independent risk factor for infertility secondary to varicocele.