Microvascular testicular blood flow as evaluated by laser Doppler flowmetry after the surgical induction of varicocele.

This study was conducted to evaluate the changes in microvascular testicular blood flow (microvascular TBF), which may be associated with varicocele. The pathology was developed through partial ligation of left renal vein in 4 groups of rats. Controls of each group underwent sham surgery. It was observed that microvascular TBF dropped and its vasomotion became inhibited once the left renal vein was partially ligated as studied by laser Doppler flowmetry (LDF). Four to five minutes later, blood flow rose to the pretreatment level and that of controls. Vasomotion reappeared with a uniform frequency and amplitude. At different periods of varicocele bearing (1, 3, 6, and 14 weeks) microvascular TBF was reevaluated. Vasomotion appeared intact without any abnormalities in the 4 groups. To examine the response of testicular microvasculature after surgical creation of the varicocele to pharmacological stimulation another group of animals received human chorionic gonadotropin (hCG) treatment 6 weeks after varicocele creation. Vasomotion was inhibited in these animals. In conclusion, LDF is a suitable tool to evaluate microvascular TBF in vivo. It can detect acute changes in blood flow that may happen at surgical induction of varicocele. In addition, the vasculature of the testis with a surgically induced varicocele can still respond to hCG stimulation.