Pathophysiology of clinical varicoceles in infertile men.

In infertile men, clinical varicoceles most often occur bilaterally. In our experience with these patients, both testicles are smaller than normal. We find more than 25% to 35% immature and tapered sperm in in the ejaculum of these men, and the motility of the sperm is usually low. We have found serotonin in the plasma of the varicoceles, and believe this biogenic amine is responsible for the poor sperm motility. We now agree that a subset of neuroendocrine cells in the prostate secrete serotonin. Bilateral varicocele surgery can improve the patient's fertility potential, and we advocate surgical treatment.