Varicoceles are dilated veins in the scrotum, (just as an individual may have varicose veins in their legs.) These veins are dilated because the blood does not drain properly from them. These dilated veins allow extra blood to pool in the scrotum, which has a negative effect on the sperm production. This condition is the most common reversible cause of male factor infertility and may be corrected by minor outpatient surgery.
Most experts do this microscopically to preserve the arterial supply and lymphatics. A sub-inguinal incision (about 1 inch above the penis and 1 inch from the midline) is usually used, as this avoids incising the abdominal muscles and creates less post-operative pain.
This definition is from Male Infertility Specialists