Varicocele is a mass of enlarged veins that develops in the spermatic cord,
which leads from the testes (testicles) up through the inguinal canal
(passageway in the lower abdominal wall) to the circulatory system. The
spermatic cord is made up of blood vessels, lymphatic vessels, nerves, and
the vas deferens (duct that carries sperm from the body). If the valves that
regulate bloodflow from these veins become defective, blood does not
circulate out of the testicles efficiently, which causes swelling in the
veins above and behind the testicles.
A varicocele can develop in one testicle or both, but in about 85% of
cases it develops in the left testicle. The left spermatic vein drains into
the renal vein between the superior mesenteric artery and the aorta; these
two arteries can compress the renal vein and thus impede bloodflow from the
spermatic vein. The right spermatic vein drains into the vena cava (the vein
that returns blood to the heart) and develops varicocele less often. A
unilateral (one-sided) varicocele can affect either testicle.
Because of the impaired circulation of blood created by a varicocele, the
blood does not cool as it does in a normal vein. The increased temperature
of the blood raises the temperature of the testes, which is believed to
contribute to infertility, as heat can damage or destroy sperm. The raised
temperature may also impede production of new, healthy sperm.
Incidence and Prevalence
Incidence of varicocele is 10-20% and is highest in men between the ages of
15 and 25. The sudden appearance of varicocele in an older man may indicate
a renal tumor blocking the spermatic vein.
Approximately 40% of infertile men have a varicocele and among men with
secondary infertility — those who have fathered a child but are no longer
able to do so — prevalence may be as high as 80%.
A varicocele develops when the valve that regulates bloodflow from the vein
into the main circulatory system becomes damaged or defective. Inefficient
blood flow causes dilation (enlargement) of the vein.
Signs and Symptoms
Most men who have a varicocele have no symptoms. Asymptomatic (symptom-free)
cases are often diagnosed during a routine physical examination. Signs and
symptoms may include the following:
- Ache in the testicle
- Atrophy (shrinkage) of the testicle(s)
- Feeling of heaviness in the testicle(s)
- Palpably (evident to the touch) enlarged vein
- Visibly enlarged vein
Recurrent or constant discomfort or pain in the genital region should be
reported to a urologist or primary care physician to determine the cause.