Varicocele: What is It? What Causes It? How is it Connected to Male Infertility?

Fifteen to twenty percent of men have one or more of them. It is the leading cause of male infertility. Yet most men are unaware they have one. What is it? A varicocele.

Varicocele: What is it?
A varicocele is pretty much the scrotal version of varicose veins in the legs. The scrotum contains a structure called the spermatic cord. This cord, which supports the testicles, is filled with nerves and veins. Varicoceles form when the valves that control the directional flow of blood within the spermatic cord malfunction, allowing blood to flow backward and pool in the scrotal veins. As the veins fill with more and more blood, they begin to swell and stretch. The result is an enlarged and tangled network of scrotal veins called a varicocele.

In some men, the swelling in the veins will become large enough for the scrotum to appear lumpy or begin to bulge. Other men will never know they have a varicocele unless a doctor feels it during a physical examination.

A varicocele does not need medical treatment unless it is large and/or painful. Treatment may also be recommended if a varicocele is the suspected cause of infertility in a man.

Varicocele: What Causes It?
As mentioned above, a varicocele forms when the valves that force the blood out of the spermatic cord and back toward the heart malfunction. Most of the blood will make it through the valves, but some of it will remain trapped and flow back into the veins of the scrotum. Why these valves fail is not currently known. It may be due to a congenital defect or other unknown cause.

Varicoceles most often form between the ages of 15 and 25 years. As a male enters puberty and continues on to maturity, the testicles grow rapidly and more blood is directed to them. If the valves cannot handle the extra demand on them, the blood will begin to build up and cause varicoceles.

Most varicoceles form on the left side of the scrotum. This is because the spermatic cord on the left side is longer than the right and exits the scrotum at a sharper angle. Approximately 85% of men with varicoceles have them on the left side. Fifteen percent of men have one on the right side and approximately 20-40% have varicoceles on both sides.

The vein of the left spermatic cord drains into the left renal vein. This is the vein connected to the left kidney. An older man may suddenly develop a varicocele on his left side if there is a problem with his kidney, such as a tumor that blocks the flow of blood into the renal vein.

Varicocele: The Connection to Male Infertility
While most varicoceles do not cause a problem, some men may experience fertility issues due to the condition. Approximately 40% of men who are infertile have a varicocele. The number increases to 80% in men who have previously fathered children but suddenly find themselves incapable of fathering another.

Men with low sperm counts, slow moving sperm, or poor quality sperm may also discover their problem lies with a varicocele. Studies show varicocele repair can increase sperm production and quality in 50-70% of these men.

The exact relation between varicocele and fertility issues is unclear. Experts theorize the increased amounts of blood around in the scrotum may raise the temperature of the testicles too high for healthy sperm production. Other theories suggest the improper blood flow in the area may leave too much metabolic waste and provide too little oxygen for healthy sperm development.

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Sources:
Center for Male Reproductive Medicine and Vasectomy Reversal:
Varicocele

eMedicine:
Varicocele

Mayo Clinic:
Varicocele - Definition
Varicocele - Symptoms
Varicocele - Causes
Varicocele - Complications

Medline Plus:
Varicocele

Teen Health:
Varicocele - What is a Varicocele? Who Gets Them?

Urology Channel:
Varicocele - Overview, Incidence and Prevalence

Varicoceles.com:
What is a Varicocele?
Symptoms
F.A.Q.s