In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan.


A varicocele is abnormal dilation and enlargement of the scrotal venous pampiniform plexus which drains blood from each testicle. While usually painless, varicoceles are clinically significant because they are the most commonly identified cause of abnormal semen analysis, low sperm count, decreased sperm motility, and abnormal sperm morphology.

The testicular veins originate in the testicle and form the pampiniform plexus. Venous blood then travels up through the inguinal canal as part of the spermatic cord, forms the internal spermatic or testicular vein, and terminates in the abdomen. The right internal spermatic vein terminates directly into the low-pressure inferior vena cava while on the left side, it joins with the relatively high-pressure left renal vein. This anatomy explains why the majority of clinically detectable varicoceles are on the left side.

Varicoceles occur in around 15% to 20% of all males but are found in about 40% of infertile males. It is unclear exactly how a varicocele impairs the production, structure, and function of sperm, although there are several theories. However, the association between clinically significant varicoceles and male infertility is undeniable. This association was first noted in the late 1800s by Barfield, a British surgeon, and was subsequently confirmed by others in the early 1900s.

Varicoceles are classified as small, medium, and large based on their clinical appearance and obvious size.

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