A varicocele is a dilatation of the pampiniform venous plexus within the scrotum. Approximately 15-20% of the healthy fertile male population is estimated to have varicoceles; however, 40% of infertile men may have them. How a varicocele impairs sperm structure, function, and production is unknown, but researchers believe it interferes with testicular thermoregulation.
Although varicoceles appear in approximately 20% of the general male population, they are much more common in the subfertile population (40%). In fact, scrotal varicoceles are the most common cause of poor sperm production and decreased semen quality. Varicoceles are easy to identify and to surgically correct.
Varicoceles are much more common (approximately 80-90%) in the left testicle than in the right because of several anatomic factors, including (1) the angle at which the left testicular vein enters the left renal vein, (2) the lack of effective antireflux valves at the juncture of the testicular vein and renal vein, and (3) the increased renal vein pressure due to its compression between the superior mesenteric artery and the aorta (ie, nutcracker effect). Also of importance is that a one-sided varicocele can often affect the opposite testicle. Up to 35-40% of men with a palpable left varicocele may actually have bilateral varicoceles that are discovered upon examination. A 2004 study by Gat et al suggested that up to 80% of men with a left clinical varicocele had bilateral varicoceles revealed by noninvasive radiologic testing.
Varicoceles vary in size and can be classified into the following 3 groups:
· Large - Easily identified by inspection alone
· Moderate - Identified by palpation without bearing down (Valsalva maneuver)
· Small - Identified only by bearing down, which increases intra-abdominal pressure, thus impeding drainage and increasing varicocele size