VARICOCELE

Varicocele

Varicocele

Introduction

Varicoceles are abnormally dilated testicular veins (pampiniform plexus) of in the scrotum, which is normally secondary to internal spermatic vein reflux. Varicocele is found in approximately 15% of the general population, 35% of men with primary infertility and in 75-81% of men with secondary infertility. It is more common on the left side. In adolescents, the incidence of varicocele is approximately 15%; the abnormality is extremely rare in prepubertal boys.

Although most men with varicoceles are able to father children, there is abundant evidence that varicoceles are detrimental to male fertility. A study by the World Health Organization (WHO) on over 9,000 men showed that varicoceles are commonly accompanied by decreased testicular volume, impaired sperm quality, and a decline in Leydig cell function (World Health Organization, 1992). Another report by Johnson and colleagues showed that 70% of healthy, asymptomatic military recruits with palpable varicoceles had an abnormality on semen analysis (Johnson, 1970). Furthermore, studies in animals (Nagler et al., 1985 and Harrison, 1986) and humans (Russell , 1957 and Witt, 1993) suggest that varicoceles cause progressive testicular damage over time. It appears that surgical repair of varicoceles not only halts this declines in testicular function but often reverses it. Whether the improvements in semen parameters, seen in 80% of men after varicocele ligation, translate into improved pregnancy and delivery rates has been a matter of ongoing controversy. Recent studies employing non-operated control groups clearly indicate that varicocelectomy does improve pregnancy rates (Zini et al., 1998).

Causes of Varicocele

A varicocele develops when the valve that regulates blood flow from the vein into the main circulatory system becomes damaged or defective. Inefficient blood flow causes enlargement (dilation) of the vein.

These one-way valves sometimes fail. The reverse flow of blood stretches and enlarges the tiny veins around the testicle to cause a varicocele, a tangled network of blood vessels, or varicose veins (see Figure 1).

Left-sided varicoceles are found in 85% of men with this problem and a right-sided varicocele is seen in 15%. The problem involves both sides in 20% of men. A unilateral varicocele may affect both testicles. The most probable explanation for the more frequent development of a varicocele on the left side alone is because the left spermatic vein is longer than the right. The left vein enters the left renal vein at a right angle near a site of compression by the mesenteric artery while the right spermatic vein drains at a softer angle into the vena cava. These anatomical factors (and the aid of gravity) promote backflow of blood in the left spermatic vein, resulting in pooling of blood and increased temperature and congestion in the testicle.

Some men with major varicoceles may show no evidence of testicular injury, while others with small or "sub clinical" (detected only by radiological tests) varicocele may be infertile. The effects of a varicocele on sperm quality and quantity are thus difficult to define and predict. The so-called "stress pattern" frequently found in men with a varicocele consists of an increase in tapered abnormal sperm forms ...