Wednesday, 26 September, 2007
Varicocele - Modern Management
Varicocele is a dilation (enlargement) of the internal spermatic veins that drain the testicle (picture on left). It is a very common condition present in 15% of the general male population and 40% of men evaluated for infertility. A varicocele develops because of defective valves that normally allow for blood to flow away from the testicle toward the abdomen. Testicular injury occurs due to abnormal back flow of blood from the abdomen into the scrotum and this creates a hostile environment for sperm development. The significance of this condition has been known for a thousand years. The first century Greek physician Celsius originally described the varicocele: "The veins are swollen and twisted over the testicle, which becomes smaller than its fellow in as much as its nutrition has become defective".
Numerous theories postulate how a varicocele can affect fertility:
1. Testicular temperature increases due to abnormal blood flow in the veins draining the testicle and in the artery entering the scrotum. Prolonged elevated testicular temperature has detrimental effects on sperm production.
2. Abnormal concentrations of adrenal and renal substances may impede development of normal sperm.
3. Abnormal venous blood flow from the scrotum increases metabolic waste products and decreases the availability of oxygen and nutrients required for sperm development.
4. Abnormal blood flow can also interfere with testosterone concentration, which in turn can interfere with sperm production. The long-term effects of compromised circulation may interfere with normal male androgen production.
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 "subclinical" (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 and decreased motility. The diagnosis of a varicocele can usually be made on physical examination of the scrotum while the patient is standing. The varicocele feels like a "bag of worms" and disappears or becomes significantly reduced when the patient lies down. The patient is asked to bear down and frequently the backflow of blood can be felt in these veins. Occasionally a varicocele may be so prominent that it can be seen through the skin. Often the testicle on the side of the varicocele is smaller than the other side. Ancillary tests such as the Doppler stethoscope and technetium isotope study may id in the diagnosis. Recently the scrotal ultrasound has been found to be an accurate way of confirming the presence of a varicocele. The size of the veins and abnormal blood flow can be seen and measured using the ultrasound.
Repair of the varicocele is indicated when the couple has documented infertility with normal or potentially normal female partner but a male with one or more abnormal semen parameters and the presence of a varicocele on physical exam. Repair should be done when a varicocele causes testicular pain or discomfort or there is a significant discrepancy between the size of the two testicles. Treatment options to aid with fertility include surgical varicocele repair, angiographic embolization, intrauterine insemination, in-vitro fertilization and medical therapy with clomiphene citrate. Surgical repair offers the best results. Semen improvement is expected in up to 70% of men and pregnancy in up to 60% of couples within the first two years after successful repair. Even in men with worst case scenarios who were not candidates for In Vitro Fertilization because they had no sperm in the ejaculate or no moving sperm, varicocele repair restored sperm or motility in 55-69% of patients. Twenty percent of these men were able to father children after varicocele repair without any other assistance.
Surgery is performed through a one and one half inch incision made below the belt line with a technique called microsurgical inguinal varicocele repair. The abnormal veins are identified using an operating microscope and are interrupted so blood can no longer pool around the testicle. The testicular artery and small lymphatic channels are identified using the microscope and are preserved. This limits potential complications. Surgery is performed on an outpatient basis and generally takes 30-45 minutes to complete. Using this approach the success rates for varicocele repair are close to 95% and the complication rate is about 1%.
Depending on the individual circumstances and the severity of the sperm abnormalities, multiple approaches to this problem can be taken. Surgical correction, intrauterine insemination and clomiphene citrate therapy can be used simultaneously to achieve a pregnancy. A recent study published in the Journal of Urology in May 2001 showed that varicocele repair improves intrauterine insemination success rates by almost double in men who have varicoceles. The most severe cases of male infertility may require in-vitro fertilization. The varicocele remains the most treatable cause of poor semen parameters and male infertility.