For normal sperm production, the testes require a temperature a few degrees lower than the core body temperature. This is done by a network of veins that surrounds the testes and drains blood back to the heart – effectively cooling that area.
When the valves within these veins are incompetent or defective, blood accumulates and the veins expand and become dilated, forming a venous lump in the scrotum. The collection of these abnormal dilated veins is known as varicocoele.
The pooling of blood around the area raises the testes’ temperature, resulting in poor and abnormal sperm production. Metabolic waste products may also accumulate in the testes. This diminishes the amount of oxygen and nutrients required for sperm development. In addition, the abnormal blood flow interferes with testosterone (male hormone) concentration, which in turn causes a reduction in sperm production. Over time, such compromised circulation may result in a disruption of normal male hormone production.
Varicocoele is more common on the left side of the scrotum. This is related to the anatomical position of the veins. Someone who has varicocoele will usually have it from early childhood but it only becomes larger and more noticeable during adolescence when there is increased blood flow to the testes. It is also more common in tall and thin men and can run in families. Occasionally, a varicocoele can develop suddenly due to a cancerous growth in the kidney which obstructs the veins. This usually happens in elderly men.
Many patients do not have symptoms. It tends to be found in infertile men – accounting for about 40 per cent of men with primary infertility (never fathered a child) and about 40 to 70 per cent with secondary infertility (have fathered children in the past but are now unable to do so).
As for treatment, there are two approaches: surgical repair and percutaneous embolisation.
In surgical correction (varicocoelectomy), all the abnormal veins are tied off (ligation). Two different surgical techniques have been used. They are open incision on the groin or scrotum and laparoscopic (key-hole) surgery using a telescope through the abdominal wall. These can be done on a day-stay basis under general anaesthesia. Post- operative pain and complications are few.
In percutaneous embolisation, which is performed by a specialist X-ray doctor (radiologist), a special tube (catheter) is inserted into a vein in the groin. Under X-ray guidance, a small metal coil is threaded through the tube into the affected vein. It is then released to block the blood flow to the affected vein and to redirect it to healthy ones.