One of my first jobs as a newly qualified doctor was as house surgeon to a distinguished vascular surgeon in one of Dublin's teaching hospitals. Twice a week, we had a theatre list and, without fail, there would be at least one case marked "ligation of varicose veins".

These cases were the bread and butter of the vascular surgeon's workload. With a prevalence of 30 per cent in women and 20 per cent in men, there was always a list of patients waiting for varicose vein surgical treatment.

What are varicose veins? They are bulging and tortuous veins that lie just beneath the skin of the legs. Veins carry blood back to the heart and, in order to keep the flow going, there are a series of valves at regular intervals along their length. The veins in the legs are under greatest pressure because of gravity. If their valves become damaged, blood collects and the vein will gradually get larger and begin to bulge.

I had always associated varicose veins with occupations such as bar work, hairdressing and bus conducting - jobs which involve prolonged standing. But Prof Austin Leahy, consultant vascular surgeon at Beaumont Hospital in Dublin, says that research has not linked standing with the risk of developing varicose veins. Nor has it shown a definite link with family history, although there is a genetic influence in that varicosities are associated with the Caucasian race. The two biggest risk factors, according to Prof Leahy, are pregnancy and being female.

There are many reasons for treating varicose veins apart from the obvious improvement in appearance. The accumulation of blood tends to cause an ache in the legs. Phlebitis is a more painful condition, in which blood clots in the damaged vein.

Long-standing varicosities cause an unpleasant skin rash called varicose eczema. This is caused by the leakage of waste products from the pooled blood into the skin around the damaged veins. The skin can eventually break down to form an ulcerated area, usually around the ankle. Varicose ulcers require intensive and prolonged treatment before they heal.

The first treatment option for varicose veins is the wearing of elasticated stockings. To be effective, they must be grade-two compression stockings which exert 20 to 30mm of mercury pressure. Unfortunately, support tights do not provide enough compression. However, it is possible to get surgical stockings which resemble socks, thus avoiding the unsightly surgical appearance of the usual white stockings. Elasticated stockings relieve cramp and discomfort and reduce the incidence of phlebitis.

There are two invasive treatment options. One involves injecting the varicose veins with a substance that causes inflammation, resulting in the obliteration of the vein. The other is surgery to remove the varicose vein entirely.

Fifteen years ago, when I assisted at vascular surgery, the operation involved an incision in the groin to access the saphenous vein. Other smaller incisions were made at the ankle and knee. The vein was literally stripped away using metal hooks - a tedious, although not very complex, procedure.

This stripping technique is still the basis for varicose vein surgery today, although Prof Leahy says: "Surgeons now adopt a holistic approach to the treatment of varicose veins, using ultrasound scanning to assess the exact site of the problem. We use surgery to treat the larger veins and injection sclerotherapy for smaller ones."

Prof Leahy is heading a multi centred study, involving researchers in the US, Germany, the UK and Ireland, into a new technique for vein surgery. "Powered phlebectomy" is showing promise as a way of both speeding up vein removal and dramatically reducing the number of incisions which have to be made. Under direct vision, using a light source, a rotating machine chews up the offending vein as it travels its length.

The new procedure is currently available at Beaumont Hospital, where it is being compared with the standard "hook and strip" technique in order to prove its superiority.

One of the key outcomes the researchers will be looking at is the incidence of side-effects. The conventional technique causes pain, pins and needles and numbness in about 5 per cent of cases. These effects are related to the number of incisions made, each of which has the potential to damage nerves. Nerve damage is a concern that Prof Leahy also has about another technique which is being studied in the UK. VNUS closure involves passing a catheter along the length of the vein to be removed. An electric current is passed through the tip of the catheter, causing the framework of the vein to shrink and break down. As the catheter is removed, the vein collapses. But because nerves always travel alongside veins, Prof Leahy is concerned that nerve damage is inevitable as part of the heating process. "The VNUS technique requires a randomised study before it could be considered for routine use," he says.

Prof Leahy is firmly of the view that each patient's treatment must be individually tailored after vigorous assessment using ultrasound scanning. Some people will require a combination of sclerotherapy for smaller veins and surgery for the larger, bulging varicosoties.

While prolonged standing is not apparently a risk factor in developing varicose veins, it can make existing varicosities worse. Which is presumably why my first "boss" rarely spent a day in the operating theatre without wearing surgical stockings under his theatre gear.

So, if your job involves standing and you have noticed the beginnings of a varicose "bulge" in your legs, you should seriously consider a modern pair of fashion-friendly compression stockings.

Dr Muiris Houston, Medical Correspondent, can be contacted at mhouston@irish-times.ie or leave messages on tel: 01-6707711, ext 8511. He regrets he cannot reply to individual medical problems.