What is VNUS Closure?

The VNUS Closure technique is a completely revolutionary way of treating varicose veins and has several major advantages over traditional surgery.

It works by insertion of a catheter probe into the vein requiring treatment. It is only 2 millimetres wide so it can be delivered through a tiny pinhole at the ankle or more usually just below the knee.

The catheter is passed up the main superficial vein (the long saphenous vein) and through its junction with the deep vein. A rubber bandage is then applied to the limb to empty out all the blood (an important difference to laser treatment which works by heating the blood within the vein rather than the wall of the vein itself).

The catheter tip is then withdrawn carefully under ultrasound image guidance to the junction of the superficial vein where it meets the deep vein. The power is then turned on and the catheter tip delivers radio frequency energy across its terminals through the wall of the vein.

Picture Below - Following VNUS Radiofrequency Closure the main vein is turned into a dead cordof tissue which gradually dissolves over several months.

The 2 millimetres section of the vein wall is resistant to the passage of the energy and anywhere where you get resistance in a circuit you get a heating effect. The wall heats up rapidly but when it reaches 85°C a tiny thermocouple on one of the four fronds cuts off the power and only restarts again when the temperature drops slightly.

This provides a negative feedback, which ensures the temperature goes no higher than 85°C. Now 85°C is hot! You would not be able to put your hands in water at that temperature. Your normal body temperature is only 37°C and so heating the vein wall to 85°C destroys the vein completely by killing it.

The catheter tip is withdrawn very slowly and so a long length of the vein can be treated and closed. (see diagram) The effect of heating the vein in this way leads to rapid thickening of the vein wall and shrinking down of the lumen. These characteristic changes can easily be seen on ultrasound so the integrity of the work is checked immediately afterwards.

The vein is destroyed forever, has no flow in it and over time is dissolved by the body’s defences, ingested and removed completely. Over a period of 6 – 12 months the vein disappears and at one year can no longer be seen on ultrasound.

Can all varicose veins be treated with VNUS?

The vast majority of patients are suitable for this excellent technique. However there are one or two notable exceptions. Occasionally the long saphenous vein is too wiggly to allow passage of the catheter or it is too near the surface to allow safe use of the technique.

Picture right - Normally the main superficial vein disappears leaving the tributaries as dead ends. There has never been any stimulus to form vascular buds since there was no incision made and dead vessels cannot form them in the first place.

Some of the heat is dissipated through the surrounding tissues around the vein and veins less than 1 cm deep when heated to 85°C may lead to internal scalding of the skin. Very superficial veins are best treated by alternative methods. The only vein that we do NOT treat with VNUS is the short saphenous vein at the back of the calf (see Anatomy section on the Vein website - www.vein.co.uk).

The reason for this is that the sural nerve, an important sensory nerve that supplies feeling to the outside of the foot and heel runs right next to this vein and treating it with VNUS would potentially cause heat damage to the nerve. However, do not despair we have a minimally invasive alternative technique for dealing with short saphenous problems developed by our clinic at Guildford.