Thrombosis Prevention

Deep Vein Thrombosis — Clots in the leg veins….and how to reduce the risks

One of the risks of having lower limb surgery is the development of blood clots in the deep veins of the leg, a condition called Venous Thromboembolism (VTE) or Deep Vein Thrombosis (DVT). If this condition develops it may present in a number of ways:

  • be completely asymptomatic, noticed only on a routine investigation by chance
  • cause pain and swelling in the leg
  • result in an embolus

An embolus is a blood clot that detaches from the leg veins and passes around the body often lodging in the lungs. This can make patients acutely unwell with chest pain and difficulty in breathing. In rare cases this condition can be fatal. Following a DVT, some patients develop long term problems with the veins of the legs resulting in permanent swelling and occasionally ulceration of the skin. Some patients have higher risk than others and this will be assessed at the pre-operative check.

The risks are small for most patients but can be reduced and there are several measures that can be taken to minimise the risk of developing VTE as a result of lower limb surgery.

  • Maintain a good volume of fluid intake (when allowed in relation to the anaesthetic)
  • Compression stockings (to be worn on the un-operated leg)
  • Calf compression pumps (these are applied in the operating theatre)
  • Early mobilisation after the operation. The nurses and physiotherapists will encourage you to be up and about as soon as this is safe to do so
  • Medication

For those patients at a higher risk of developing VTE which include those who require a plaster on the leg, a medicine is advised to thin the blood and reduce the risk. There are a number of options but usually this consists of a daily injection of heparin (20mg or 40mg) starting approximately 8 hours from surgery, continuing until the plaster is removed or for 6 weeks whichever is the shorter.

A new medicine is available called Rivaroxaban (Xarelto) which is taken as a tablet (10mg) once a day in place of heparin. The advantages are that it is taken by mouth not injection and the side effects are less. Rarely, heparin can reduce the level of platelets in the blood stream, which does not seem to happen with Rivaroxaban.

The treatment for the prevention of VTE has been reviewed by NIHCE (National Institute for Health & Clinical Excellence) and the above protocol is approved. The cost of the treatment has not, however been clearly defined and you are advised to check with your insurance company what is covered after your surgery or with your GP whether you are eligible for prophylaxis under the NHS. If neither supports the use of the protocol advised then you would be expected to cover the cost yourself.

MG Uglow FRCS (Tr&Orth), Based on NICE Guidance 92, January 2010.