Lumbar sympathetic block

What are the sympathetic nerves?

The sympathetic nerves run on the front surface of the spine (not in the spinal canal). The sympathetic nerves control things people do not have to think about such as the warmth of our legs. Sometimes, leg pain can be eased by blocking the sympathetic nervous system.

How does steroid injection work?

A sympathetic nerve block involves injecting medicine around the sympathetic nerves in your lower back. By doing this, the sympathetic system is temporarily blocked in the hope of reducing or eliminating pain. If the initial block is successful, then additional blocks may be repeated.

Before the injection

You will need to inform the pain doctor at least a week before the procedure if you are taking warfarin or Clopidogrel (blood thinning medicine). Warfarin may need to be stopped 1 week before. However, not all patients will be asked to stop taking these drugs and the pain doctor will make the decision on a case by case basis. If you are on anti-diabetic medication, you should inform the doctor.

How is it done?

A lumbar sympathetic block is performed as a day case procedure. Usually this is discussed with you in Outpatients and a consent form needs to be completed. You will be admitted to Jefferson Day Ward and seen by one of the pain doctors who will ask you if you have any questions. Shortly before the injection you will need to change into a hospital gown. For this injection you will lie on your front or side. This injection is performed using x-rays. A plastic cannula will be inserted in the back of your hand and sedating medication will be given. We will monitor your breathing and circulation.

Your back will be cleaned with antiseptic solution. Local anaesthetic is injected into the skin to numb the area. There may be some discomfort in the back at the time of the injection. Depending upon the reason for this procedure either local anaesthetic or phenol may be injected. It may be done on one or both sides. A small dressing will be applied at the site of the injection, which can be removed after 24 hours.

What are the side effects?

• Pain and bruising at the injection site. This is related to the needle used to block or destroy sympathetic nerves. This settles in a day or two.
• As the injection site is very close to major blood vessels there is a rare risk of internal bleeding
• Haematuria (passing blood in urine) may be noticed for a day or two as the needle may rarely go into your kidney
• This injection may not relieve your pain or may last for a very short duration
• Injection of phenol may be rarely associated with neuralgia (burning groin pain), paraplegia or failure of ejaculation.

Who do I contact if I have any problems after the procedure?

Your first point of contact will be your own GP, especially if the problem occurs outside normal working hours. If there are any problems with this, you can contact The Walton Centre during normal working hours, on 0151 525 3611 and ask to speak to the secretary of the doctor who did the procedure.

If you require any additional information or you have any further questions, then please discuss this with your consultant prior to starting the treatment.