Intervertebral disc decompression
In between the vertebrae in your spine there are spinal discs (also known as intervertebral discs), and in the middle of each spinal disc is a jelly-like substance which is called the nucleus pulposus. Occasionally, the nucleus pulposus bulges through the outer ring which normally keeps it in place. This is known as herniation of the intervertebral disc or a ‘slipped disc’ and is a major cause of lower back pain which affects mobility, physical function and quality of life in addition to the financial cost.
Intervertebral disc decompression treatments are used to treat small- to medium-sized hernias of intervertebral discs by reducing the volume of the nucleus pulposus. This reduces the pressure between the discs and creates space for the herniated fragment to implode inwards, reducing pain and improving mobility and quality of life.
This involves the percutaneous removal of the nucleus pulposus by a variety of chemical, thermal and mechanical techniques.
How does the procedure work?
All the procedures are performed as an out-patient procedure under fluoroscopic or CT guidance. The percutaneous approach to the intervertebral disc is the same for all techniques. You will lie on your stomach and a needle will be inserted, followed by the device used for the procedure. The interventional radiologist uses a gel that shows up under X-ray to ensure that they have the correct angle to reach the middle of the nucleus pulposus, whilst avoiding injuring the nerve root.
There are a number of procedures available to reduce the amount of nucleus pulposus and so relieve the pressure. Cryoablation reduces the volume by forming ionic plasma, while percutaneous laser disc decompression reduces the volume by vaporising the middle part of the nucleus pulposus. For chemodiscolysis, a small quantity of ethanol gel or ozone is introduced into the nucleus pulposus, or alternatively, medical devices can be used to remove a small part of the nucleus pulposus.
Why perform it?
It is used to treat small- to medium-sized contained intervertebral disc herniation which has caused back pain, sciatica or leg pain that has limited the patient’s activity for at least six weeks. The diagnosis will be confirmed using MRI before you can be considered for the procedure.
The procedure may also be recommended to treat pain caused by nerves which has shown no significant improvement after conservative therapy. This has been shown to have high success rates.
What are the risks?
The complications which you may experience during intervertebral disc decompression can result from the technique or the devices used in the procedure, such as if the catheter breaks or there is an injury to the nerve root. Post-operative complications include bleeding, infection and other general complications.
The most common complication of percutaneous disc decompression techniques is infection, which occurs in up to 0.24% of patients, and may develop into an abscess if left untreated.
There are a number of other, less common, complications of this technique. You may experience complex regional pain syndrome, in which the patient suffers from severe pain, swelling and changes in the skin. The area at the bottom of your spinal cord filled with fluid may be punctured, which can cause a headache, haemorrhage and injury to a nerve. You may have an allergic reaction to one of the agents used in the procedure. After an intervertebral disc decompression in the middle of your spine, you may develop pneumothorax, which is the abnormal collection of gas or air in the space between the lung and chest wall. Another possible complication is fainting, which can occur after an intervertebral disc decompression in your neck.
1. Kelekis, AD, Filippiadis, DK, Martin, J-B, Brountzos, E. Quality assurance guidelines for percutaneous treatment of intervertebral discs. Cardiovasc Intervent Radiol. 2010 Oct; 33(5):909-13.