Neurosurgery patient information - thoracic discectomy

Your operation: Thoracic Discectomy
Prolapsed intervertebral disc
The normal intervertebral disc acts as a shock absorber between neighbouring vertebrae –
the building blocks of the spine. Degenerative or wear and tear changes in the spine can
cause the soft inner core of a disc to bulge – or prolapse – outside of its tough outer ring. In
the spine of the chest – the thoracic spine – this can cause a band of pain around the body
by causing pressure on a spinal nerve or weakness of the legs by causing pressure on the
spinal cord. Most thoracic disc prolapses do not require surgical treatment. However in
patients with severe pain that does not respond to other therapies and in others with
worsening leg weakness, surgery to take the pressure off the nerves or spinal cord may be
required.
The operation : Thoracic Discectomy
There are two routes employed to reach a prolapsed intervertebral disc in the thoracic spine
without disturbing the delicate spinal cord.
Costotransversectomy
Through a curved cut on the back a hands-width away from the midline, a rib is exposed and
followed towards the spine before its end is removed.
Thoracotomy
Through a cut on the side of the chest along the line of a rib, the cavity of the chest is
opened. The anaesthetist will then allow the lung on that side to collapse before the end of a
rib is removed.
The choice of operative route will depend on the exact position of the disc prolapse relevant
to the spinal cord. Whichever is chosen, once the disc is exposed it can then be drilled
before being carefully separated from the nerves of the spine.
Aim of surgery
The main aim of surgery is to take the pressure off the spinal cord in order to halt the
progression of leg weakness. Although this weakness may improve to some degree it is
unusual for it to return to normal. Band like pain around the body may improve but back
pain is unlikely to do so. This is because the underlying wear and tear change will remain.
Risks of surgery
As with all spinal surgery damage to the spinal cord leading to numbness or weakness below
the operated level is an outside possibility. This includes a very small chance of paralysis of
the legs or problems with bladder or bowel control. Bleeding may occur during the operation
and require blood transfusion. Infection may occur in the wound or in the disc space
requiring antibiotic treatment. Spinal fluid may leak from the wound requiring bed rest, extra
stitches or a drain to by-pass the leak. Very rarely the small amount of the spine removed
during the surgery may be sufficient to affect the stability of the spine and in this event
further surgery may be required.
When a thoracotomy is required as the surgical route there is a risk of blood, air, spinal fluid
or infection collecting in the cavity of the chest after the operation and interfering with
breathing. A drain is usually left in the chest after the surgery to minimise these risks.
Although these are major operations the risk to life is still very small.
After the surgery
If a chest drain is required it will be removed when it no longer drains a large volume of fluid.
You will then be able to mobilise freely. Your pain will be controlled with pain-killing
medication. You will be allowed home as soon as your mobility and level of pain safely
permit it – probably about 3-5 days after surgery , a little longer if a thoracotomy is needed.
You should be able to return to work in 4-6 weeks, longer if you have a very physical job.
You will be followed up in the out patient clinic in 2-3 months.

Figure 1
A CT scan showing a large thoracic disc prolapse reducing the size of the spinal canal