A microdiscectomy is the surgical treatment of sciatica when it is caused by a prolapsed disc. A ‘discectomy’ is the surgical removal of the disc material that is irritating the nerve root. A microdiscectomy is a discectomy performed using an operating microscope. The microscope provides magnification as well as an excellent light source. The use of a microscope allows for a smaller incision as well as making the operation safer. A microdiscectomy is performed in patients who have persisting pain that has not been relieved by rest or injections, or who develop progressive neurological signs and symptoms such as weakness and numbness. Over 90% of patients are very satisfied with their outcome following a microdiscectomy.

How do we do it?

A microdiscectomy is done under a general anaesthetic. You will meet the anaesthetist on the ward prior to your surgery who will explain the anaesthetic to you. The operation takes about 75 minutes. Once asleep the patient is placed on their front on the operating table. X-ray is used to identify the correct area of the lower back, and a small incision is made. The muscle is separated off the spine, and a small amount of bone and the ligament covering the nerves is removed.

The nerves are then inspected and gently retracted to the side to allow access to the disc prolapse. A small incision is then made in the back of the disc and the disc prolapse is then removed. The rest of the disc is left behind.

At the end of the operation the wound will be closed with dissolvable stitches and covered with a dressing.

If you are on any medication that has the potential to thin your blood such as aspirin, clopidogrel, warfarin or any other blood thinning medication then we do need to know about this prior to the date of your injection as this will usually need to be stopped prior to your operation.

If you take anti-inflammatory tablets then you must stop taking them 7 days before your surgery.

What are the Risks of Microdiscectomy?

Infection

The risk of infection is less than 1%. All patients receive a dose of intravenous antibiotics when they are going off to sleep. If you develop an infection it is most likely to be a superficial wound infection that will resolve with a short course of oral antibiotics. Occasionally an infection can spread into the disc space. This is called discitis. This is much more serious and may result in further damage to the disc. If this occurs you may require a prolonged course of intravenous antibiotics or additional surgery.

Bleeding

Blood loss is usually minimal with a discectomy. However, there are large blood vessels in front of the disc and there are reported cases of these blood vessels being damaged during surgery resulting in a very serious and potentially life-threatening blood loss. This type of bleeding is rare and is reported to occur in approximately 1 in 25 000 cases.

DVT

Developing blood clots in the legs (deep vein thrombosis – DVT) is a risk of any surgery. We worry about DVTs as bits can break off a travel around your body. This is called an embolus. An embolus can affect your breathing, cause you to have a stroke, and could potentially be fatal. DVTs occur in approximately 1 in 200 patients having back surgery. An embolus is a much less common occurrence. We minimize the risk of DVT by asking patients to wear hospital stockings following their surgery (TEDS), and mechanical pumps during and immediately after surgery. These pumps squeeze your lower legs, helping the blood to circulate. They are put on when you go to sleep and stay on until you start to mobilize. We encourage early mobilization as this also helps to prevent DVTs. If a patient is considered to be high risk for a DVT then we will prescribe blood thinning medication for a couple of weeks after your surgery.

Nerve Injury

To expose your disc prolapse the nerve root needs to be retracted. In doing this there is a very small risk of physical damage to the nerve. This can lead to loss of nerve function, with persisting leg pain, weakness, and numbness. It is possible that a nerve injury could affect your bladder and bowel function, as well as erectile function in men. Nerve injuries are usually temporary but may be permanent.

Dural Tear

Occasionally the lining to the nerve (the dura) can be damaged causing the leakage of the fluid that surrounds the nerves (the cerebro-spinal fluid). Some tears are managed conservatively, whilst others require surgical repair. Patients who have had a dural tear may be asked to stay in bed for a short period of time following their operation on flat bed rest. This would normally be for between 24 hours and 5-days. Occasionally a persistent leakage of spinal fluid occurs which may require further surgery.

Recurrent Disc Prolapse

A discectomy is an operation to deal with your current difficulties. It is not a cure for a problem disc. There is a risk that further piece of disc material may prolapse. This can occur at any time, but is most common in the first few weeks following surgery. A recurrent disc prolapse is treated in the same way as the original disc prolapse, and may require a repeat (revision) discectomy. The risk of a recurrent disc prolapse that requires further surgery is 5%.

Scar Tissue

Scar tissue can form around the nerve and can mimic the symptoms of a disc prolapse. This is not common. We will usually try and treat this with injections rather than further surgery.

Back Pain

A microdiscectomy is performed primarily for leg pain. During surgery the disc prolapse is removed, but we are unable to repair the already damaged disc. Consequently, there may be some on going back pain after a microdiscectomy. A small proportion (less than 10%) of patients who have a discectomy require treatment for back pain in the future.

Risks Associated with Having an Operation Lying on your Front

when getting you ready for surgery, care is taken to ensure that everything is protected. The does however remain a small risk of pressure damage. This can cause some temporary skin damage to the tip of your nose and your chin. This would normally completely recover over 2-3 weeks. There is a very small risk of some damage to your vision. Visual damage is reported as occurring in 1 in 10 000 cases.

Medical Complications

Following any operation there is a small risk of post-operative medical complications, such as chest infections or urine infections.

What can I Expect Following my Microdiscectomy?

When you wake up following your microdiscectomy your leg pain should feel better. You will feel bruised in your lower back at the site of the operation. We try and minimize this by injecting local anaesthetic around the wound. The post-operative back pain will take a couple of weeks to settle down. The wound will be closed with a dissolvable suture, so there will be no stitches that need to be taken out. Your wound will require minimal attention after discharge. You will be in hospital for 1-2 nights. Before you go home the nurses will explain how you need to look after your wound. A physiotherapist will see you before you are discharged.

For the first 6-weeks you will need to take things relatively easy. During this time you need to avoid heavy lifting, as well as any prolonged sitting and standing. Many patients can get back to work within a couple of weeks from surgery, although often with some restriction of activity. During the first 6-weeks you should limit activity to gentle walking and stretches. After 6-weeks you can increase your activity as comfort allows. Walking, swimming, cycling and core stability exercises can all be beneficial. You should try to avoid any un-necessary heavy lifting and high impact exercise for 12-weeks following your surgery. You should be back to your normal level of activity by 12-weeks.

Following surgery the leg pain is often immediately better. However, many patients have residual, patchy numbness. This should not interfere with your function. If this does recover it may take up to 18-months to do so.

Returning to Work

People with non-manual jobs will normally be able to return to work after 2-4 weeks. If possible initially it can be helpful to plan to do some work from home. It will be 3-months before you can return to manual work.

Driving

There is no restriction with the DVLA, though there will be with your insurance company. You will need to be able to undertake an emergency stop, and be in complete control of your car at all times without being distracted by pain. If this is not the case then your insurance will NOT be valid. Most patients are back to driving within 2-3 weeks of their disc surgery.

Flying

You should not fly for 2-weeks following your surgery. You should not undertake any long haul flights for 6-weeks. If traveling on a long haul flight within 6-months of your operation then you should wear your hospital stockings when flying.

What Next?

Once your sciatica has resolved you must continue to look after your back. The fact that you have had a disc prolapse does not preclude a normal lifestyle. However, we would recommend that you:

Exercise: Undertaking an exercise program that aims to improve and maintain aerobic fitness is important. This may include regular brisk walking, swimming or cycling. Specific exercises to maintain flexibility and strengthen the abdominal and spinal muscles are important.

Avoid smoking: Smoking is associated with increased back pain and poorer outcomes from spinal surgery.

Avoid obesity: Being overweight forces the spine to carry unnecessary loads, and is associated with back pain.

Avoid heavy lifting: Patients who have had major spinal problems or surgery should be cautious with heavy lifting and prolonged manual work, as this may cause a recurrent disc prolapse or further back injury. When you have to lift you should do so by bending your knees and keeping your back straight, rather than bending at the waist.

Follow-Up

You will be seen back in the clinic a few weeks after your microdiscectomy to see how you are getting on, and to answer any further queries that you may have. An appointment will be made for you before you are discharged.