GP PI Disc Back Pain Greg Malham: Lumbar Microdiscectomy

Lumbar Microdiscectomy

Definition

This is an operation to remove a disc prolapse (or "slipped disc"), which is compressing (or "pinching") a nerve in the lower back supplying the leg.

 

 Lumbar =

Lower Back

 Microdiscectomy =

Removal of prolapsed disc or disc fragment through a small incision using magnification

 Magnification is achieved by opearting glasses (Loupes) or a microscope.



Indications

Lumbar radicular pain (sciatica)

Lumbar radiculopathy (leg pain, numbness and weakness)

Cauda equina syndrome (pressure on the nerves supplying the bladder, bowel and genital region. Causing problems passing urine, incontinence and numbness around the genital region and "saddle area" (buttocks)).

A lumbar microdiscectomy operation is intended to relieve leg pain and weakness. It is not to improve back pain and there is a small chance microdiscectomy may worsen any existing back pain.



Success of the operation

The aim of the operation is to improve leg pain, numbness and weakness with a success rate of approximately 70 - 90%. The outcome will be lower the more severe and the longer you have the symptoms and signs before having the operation. No change in symptoms (no better or worse) occurs in 10% of patients.

If you have cauda equina syndrome, surgery should be performed urgently. However, even with surgery a complete recovery may not occur.



Risks of the operation

The total risk of lumbar microdiscectomy is approximately 2% or 1: 50.

Specific risks associated with lumbar microdiscectomy are infection, bleeding, fluid leak from the lining of the nerves (CSF leak), nerve root damage causing leg numbness and weakness, and a recurrent disc prolapse, which usually occurs in the first 4 - 6 weeks after the operation.

General risks associated with any surgical procedure are general anaesthesia, drug reaction, clots in the legs, (DVT), which can travel to the lungs (pulmonary embolus), pneumonia, urinary tract infection, heart attack, stroke and death.



Before surgery

Inform Mr. Malham about any medical conditions or previous operations.

If you have a medical condition such as diabetes, heart problems, high blood pressure or asthma, Mr. Malham may arrange for a specialist physician to see you for pre operative assessment and look after you following the operation.

Inform Mr. Malham of medication that you are taking and/or allergies to medications.

Stop Warfarin 5 days prior to surgery, and stop Aspirin/Plavix 10 days prior to surgery as these medications thin the blood.



Operation

The microdiscectomy operation is performed under general anaesthesia.

You will be carefully positioned face down on a special frame. The level of your operation is checked by x-ray and the skin marked. The skin is carefully cleaned with antiseptic and the skin is made numb with local anaesthetic. A small skin cut is made and then dissection between the bone and back muscles is carefully undertaken, allowing a special tube retractor to be inserted holding the muscle out of the way.

The correct spine level is checked with an x-ray.

A special drill is then used to make a small bone opening, allowing exposure of the compressed nerve. The bony opening where the nerve exits the spine is widened allowing the nerve to be gently protected so the disc prolapse pressing on the nerve can be carefully removed. Any damaged disc is then further removed from the disc space, freeing the nerve root from any compression. Healthy disc is left.

A small dissolvable pad called Gelfoam is soaked in local anaesthetic and antiinflammatory steroid and placed over the nerve to reduce any swelling or bruising.

The lining around the muscle is then closed with dissolvable stitches and the skin closed with dissolvable sutures or skin clips as required. A small wound dressing is then applied. You will be rolled back onto your bed, awoken from anaesthetic and the breathing tube will be removed.



After surgery

You will be carefully watched in the recovery ward in theatre for one hour after the operation, and then be transferred back to the neurosurgery ward. The nursing staff will carefully monitor your breathing, heart rate, blood pressure and leg strengths regularly.

You will have pain relief from a drip into your vein, which you can control with a button to push (PCA = patient controlled analgesia). This has a safety cut out so that you cannot overdose on pain medication.

The nurses will give you sips of water until you get stomach rumbling (return of bowel sounds) or passing of wind, indicating that your stomach and intestines are working again. If you drink or eat too early you may feel sick or vomit.

The next day you will be able to get out of bed and walk around with the physiotherapist and nurses.

Once you are comfortable and walking, the drip will be removed from your arm and regular tablets and injections for pain relief will replace the PCA if required.

Once you are comfortable walking around and independent you will be able to go home, which is normally 1 - 3 days following the operation.

You may require rehabilitation as an inpatient or as an outpatient to help your recovery. This will be discussed with you and arranged by Mr. Malham if appropriate.

Any skin clips will be removed 10 days after the operation, either by your GP or by the district nurse visiting your home.

You will be provided with pain relief medication or a prescription prior to leaving hospital.

Do not drive for a period of 4 weeks following the surgery or until you have seen Mr. Malham for postoperative review. You can travel in a car as a passenger with the seat reclined 30 degrees in order to keep your back straight. Be careful getting in and out of a vehicle.

Do not perform heavy lifting or vigorous physical work for four weeks after the operation. You should avoid bending and twisting activities and sitting for greater than 20 - 30 minutes. Keep your back straight. You can stand, walk or lie down and sit for meals on a straight chair.

You will be encouraged to walk 3 - 4 small walks per day, building from 4 x 5 minute walks up to 4 x 20 - 30 minute walks per day over a 4 - 6 weeks period, rather than one long walk, as this will cause pain and stiffness.

The leg pain, numbness and weakness will slowly improve after the surgery. The pain and weakness will improve over a few weeks, depending on the severity and duration that you had problems before you had surgery. The numbness will reduce but may never return to normal because of damage to the small fine sensation nerves on the outside of the nerve root. These are damaged by pressure from the disc prolapse or bone spurs (osteophytes).

You will be reviewed at Mr. Malham's rooms four weeks after the operation and an appointment will be given to you prior to discharge from hospital. You may wish to ring the rooms once you are home to obtain a time that suits you.