Lumbar Discectomy adverse outcomes

This operation involves removing a portion of the disc which is protruding backwards into the tunnel (spinal canal) where the nerves to the legs run.  The operation is usually done for persisting "sciatica" (pain in the leg) which is caused by the nerve in the spinal canal being irritated by the piece of disc.  It is NOT done with the hope of easing any low back discomfort although sometimes this does occur.

 The following list covers most of the common and/or serious risks of discectomy.  However, you need to remember that the vast majority of patients have a good or excellent outcome from this operation and you need to keep in perspective the small chance of any of these events below occurring against the likely benefits of this operation

 INFECTION: Infections can either be close to the skin surface (superficial) or deep in the wound (deep).  The risk of a superficial wound infection is approximately 5 in 100 (5%).  The risk of a deep infection is less than1 in 100 (1%).  There is a less than 1 in 1000 (0.1%) risk of an infection of the sac containing the nerves (dura) or in the fatty space around the sac (epidural space) or of the disc (disciitis).  Extremely rarely the build up of pus may cause nerve damage and require further surgery to drain the pus.

 NERVE DAMAGE:  The risk of direct surgical damage of the nerves is less than 1 in 1000 (0.01%).  Nerve damage can cause only slight numbness or weakness to total loss of function of the damaged nerve; however, permanent loss of nerve function is even more unlikely.  The nerves to the bladder and bowel and for sexual function are the last nerves to leave the spinal canal and therefore bowel and bladder problems and sexual dysfunction may occur if these nerves are damaged.

 DURAL TEARS:  The sac (dura) containing the nerves is usually very strong but in the presence of inflammation can become weakened.  It is then prone to being torn when the nerves and the sac are moved around during the surgery to gain access to the disc.  This occurs in approximately 1 in 100 (1%) patients.  Often the tear can be sutured or patched but you may be required to spend some days after the operation flat in bed.  Very rarely with persisting leakage of the fluid in the sac (CSF) a further operation may be required to stop this. There have been isolated reports of cerebral (brain) haemorrhage occurring after dural tears. 

ARACHNOIDITIS/EPIDURAL SCAR: Scarring occurs around the nerves and the sac (epidural scar) quite commonly but may cause ongoing sciatica in a few patients (less than 2 in 100 (2%)).  The scarring can be caused by both the associated inflammation from the disc prolapse and from the surgery.  Less commonly (less than 1 in 100 (1%)) scarring occurs within the nerve itself (arachnoiditis).  Further surgery is unlikely to improve persisting symptoms from arachnoiditis and epidural scar.  Indeed if either of these problems occur treatment is limited.

 HAEMATOMA/EPIDURAL HAEMATOMA: Following any surgery excessive bleeding may occur.  The blood may then accumulate and form a clot (haematoma).  The risk of developing a superficial haematoma is less than 5 in 100 (5%).  The risk of a deep haematoma which surrounds the nerves (epidural haematoma) is less than 1 in 1000 (0.1%).  An epidural haematoma may press on the nerves and cause them to stop functioning properly and may necessitate further surgery to remove the blood clot.

 RECURRENT DISC PROLAPSE: There is an approximate 2-3 in 100 (2-3%) risk of a further disc prolapse occurring at the same level in the spine.  However this is the same whether or not the disc is removed surgically or left to settle naturally.

 DVT or PE: DVT (Deep Vein Thrombosis) refers to clots forming in the deep veins of the legs.  DVT's which cause symptoms occur in less than 5% (5 in 100) patients.  Clots may travel from the deep veins in the legs and lodge in the blood vessels in the lungs (PE or Pulmonary Embolus).  When this happens it may cause no symptoms at all but occasionally it can cause breathlessness and chest pain.  Extremely rarely ie, less than 1 in 1000 (0.01%) it can cause sudden death.

Please also note that it has been shown that smoking significantly increases the risks and complications of surgery and reduces the chance of a successful outcome.