What is an anterior cervical discectomy?
This operation is done to remove a part of the disc that is pressing on a nerve and causing arm pain. Sometimes this is done from the back of the neck (cervical foraminotomy) and sometimes from the front (anterior cervical discectomy and fusion). The choice depends mostly on the anatomy of the disc prolapse. If the disc is mostly out to the side, away from the spinal cord, it can be removed from behind and no fusion is required.
If the disc is more central, it needs to be removed from in front. This also involves a fusion as all of the disc is removed.
How is it done?
You will be admitted on the morning of surgery and the operation will be done under general anaesthetic. You will be placed flat on your back on the operating table with your head and neck supported. A small three centimetre incision is made in a skin crease on the right side of the neck.
The windpipe and oesophagus are retracted over to the left and a retractor is inserted. An x-ray is taken to mark the correct level and then the disc is completely removed. A hole is drilled centred on the disc space and through this the back of the disc space and the prolapsed part of the disc are removed.
A graft is then inserted into the hole. This is either a bone dowel removed from the hip or a titanium cage filled with bone.
The holes in the side of the cage allow bone to grow through into the adjacent bone. The main advantage of a cage is that bone graft does not need to be taken from the hip, thus avoiding the most painful part of the operation.
Whichever graft is used, the size is about 2mm greater than the hole. This ensures that the graft fits firmly and also it reexpands the narrowed disc space and helps to widen the foramen where the nerve exits the spine. Once the graft is inserted, the retractor is removed and the wound closed. A dissolving stitch is used under the skin so that no stitches need to be removed later.
What to expect post-operatively
In most cases you will notice an immediate improvement in your arm pain. Any weakness or numbness is likely to improve gradually and may take a few months. Numbness is usually the last thing to get better and depending on how much damage has been done to the nerve by the pressure from the disc prolapse it may never go away completely.
Postoperatively you will be able to lie in any position that you find comfortable and the physiotherapist will get you up out of bed the following morning. Your throat will be sore but this will improve fairly quickly. Most people are able to go home after three or four days. You will have some aching in the back of the neck and across the shoulders which will gradually improve as the fusion unites. The length of time that you need to take off work will depend on what you do. If you work in a sedentary occupation and are able to return on reduced hours with no lifting or work above your shoulders, you will probably only need three or four weeks off work. On the other hand if you work in a heavy manual job you may need up to three months off work until the fusion unites. In most cases it is best to avoid any lifting for six weeks and then to gradually increase activities over the following six weeks. The physiotherapist will give you a booklet explaining what exercises to do. You will be given an appointment to see me in my rooms in 4 to 6 weeks.
Are there risks involved?
There are risks involved with anything in life and surgery is no different. Some of these risks are common to most or all operations and some are specific to the particular procedure.
The following are the most common or most serious complications. Other problems may occur rarely and it is impossible to list every one of them. Just try to list all of the possible things that could happen on your drive to work-a car crash is obvious; an aeroplane crashing onto the road in front of you is also possible but extremely unlikely and would not normally be considered common enough to affect your decision to drive. If there is anything in particular that you are concerned about, please ask me.
General risks of any operation
Anaesthetic complications such as heart attack, drug allergy or even death are possible but very rare.
Blood clots in the leg (DVT) or lung (pulmonary embolus) may occur unexpectedly but are very uncommon in otherwise healthy people.
Infections such as pneumonia, wound infection or urinary tract infection may occur after any operation.
Bleeding may occur especially in people taking aspirin. It is therefore recommended to cease aspirin (also called Cartia or Disprin) two weeks before elective surgery.
Because there are a lot of structures in the neck in front of the cervical spine, there is a wide range of potential complications. Most of these are rare.
It is common to develop some numbness of the skin on the front of the neck due to cutting of the small cutaneous nerves. This cannot be avoided and the numbness gradually disappears over several months. The retraction of the oesophagus and trachea to allow access to the front of the cervical spine causes some pain on swallowing in most cases and very rarely a more serious injury may occur to these structures. The carotid artery is retracted to the right side and injury to this would have the potential to cause major bleeding or a stroke but is fortunately extremely rare.
The nerve that supplies the vocal cords runs very close to the operative site and if this is stretched by the retraction it can cause a hoarse voice for approximately two months which then recovers. This occurs in 2%-4% of anterior cervical discectomies. If the nerve is completely severed the hoarseness is permanent, although it can be improved by an injection into the vocal cord. Permanent damage such as this is very unusual. Neville Wran, the ex-premier of New South Wales, has a hoarse voice because of injury to this nerve.
The fusion may fail to unite but this is much less common in the neck than in the low back. Even if it does not unite completely it is very rare that this causes significant problems.
The implant may potentially dislodge or break requiring revision surgery but I have not seen this happen.
Wound infection is uncommon and would normally be treated with antibiotics.
Bleeding is rare but very occasionally there can be significant bleeding into the neck requiring re-opening of the wound to relieve pressure on the airway.
Arm pain is relieved or significantly improved in approximately 90% of cases. In up to 10% of patients surgery may fail to relieve the arm pain for unknown reasons. Arm pain may return at a later date due to scarring but this is less common in the neck than in the lumbar spine.
Damage to the nerve root causing numbness or weakness in the arm is possible but uncommon.
Damage to the cervical spinal cord is very rare but at the worst has the potential to cause quadriplegia (numbness and weakness in all four limbs).
Coming into hospital for surgery
These days, most operations are done on the same day as admission. You will need to come to the hospital admissions area at the advised time. If you have not already sent in the hospital admission forms, bring them with you.
You will need to fast for 6 hours which means nothing to eat or drink after the time notified.
You will usually be able to take your normal tablets but medications that affect your bleeding will usually be stopped preoperatively. Aspirin, (also called Disprin or Cartia),and Plavix (also called clopidogrel) should be stopped for two weeks if possible before an elective operation. Fish oil should be stopped for a week. Anti-inflammatories should be stopped for 48 hours. Warfarin will need to be discussed with me and your GP.
Make sure you bring your Xrays as these will be essential for most operations. If you cannot find them please let me know early so that they can be repeated if necessary.
If you would like to have a private room that should be indicated on the hospital admission forms. There are only a finite number of single rooms and sometimes it will not be possible to go straight into one, but if you indicate your preference every effort will be made to move you into a private room as soon as possible. (I do not have any say in this except in cases of medical need eg infections).
I will see you in hospital before you go to the operating room and the anaesthetist will also see you preoperatively and will want to know about your general health and any medications you are on. Please bring your usual tablets with you.