The drawing on the left demonstrates an incision in the abdomen with self-retaining retractors holding the skin open. The disc (arrow) can be seen. The drawing on the right demonstrates the anterior longitudinal ligament that runs in front of the spine. This ligament is incised and the disc removed.
These drawings demonstrate how the disc is incised and removed by instruments to clear the disc space between the vertebrae. This is the space that is filled by a spacer and bone chips to allow the two vertebrae to grow together (fuse). Some of these spacers can be used on their own and others require a posterior (from the back) fusion as well.
(This is the section that explains the detail of the operation or procedure above and should be read in conjunction with the section Your Back Operation).
An anterior lumbar interbody fusion (ALIF) is performed to remove a damaged disc. The aim of the operation is to remove the whole disc and to replace it with a spacer and bone chips harvested from your hip (iliac crest) or from donor bone to allow a fusion to grow with time between the two adjacent vertebrae where the disc originally was. This means that the mobility of that section is removed by the growing fusion.
The reason why the disc is removed is because the disc is causing local back pain and referred pain through inflammation or pain down the leg due to the compression of a nerve root.
The idea behind replacing the disc that is removed with a spacer and bone or bone alone, is to remove the origin of the pain, recreate the natural spinal curve, to remove the compression of the nerve structures and finally to create a solid bone block. This creation of a solid bone block does not happen before one year or even longer after the operation. The advantage of operating on the spine from the front is that most of the surgery takes place in front of the spinal canal, and not around the nerves. The further advantage is that in the ALIF procedure there is no or minimal damage to the spinal muscles, which are very important in the normal mobility and stability of the spine.
Sometimes the specialist will perform an ALIF at the lowest level of the lumbar spine (L5/S1) and perform an artificial disc arthroplasty on the level directly above (see the section Lumbar Total Disc Arthroplasty).
This is frequently performed where the two lowest discs in the spine are damaged and allows the upper level to move freely and not place stress on the levels above.
When undergoing this operation, you will be lying on your back. Your specialist will make a small cut across your belly. This cut can vary from four to ten centimetres to a slightly larger cut, depending on technical factors. It can be a cut across your belly in the position where a cut is sometimes made for a caesarean section or slightly higher, closer to the belly button.
The length of the cut is actually of little consequence to the success of the operation and your specialist would never complicate the operation by limiting the length of the cut. In some cases the specialist will operate through the abdominal sac (peritoneum) that houses the abdominal organs. In other cases the specialist displaces the peritoneum which contains the abdominal organs to one side and then reaches the spine without penetrating into the cavity (peritoneal cavity).
Your specialist then has to temporarily displace the great vessels (aorta, iliac artery, vena cava and iliac vein) away from the disc space. Furthermore, the tubes that carry the urine might be in the way and have to be displaced too. The sympathetic nervous system that regulates the lymph flow in the legs as well as erection and ejaculation in males and vaginal lubrication in females, can also be violated in the procedure. Your specialist should have appropriate training in performing this approach before embarking on this procedure.
When the vertebrae are encountered, the outer ring of the disc is normally incised, opened like a trapdoor and then the entire core of the disc is removed. Thereafter, the implant, which may be a spacer filled with the patient’s own bone, bone from the bone bank or synthetic material (inducing bone-growth) is placed in the previously distracted and prepared disc space.
Following this, the outer layer of the disc is closed with a stitch and the whole abdomen is closed with sutures. In some cases, the anterior interbody fusion is followed by a postero-lateral fusion (see the section Lumbar Fusion) to increase the chances of fusion and allow the patient to be active earlier in the recovery phase.
You would be expected to get out of bed quite soon and usually on the first day following surgery or even on the same day. You may usually walk around as much as you want. It is important that you eat and drink nothing until your specialist specifically allows you to.
The reason for this is because of the possibility of your gut being temporarily paralysed from the surgery. This is mostly because of the traction that is placed on it during surgery to keep it out of the way when the specialist operates around the abdominal sac.
You would normally be discharged at about five to ten days after surgery, depending on the degree of pain and disability you are experiencing and on the absence of any complicating wound factors or concern about your general health at the time.
The hospital staff will assist you in obtaining your follow-up consultation bookings, the prescribed analgesics to take home, the sick leave-certificate to be provided by your doctor and the instructions regarding wound care provisions in the post-operative period.
It is incredibly important to get a lot of rest and exercise following your surgery. Do not try to rush back to work. It is important to walk for exercise and also exercise in conjunction with the guidelines from your physiotherapist. You may perform activities only as prescribed by your specialist. You should refrain from exercises that involve impact for at least six to nine months. This would include jogging, mountain biking, speed boating, water skiing, volleyball, equestrian pursuits and other strenuous activities.
Routinely you will receive a date for your follow-up appointment with your specialist. This may vary from anything between two and six weeks, but you will be seen earlier if there are any complications. It is important to realise that you will have to protect your back for the rest of your life and apply good back habits (see the section Caring for your Spine).