Surgical Procedures
ANTERIOR INTERBODY LUMBAR FUSION


1. WHAT IS THE BASIC STRUCTURE OF THE SPINE?

The spine is composed of vertebrae, disks, spinal cord and nerves. Typically, the vertebrae are referred to as the "spine." These vertebrae are strong and flexible bones that support the trunk and protect the spinal cord and nerves. The disk is the soft structure located between the vertebrae. These disks act as cushions which enable the vertebrae to move.

2. WHAT IS A LUMBAR FUSION?

A lumbar fusion is when two or more vertebrae in the back are "fused" together to create a solid bridge of bone between the vertebrae and across the disk space. A fusion is usually performed to eliminate movement between vertebrae and stabilize a painful or unstable segment of the spine. Once a segment of the spine is stabilized, the patient usually experiences some relief of pain. Surgery is not usually recommended unless there is a more than 70% chance of improving the level of pain. This approximately 70% chance of improvement does not necessarily mean you will be completely pain free, but rather that your level of pain should be significantly improved. It means that there may be significant chance your pain will not improve. However, each situation is unique. There is also a small chance that you may become significantly worse.

3. WILL I LOSE MOBILITY ONCE A PORTION OF MY SPINE BECOMES SOLID BONE?

It depends, in part, on how much of the spine is fused. The spine will not move as much, but you may not notice it because it is only a small portion of your spine. Most people believe that the spine enables you to bend over at the waist-- this motion actually occurs mostly at the hips. There are patients who have their entire spines fused yet are still able to touch their fingertips to the floor.

4. WHAT HAPPENS DURING AN ANTERIOR LUMBAR FUSION?

At the hospital you are taken to the area where an anesthesiologist explains the anesthesia process. You are then taken to the Operating Room and given a general anesthetic to put you to sleep. After you are asleep you are carefully positioned on the table. You may be positioned on your side or on your back, depending on the needs of your particular case. An incision is made through your abdominal muscles. This incision may be directly in the front of your abdomen and may be straight, horizontal or vertical. Sometimes it is more towards your flank and somewhat diagonal in direction. This depends on which levels of your spine need to be fused and the number of levels involved. The surgery is then done by moving the abdominal contents over and then identifying the great vessels, called the aorta and the inferior vena cava. These are also carefully retracted over the spine. At this point, we are able to look directly at the front part of the spine. In the usual anterior lumbar interbody fusion, the disk is removed as completely as possible. A bone graft may be taken from your pelvis or sometimes "local" bone from the vertebra is used. This graft is combined with a spacer device, sometimes called a cage. There are various spacers/cages available. Some are metal or carbon fiber, and others are made form donor (cadaver) bone. The specific requirements of your case will determine the correct space/cage choice.


5. HOW IS AN ANTERIOR LUMBAR INTERBODY FUSION DIFFERENT FROM POSTERIOR LUMBAR FUSION?

In a posterior lumbar fusion, the fusion is done through the back part of the spine. The muscles are dissected from the spine. The bony surfaces of the spine are exposed and small pieces of bone are laid across the back part of the spine. In an anterior fusion, the surgery is done through the front part of the spine, which makes it necessary for us to go through your abdomen. Instead of using chips of bone graft to span the space, a solid piece of bone is generally used, in the form of a shaped bone graft or cage filled with bone. In the anterior fusion, the bone graft is packed directly between the vertebral bodies, whereas in the posterior fusion the bone is laid across the back part of the spine.

6. WHEN IS AN ANTERIOR FUSION CHOSEN INSTEAD OF A POSTERIOR
FUSION?

An anterior fusion is chosen for several reasons. Your surgeon may feel that with the new cage technology and your particular situation that an anterior fusion is a better way to obtain a fusion. However, anterior fusion is also used with to a posterior fusion to obtain a higher percent of fusion rate. In certain spinal deformity situations (eg. scoliosis), multiple disks are removed from the front of the spine to "loosen up" the spine and improve the correction of the deformity.

7. WHY ARE CAGES or SPACERS USED?

Cages and spacers are used to increase the rate of fusion. They also restore a more normal spinal alignment. In addition they may help to decompress pinched nerves by restoring the height of a collapsed disk.

9. DOES SMOKING HAVE AN EFFECT ARE MY FUSION?

Research shows that the spine fusion rate is greater than 90% in nonsmokers and less than 60% in smokers. It appears that with the cage technology the difference is not quite as great but there is still certainly a lower fusion rate in patients who smoke. In addition, there is a higher infection rate in people who smoke. Many surgeons will not perform a fusion in patients who smoke because of the higher rate of nonunion and infection. If you smoke, be prepared to discuss the situation in detail with your physician.

10. WHAT WILL MY HOSPITAL STAY BE LIKE?

You will check into the hospital approximately two hours before surgery (the nurse will give you a time and directions). You will wait in the holding area of the operating room for about 30 minutes before surgery. This is where you will meet your anesthesiologist and have your IV's initiated. After surgery you will wake up in the Recovery Area where you will remain for 1 to 2 hours. There will be a catheter in your bladder. The catheter is usually removed on the 2nd day. However, if you are unable to urinate you may need to be re- catheterized. Due to the anesthesia and medications, many patients have a poor recollection of this time period. The first 2 days will be difficult. The most painful part of recovery is usually the site of the bone graft. In order to obtain an adequate amount of graft, the gluteal muscles had to
be dissected. As you walk these muscles will pull on the graft site. This area will be painful until the scar matures, which may take anywhere from 4 to 6 weeks. We will try very hard to keep you as comfortable as possible with IV narcotics. You will be able to control the amount of pain medication you receive by using a small push button. You can push the button as often as you need and the machine will control the dose. We have been very happy with the amount of pain control we can obtain with this machine.

The combination of narcotics, anesthesia, and spine surgery may cause you to experience some nausea. We allow only ice chips or small amounts of liquids until you are passing gas. If fed too soon, you may become distended and even more nauseated. About 20% of our patients are fairly nauseated within the first 24 hours. This problem is usually resolved by the second or third day.

We encourage you to get out of bed on the first or second day. By the third day we insist that you are ambulating. We have found that there is a lower incidence of lung, bladder, and vascular complications the earlier the patient is mobilized.

11. WHEN CAN I SHOWER?

The wound drains (if used) are usually removed on the second day. You may shower on the 10th day and blot the wound dry. There are small tapes on your skin that you will need to pull off after the 10th-14th day. The sutures do not need to be removed, as they will eventually be absorbed into the skin. Occasionally metal staples are used to close the wound and these will be removed on your 1st office visit (about 14 days after surgery). You should not swim, bath, or otherwise submerge your wound until it is completely sealed (3-4 weeks after surgery).

12. WHEN CAN I GO HOME, AND WHAT WILL I BE ABLE TO DO?

You may go home once your pain can be controlled with pills, your incision is not draining, and your bowel and bladder are functioning normally. Most patients are ready to go home by the third or fourth day after surgery.

Within the first few weeks following discharge, we encourage you to begin walking for one half-hour to two hours each day. If you were given a brace, you must wear it during the day although you can remove it to sleep or shower. You should be able to go up and down stairs, and perform basic daily activities without too much of a problem. You should avoid bending at the waist as that increases the stress across the fusion site. It usually takes a minimum of 4 to 6 months for the fusion to heal. The time frame in which you can return to work depends on your recovery. Each patient has a unique set of work-related issues, which will need to be discussed with the doctor. The first office visit should be scheduled two to four weeks after you are discharged. The purpose of this visit is to check your incision and make sure you are progressing as planned. The second visit is typically scheduled 3 months after surgery. During this visit the status of your fusion is assessed. Each physician has his own approach to rehabilitation some more vigorous than others. Your physician will prescribe a rehabilitation program based on your specific needs. You may drive when you are strong enough to safely push on the brake pedal (i.e. in a "panic" stop) and are not taking narcotic pain medicines that may impair your thinking. This is generally between 4 to 6 weeks after surgery.

13. WILL I NEED A BLOOD TRANSFUSION?

A spinal fusion is a major surgery which may require a blood transfusion. However, if you are having just a one or two level anterior fusion, the blood loss has been shown to be quite minimal. We have generally not had people pre-donate blood for just an anterior fusion. However, if the fusion is being done in conjunction with a posterior fusion, then a blood transfusion may be required. If you require blood, you can donate it yourself or use the Blood Bank. The blood bank is very safe. The approximate risk of contracting AIDS (HIV) is less than one in 250,000, and the risk of contracting hepatitis is about one in 20,000. Prior to surgery, our office will arrange pre-donations through the blood bank.