Anterior Lumbar Interbody Fusion (ALIF)
Anterior lumbar interbody fusion (ALIF) is a type of spinal fusion that utilizes an anterior (front – through the abdominal region) approach to fuse (mend) the lumbar spine bones together. Interbody fusion means the intervertebral disc is removed and replaced with a bone (or metal) spacer, in this case using an anterior approach.
The anterior technique is often favored when multiple spinal levels are being fused and multiple discs need to be removed. ALIF may be performed in conjunction with or without a posterior decompression (laminectomy) and/or instrumentation (use of metal screws/rods). The anterior ALIF approach is also ideal when only one spinal level is fused and a posterior decompression and/or instrumentation are not required. Although the anterior lumbar ALIF approach involves retracting (moving out of the way, temporarily) large blood vessels (aorta, vena cava) and the intestines, there is a wide exposure of the intervertebral disc without retraction of the spinal nerves and neurologic structures (and therefore, a decreased risk of neurologic injury).
ALIF is commonly performed for a variety of painful spinal conditions, such as spondylolisthesis and degenerative disc disease, among others.
Anterior lumbar interbody fusion (ALIF) Procedure
The surgery is performed utilizing general anesthesia. A breathing tube (endotracheal tube) is placed and the patient breathes with the assistance of a ventilator during the surgery. Preoperative intravenous antibiotics are given. Patients are positioned in the supine (lying on the back) position, generally using a special, radiolucent operating table. The surgical region (abdominal area) is cleansed with a special cleaning solution. Sterile drapes are placed, and the surgical team wears sterile surgical attire such as gowns and gloves to maintain a bacteria-free environment.
A 3-8 centimeter (depending on the number of spinal levels to be fused) transverse or oblique incision is made just to the left of the umbilicus (belly button). The abdominal muscles are gently spread apart, but are not cut. The peritoneal sac (containing the intestines) is retracted (moved to the side) to the side, as are the large blood vessels. Special retractors are used to allow the surgeon to visualize the anterior (front part) aspect of the intervertebral discs. After the retractor is in place, an x-ray is used to confirm that the appropriate spinal level(s) is identified.
The intervertebral disc is then removed using special biting and grasping instruments (such as a pituitary rongeur, kerrison rongeur, and curettes). Special distractor instruments are used to restore the normal height of the disc, as well as to determine the appropriate size spacer to be placed. A bone spacer (metal or plastic spacers may also be used) is then carefully placed in the disc space. Fluoroscopic x-rays are taken to confirm that the spacer is in the correct position.
The wound area is usually washed out with sterile water containing antibiotics. The deep fascial layer and subcutaneous layers are closed with a few strong sutures. The skin can usually be closed using special surgical glue, leaving a minimal scar and requiring no bandage.
The total surgery time is approximately 2 to 3 hours, depending on the number of spinal levels involved.
Most patients are usually able to go home 3-4 days after surgery. Patients will typically stay longer, approximately 4-7 days, if a posterior spinal surgery is also performed. Before patients go home, physical therapists and occupational therapists work with patients and instruct them on proper techniques of getting in and out of bed and walking independently. Patients are instructed to avoid bending at the waist, lifting (more than five pounds), and twisting in the early postoperative period (first 2-4 weeks) to avoid a strain injury. Patients can gradually begin to bend, twist, and lift after 4-6 weeks as the pain subsides and the back muscles get stronger.
Patients are generally not required to wear a back brace after surgery. Occasionally, some patients may be issued a soft or rigid lumbar corset that can provide additional lumbar support in the postoperative period, if necessary.
The wound area can be left open to air. No bandages are required. The area should be kept clean and dry.
Patients can shower immediately after surgery, but should keep the incision area covered with a bandage and tape, and try to avoid the water from water hitting directly over the surgical area. After the shower, patients should remove the bandage, and dry off the surgical area. Patients should not take a bath until the wound has completely healed, which is usually around 2 weeks after surgery.
Patients may begin driving when the pain has decreased to a mild level, which usually is between 7-14 days after surgery. Patients should not drive while taking pain medicines (narcotics). When driving for the first time after surgery, patients should make it a short drive only and have someone come with them, in case the pain flares up and they need help driving back home. After patients feel comfortable with a short drive, they can begin driving longer distances alone.
Return to Work and Sports
Patients may return to light work duties as early as 2-3 weeks after surgery, depending on when the surgical pain has subsided. Patients may return to moderate level work and light recreational sports as early as 3 months after surgery, if the surgical pain has subsided and the back strength has returned appropriately with physical therapy. Patients who have undergone a fusion at only one level may return to heavy lifting and sports activities when the surgical pain has subsided and the back strength has returned appropriately with physical therapy. Patients who have undergone fusion at two or more levels are generally recommended to avoid heavy lifting, laborious work, and impact sports.
Results and Outcome Studies
The results of anterior lumbar interbody fusion (ALIF) surgery in the treatment of symptomatic spondylolisthesis and degenerative disc disease are generally excellent. Numerous research studies in medical journals demonstrate greater than 87-97% good or excellent results from ALIF surgery. Most patients are noted to have a significant improvement of their back pain and return to many, if not all, of their normal daily and recreational activities.