Anterior Lumbar Interbody Fusion (ALIF)

Overview

Low back pain (LBP) is one of the most common health problems, with a 1-month prevalence of 23.2 %, and it is also the leading single cause of work absence. LBP is most commonly caused by symptomatic intervertebral disc degeneration, which results in an intervertebral foramen and spinal canal stenosis.

Lumbar fusion is a common treatment for low back pain caused by degenerative disc disease. Anterior lumbar interbody fusion (ALIF) has emerged as a viable treatment option for achieving indirect foraminal decompression while maintaining high fusion rates.

Many surgical options have been established for a variety of lumbar pathologies that do not respond to conservative treatment. Lumbar fusion is critical in the treatment of incapacitating low back and leg pain caused by continued abnormal motion in the affected segment.

What is Anterior lumbar spine fusion?

Anterior lumbar interbody fusion (ALIF) is a type of spinal fusion in which the lumbar spine bones are fused together via an anterior (front – through the abdominal region) approach. Interbody fusion is a surgical procedure in which the intervertebral disc is removed and replaced with a bone (or metal) spacer, in this case via an anterior approach.

When multiple spinal levels must be fused and multiple discs must be removed, the anterior technique is often preferred. Fusion is the joining of two or more bones in order to stop painful motion and correct their alignment. The disc is removed through an incision in the front of the belly. To restore height and relieve nerve pinching, a bone graft is placed in the empty space. During the healing process, the bones join together to form a single solid piece.

Despite being a well-established procedure for a specific spine pathology, there are currently no conclusive studies demonstrating that one technique is more effective than others. However, the ALIF technique has some advantages. It allows for the removal of more disc material as a pain resource than other approaches, provides a larger bone-graft contact area, and avoids extensive paraspinal muscle dissection.

It can also increase the height of the disc space and the foraminal area, resulting in indirect nerve root decompression. Furthermore, lordotic cages can correct lumbar lordosis and improve sagittal balance.

Although most spinal surgeries are performed from the back, your surgeon may opt for an anterior approach for a variety of reasons, including:

• If you have had previous spinal surgeries using a posterior (back) approach, you should avoid having multiple surgeries in the same area.
• To provide easier access to the intervertebral disk.
• To be able to increase the amount of lordosis (swayback) in your spine.
• To potentially assist you in recovering faster.

When only one spinal level is fused and a posterior decompression and/or instrumentation are not required, the anterior ALIF approach is also ideal. Despite the fact that the anterior lumbar ALIF approach involves retracting 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, resulting in a lower risk of neurologic injury.

There is also a less common transperitoneal approach that allows access to the spine via the abdomen. This adds a lot of unnecessary morbidity to the procedure, so it is used much less frequently.

Because the large blood vessels that continue to the legs are located on top of the spine, many spine surgeons will perform this surgery in collaboration with a vascular surgeon who will mobilize the large blood vessels. After the blood vessels are relocated, the disc material is removed and a bone graft, or bone graft and anterior interbody cages, is inserted.

ALIF indications 

Spondylolisthesis, scoliosis, recurrent disc prolapse, severe lumbar canal or foraminal stenosis, spinal instability, and severe disc degeneration are common indications for ALIF (wear and tear). It is typically used to treat symptoms like sciatica (leg pain), pins and needles, numbness or weakness in the legs or feet, and back pain.

Advantages of ALIF Surgery

Unlike the PLIF and posterolateral gutter approaches, the ALIF approach preserves both the back muscles and nerves. Another benefit is that placing the bone graft in front of the spine compresses it, and bone in compression tends to fuse better. Finally, a much larger implant can be inserted through an anterior approach, which improves the fusion construct's initial stability.

ALIF is a well-tolerated procedure that is associated with less pain and a quicker recovery than spinal fusion surgery performed from the back of the spine. It enables the placement of a much larger cage than other types of spinal fusion, providing more stability and a higher chance of solid fusion.

It allows for more accurate correction of spinal deformity or imbalance, which may be associated with improved long-term outcomes in terms of pain, quality of life, and a lower risk of developing problems at adjacent levels of the spine.

Surgical Technique

ALIF has been shown to be effective in many spinal disorders that necessitate anterior column support and fusion. In comparison to posterior spine approaches, the retroperitoneal anterior approach avoids iatrogenic trauma to the paraspinal muscles and spinal nerves, as well as epidural scarring and perineurial fibrosis, and does not require the removal of posterior bony structures.

In contrast to the posterior or posterolateral approaches used by most spine surgeons, such as posterior/transforaminal lumbar interbody fusion (PLIF/TLIF), ALIF allows reexpansion of the lateral foramen and indirect decompression of the spinal nerve. There is a very low chance of neurological damage.

The anterior approach, on the other hand, necessitates exposure and mobilization of the great blood vessels, peritoneal contents, ureter, and sympathetic plexus, posing the risk of atypical in the realm of standard spine procedure complication, the rate of which can be relatively high.

The surgery is carried out under general anesthesia. During the surgery, a breathing tube is inserted, and the patient breathes with the assistance of a ventilator. Antibiotics are administered intravenously prior to surgery. Patients are generally positioned on their backs on a special, radiolucent operating table. A special cleaning solution is used to clean the abdominal area. To maintain a bacteria-free environment, sterile drapes are used, and the surgical team wears sterile surgical attire such as gowns and gloves.

Because the anterior abdominal muscle runs vertically in the midline, it does not need to be cut and easily retracts to the side. The abdominal contents are contained within a large sack that can also be retracted, allowing the spine surgeon to access the front of the spine without entering the abdomen.

Just to the left of the umbilicus, a 3-8centimeter transverse or oblique incision is made. The abdominal muscles are gently separated but not cut. After the retractor is in place, an x-ray is taken to ensure that the correct spinal level(s) has been identified.

The intervertebral disc is then extracted with the aid of special biting and grasping instruments. Special distractor instruments are used to restore the disc's normal height and to determine the appropriate size spacer to be placed. The disc space is then carefully filled with a bone spacer. To ensure that the spacer is in the proper position, fluoroscopic x-rays are taken.

The wound is usually washed with sterile water laced with antibiotics. A few strong sutures are used to close the deep fascial layer and subcutaneous layers. The skin can usually be closed with special surgical glue, leaving only a small scar and eliminating the need for a bandage.

Depending on the number of spinal levels involved, the total surgery time ranges between 2 and 3 hours.

What do you need to do before surgery?

We will most likely arrange for some rehabilitation with one of our exercise physiologists or physiotherapists prior to surgery. This is to get you in the best possible shape for surgery.

• If you are overweight, you should make every effort to lose the excess weight.
• If you smoke, you should quit.
• If you take aspirin, warfarin, or other anticoagulants, please notify the Precision Brain Spine and Pain Centre team so that we can advise you on when and how to discontinue them.

Post-Operative Care

It is normal to experience some pain following surgery, particularly at the incision site. Pain medications are typically administered to help control the pain. While tingling or numbness are common and should subside with time, they should be reported to your neurosurgeon.

Most patients are able to return home 3-4 days after surgery. If a posterior spinal surgery is also performed, patients will typically stay for 4-7 days. Before patients are discharged, physical and occupational therapists work with them to teach them proper techniques for getting in and out of bed and walking independently.

To avoid a strain injury, patients are advised to avoid bending at the waist, lifting (more than five pounds), and twisting in the early postoperative period (first 2-4 weeks). After 4-6 weeks, patients can gradually begin to bend, twist, and lift as the pain subsides and the back muscles strengthen.

Within a few hours of surgery, the majority of patients are up and moving around. This is encouraged in order to maintain normal circulation and avoid blood clot formation in the legs.

You should be able to drink within 24 hours, depending on how quickly your bowels contract and when you begin passing wind. The next day, a CT scan will be performed to check the position of the screws and cage. After a brief period of inpatient rehabilitation, you will be discharged home when you are comfortable.

Medications

You will be sent home with your regular medications as well as some pain relievers. After a few weeks, when your back pain has subsided, you can begin to wean yourself off your pain medications. It is critical not to discontinue all pain medications at once, as this can result in a recurrence of pain.

It is not uncommon for patients to be on pain medications for several months after spinal fusion surgery. Blood thinning medications (Plavix, Warfarin, Pradaxa, Xarelto, and others) can usually be resumed one week (7 days) after surgery.

Brace

In most cases, patients are not required to wear a back brace following surgery. Some patients may be given a soft or rigid lumbar corset to wear in the postoperative period if additional lumbar support is required.

Wound Care

Unless otherwise instructed, your sutures will be dissolvable and will not need to be removed. It is critical that you keep your wound dry for one week after surgery. You will be given waterproof dressings. You can shower with this dressing on and then replace it afterward or when it becomes soiled.

It is critical not to wear any restrictive clothing that is too tight around the wound or rubs on it. You can wet the wound after seven days. It is best to avoid scrubbing or rubbing the wound while in the shower. After two weeks, you can swim and immerse the wound completely in water.

Shower

Patients can shower immediately after surgery, but they should cover the incision area with a bandage and tape and try to avoid getting water directly on the surgical area. Patients should remove the bandage and dry off the surgical area after taking a shower. Patients should not bathe until the wound has healed completely, which is usually around 2 weeks after surgery.

Driving

Patients may resume driving once the pain has subsided to a mild level, which is usually 7-14 days after surgery. Patients should not drive if they are taking pain relievers. When driving for the first time after surgery, patients should make it a short trip and bring someone with them in case the pain flares up and they need assistance driving back home. Patients can begin driving longer distances on their own after becoming comfortable with a short drive.

Return to Work and Sports

Patients may be able to return to light work duties as soon as 2-3 weeks after surgery, depending on how quickly the surgical pain subsides. If the surgical pain has subsided and the back strength has returned appropriately with physical therapy, patients may return to moderate level work and light recreational sports as soon as 3 months after surgery.

Patients who have only had one level of fusion may resume heavy lifting and sports activities once the surgical pain has subsided and their back strength has been restored appropriately through physical therapy. Patients who have had two or more levels of fusion are generally advised to avoid heavy lifting, laborious work, and impact sports.

Physiotherapy

Physiotherapy is usually not necessary during the first 12 weeks following a spinal fusion. The physiotherapist in hospital or rehabilitation may have given you some gentle exercises that you are able to perform. Although these gentle exercises are permissible, aggressive physiotherapy is not required for the first 12 weeks following spinal fusion. It is best to concentrate on a walking program.

Follow up

In general, the outcomes of anterior lumbar interbody fusion (ALIF) surgery for symptomatic spondylolisthesis and degenerative disc disease are excellent.

Numerous research studies published in medical journals show that ALIF surgery produces 87-97 percent good or excellent results. Most patients report significant improvement in their back pain and are able to resume most, if not all, of their normal daily and recreational activities.

Increases in energy and activity indicate that your post-operative recovery is on track. Maintaining a positive attitude, eating a healthy, well-balanced diet, and getting plenty of rest are all great ways to speed up your recovery.

Swelling, redness, or discharge from the incision, as well as fever, should be reported to the surgeon as soon as possible.

Your neurosurgeon will evaluate you in 6-8 weeks. Until then, you should avoid lifting objects weighing more than 2-3kg and bending or twisting movements. Patients who smoke or are extremely overweight have poorer outcomes from fusion surgery. As a result, it is critical that you stop smoking permanently before your surgery and try to lose as much weight as possible.

Doctor’s Visits and Follow-Up

Patients will return to the doctor for a follow-up visit 12-14 days after surgery. The incision will be examined. The anterior wound has no sutures that need to be removed. If necessary, medications will be refilled. Patients are usually seen every 4-6 weeks after that, and an x-ray is taken to ensure the fusion area is stable and healing properly. Patients will be given a prescription to begin physical therapy for gentle back exercises 8-12 weeks after surgery.

Complications 

The majority of ALIF surgeries can be performed safely and without complications. However, there are risks associated with both the anaesthetic and the procedure itself, as with any surgical procedure.

Risks of Anesthesia

Your anesthetist will discuss the risks of anesthesia with you prior to surgery. It is critical that you provide us with your correct age as well as any previous medical problems, as this can affect the risk of anesthesia.

General Risks of Spine Surgery

Although spine surgery is generally safe, there are some risks associated with any operation on the spine. These are some examples:

• Infection rate of 1-2 percent
• Bleeding. This can happen during surgery and may necessitate a blood transfusion. It can also happen soon after surgery. A second operation is rarely required to drain the bloodclot and stop the bleeding.
• a spinal fluid leak (CSF leak)
• There is a low risk of significant neurological injury resulting in paralysis.
• Chronic discomfort

Specific Risks of Anterior Lumbar Interbody Fusion

The specific risks will be discussed in detail prior to your surgery but may include:

Pain in the lower back

• Nerve injury causing pain, numbness, weakness in the legs
• Nerve injury causing bowel or bladder problems
• Progressive deformity of the lumbar spine - kyphosis or spondylolisthesis
• Incomplete decompression of posterior pathology (unable to reach the back of the spine)
• Persistent symptoms
• Recurrence of symptoms
• Adjacent segment disease - problems at spinal levels next to the fused level
• Abdominal viscera Injury - bowel injury
• Vascular Injury - arterial or venous
• Ureteric injury

The most common iatrogenic injury is venous injury, but arterial wall dissection or rupture is the most serious; therefore, careful preoperative evaluation of vessels on magnetic resonance imaging (MRI) or abdominal computed tomography angiography (CTA), meticulous preparation and manipulation of an iliolumbar vascular complex are required. Despite the risks of the procedure, ALIF has been widely accepted for a variety of lumbar pathologies.

When to seek the assistance of a Neurosurgeon?

If you experience any of the following symptoms after being discharged from the hospital, you should contact your neurosurgeon as well as your primary care physician:

• Leg pain, weakness, or numbness that is worsening
• Back pain is getting worse.
• Having difficulty passing urine or controlling your bladder or bowels
• You're having trouble walking or keeping your balance.
• Fever
• Swelling, redness, fever, or a wound infection are all symptoms of a wound infection.
• Fluid leakage from the wound
• Your calf muscles may be in pain or swollen (ie. below your knees)
• Shortness of breath or chest pain

New Trends

With newer technologies and improved instrumentation, your surgeon may be able to perform this surgery through a smaller incision in the front of your spine. This method can help you feel better faster by reducing pain. The biological fusion of the spine, on the other hand, takes the same amount of time whether you have traditional or minimally invasive surgery.

To accelerate fusion, new technology is being developed, including a variety of biologic materials and cages. Consult your surgeon about these newer options.

Conclusion 

Anterior Lumbar Interbody Fusion (ALIF) is a surgical procedure that fuses the lumbar spine through an approach from the front of the spine through the abdomen. ALIF is an acronym for:

The anterior lumbar interbody fusion (ALIF) is similar to the posterior lumbar interbody fusion (PLIF), but the disc space is fused in the ALIF by approaching the spine through the abdomen rather than the lower back. The ALIF approach involves making a three- to five-inch incision on the left side of the abdomen and retracting the abdominal muscles to the side.