Anterior Lumbar Interbody Fusion

What is an ALIF?

An anterior lumbar interbody fusion (ALIF) is an operation on the lower back which is performed from the front, in other words through the abdomen. It is most commonly used to treat lower back pain resulting from a damaged or degenerate intervertebral disc, or spondylolisthesis (slippage of one bone on the other). The goal is to stabilise the spine so that pain (and sometimes deformity) is reduced. Anterior lumbar interbody fusion (ALIF) involves the removal of one or more intervertebral discs and the joining of two or more spinal bones (vertebrae) together using screws and a cage.

Why might I need an ALIF?

An ALIF is advised for some patients who may have the following conditions:

1. Discogenic lower back pain (pain arising from the intervertebral disc)
2. Spondylolisthesis (slippage of one vertebra on another, with pain and instability)

Surgery is usually recommended when all reasonable conservative measures (pain medications, nerve sheath injections, physical therapies, braces etc.) have failed.

When is an ALIF not recommended?

An ALIF may not be recommended when there is:

1. Obesity (this makes the approach difficult)
2. A history of multiple abdominal surgeries (this may make the approach hazardous)
3. Significant pressure on the spinal nerves (this requires a decompressive procedure, which is performed from the back)

In some cases, an ALIF may be followed by a posterior decompression and/or stabilisation procedure.

What are the potential benefits of an ALIF?

The goals of an ALIF may include:

• Reduction of back pain
• Stabilisation of an unstable spine
• Medication reduction
• Prevention of deterioration
• Improved lower back and leg function
• Improved work and recreational capacity
• Improved quality of life

The chance of obtaining a significant benefit from surgery depends upon a wide variety of factors. Your surgeon will give you an indication of the likelihood of success in your specific case.

What are the possible outcomes if treatment is not undertaken?

If your condition is not treated appropriately (and sometimes even if it is), the possible outcomes may include:

• Ongoing pain
• Problems with walking
• Depression and anxiety

What are the specific risks of an ALIF?

Generally, surgery is fairly safe and major complications are uncommon. The chance of a minor complication is around 4 or 5%, and the risk of a major complication is 2 or 3%. Over 90% of patients should come through their surgery without complications.

The specific risks of an ALIF include (but are not limited to):

• Failure to fuse (non-union)
• Fail to benefit symptoms or to prevent deterioration
• Worsening of pain
• Infection
• Blood clot in wound requiring urgent surgery to relieve pressure
• Cerebrospinal fluid (CSF) leak: this risk is much higher in revision (re-operation) surgery
• Surgery at incorrect level (this is rare, as X-rays are used during surgery to confirm the level)
• Blood transfusion
  • surgery is performed very close to the large blood vessels that go to the legs
  • injury to these large blood vessels may cause substantial blood loss
• Screw and/or cage breakage, movement, or malposition, sometimes requiring further surgery
• Cage or graft dislodgement (expulsion)
• Nerve damage (weakness, numbness, pain) occurs in less than 1%
• Major neurological problems are fortunately rare, but include:
  • paraplegia (paralysed legs)
  • incontinence (loss of bowel/bladder control)
  • impotence (loss of erections)
• Chronic pain (may require further surgery)
• Failure to fuse (pseudoarthrosis)
• Adjacent segment disease (deterioration of the disc above or below due to the extra stress caused by the fusion)
• Injury to the bowel, ureter (the tube running from your kidneys to the bladder), or spermatic cord
• Retrograde ejaculation in men
  • occurs in less than 5% of cases (the real figure is probably closer to 1%)
  • the nerves (known as the superior hypogastic plexus) that control ejaculation are draped over the front of the L5-S1 disc
  • these nerves are very sensitive, and ejaculation can be disrupted
  • ejaculation then occurs into the bladder, rather than out through the penis
  • erection and sex drive are rarely affected
  • it often resolves with time (several months to a year)
• Incisional hernia (this may require corrective surgery)
• Post-operative ileus (slowing of the bowels, which usually settles over a few days)
• Injury to the diaphragm or kidney
• Deep venous thrombosis and pulmonary embolism (formation of blood clots in the leg veins, and these may break off and travel to the lungs, which can be life-threatening)
• Death (this is extremely rare)

What do I need to tell the surgeon before surgery?

It is important that you tell your surgeon if you:

• Have blood clotting or bleeding problems
• Have ever had blood clots in your legs (DVT or deep venous thrombosis) or lungs (pulmonary emboli)
• Are taking aspirin, warfarin, or anything else (even some herbal supplements) that might thin your blood
• Have high blood pressure
• Have any allergies
• Have any other health problems

What do I need to do before surgery?

Before Surgery

• You may not eat anything after midnight, the night before surgery and must cease drinking clear fluids (water, apple juice, black tea) 2 hours prior to your admission time (unless otherwise instructed.)
  • Note: However, you may continue to take your routine medications (for example, heart and blood pressure medications), on the morning of surgery with a sip of water (unless otherwise directed). Please bring all your regular medications with you to hospital.
• Consult with your surgeon if you are taking blood-thinning medications,
  • NSAIDs, or Insulin. Examples include Coumadin (Warfarin), Plavix (Clopidogrel), and Aspirin; Nonsteroidal Anti-inflammatory Drugs (NSAIDs) such as Motrin (Ibuprofen), Aleve (Naproxen), Feldene (Piroxicam); or Insulin.
• Carefully read the hospital admission form, complete it and send it to the mater hospital at least one week before your operation.
• Have your blood tests done 3-7 days prior to your date of admission.
• Please shower on the morning of admission. Do not use powder, apply perfume, makeup or nail polish and wear cotton underwear if possible.
• Please be sure to take the following to the hospital admission on the day of the operation;
  • Surgery consent form
  • MRI/Xray/C.T Scans

On arrival at the hospital, inform the receptionist that you are there to have an operation. You will be taken to the pre-operative area to be prepared for surgery.

• Before your surgery it is imperative that you stop smoking, and you should not smoke for at least 12 months after. Smoking impairs the fusion process and leads to worse outcomes following spinal surgery.
• If you are fairly overweight, it is advisable that you engage in a sensible weight loss program before your surgery. Please discuss this with your GP and surgeon.
• In order to prevent unwanted bleeding during or after surgery, it is critical that you stop taking aspirin, and any other antiplatelet (blood-thinning) medications or substances including herbal remedies at least 10 days before your surgery. However, do not do this without prior consent from your Doctor.
• If you normally take Warfarin, you will usually be admitted to hospital 3 or 4 days before your surgery. Your warfarin will be ceased at that time (it takes a few days to wear off) and you may be commenced on shorter-acting anti-clotting agents for a few days. These can then be stopped a day or so before surgery.
• Ideally, you should take a Zinc tablet a day, commencing one month before surgery, and continuing for 3 months after. This should help wound healing.

Who will perform my surgery? Who else will be involved?

Surgery will be carried out by your surgeon.

An experienced vascular surgeon usually performs the approach, in order to make the operation as safe as possible. You will be reviewed by the vascular surgeon before a final decision to proceed with an ALIF is made.

A surgical assistant will be present and an experienced consultant anaesthetist will be responsible for your general anaesthetic.

How is an ALIF performed?

A general anaesthetic will be administered to put you to sleep. A breathing tube („endotracheal tube‟) will be inserted and intravenous antibiotics and steroids injected (to prevent infection and post-operative nausea). Calf compression devices will be used throughout surgery to minimise the risk of developing blood clots in your legs. A catheter will be inserted into your bladder to prevent bladder distension during surgery and to monitor urine output. You will be placed face-up on the operating table.

Your abdomen will be cleaned with antiseptic solution and some local anaesthetic will be injected.

An 8-12cm incision is made on the left side of the abdomen or in the midline, usually just below your umbilicus (belly-button). The abdominal muscles (rectus abdominus) are gently pulled to one side and the sac containing the abdominal contents (peritoneum) is similarly retracted. This is known as a retroperitoneal approach.

Sometimes, a transperitoneal approach is utilised: the peritoneum is incised and the abdominal contents retracted to approach the spine more directly.

The large blood vessels that run to the legs (the aorta and vena cava) are gently mobilised retracted off of the anterior aspect of the spine. The ureter is also identified and protected. At L5-S1, the superior hypogastric plexus is gently mobilized to expose the disc space.

A small needle is then inserted into the disc and an x-ray is performed to confirm that the surgeon is at the correct disc is being exposed.

A microdiscectomy is performed. This is done by first cutting the outer annulus fibrosis (fibrous ring around the disc) and removing the nucleus pulposus (the soft inner core of the disc). Disc removal is performed using a combination of special instruments.

The boundaries of the disc space (the vertebral end-plates) are then carefully prepared to facilitate fusion.

A special interbody cage (made of carbon fibre, PEEK, or trabecular metal) is then inserted into the disc space and secured in place with screws. This cage is typically filled with a combination of bone shavings, tricalcium phosphate, and bone morphogenetic proteins.

A final X-ray is taken and the wound is closed with dissolving sutures or with staples.

What are the costs of surgery?

Private patients undergoing surgery will generally have some out-of-pocket expenses.

A quotation for surgery will be issued, however this is an estimate only. The final amount charged may vary with the eventual procedure undertaken, operative findings, technical issues etc. Patients are advised to consult with their Private Health Insurance provider and Medicare to determine the extent of out-of-pocket expenses.

Separate accounts will be rendered by the anaesthetist and sometimes the assistant, and hospital bed excess charges may apply. Medical expenses may be tax deductible (you should ask your accountant).

You should fully understand the costs involved with surgery before going ahead, and should discuss any queries with your surgeon.

What is the consent process?

You will be asked to sign a consent form before surgery. This form confirms that you understand all of the treatment options, as well as the risks and potential benefits of surgery. If you are unsure, you should ask for further information and only sign the form when you are completely satisfied.

What happens immediately after surgery?

• During your first few hours on the ward, you will be monitored closely by the nursing staff. You will be given fluids by an intravenous drip and may have a drain coming from your wound. This is all normal procedure. If you have any pain or feel any sickness it is important to inform the nursing staff so they can keep you comfortable and aid your recovery. The majority of patients are allowed fluids to drink once you are awake, however with some surgery fluids and what you are allowed to eat will be restricted for the first day or so
• It is usual to feel some pain after surgery, especially at the incision site. You will be given regular pain relief but if this does not keep your pain under control, please speak to the nursing staff. Do not just wait till the next pain medication is due. Some patients experience mild episodes of muscle spasms in their back and legs (after low back surgery) or in their neck and arms (after neck surgery). Ice/heat packs or muscle relaxants can be used to lessen the discomfort.
• While tingling sensations or numbness is common, and should lessen over time, they should be reported to your surgeon.
• Most patients are up and moving around within several hours of surgery with the assistance of nursing staff. This is encouraged in order to keep circulation normal and avoid blood clot formation in the legs. The vast majority of spinal patients are allowed to walk to the bathroom with the help of nursing staff when they are fully awake from surgery. If you want to use the toilet, you must ask the nursing staff for assistance.
• Unless specified by your surgeon, you will commence rehabilitation the day following your surgery. This means all drips, drains and other appendages will be removed and you will be assisted out of bed on day 1 and walked to the bathroom for a shower.
• A CT scan will be performed the next day to check the position of the screws and cage.
• The majority of patients are discharged home after 3-5 days, however this will depend on when you are comfortable.

Preparing to go home

Post operative care and instructions:

• Maintain a normal healthy diet high in fibre to avoid constipation.
• Keep your dressing dry and clean for 7 days after surgery to prevent infection. Leave dressings intact unless damp or ooze present from wound. (If dressing damp or wound has oozed, get someone to change it for you with the dressings provided to you from the ward.) Ensure they wash hands carefully first.
• You may shower if you cover the incision with plastic wrap to keep it dry. A shower chair can be used if needed, otherwise use a special non-slip mat.
• It is important if you have a low toilet, to consider loaning a plastic extension, or over the toilet seat. These can be hired from some chemists.
• Steri-strips® (incision tapes) may have fallen off or be removed 7 – 10 days after surgery.
• Incision and dressing care may vary from patient to patient. Please make sure you understand your surgeon‟s instructions before you leave the hospital.
• You will need to wear a special brace for 3 months after surgery whilst you are sitting, standing or walking. You will need to take it easy for 8 weeks, but should walk for at least an hour every day. You should avoid sitting for more than 15-20 minutes continuously during this time.
• Change position regularly, do not lie in one position for too long (you will get stiff and sore).
• Take pain medication regularly as prescribed and advised. (Do not keep taking pain medication unless you really need it once the pain of the operation has worn off).
• No stooping, bending or twisting of your back. Keep your back straight and bend your knees using your thigh muscles.
• No sitting in soft chairs or sofas that allow your back to curve. Sitting may be uncomfortable, so limit your time sitting in a chair (20-30 minutes).
• Sit and stand straight, do not sit slouched or leaning over to one side in a chair.
• No stretching to reach high cupboards or shelves.
• No jogging. Short, frequent short walks are better than long walks.
• No lifting, housework or yard work during the first six (6) weeks or until allowed by your doctor.
• No driving or long car journeys until consulting with your surgeon at the first post-operative visit
• You should continue wearing your TED stockings until your post-operative review after surgery.

Follow the Guidelines for Physical Activity after Surgery

• Light activities such as walking may be started on the day of surgery. Your physical activities should progress gradually by alternating activity with rest.
• Plan for short, regular walks with rest periods.
• Each day increase your walking distance on a gradual basis.
• Once your sutures have been removed and the wound has completely healed (usually 2-3 weeks post-operation) you may go swimming (mainly just walking in the pool and a little gentle swimming. (No pool games or diving in.)
• Sexual activity is permitted within the bounds of your comfort. Consult with your surgeon.
• • At 6-8 weeks it is likely that you will be able to return to work on “light duties” and to drive a motor vehicle on short trips. This, and the step-wise progression in your physical activities, will be determined on an individual basis and with your surgeon at your 6 week post-operative check up.
• Bear in mind that the amount of time it takes to return to normal activities is different for every patient. Discomfort should decrease a little each day. Increases in energy and activity are signs that your post-operative recovery is progressing well. Maintaining a positive attitude, a healthy and well-balanced diet, and ensuring plenty of rest are excellent ways to speed up your recovery

When to Call Your Doctor

Call Your Doctor if You Experience Any of the Following Symptoms:

• If you feel warm or chilled, take your temperature. Call your doctor with a temperature of 38.3 °C or above.
• Increasing redness and swelling at the incision site.
• Chest pain or shortness of breath.
• Nausea or vomiting.
• Severe constipation.
• Changes in the amount, appearance, or odour of drainage from your incision.
• New or increased changes in sensation/presence of numbness in extremities.
• Severe pain that is not relieved by medication and rest.
• Problems passing urine or controlling your bladder or bowels.
• Problems with your walking or balance
• Questions or problems not covered by these instructions