Anterior Cervical Discectomy and Fusion Surgery

Anterior cervical discectomy and fusion is a surgery performed for herniated intervertebral disc in cervical spine. This surgery remains the most widely done and preferred procedure for symptomatic cervical disc herniations.

Anterior cervical discectomy and fusion(short form ACDF) is the commonest procedure performed for herniated cervical discs. Anterior refers to front, as the surgery is performed through the front of neck. Fusion refers to fixation, which means that the disc space is immobilised using metallic plates and screws. This immobilisation leads to a bony union across the disc space through new bone formation which is considered essential for long term success.

What are the indications for Anterior Cervical Discectomy and fusion surgery?

The ACDF surgery is performed for herniated discs in the cervical spine. The herniated disc which causes significant symptoms like intractable pain, or weakness in arm. Following are some of the common indications for this surgery.

• Radiculopathy- This refers to pain going into the along the path of a nerve. The nerve is usually the one being compressed by the nerve root.
• Weakness in arm- If there is weakness in any muscle group caused from nerve root compression, surgery is usually indicated.
• Myelopathy- A term used to describe direct pressure on the spinal cord. In case of large disc herniations, the spinal cord may get compressed and cause weakness in legs and difficulty in walking.
• Persistent neck pain- Neck pain from disc herniations, which is not responding to physiotherapy and medications.

The pattern of pain and weakness is usually defined by the level of disc prolapsed and nerve root compressed(1).

Also read- Is Smartphone the cause of your neck pain?

How is ACDF surgery performed?

Anterior cervical discectomy and fusion surgery is usually performed under General Anaesthesia. In most cases, the patient is admitted one day before surgery and is evaluated for general fitness for surgery. In young patients without medical problems, the patient can be admitted a few hours before the surgery also.

The surgery is done with patient in supine position. The incision is made in such a fashion that it lies in one of the skin folds of the neck so that the future scar is not separately visible. After the skin incision, further surgery is done under an operative microscope. The surgeon then separates the large blood vessels, trachea and the oesophagus to reach the front of the cervical spine. Then the annulus of the affected cervical disc is cut and complete disc is removed. The disc fragments causing pressure on the nerve root are also removed. This is called decompression of nerves.

After the decompression/discectomy, the surgeon proceeds to fusion part of surgery. In the emptied disc space, a bone graft or a cage is placed to maintain the height of the disc space and to promote bone formation between the two vertebra. Nowadays, most surgeons prefer putting PEEK(Polyethyletherketone) cages in the disc spaces. Over this cage a titanium plate is put across the upper and lower vertebral body to prevent any movement between them.

The entire procedure usually takes 80 to 90 minutes. Sometimes more than one disc levels need to to be operated and therefore, the time duration of surgery increases. For a three level disc herniation the duration of surgery would be two and half hours.

Recovery after Anterior cervical discectomy and fusion

After the surgery the patients are observed in a post-op ICU for 4 to 6 hours. After this observation period, most patients can be shifted to ward. Patients are encouraged to keep moving their legs while in bed. They can start walking whenever they feel comfortable. This is important to prevent blood clots in the legs.

Most patients feel quite comfortable on first post-operative day. The major problems at this stage include pain at the surgery site, some pain during swallowing and some harshness in voice. These problems start to settle down in 5 to 7 days after surgery. Warm liquids, and steam inhalation prove beneficial in these problems.

Patients are allowed to take soft diet from post-op day 1 and progress to solid diet as per their comfort. Any surgical drains kept, is usually removed on first or second post-op day. Most patients are ready for discharge by second day of surgery.

High volume centres for spine surgery use Enhanced recovery protocols to reduce the hospitalisation times and improve outcome.(2)

What are the complications following ACDF surgery?

Like any surgery, ACDF can also lead to certain complications. Below are the most frequently encountered complications after ACDF surgery.

• Infection- is exceedingly rare after this surgery. The rate of infection is well below 0.5%.(3) Sometimes the infection can present weeks after the surgery in a delayed fashion.
• Dysphagia- or difficulty in swallowing. This is fairly common and may be present in up to 70%of patients after surgery. This occurs due to some swelling of the oesophagus, caused by pressure from retractors during surgery, This settles down in 5 to 10 days after surgery.
• Hoarseness of voice- Many patients may encounter some harshness of voice transiently after surgery. In some patients injury to the Recurrent laryngeal nerve during surgery may lead to permanent hoarseness of voice. This injury is also very rare.
• Major bleeding- is also rare and be caused by injury to any large artery or vein inside the neck. The surgeon approaches the spine by creating a corridor close to the carotid artery. Sometimes the carotid artery or some branch may get injured during surgery causing major bleeding. This will need immediate repair.

There are many more complications that may be seen after this surgery but they are not very frequent. This may include weakness in lower body, injury to nerves, and misplaced screws to name a few.

Delayed complications, that present after months may be due to loosening of implants(Plate and screws) or extrusion of graft (either bone or PEEK cage) from the disc space. This may lead to increasing pain in the neck and may need revision surgery.

Do I need to wear a collar after ACDF?

Even though not mandatory, but use of a hard cervical collar after ACDF surgery is recommended for 6 weeks. The use of collar has shown to significantly reduce post-operative pain after surgery. (4) It also gives the patient a sense of security and increases fusion rates.

Disclaimer- This is for the general awareness of the patients and cannot replace expert medical advice. Treatment of neck pain is decided by a clinician after necessary clinical examination and relevant investigations.

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References

1. Cervical Disc Herniation
2. Enhanced recovery after spine surgery: a systematic review.
3. Anterior Cervical Infection: Presentation and Incidence of an Uncommon Postoperative Complication
4. Is there a need for cervical collar usage post anterior cervical decompression and fusion using interbody cages? A randomized controlled pilot trial

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