Anterior Cervical Decompression (Discectomy)

A cervical disc herniation can be removed through an anterior approach to relieve spinal cord or nerve root pressure and alleviate corresponding pain, weakness, numbness and tingling. This procedure, called a cervical discectomy, allows the offending disc to be surgically removed.

The anterior approach to the cervical spine (from the front of the neck) can provide exposure from C2 down to the cervico-thoracic junction. Spine surgeons often prefer it because it provides good access to the spine through a relatively uncomplicated pathway. All things being equal, the patient tends to have less wound pain from this approach than from a posterior operation.

After a skin incision is made, only one thin vestigial muscle needs to be cut, after which anatomic planes can be followed right down to the spine. The limited amount of muscle division or dissection helps to limit postoperative pain following the spine surgery. The main trouble that patients have after surgery is a sore throat and difficulty swallowing, which produces a sense of a ‘lump in the throat’ caused by the surgical manipulation of the area.

The general procedure for the decompression surgery includes the following:

1. Surgical approach

• The skin incision is one to two inches and horizontal, and can be made on the left or right hand side of the neck.
• The thin platysma muscle under the skin is then split in line with the skin incision and the plane between the sternocleidomastoid muscle and the strap muscles is then entered.
• Next, a plane between the trachea/esophagus and the carotid sheath can be entered.
• A thin fascia (flat layers of fibrous tissue) covers the spine (pre-vertebral fascia) which is dissected away from the disc space.

2. Disc removal

• A needle is then inserted into the disc space and an x-ray is done to confirm that the surgeon is at the correct level of the spine.
• After the correct disc space has been identified on x-ray, the disc is then removed by first cutting the outer annulus fibrosis (fibrous ring around the disc) and removing the nucleus pulposus (the soft inner core of the disc).

3. Dissection

• Dissection is carried out from the front to back to a ligament called the posterior longitudinal ligament. Often this ligament is gently removed to allow access to the spinal canal to remove any osteophytes (bone spurs) or disc material that may have extruded through the ligament.
• The dissection is often performed using an operating microscope or magnifying loupes to aid with visualization of the smaller anatomic structures.

Possible risks and complications of anterior cervical discectomy surgery may include:

• Inadequate symptom relief
• Failure of bone graft healing (a.k.a. non-union or pseudarthrosis)
• Persistent swallowing or speech disturbance
• Nerve root damage
• Damage to the spinal cord (about 1 in 10,000)
• Bleeding
• Infection
• Damage to the trachea/esophagus

Also, the small nerve that supplies innervation to the vocal cords (recurrent laryngeal nerve) will sometimes not function for several months after neck surgery because of retraction during the procedure, which can cause temporary hoarseness. Retraction of the esophagus can also produce difficulty with swallowing, which has usually resolved within a few weeks to months.

There is little chance of a recurrent disc herniation because most of the disc is removed with this type of surgery.

An anterior cervical fusion is usually done as part of a cervical discectomy. The insertion of a bone graft into the evacuated disc space serves to prevent disc space collapse and promote a growing together of the two vertebrae into a single unit. This ‘fusion’ prevents local deformity (kyphosis) and serves to maintain adequate room for the nerve roots and spinal cord.

• Article written By:
• Peter F. Ullrich, Jr., MD

October 7, 2005

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