Lateral Neck Dissection
a.k.a. Modified Radical or Functional Neck Dissection

When an ultrasound-guided FNA has confirmed that a lymph node in the lateral neck area (outside the left or right carotid artery) contains cancer, a lateral neck dissection is necessary.

Lymph nodes that are outside the area bounded by the carotid arteries cannot be removed through the incision used for a thyroidectomy. The incision used for a lateral neck dissection usually extends from the end of the thyroidectomy incision up to just behind the earlobe.

A lateral neck dissection removes all of the lymph nodes along your jugular vein from your jaw bone down to your collar bone. It is referred to as a "modified" or "functional" neck dissection because we remove the lymph nodes without removing any vital nerves, blood vessels, or muscles.

Occasionally, the lymph nodes are stuck to one or more of the following structures, requiring their removal:

  • Internal Jugular Vein: The internal jugular veins are large veins on either side of the neck that help to drain blood from the brain and head back to the heart. One jugular vein can be removed without causing any symptoms. About 5% of lateral neck dissections for thyroid cancer require removal of an internal jugular vein.
  • Sternocleidomastoid muscle: This muscle helps you to bend and turn your head. If it is removed, you may have some weakness in your neck and will have a cosmetic defect due to its absence. This muscle is rarely removed for thyroid cancer.
  • Spinal accessory nerve: This nerve controls the muscles that allow you to raise your arm above your head. If it is removed, you may be unable to raise your arm above your shoulder and may have pain in the shoulder. This nerve is rarely removed for thyroid cancer.

The operation typically lasts 2-4 hours (in addition to the time required for a thyroidectomy and/or central neck dissection if being done at the same surgery). One or two thin plastic tubes (drains) are placed at the time of the surgery and will come out the skin below your collar bone. A cosmetic skin closure is performed after the tube is removed. It is normal for there to be some numbness of the skin on the jaw, neck, and ear. Most of the time this numbness is temporary, but it can last several months.

Risks of Lateral Neck Dissection

The main complications of a lateral neck dissection involve the numerous nerves which run through the neck. The risk of injury to each nerve is about 1%. The nerves at risk are as follows:

  • Spinal accessory nerve: This nerve connects to two muscles in the shoulder, the sternocleidomastoid and trapezius. Injury may result in shoulder pain and/or difficulty in raising the arm above the head.
  • Vagus nerve: This nerve gives rise to the nerve to the vocal cord (recurrent laryngeal nerve). Injury to this nerve will result in hoarseness.
  • Phrenic nerve: This nerve supplies the diaphragm, which is the muscle that helps you breathe. Most people who have an injury to one phrenic nerve do not experience any major breathing problems. However, if you have lung disease or are an endurance athlete, injury to a phrenic nerve may cause breathing difficulty.
  • Hypoglossal nerve: This nerve controls the muscles of the tongue. Injury causes the tongue to deviate to the side when stuck out and may cause difficulty with speech or chewing. These problems usually improve with time.
  • Marginal mandibular nerve: This nerve controls the muscles around the corner of the mouth. Injury to this nerve may cause the corner of the mouth to droop.

In addition to injury to nerves, there is a small risk (1% or less) of significant bleeding, infection, leakage of lymph fluid, or shoulder pain. Fluid collection in the neck rarely occurs after the drain is removed.

This information is provided by the Department of Surgery at the University of Colorado School of Medicine. It is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition.