Cancers of the mouth and oropharynx can spread to lymph nodes in your neck. 

Why you need surgery to remove the lymph nodes

Lymph nodes are small bean shaped glands found throughout the body, including the head and neck area. They are often the first place cancer cells spread to when they break away from a tumour.

Surgery to remove the lymph nodes in the neck is called a neck dissection. Surgeons don't routinely do a neck dissection on everyone because it can have long term side effects. They have to consider carefully who will benefit from it. 

Before your operation, your surgeon might know there is cancer in your lymph nodes. In this case, you have a neck dissection during your surgery to remove the cancer. 

Sometimes your surgeon doesn't know if there are cancer cells in your lymph nodes before you have surgery. In this case, your surgeon will suggest removing the lymph nodes closest to the cancer. They send the nodes to the laboratory to check them for cancer cells.

If there is cancer in the lymph nodes you might need to have more surgery to remove more nodes. Or you may have radiotherapy to that area. 

There are different types of neck dissection:  

• selective neck dissection
• modified radical neck dissection
• radical neck dissection

Selective neck dissection

Your surgeon removes lymph nodes from some areas of your neck. It is usually the areas closest to the cancer. 

Modified radical neck dissection

There are different types of modified radical neck dissection.

Your surgeon may just remove most of the lymph nodes between your jawbone and collarbone on one side of your neck.

Or they may also remove one or more of the following: 

• a muscle on the side of your neck called the sternocleidomastoid muscle
• a nerve called the accessory nerve
• a vein called the internal jugular vein

Radical neck dissection

You have nearly all the nodes on one side of your neck removed. Your surgeon will also remove:

• the sternocleidomastoid muscle
• a nerve called the accessory nerve
• the internal jugular vein

Side effects of neck dissection

These operations are important for getting the best chance of stopping the cancer from spreading or coming back. But there are some side effects. These depend on which of the following nerves or muscles have to be removed.

Accessory nerve

The accessory nerve controls shoulder movement. So if you have it removed, your shoulder becomes stiffer and more difficult to move. Raising your arm over your head on that side can also become more difficult.

After a selective neck dissection, the weakness in your arm is usually temporary.

But if the surgeon completely removes your accessory nerve, the damage is permanent. Usually you see a physiotherapist, who teaches you exercises to help improve the movement in your neck and shoulder. It is important to do these exercises regularly.

Some people still have problems with pain and movement a year after surgery, despite doing their exercises. If this happens, a referral to a shoulder surgery specialist may be considered.

Sternocleidomastoid muscle

Removing all of your sternocleidomastoid muscle doesn't usually cause a problem. But it does make your neck look thinner and sunken on that side.

After a neck dissection on both sides in which both of these muscles are removed, you do have some difficulty bending your head forward. Physiotherapy can help to improve movement and prevent stiffness.

Cranial and spinal nerves

The cranial and spinal nerves supply the head and neck area. A neck dissection can damage some of these nerves. If this happens you might have:

• numbness in the ear on the same side as the operation
• loss of movement in the lower lip
• loss of movement on one side of the tongue
• loss of feeling on one side of the tongue

Swelling (lymphoedema)

After surgery, the area can be swollen. This should go down within a few weeks. If you have had lymph nodes removed, there is a risk of developing swelling later on. This swelling is called lymphoedema (limf-o-dee-ma).

The lymph nodes are part of your body's drainage system. Removing them can affect the natural circulation and drainage of tissue fluid in this area. Lymphoedema in the head or neck can also cause symptoms inside your mouth and throat. For example, swelling of your tongue and other parts of your mouth.

Tell your doctor if you:

• have any swelling or a feeling of fullness or pressure
• find it difficult to swallow
• have changes in your voice

Exercises for lymphoedema

If you have lymphoedema, your physiotherapist or specialist nurse will usually go through these exercises with you. Using your head, neck and shoulder muscles may help to reduce swelling. 

Below are 2 videos that can help you with these exercises. Both are by a physiotherapist called Carla from the lymphoedema team at University College Hospital London. Speak to your doctor or lymphoedema specialist if you are unsure about doing any of them.

The first video shows you how to do breathing exercises. The second video shows you how to do head and neck exercises. It is important to do the breathing exercises before and after the head and neck exercises. 

These exercises should not be painful, so you must stop them if you have any pain. If the pain doesn't get better contact your doctor. Do each exercise slowly and gently, and it may help to rest in between.

The video about deep breathing exercises is 1 minute long.

The video about head and neck exercises is just under 3 minutes long.