Overview of Radical Neck Dissection
The practice of performing neck surgeries for head and neck cancer has been around for almost two hundred years. Doctors in the early 19th century already knew that head and neck cancers that had spread to the neck lymph nodes often had grim outcomes. While some doctors suggested removing the lymph nodes from the neck to tackle these cancers, it was Dr. George Crile who first recommended a particular technique in a 1906 article. This involved removing not just the lymph nodes from the side of the neck, but also important structures like the spinal accessory nerve, the internal jugular vein, and the muscle on the side of the neck known as sternocleidomastoid.
This technique was very invasive and resulted in a visible change in appearance and loss of function. So experts started refining the method to make it less problematic while still effectively treating cancer. In the 1960s, Drs. Bocca and Suarez recommended a modified version of the technique that aimed to save at least one of the non-lymphatic structures like the spinal accessory nerve, internal jugular vein or the sternocleidomastoid muscle.
As our understanding of how lymph nodes are connected in the head and neck improved, procedures have been more tailored to effectively remove the specific lymph nodes directly linked to the location of the tumor, while leaving as much healthy tissue as possible. Sometimes these neck surgeries are carried out as a precaution for tumors that have up to a 15-20% chance of spreading quietly to the neck.
In 2002, the American Academy of Otolaryngology-Head and Neck Surgery set up a standardized naming system for these procedures to help communicate their scope. “Radical neck dissection” refers to the technique that removes not just the lymph nodes but also the spinal accessory nerve, internal jugular vein and sternocleidomastoid muscle. If at least one of these structures is preserved, it’s called “modified radical neck dissection”. The term “Selective neck dissection” is used when only certain lymph nodes are removed depending on the likelihood of disease spread. “Extended neck dissection” further expands the scope to remove additional lymph nodes not considered in a radical neck dissection.
Anatomy and Physiology of Radical Neck Dissection
The neck is a very intricate part of the human body with a multitude of structures. To perform surgery on it safely and accurately, doctors need to fully understand the different components present and how they interact with one another. Let’s talk about the important sections of the neck and their key characteristics.
The neck contains lymph nodes, small gland-like structures that help the body fight infection. These are grouped into seven different regions, or levels:
Level I includes two types of nodes. Level Ia is bordered by two muscles at the sides, the hyoid bone at the bottom and the jawbone at the top. Level Ib’s limits include two muscles, the end of a salivary gland, and the jawbone. Within this level, you’ll find nerves called the lingual and hypoglossal, a duct, and the facial artery and vein.
The next level, Level II, also splits into two, with distinct borders formed by different anatomical structures; such structures include muscles, veins, and the skull base. There’s a nerve known as Cranial Nerve XI, which divides this level an runs under a muscle and an artery. This nerve can be found in various locations around a vein in most people.
Level III lies next, bordered by muscles, a bone called the hyoid and a part called the cricoid cartilage. An important structure here is the phrenic nerve which lies beneath some muscles and deep layers of the neck.
Level IV, similarly, is encircled by bones, muscles, cartilage and the clavicle. From just below the skin to deep in the neck, it contains an array of structures including a muscle, the carotid sheath, a duct, an artery and more. At the bottom of this level, one could encounter the lung tops.
Level V nodes are found between the trapezius muscle on the side and the sternocleidomastoid muscle in the front, down to the clavicle. It’s split into two sections by a line extending from the cricoid. Notably present in this level is the phrenic nerve which can be found overlying some muscles whilst the brachial plexus is located between two muscles.
Level VI contains the central compartment nodes and is compartmentalized by the large carotid arteries on either side, the hyoid on top, and the sternum on the bottom. A nerve, glands and the windpipe can be found within this region.
Last on the list is Level VII, at the top of the chest cavity, bordered by the end of the breastbone and a large artery.
Knowing which level is involved is important for mapping out the spread of diseases like cancer from different parts of the head and neck. For instance, the upper three levels get involved when it comes from the mouth, whilst the throat might involve Levels II to IV. Cancer of the thyroid affects mainly Level VI.
Why do People Need Radical Neck Dissection
A neck dissection, which is a surgical procedure to remove some or all the lymph nodes from the neck area, is typically performed when a person has advanced tumors or clinically positive nodal disease. This means the disease has been detected by physical examination or imaging tests, like an X-ray or an ultrasound.
A subtype of neck dissection, known as radical neck dissection, is performed only when the disease is detected as clinically positive and involves some specific structures in the neck: the sternocleidomastoid muscle (this is the muscle you can feel on the side of your neck when you turn your head), the internal jugular vein (a major vein in your neck), and the 11th cranial nerve, which helps control some shoulder and neck movements.
Selective neck dissection and modified radical neck dissection (MRND) are the most common procedures for treating resectable neck disease. Resectable means that the disease can be removed surgically.
Selective neck dissection means we’re only removing certain nodes. This procedure is often used when a person’s disease is classified as “high T-stage (T3-T4)”. This is a way of saying the disease has advanced into deeper tissues, but no nodes have been detected as having disease. It may also be used when the risk of cancer spreading to the neck (cervical metastasis) is high, specifically greater than 20%.
MRND, on the other hand, involves the thorough removal of the nodes in the neck (levels I-V, categorizing different areas of the neck). However, important structures like the 11th cranial nerve, sternocleidomastoid muscle, and internal jugular vein are preserved to some extent depending on the type. For type I MRND, the 11th cranial nerve is saved. For type II, both the 11th cranial nerve and the internal jugular vein are kept, and for type III, these two along with the sternocleidomastoid muscle are saved. These subtypes allow us to tailor the surgical approach to the patient’s specific needs.
When a Person Should Avoid Radical Neck Dissection
There are some cases when a neck dissection, which is a surgery to remove lymph nodes, cannot be done. For example, if the disease can’t be surgically removed because it has spread too widely, such as to the base of the skull or the muscles deep in the neck, surgery isn’t an option. If the disease has reached the carotid artery, the main artery in the neck, it may or may not allow for surgery. In cases where the carotid artery can be temporarily blocked, medical imaging studies with a specific type of CT scan may be done ahead of surgery to decide if rebuilding the artery is necessary. These procedures are not guaranteed to improve the chances of survival but might be used if there is a high risk of the artery bursting.
There are also scenarios that might make the surgery too risky or not beneficial for the patient. For example, if the person has a blood disorder that isn’t well controlled, which could lead to excessive bleeding, the surgery may not be appropriate. The same applies if the person is in poor health overall, with a high risk of complications from anesthesia or if they have cognitive difficulties. The surgeon must always consider if the surgery could do more harm than good, due to other health concerns the patient might have and the stress surgery puts on the body.
Equipment used for Radical Neck Dissection
When a doctor performs a neck dissection, there are a number of special tools that they use. These tools can sometimes vary depending on the doctor performing the surgery, but here are some common ones used in our medical facility:
- 15 blade scalpels: This is a type of sharp knife used in surgeries.
- Monopolar cautery with the protected tip: This is a device that uses electricity to control bleeding during surgery.
- Bipolar bayonet forceps: This is a type of pincers or tongs used to grasp or hold things during surgery.
- Surgical laparotomy sponges: These are used to soak up blood or other fluids during surgery.
- Sterile saline for irrigation: This is a saltwater solution used to clean the surgical area.
- Suction: This is a device used to remove blood or other fluids from the surgical area.
- Elastic stays: These are used to keep the surgical area open.
- Various retractors: These are tools used to hold back the tissues or organs during surgery.
- Various pickups: These are tools used to lift or hold tissues or organs during surgery.
- Small and medium surgical clips: These are used to control bleeding during surgery.
- Right angle clamp: This is a tool used to grasp or hold tissues or organs during surgery.
- Double-prong skin hooks: These are used to hold back the skin during surgery.
- Nerve hook: This is used to gently move nerves during surgery.
- Fine-tipped and regular hemostats or Schnidt tonsil clamps: These are used to control bleeding during surgery.
- McCabe dissector: This is a tool used to separate tissues and organs during surgery.
- Allis clamps: These are used to grasp or hold tissues during surgery.
- Scissors: These are used to cut tissues during surgery.
- Sutures for vessel ligation: These are special stitches used to tie off blood vessels.
- Suture and/or staples for closure: These are used to close the surgical incision after the operation is completed.
Who is needed to perform Radical Neck Dissection?
The team performing the surgery should at least comprise of four key individuals. These include an anesthetist who is responsible for putting you to sleep and monitoring your vital signs during the operation, a circulating nurse who helps in coordinating the operation and ensuring everything is in place, a surgical technologist who assists the surgeon with the operation, and of course, the operating surgeon who conducts the actual surgery on you. If possible, a surgical assistant is also recommended to support the surgeon during the operation.
Preparing for Radical Neck Dissection
Before undergoing surgery, every patient needs to be examined by a medical specialist who provides anesthesia, the medication that makes you sleep during surgery. If a patient has heart problems or multiple health issues, they may need to get approval from their regular doctor before receiving anesthesia.
If a patient is taking blood-thinning medication, their doctor must have a plan to manage this medication around the time of the surgery. This is to reduce the risk of excessive bleeding during and after the procedure.
If a patient has a condition or a past treatment such as previous radiation or neck surgery that could block their airways, extra precautions may need to be taken. These patients may require a special procedure where a small, flexible tube is inserted into the airway to help with breathing. This is done while the patient is awake and is coordinated with the anesthesiologist.
Patients who are being treated for cancer need to complete a number of tests before surgery. These include a biopsy, which is a test where a small piece of tissue is removed and checked for cancer. They also need imaging scans of their head and neck and either a PET-CT or chest CT scan. PET and CT scans are special types of X-rays that can help show if the cancer has spread to other parts of the body. These tests are important in helping doctors understand more about the stage and spread of the cancer, which helps guide the treatment plan.
How is Radical Neck Dissection performed
Procedure for Preparation: The patient lays flat on their back on the bed. The bed is then rotated to allow the doctor full access to the patient’s head and neck from either side. A special roll under the shoulders might be used to stretch the neck. It’s crucial that the head should not hang off the bed and must be supported to prevent any neck injury.
Surgical Process for Radical Neck Dissection:
There are a number of ways that the first incision, or cut, can be made, but one of the most common is the “hockey stick” incision. This incision starts at the point behind your ear (the mastoid tip) and goes down, then curves towards the middle of your neck. This creates a “Y” shape and can help the surgeon access the lower and rear parts of the neck.
The doctor then lifts the skin flaps from the jawbone to the collar bone. The front flaps should be raised to the outside border of the strap-like neck muscles while making sure to avoid the tube-like structure that’s been placed for breathing. The back flaps should be raised to the front border of the trapezius muscle that runs down your neck and upper back. The skin flaps are then retracted or pulled back using sutures or elastic supports.
Following that, the doctor identifies the sterno muscles, one of the major muscles in the neck, and divides the fascia- a sheet of connective tissue that surrounds the muscle. They then identify the carotid sheath, a packet of major neck arteries and veins, which lies deep within the muscle. They then separate the sternocleidomastoid muscle, known also as the SCM muscle, which runs from the back of the ear to the collar bone, into two parts.
They then ligate, or tie-off, the bottom end of the jugular vein, one of the major veins in the neck, while making sure to not include any other important vessels or nerves. After that, the doctor rolls superiorly, or upwards, the sternocleidomastoid muscle and the jugular vein. This will help the doctor to access the supraclavicular lymph nodes, which help fight infections, and the floor of the neck.
The patient then undergoes careful dissection through the lower part of the parotid gland, which is one of our saliva-producing glands, and then through the muscle at the top of the neck, near the ear. After this process, the wound is cleaned and surgical drains are placed. The wound is then closed in layers, these include the platysma, dermis, and skin.
Modified Radical Neck Dissection:
The ‘modified’ version of the neck dissection procedure involves the same incisions and lifting of the skin flaps as the first procedure mentioned. The process starts with making a cut into the sheath, or outer layer of the muscle, and proceeding deeper into the upper third part of the muscle to access a specific nerve. Once the nerve is identified, the doctor can lift and ‘roll’ all the fat and lymph nodes, carrying bacteria-fighting white blood cells, towards the mid part of the neck. Once at the carotid sheath, the packet of nodes and tissues is divided at the level of the collarbone.
After completing these procedures, the doctor then ligates any emerging branches of the jugular vein while lifting the remaining nodes and tissues upward to the level of the bone in the throat known as the hyoid.
Lastly, the doctor identifies and protects the facial nerve before lifting the ‘fascia’ or outer layer over the submandibular gland, a saliva-producing gland present in the lower part of the face. After the neck part is dissected, the neck is then irrigated, drains are placed and the wound is closed in a layered fashion.
Possible Complications of Radical Neck Dissection
During surgery, there can be potential issues, such as bleeding from major blood vessels, the formation of a chyle fistula (an abnormal connection that allows a milky fluid called lymph to leak into the body), collapsed lung (pneumothorax), and damage to several nerves. The spinal accessory nerve, which helps control movements in the shoulders and neck, is often at risk with a reported injury rate of 33% in certain neck surgeries, as shown by a recent study. Additionally, the marginal mandibular branch, a nerve that affects facial movements, can also be injured, with rates between 5% to 12%.
After surgery, complications are not common but can occur. These include the wound splitting open (wound dehiscence), the formation of an abnormal opening either on the skin or between the throat and skin (known as a percutaneous or pharyngocutaneous fistula), infection, a collection of blood within the wound (hematoma), the formation of a sialocele (a pocket of saliva that creates a swelling under the skin), and chyle fistula.
What Else Should I Know About Radical Neck Dissection?
Performing surgery on the neck, specifically known as a ‘radical neck dissection,’ is a reliable method to remove severe cancer in the neck area. This procedure affects the internal jugular vein (a major vein in the neck), the sternocleidomastoid muscle (a muscle running along both sides of the neck), and the eleventh cranial nerve (a nerve in the brain).
However, in order to reduce harmful side-effects, this surgery has been adjusted over time. For less severe cases, a less extensive version called ‘modified radical neck dissection’ is used. In some instances, ‘selective neck dissection’ is chosen, which involves removing fewer structures in the neck. Both of these alternatives have now taken the place of the traditional procedure.
