The Origins of Functional Neck Dissection

''If you think you have discovered something new, it is because you do not read enough.'' This popular statement summarizes the philosophy of most innovations in the field of science. The great contributions to human knowledge are always the result of a combination of previous research and personal experience. However, almost every important scientific discovery is linked to a person's name. Functional neck dissection must be associated with the name and the person of Osvaldo Sua rez.

It is true that from the very beginning it became evident to many that radical neck dissection was too aggressive in a large number of situations. Some surgeons like Truffert, Silvester Begnis, and others tried to modify what was considered to be the standard approach at that time, but their attempts were not fully successful. However, they laid the foundations on which future developments could be built. Osvaldo Sua rez must be credited as the person responsible for gathering the previous knowledge with his own experience—oncological and anatomical—into a new approach for the management of neck metastasis in patients with head and neck cancer. The result of this combination of background, experience, and surgical ability was called functional neck dissection.

Two different factors should be considered on functional neck dissection: (1) the spirit of the procedure and (2) its surgical technique.

The Spirit of Functional Neck Dissection

The main goal of the ''functional'' approach to neck dissection proposed by Sua rez is the removal of all lymphatic tissue in the neck, preserving the remaining neck structures. This is achieved by

Figure 1-1 Osvaldo Suarez signed this certificate, along with the remaining attendants, in recognition of the course on vestibular disorders given by C. Gaviian, MD, in Cordoba, Argentina (November 1968).

Figure 1-1 Osvaldo Suarez signed this certificate, along with the remaining attendants, in recognition of the course on vestibular disorders given by C. Gaviian, MD, in Cordoba, Argentina (November 1968).

using the fascial planes of the neck that surround most cervical structures and separating them from the adjacent lymphatic tissue (see Chapter 2).

As long as the tumor cells remain confined within the lymphatic system of the neck, they can be safely removed by carefully stripping the neck structures from their fascial covering. There is no oncological benefit from removing the sternocleidomastoid muscle, internal jugular vein, or any other important neck structure, when cancer is locked up inside a partially isolated lymphatic space. The situation changes when the lesion invades the walls of this anatomical container, fixing the nodes to surrounding structures. Then, the tumor is no longer a ''nodal cancer'' but becomes a ''neck cancer.'' This situation invalidates the ''functional'' spirit and justifies the use of a classic approach with removal of the involved neck structures.

Therefore, the spirit of functional neck dissection is to take advantage of the particular anatomy of the neck to remove all or part of the lymphatic system, with preservation of the remaining neck structures. The key words in this definition are all and part of. The spirit of functional neck dissection does not take into consideration the extension of the removal. Functional neck dissection only intends to use the fascial planes of the neck to carry the desired removal without disturbing the surrounding structures. It may include all the lymphatic tissue of the neck — all nodal regions — or only some selected groups, according to the expected incidence of cervical metastasis, the location and extent of the primary tumor, and the preferences of the surgeon. When the operation was adopted by American surgeons, these important words vanished, and the concept of functional neck dissection — the spirit of the procedure —was seriously affected.

For supraglottic cancer, Osvaldo Suarez never included in the resection the submental and submandibular lymph nodes (area I). Obviously, he also did not include the central compartment of the neck (area VI) for these lesions. However, he still considered this to be a functional neck dissection, as long as the main principle of dissecting through fascial planes was guiding the surgeon's hands.

It may be argued that preservation of some nodal groups requires cutting through the fibrofatty tissue that contains the lymphatic system of the neck, something that seems to be in contradiction with the basic principle of fascial dissection. This is only a theoretical concern with no practical implications, as has been proved by the results of the functional approach over the years. In fact, it must be remembered that nodal groups are only a schematic representation of the lymphatic system of the neck, which is really configured in different chains that follow the course of the major cervical vessels and nerves (see Chapter 2). Modified radical neck dissection with spinal accessory nerve preservation also requires sectioning the lymphatic container in the upper part of the neck to preserve the anatomical integrity of the nerve between the jugular foramen and the sternocleido-mastoid muscle. The theoretical drawbacks of this maneuver — cutting through lymphatic tissue and violating fascial barriers — have never been a problem with respect to oncological results, as long as its indications are carefully observed.

To summarize, the spirit of functional neck dissection may be compared with the philosophy of partial laryngectomy. Total laryngectomy goes against the organ and removes the whole larynx with the tumor that it contains, whereas partial laryngectomy is directed against the tumor and preserves the functioning part of the larynx that is not involved by the tumor. Both approaches have their own rationale, role, and indications, and neither can be considered to be a modification of the other. The same can be said of functional and radical neck dissection.

Surgical Technique of Functional Neck Dissection

We give special emphasis to the difference between the spirit (i.e., functional neck dissection as a concept), and the surgical technique (i.e., just one more operation). As a surgeon one can apply the spirit without the surgical technique and vice versa.

The technical details of the functional approach play a secondary role for the understanding of the procedure, although they have been given a major interest. Factors such as the extension of the operation, its technical difficulty, the time required to perform the procedure, and others have been the center of debate for many years. It is true that most of them deserve some attention, but, obviously, they are not the main issue.

Concerns about the extension of the operation have been discussed previously and will be emphasized in other chapters of this book. Technical difficulty is a relative problem. For those, like us, who have been trained in this operation since the very beginning of our professional careers, functional neck dissection is much easier than the classic radical operation. Why? Simply because we have performed many more functional operations than radical procedures. This demonstrates the relativity of the issue of difficulty. The same can be said about the idea of functional neck dissection as a time-consuming operation. Obviously, for the N0 neck it will take more time to perform a complete functional neck dissection than a radical operation. However, the time difference will also depend on the experience of the surgeon, and, again, those familiar with the functional operation will find the difference to be less important. This is not to mention the cosmetic, anatomical, and functional disadvantages of performing radical neck dissections in N0 necks —something that very few appropriately trained surgeons will still support today.

Another technical factor that Osvaldo Sua rez usually emphasized was the type of dissection performed (e.g., knife vs. blunt dissection). As an anatomist, he stressed the advantage of knife dissection over blunt dissection to follow the fascial planes of the neck. Some of us learned his lesson and still use the scalpel for most of the surgical steps in functional neck dissection. The technical details for a successful knife dissection along with some practical tips are given in the text.

The Functional Approach: Combination of Spirit and Technique

Applying the technical details of functional neck dissection without understanding the spirit of the procedure results in a large number of different operations, be they selective operations, modified procedures, limited neck dissections, or any other name that we would like to use. This is in part what happens with most neck dissection classifications currently used in the literature. On the other hand, understanding the spirit of the procedure but using wrong technical abilities produces a messy operation that is difficult to understand and teach. The operation will not look appealing and the observer will have the same feeling that we had back in 1968 when we saw the first film on functional neck dissection.

As for any other human activity, approaching perfection requires a balanced combination of ideas and skills. This is achieved only by putting together the technical details with the spirit of the procedure. This is what we call functional neck dissection.

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