6 Radical Neck Dissection Abstract Radical neck dissection was historically the standard of care for the management of cervical nodal metastases. A radical neck dissection includes the complete resection of all five levels of the cervical lymphatics, and additionally sacrifice of the spinal accessory nerve, sternocleidomastoid and the internal jugular vein. This procedure causes considerable morbidity, predominantly from shoulder dysfunction, and numerous studies have since demonstrated that the surgical preservation of non-invaded structures was oncologically sound. More recent modifications of neck dissection are now performed that selectively remove the lymph nodes in the anatomic levels that are at highest risk for harboring metastatic nodal disease while preserving key structures, and carry much less morbidity. The following chapter addresses the history, techniques, morbidity, post-operative considerations, and potential complications of a radical neck dissection. Keywords: radical, neck, dissection The initial concept of surgically removing cervical lymphatics en bloc represented a major conceptual advance in oncology. The first reports of removal of neck metastases came from independent efforts of four European surgeons: von Langenbeck, Billroth, von Volkmann, and Kocher.1 Later, Sir Henry Butlin demonstrated that surgically removing metastases from the neck for oral cavity cancer improved survival. In 1888, a Polish surgeon, Franciszek Jawdynski, reported on a procedure similar to a radical neck dissection (RND). Early surgeries resulted in serious complications and morbidity. In 1906, George Crile popularized the systematic en bloc RND2 that included the removal of all structures in the neck from the mandible to the clavicle, superficial to the deep muscles of the neck, except the carotid artery, brachial plexus and the vagal, lingual, and hypoglossal nerves. The specimen encompassed lymph nodes and fibrofatty tissue spanning levels I to V and includes the spinal accessory nerve (SAN), sternocleidomastoid muscle (SCM), and internal jugular vein (IJV). Recognizing that loss of these structures caused patients significant functional and cosmetic morbidity, Suarez modified the procedure in 1963 to preserve nonlymphatic structures when oncologically feasible. Bocca3 and Martin et al4 further refined the surgical procedure terming it a “functional neck dissection.” The adapted procedure became widely adopted as it became clear that this modification was both oncologically safe and imparted less morbidity to the patient by preserving structures that were uninvolved by disease. Since then, many retrospective studies have repeatedly demonstrated the oncologic safety in preserving these structures. Knowledge of lymphatic drainage patterns specific to neck dissection has led to further evolution of this procedure into what is today referred to as the modified RND and selective neck dissection. Although Crile’s neck dissection was initially the “gold standard neck dissection,” with modifications in the subsequent four decades following the initial description, it is now referred to as the RND. This term is appropriate because it is a radical removal of sites of metastatic spread to the neck, sacrificing the SAN, SCM, and IJV. However, it is rarely required today, except in cases of extensive disease, and the evolution of the procedure to less aggressive resection has greatly improved the postoperative quality of life for patients. Surgeons at Memorial Hospital first classified the cervical lymph nodes into levels and later Byers et al described the levels most at risk for spread based on the primary tumor site in the head and neck.5 When it became clear not all cervical lymphatics needed to be resected that an RND encompassed, surgeons modified the neck dissection to involve the lymphatics at highest risk for disease spread. Furthermore, the SAN, IJV, and SCM were preserved unless there was disease involvement. Because there were so many variations between lymphatic levels and structures sacrificed, the American Head and Neck Society (AHNS) standardized the terminology for classification of neck dissection in 1991 and there have been multiple revisions thereafter.6 Most recently, the AHNS defined the RND as a cervical lymphadenectomy including en bloc removal levels I to V, the IJV, SCM, SAN, and the submandibular gland.7 According to the AHNS classification, any neck dissection that preserves the three structures should be termed a “modified RND” and preserved structures should be stated when naming the procedure, an adaptation of Medina’s terminology for structures preserved published in 1989. Ferlito et al proposed a further modification to this terminology suggesting that each level and structure resected should be clarified, with an RND termed ND (I–V, SCM, IJV, and cranial nerve [CN] XI).8 Due to the rarity of patients requiring an RND and sacrifice of the SAN, SCM, and IJV, the “modified” RND is now the standard of care for most patients with metastatic nodal disease where one or more of these structures can be preserved. RND imparts considerable comorbidity to the patients and should be avoided when oncologically possible. The term “modified RND” refers to preservation of nonlymphatic structures, whereas the term “selective neck dissection” refers to preservation of levels of lymphatics. The standardization of terminology is important to communicate to other practitioners which levels were dissected and which structures were resected for postoperative management. Stating that a patient had an RND accurately transmits the idea of extensive or invasive metastatic nodal disease in the neck. The goal of curative oncologic surgery should be the complete removal of all neoplastic tissue. Surgeons must balance the oncologic advantages of RND against the morbidity it brings to the patient. An RND is now performed only when necessary due to the extent and growth pattern of the disease. In most cases, this is due to disease invading the SCM, IJV, and SAN. Uncommonly, an RND is performed due to direct spread of a primary tumor. Although neck dissections are not pathologically assessed for margins unless it is an en bloc resection of direct tumor spread, surgeons have applied the same reasoning that is used in tumor resection when resecting the lymphatics of the neck. That is, preferably, the disease will be surrounded by nondiseased (normal) tissue. In most dissections, this means the disease is within the capsule of the lymph node, but this is not typical of nodal disease in most cases requiring RND. However, in cases with extracapsular spread, the resection of adjacent structures such as SCM, IJV, and SAN may be required to get a “margin” around the disease, justifying the RND. Some have suggested that RND is appropriate routinely for N3 disease of the upper neck, invasion of the SAN, and/or recurrent or persistent disease following definitive radiotherapy, chemoradiotherapy, or previous selective neck dissection.9 Presumably, the recommendation of RND for all N3 diseases implies that a 6-cm metastasis would encompass the SAN and involve the SCM and IJV due to the confined anatomy of the neck and restricted space for spread. Such a global suggestion also likely stems from concerns that the posttreatment scarring may obscure tissue planes, making the clean removal of disease from the SAN, IJV, and SCM challenging. However, the specific relationships between disease and each anatomic structure in the neck should be better evaluated on a case-by-case basis, and adaptations and consideration of risks of involvement of each structure must be applied to each individual patient. It is possible that not all three structures (SAN, IJV, and SCM) implicit in RND need to be resected in every patient who has had a previous neck dissection or radiation. Regarding indications for RND, some patients may have such extensive disease that more extended resection is needed than a traditional RND. Surgery may necessitate resection of structures outside the scope of a typical RND, including the strap muscles, digastric, omohyoid, cervical rootlets, brachial plexus, hypoglossal nerve, facial nerve, phrenic nerve, carotid artery, the skull base, or deep muscles of the neck. Involvement of these structures, especially the carotid artery, portends a very poor prognosis and thus may call into question the goals of the operation. It is important to note not all cervical nodal disease may be surgically resectable. If disease may not be cleared even with extended RND, the morbidity of the surgery may not be justified. For example, if the carotid artery is involved and cannot be safely sacrificed or when sacrifice of the carotid is not guaranteed to remove all disease in the neck, it may be wiser to consider nonsurgical options including systemic therapy, radiation therapy, or entry into a clinical trial. Ultimately, the surgeon needs to discuss the options with the patients and tailor individualized treatment to each patient’s particular clinical situation. Documentation of arm and shoulder range of motion and strength should be made prior to surgery to assess SAN and brachial plexus function. Photos may aid in the preoperative counseling of the patient to set expectations for postoperative neck, shoulder, and arm function ( Patients should be counseled preoperatively about the possible morbidity of RND, but the decision to resect structures is sometimes made intraoperatively when assessment of resectability of the disease can be better assessed. As a general guideline, if a structure is not clearly involved by disease, and a clean resection can be achieved, then it should be structurally preserved. One example may be a metastasis that is immobile in preoperative clinical evaluation because it is adherent to the SCM. Intraoperatively, after the skin and platysmal flaps are raised and superior and inferior SCM attachments are released, the tumor may become more mobile. Tumor fixation to the SCM may make it seem immobile, but there may be tissue planes between the IJV and SAN that facilitate its removal, and allow preservation of these structures. Conversely, some neck dissections may require removal of parapharyngeal and paraspinal lymphatics that are not included in the levels I to V of the RND. CT or MRI images with intravenous contrast should be carefully evaluated to assess relationships between nodal disease and normal structures ( Fig. 6.1 Depressed right shoulder following radical neck dissection with resection of the spinal accessory nerve. Fig. 6.2 Axial MRI showing metastatic carcinoma invading the internal jugular vein, sternocleidomastoid muscle, and deep neck musculature.
6.1 History
6.2 Classification/Terminology
6.3 Indications for Radical Neck Dissection
6.4 Preoperative Counseling and Evaluation
Fig. 6.1). The patient should be counseled about potential postoperative morbidity and the need for rehabilitation prior to surgery. Expected contour changes to the neck, numbness, the expected incision line, and possible deficits of the particular CNs at risk should be reviewed. Other risks of surgery including bleeding, infection, chyle leak, carotid injury, stroke, nerve deficits, unresectable disease, and possible rapid recurrence despite surgery may be discussed. Postoperative morbidity intrinsic to the RND that is additional to the modified radial or selective neck dissection includes impaired shoulder and arm mobility, weakness, pain, cosmetic deformity, and lymphedema. In the rare case of bilateral IJV sacrifice, the patient must be counseled of the risk of potential facial and neck edema and decreased cerebral venous outflow. Counseling the patient preoperatively about the need for postoperative physical therapy may improve compliance with a postoperative rehabilitation program.
Fig. 6.2, 
Fig. 6.3, 
Fig. 6.4).
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