What is a radical neck surgery?

Neck Dissection Classification

The classification for neck dissection recommended by the AHNS is based on the following rationale: (1) that RND is the standard basic procedure for cervical lymphadenectomy, and all other procedures represent one or more modifications of this procedure; (2) when modification of the RND involves the preservation of one or more nonlymphatic structures, the procedure is called amodified radical neck dissection; (3) when the modification involves the preservation of one or more lymph node groups that are routinely removed in the RND, the procedure is called aselective neck dissection; and (4) when the modification involves the removal of additional lymph node groups or nonlymphatic structures relative to the RND, the procedure is called anextended radical neck dissection. This classification has been updated by the AHNS classification and is outlined inTable 118.3.9,34,35 This version includes modifications of the original classification in an effort to remain contemporary and to follow the current philosophy of lymph node metastases management. In a 2010 editorial,36 a joint international effort was carried out to improve the classification even further to facilitate its use and, hence, to ease its incorporation into everyday practice worldwide. It is based on the proposal by the Japanese Neck Dissection Study Group.37,38 The main changes in the proposal by the international group include use of the symbolND to represent the termneck dissection. A prefix is included to denote the side of the neck upon which the dissection has been performed usingL forleft andR forright. If bilateral, both sides must be classified independently. The second component of the description should be the neck levels and/or sublevels removed, each designated by the Roman numerals I through VII, in ascending order. The third component of the description is the nonlymphatic structures removed, and each is identified through the use of specified acronyms for the SCM, IJV, hypoglossal nerve (CN XII), SAN (CN XI), SAN, external carotid artery (ECA), ICA, CCA, facial nerve (CN VII), vagus nerve (CN X), sympathetic nerve chain (SN), phrenic nerve (PN), skin (SKN), parotid gland (PG), SG, and deep cervical muscles (DCM).36 Although this latest classification has the advantage of being more precise in denoting the extent and nature of almost any cervical lymphadenectomy performed, it remains to be seen whether it will gain widespread adoption and become the preferred method. One disadvantage of its use is the awkwardness in verbalizing the various subsets. A comparison of the two nomenclature systems is outlined inTable 118.4.

Of note is the existence of other classifications for neck dissections, such as the one for treating thyroid cancer. Different authors and organizations have suggested classifications based on anatomic and cancer distribution patterns typical for different thyroid cancers.38a-c Since the classification is a crucial step in cancer management including staging, surgery, nonsurgical treatments, prognostication and for proper communication between healthcare personal in different institutions and countries, there is a need for either familiarization of the different classification systems or adoption of a common system. We believe that the AHNS classification system has the advantage of being modular and can, therefore, be used to describe neck dissections done for different tumors and throughout management course, thereby avoiding confusion among healthcare providers and enabling accurate reporting and discussion.

CLASSIFICATION OF NECK DISSECTION

Neck dissections can be classified into one of three basic types: comprehensive, selective, and extended. Comprehensive neck dissections remove all of the nodes removed by the classic radical neck dissection and may preserve several or all of the nonnodal structures typically resected in radical neck dissection. In the past, modified neck dissection was identified by number. The current classification system notes the levels removed and the structures preserved (Fig. 78-11).

Selective neck dissections are designed to remove specific nodal groups. Which nodal groups are removed is dependent on the site and stage of the primary cancer. Although these procedures were initially used only for the elective management of the clinically negative neck, they are now used for removal of clinically involved nodes in selected cases. Clinical pathologic studies performed by Byers and colleagues 25 years ago provide the basis for the selection of specific nodal groups at highest risk for occult metastatic disease.13 The anterior (or supraomohyoid) neck dissection was designed to remove nodes in levels I to III and is characteristically used when cancer originates in the oral cavity. Levels II through IV are removed for primary cancer originating in the supraglottic larynx and hypopharynx. Levels II through V are removed in cases of cancer of the posterior scalp along with the suboccipital nodes under the trapezius muscle posterior to level V. As such, this “posterior lateral neck dissection” is a form of extended neck dissection even though nodes in level I are not resected.

Extended neck dissections such as paratracheal dissections may be performed for lesions likely to involve the nodes in level VI, primarily cancer involving the subglottic larynx and thyroid gland.

Neck Dissection and Laryngectomy

Neck dissection is commonly performed in isolation or during laryngectomy to prevent or treat any local spread of head and neck malignancy.168,169 The extent of a neck dissection operation is based on the extent to which the neck’s six lymph node levels are involved, as well as on the extent to which additional structures (spinal accessory nerve, internal jugular vein, and sternocleidomastoid muscle) are removed. Depending on the degree to which the tumor can be removed and recurrence or spread can be prevented, as well as the extent that phonation and swallowing can be preserved, various surgical options are exercised. Limited disease is sometimes managed by radiation, by laser and microsurgery, or by partial laryngectomy, thus preserving organ function. In total laryngectomy, the larynx is removed in its entirety, with the airway ending in a stoma formed by bringing the cut end of the trachea to the neck surface (with the result that the trachea now becomes independent of the esophagus.) Often a perforation between the trachea and the esophagus (tracheoesophageal puncture) is made to allow eventual placement of a voice prosthesis.170 In some cases the procedure is supplemented with microvascular free tissue transfer (free flap).

Anesthesia can be induced through a standard intravenous line, followed by large-bore intravenous and arterial lines placed after induction. A central line can usually be avoided, with systolic pressure variation of the arterial line tracing and other clinical findings to guide fluid replacement. Although nerve function monitoring is usually required during the neck dissection phase, neuromuscular blockade is acceptable at the beginning. When neuromuscular blockade is no longer desirable, opioid infusions (e.g., remifentanil) are often used to maintain adequate analgesia in conjunction with an inhaled anesthetic agent. Many clinicians prefer using a balanced technique in preference to deep inhalational anesthesia or TIVA (propofol with or without remifentanil) to avoid the troublesome hypotension. Excessive intravenous crystalloid administration should be avoided to prevent operative site edema.

In total laryngectomy cases, a tracheostomy is customarily performed near the beginning of the procedure by using a wire-reinforced ETT placed into the stoma. (Warning: accidental endobronchial intubation commonly occurs in this setting.) In some cases, the patient is turned 180 degrees from the anesthesia machine; care must be taken to ensure that nothing is disconnected in the process. Extubation in such cases is extraordinarily simple; the ETT should be removed from the stoma when extubation criteria are met. Should reintubation ever become necessary, one merely reintroduces the tracheal tube into the stoma. The patient is then simply brought to the postanesthesia care unit with an oxygen mask placed over the stoma, although when a free flap has been performed, the patient is often brought to the ICU intubated, ventilated, and sedated (depending on the surgeon’s preferences and local protocols.)

The Goals of the Neck Dissection

The classical goal of a lymph node dissection is to “eradicate all metastatic disease.” With the evolution of approaches in head and neck cancer, this goal has expanded over the years. Originally, the procedure was a first-line treatment and it was intended to cure the patient of clinically metastatic cancer; and in such a way, it is a therapeutic operation.

A different goal of neck dissection is the dissection of persistent nodal disease after chemoradiation. The concept of performing a lymphadenectomy after induction chemotherapy or radiotherapy was already introduced in the second half of the last century, but it was never adopted widely due to severe surgical complications. It was also feared that postponing definitive therapy would have a negative impact on prognosis. With the introduction of organ preservation protocols in the 1990s, patients with locally advanced disease would undergo definitive irradiation in combination with cisplatin-based chemotherapy followed by a staged modified neck dissection. Later on, it was demonstrated that dissection of the involved lymph nodes only was equally effective and safer.11

Head and neck oncologists were also confronted with the question of how to deal with non-detectable or occult metastasis. One of the solutions that emerged was the diagnostic or elective neck dissection. In this approach, all or only those levels at risk are dissected; and if the presence of tumor-positive nodes is confirmed by histopathology, the patient will benefit from adjuvant radiotherapy. If nodal metastasis can be excluded, no further therapy will be necessary. A next step in development was the sentinel node concept. Here, a radioactive tracer substance is injected around the tumor bed, and the draining lymph node(s) are identified by lymphoscintigraphy. In the following surgical procedure, these node(s) are removed, which is often aided by a gamma probe or fluorescence, and sent in for histopathology. When one or more nodes are identified as positive, the patient may be advised to undergo a completion neck dissection, with or without postoperative irradiation.

The sentinel node concept is most suitable for primary tumors that are easily injectable. In the head and neck area, it is most widely applied to cutaneous melanoma and early-stage carcinomas arising in the oral cavity. The procedure is applied if the patient is staged N0 after imaging and, preferably also after ultrasound guided cytology. Although this modality has not been used widely in tumors of the oral cavity, its sensitivity and specificity is impressive.13 Prospective studies are needed to evaluate the impact of the sentinel node concept on survival compared to elective neck dissection.

The goal of neck dissection may be defined in two ways: it is either a therapeutic or a diagnostic procedure.

Neck Dissection

Neck dissection is frequently used to address OP malignancies. The extent of dissection is variable depending on the tumor pathology, location, and extent of disease and is discussed elsewhere in this text. However, details pertinent to transoral resection of OP neoplasms will be reviewed here. Issues to consider in relation to transoral resection are timing, vascular control, and development of an orocervical communication or pharyngocutaneous fistula.

Neck dissection can be performed either at the time of transoral tumor resection or after several weeks have passed to allow for healing. Delayed neck dissection may offer the surgeon a second chance to address delayed positive surgical margins; it may decrease the need for tracheostomy, because laryngopharyngeal swelling will be less; and it avoids creating a communication between the oropharynx and neck.79 For these reasons, Weinstein and colleagues65 recommend a delay of 1 to 3 weeks between primary resection and neck dissection. However, simultaneous neck dissection exposes the patient to a single anesthetic, requires a single hospitalization, provides important information for staging, and does not delay adjuvant therapy, which is normally started within 3 to 4 weeks following primary surgical intervention.79

As discussed earlier, if the relationship between the carotid artery and the tumor extent, especially in tonsillar tumors, is unclear preoperatively, it is prudent to perform a neck dissection prior to transoral resection. In this way the surgeon can identify and control the vasculature. A cotton pad can be placed between the carotid artery and oropharynx to protect the great vessels from inadvertent injury during primary tumor removal. Whereas the complications associated with transoral OP surgery are certainly less than those for open surgical approaches, postoperative bleeding can be serious and potentially life threatening. For this reason, Salassa and colleagues recommend tying off the entire external carotid system for large pharyngeal defects with exposure of named arteries.74 For moderate pharyngeal defects the surgeon should ligate the lingual, facial, and possibly the superior laryngeal arteries depending on their relative risk (RR) for exposure in the specific defect. Regardless, both approaches necessitate neck dissection at the time of tumor removal.

Finally, whereas the risk of communication between the oropharynx and neck is higher during concomitant neck dissection, persistent pharyngocutaneous fistulae are rare.80,81 In a retrospective study of 148 consecutive patients who underwent TORS and neck dissection, orocervical communication was identified intraoperatively in 28% (42/148), and a resultant pharyngocutaneous fistula was reported in just 4% (6/148).79 In order to identify all orocervical communications, the oropharynx should be rigorously irrigated with sterile saline. The goal is to see the pharynx “bulge” into the neck without a fluid leak. If a leak is identified, it should be repaired intraoperatively. For communications smaller than 1 cm, primary closure can be performed, followed by application of Tisseel (Baxter Bioscience, Deerfield, IL) on the cervical side. A suction drain should be placed in the neck and removed once drain output is less than 10 mL in 24 hours. Patients can be started on a clear liquid diet on postoperative day 1. For communications greater than 1 cm, Moore and associates recommend primary closure if feasible and local muscle coverage with the submandibular gland, mylohyoid, digastric, or sternocleidomastoid muscles, followed by Tisseel applied over this repair in the neck.79,81 In these patients, a suction drain is left with similar drain parameters, a nasogastric feeding tube is placed, and the patient is kept strictly nothing by mouth (NPO) for the first 24 to 48 hours; they are then slowly advanced to a clear liquid diet and ultimately to a regular diet, if no leak is identified.

Treatment

Treatment of SCCa of the tongue begins with a complete history and physical examination, including nasopharyngoscopy. This is followed by appropriate tests, including CBC with differentials, electrolytes, liver function tests, chest radiographs, and CT with contrast. The role of PET scanning for occult metastasis continues to evolve.

The treatment of SCCa is site specific; surgical ablation with minimum 1 to 1.5-cm margins is the main modality of treatment. Most oral cavity tumors are approached intraorally; however, some tumors may need to be accessed extraorally via a transfacial approach. When the tumor is located in the mandible, the inferior border can be preserved (marginal mandibulectomy), depending on the degree of infiltration. However, when the cancellous portion of the mandible is invaded, segmental resection is required to maintain oncologic safety.

A common procedure that accompanies the removal of the tumor is the removal of the fibrofatty contents of the neck, for treatment of cervical lymphatic metastases and for complete staging of the cancerous process (see the section Neck Dissections later in this chapter).

Reconstruction and rehabilitation. Depending on the defect, the reconstructive surgery can be divided into soft tissue and/or bony reconstruction. Closing the defect primarily is ideal if it can be accomplished. Soft tissue surgical procedures include closure by secondary intention, skin grafts, local flaps, or microvascular free flaps. Simultaneous bony reconstruction can be accomplished using vascularized free flaps from the iliac crest, scapula, or fibula when needed. When large ablative and reconstructive procedures are performed, they can be performed simultaneously (see Chapter 12). Depending on the amount of healing and dysfunction anticipated, a percutaneous endoscopic gastrostomy tube and elective tracheostomy can be performed to secure the airway and aid in the nutritional support of the patient during the postoperative period.

Radiation therapy. Radiation therapy can be used as a primary or an adjuvant therapy. Primary radiotherapy is usually reserved for patients with significant comorbidities or when the primary tumor or the patient is not amenable to surgery. This is not a primary indication for early-stage SCCa because of the associated morbidity, including dysphagia and xerostomia. Another significant risk is the development of metachronous lesions after radiation therapy.

Postoperative radiation therapy is commonly used as a part of the comprehensive treatment. The indications for its use include positive or near margins, significant perineural or perivascular invasion, bone involvement, multiple nodal involvement, extracapsular spread, or stage III or stage IV disease. Typically, about 6,000 cGy in divided doses is administered, and treatment is initiated soon after healing from the initial surgery is complete. Surgery combined with radiation therapy and chemotherapy has increased the 5-year survival rates for stage III and stage IV cancers by 10%.

In the current patient, a right partial glossectomy via a transoral approach was performed with 1.5-cm margins. The status of the margins was evaluated using frozen section microscopy, which demonstrated negative margins. An ipsilateral supraomohyoid neck dissection (levels I through III) was completed for staging, which revealed no positive lymph nodes. The tongue defect was reconstructed with a radial forearm free flap, anastomosing with the facial artery and vein. An elective tracheostomy was performed.

After complete healing, the patient was followed closely for signs of recurrence (85% of recurrences occur in the first 3 years after initial treatment).

6 What are the differences among radical, modified radical, and selective neck dissections?

Radical neck dissection, or cervical lymphadenectomy, consists of cervical dissection with removal of the sternocleidomastoid muscle, omohyoid muscle, internal jugular vein, spinal accessory nerve, cervical plexus nerves, submandibular salivary gland, tail of parotid gland, and all intervening lymphoareolar tissue containing lymph nodes (described as nodal levels I through V). The principal indication for radical neck dissection is surgical management of bulky (N2 or greater) cervical nodal metastasis. However, given the evolution of neck dissection to more function-sparing yet oncologically sound operations, this procedure is not used that often in contemporary practice. Furthermore, the radical neck dissection is not indicated in the absence of palpable cervical metastasis (Fig. 54-2).

Modified radical neck dissection removes all of the same lymph node groups as the radical neck dissection but spares at least one of the nonlymphatic structures removed with the radical neck dissection such as the sternocleidomastoid, accessory nerve, or internal jugular vein (Fig. 54-3).

Selective neck dissection removes the cervical lymph nodes considered to be at high risk for metastasis from a given primary site. Selective neck dissections are generally performed on an elective basis. Rather than use specific names for a particular neck dissection, it has become standard practice to call the neck dissection performed according to the levels of the neck dissected and the nonlymphatic structures resected. Thus a modified radical neck dissection type I should be called a selective neck dissection of levels I through V with resection of the sternocleidomastoid muscle and the internal jugular vein.

Classification

Neck dissections are classified primarily based on which lymph node groups of the neck are removed and secondarily on the anatomic structures that may be preserved, such as the spinal accessory nerve, the sternocleidomastoid muscle, and the internal jugular vein. Neck dissections are divided into four categories: radical, modified radical, selective, and extended (Table 11.10).371,372

The radical neck dissection consists of removal of all five lymph node groups of one side of the neck (levels I–V). This includes removal of the sternocleidomastoid muscle, the internal jugular vein, and the spinal accessory nerve. The modified radical neck dissection refers to excision of all lymph nodes routinely removed by radical neck dissection, with preservation of one or more of the nonlymphatic structures (i.e., spinal accessory nerve, internal jugular vein, sternocleidomastoid muscle) routinely removed in radical neck dissection. The Committee recommends that the structure(s) preserved be specifically named, for example, modified radical neck dissection with preservation of the spinal accessory nerve.372

An SND is any type of cervical lymphadenectomy in which one or more of the lymph node groups that are routinely removed in a radical neck dissection is preserved. Which lymph node groups are removed is based on the pattern of metastases, which is predictable relative to the primary site of disease.343 The four subtypes of SND are supraomohyoid, posterolateral, lateral, and anterior neck dissection. The revised classification no longer uses these names, except in the description of specific lymph node levels. Each variant is depicted by SND and the use of brackets to denote the levels or sublevels removed, for example, SND (I–III), SND (II–IV), or SND (VI; see Table 11.10).372 The term extended radical neck dissection refers to a neck dissection that is extended to include either lymph node groups or nonlymphatic structures that are not routinely removed in a standard radical neck dissection. An adequate neck dissection typically will include 15 or more lymph nodes in a previously untreated patient.

Classification of Neck Dissections

Robbins and co-workers defined a classification system outlining the various types of neck dissection.7

Radical Neck Dissection

Radical neck dissection (RND), first described by Crile in 1906,17 is a block resection of all regional lymph nodes, including those in the internal jugular vein, sternocleidomastoid muscle, and spinal accessory nerve. RND does not include the removal of periparotid, occipital, retropharyngeal, or midline visceral nodes. This operative procedure has significant long-term morbidity, including cosmetic deformity, shoulder dysfunction, chronic neck and shoulder pain, cutaneous paresthesia, neck asymmetry, and edema. RND is reserved for patients with advanced head and neck cancer.