Functional neck dissection: The Latin approach

Functional neck dissection: The Latin approach

Operative Techniques in Otolaryngology (2004) 15, 168-175 Functional neck dissection: the Latin approach Javier Gavilán, MD, Jesús Herranz, MD, Lourd...

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Operative Techniques in Otolaryngology (2004) 15, 168-175

Functional neck dissection: the Latin approach Javier Gavilán, MD, Jesús Herranz, MD, Lourdes Martín, MD From the Department of Otorhinolaryngology, La Paz University Hospital, Madrid, Spain. Functional neck dissection (FND) was first described by Suárez in the early 1960s.1 Although the operation has been called “modified radical neck dissection,” FND is not a modification of the operation described by Crile in 1906.2 because its anatomic and surgical principles are not derived from those of the Crile operation. FND is based on specific anatomic concepts regarding the relationship between the lymphatic structures and the fascial system of the neck. The terminological difference may appear irrelevant from a practical standpoint but it is crucial to understand the rationale and surgical technique of the procedure.3

Rationale and anatomical basis The anatomical description of the fascial layers of the neck has suffered a number of different descriptions. For practical reasons, we will consider 2 distinct fascial layers in the neck, the superficial cervical fascia, and the deep cervical fascia. The superficial cervical fascia corresponds to the subcutaneous tissue. The deep cervical fascia is the key element for functional neck dissection because it surrounds the neck enveloping different structures. For teaching purposes 2 different layers are considered within the deep cervical fascia: a superficial and a deep or prevertebral layer (Figure 1). The superficial layer of the deep cervical fascia, also known as investing or anterior fascia, completely envelops the neck with the exception of the skin, platysma muscle, and superficial fascia. From posterior to anterior, the superficial layer splits to enclose the trapezius, the portion of the omohyoid muscle that crosses the posterior triangle of the neck, and the sternocleidomastoid muscle. In a similar way it envelops the strap muscles, before ending in the midline. The deep or prevertebral layer, like the superficial layer, attaches posteriorly at the spinous process of the cervical vertebrae and ligamentum nuchae. This fascial layer covers the splenius, levator scapulae and scalene muscles, reaching the transverse process of the vertebral bodies. From here, it crosses the midline were it attaches to the transverse process of the cervical vertebrae of the opposite side, passing posAddress reprint requests and correspondence: Javier Gavilán, MD, Servicio de ORL, Hospital Universitario La Paz, Paseo de la Castellana, 261, 28046, Madrid, Spain. E-mail address: [email protected]

1043-1810/$ -see front matter © 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.otot.2004.07.007

terior to the esophagus and anterior to the spine. Is this prevertebral part that gives its name to this fascial layer. The space between the sternothyroid and the anterior scalene muscles is filled by the carotid sheath (Figure 1). This vascular sheath runs from the base of the skull to the root of the neck. It has independent compartments for the internal jugular vein, the carotid artery, the vagus nerve, and the ansa cervicalis. It attaches to the prevertebral layer at the level of the anterior scalene muscle. The cervical portion of the sympathetic trunk runs posterior to the carotid sheath. Fascial compartmentalization allows the removal of cervical lymphatic tissue by separating and removing the fascial walls of these “containers” along with their contents from the underlying vascular, glandular, neural, and muscular structures.

Indications and limitations To be safe, functional neck surgery requires all metastatic disease to be confined within the lymphatic tissue. Thus, this approach is ideal for N0 patients with a high risk of occult metastasis. An additional advantage of functional neck dissection is that it may be performed simultaneously on both sides of the neck without increasing morbidity. In patients with small palpable nodes, FND is still a valid option as long as some principles are carefully observed. The nodes should not be greater than 2.5 to 3 cm in greatest diameter. This is justified by the need to have all metastatic disease confined within the lymph node capsule. Although extracapsular spread is possible in lymph nodes of all sizes, it is well known that extracapsular spread increases with increasing lymph node size. Gross extracapsular extension results in lymph node fixation to contiguous structures. Therefore, lymph node mobility must be carefully assessed before surgery. This is even more important than the absolute size in centimeters because small nodes may be fixed, thus preventing a functional approach in these cases. In no instance FND should be attempted in patients with fixed nodes. If at surgery there is any doubt about the feasibility of the functional operation, the suspicious structure must be removed with the specimen. Cancer cells cannot be pursued with a scalpel and surgical demonstrations of “technical expertise” are unacceptable in cancer patients and must be reserved to the dissection room.

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Figure 1 Horizontal cross-section of the neck at the level of the fifth cervical vertebra. The superficial layer of the deep cervical fascia is represented by a solid black line, the prevertebral layer by a dashed line, and the carotid sheath by a dotted line.

169 ication and prophylactic antibiotics are used according to the usual protocol. The patient’s neck and upper chest are shaved and prepared for the operation. We do not use routinely infiltration of local anesthetics. The operation is performed under general endotracheal anesthesia, with the patient in the supine position and the neck fully extended. Elevating the upper half of the operating table to approximately 30° will decrease the amount of bleeding during surgery. We strongly recommend that one perform most steps of the operation using knife dissection. The fascial planes of the neck are mainly avascular and can be easily followed with the scalpel. For knife dissection to be really effective the tissue must be under traction. An important task of the assistants throughout the operation is to apply adequate pressure to the dissected tissue.

Incision and flaps The number of palpable nodes is not a contraindication for FND as long as all nodes fulfill the previously mentioned criteria. The same can be said with respect to the location of the primary tumor. Functional neck dissection is as safe for supraglottic tumor as it is for piriform sinus cancer, as long as the indications are carefully followed in both situations. By definition, FND is not possible in patients previously treated with radiotherapy or other types of neck surgery. In these patients the fascial planes have disappeared as a consequence of the previous treatment. Thus, fascial dissection is not possible anymore. Is in these cases where the concept of “modified radical neck dissection” appears as an alternative to radical neck dissection to preserve structures not involved by the tumor. The dissection will be made according to the basic principles of radical neck dissection, but preservation of uninvolved neck structures will be accomplished according to the surgical scenario. This is a clear example that illustrates the difference between functional and modified radical neck dissection.3

Surgical technique This article describes the surgical technique for a complete functional approach to the neck in which all cervical nodal groups are removed. For teaching purposes, the surgical steps are sequentially detailed. However, not every single surgical step of those mentioned below must be considered mandatory for every malignant head and neck tumor. The surgeon must be able to decide, according to the location of the primary tumor and his or her own personal experience, what nodal groups should be included in the dissection and which can be preserved, and then proceed accordingly skipping the surgical steps which are not considered necessary.

Preoperative preparation and operating room setup The patient should be prepared as for any major operation. All routine laboratory tests must be performed, including ECG and chest radiographs. The anesthesiologist performs a preoperative evaluation before surgery. Premed-

The exact location and type of skin incision will depend on the site of the primary tumor and whether a unilateral or bilateral neck dissection is planned. A popular incision in our practice is the classic Gluck incision—which is basically an apron flap incision. A vertical posterolateral arm may be used to approach the supraclavicular area when needed. For a bilateral functional neck dissection the incision extends between both mastoid tips, crossing the midline at the level of the cricoid arch. This incision allows good exposure when the neck dissection is to be combined with total or partial laryngectomy. When the operation includes a total laryngectomy the tracheostomy is usually incorporated in the incision. On the other hand, for partial laryngectomies and other tumors requiring temporary tracheostomy a small independent horizontal incision is made at the level of the second tracheal ring for the tracheostomy. Other incisions that can be used for FND are the double-Y incision of Martin, the single-Y incision, the Schobinger flap, the Conley modification of the Schobinger flap, the Mac Fee parallel transverse incision, or the H incision. Many other skin incisions may be used depending on the clinical characteristics of the lesion and the personal preference of the surgeon. After the incision is completed, the skin flaps are elevated deep to the platysma muscle, preserving the superficial layer of the cervical fascia. The limits for a complete functional neck dissection are similar to those of the classic radical neck dissection (Figure 2).

Dissection of the sternocleidomastoid muscle The goal of this maneuver is to completely unwrap the muscle from its surrounding fascia. Before approaching the fascia of the sternocleidomastoid muscle, the external jugular vein must be ligated and divided. The dissection of the sternocleidomastoid muscle (Figure 3) begins with a longitudinal incision over the fascia, along the entire length of the muscle. This cut is made with a number 10 knife blade and must be placed near the posterior border of the muscle. Using several hemostats the fascia is retracted medially while the surgeon carries the dissection toward the anterior

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Operative Techniques in Otolaryngology, Vol 15, No 3, September 2004 muscle, to meet the anterior dissection. This maneuver completely releases the muscle from its surrounding fascia. Including the posterior triangle of the neck in the field of dissection requires a combined approach, both posterior and anterior to the sternocleidomastoid muscle (Figure 4). In the upper half of the neck (above Erb=s point) the dissection is performed anterior to the sternocleidomastoid muscle, whereas in the lower half of the neck (below Erb=s point) the dissection is performed posterior to the sternocleidomastoid muscle. The tissue dissected from the lower half of the neck (supraclavicular fossa) will then be passed beneath the sternocleidomastoid muscle to join the main part of the specimen.

Dissection of the sumandibular fossa

Figure 2 Boundaries of a complete functional neck dissection on the right side of the neck. (1) midline, (2) inferior border of the mandible, (3) clavicle, and (4) trapezius muscle. Shinning through the fascia, the following structures are visible: (5) great auricular nerve, (6) sternocleidomastoid muscle, (7) strap muscles, (8) platysma muscle, (9) external jugular vein, (10) anterior jugular vein, and (11) submandibular gland.

margin of the muscle. Fascial retraction should be performed with extreme care since the thin superficial layer of the cervical fascia is the only tissue now included in the specimen. When the dissection reaches the anterior border of the sternocleidomastoid muscle the muscle is retracted posteriorly to continue the dissection over its medial face. As the deep medial face of the muscle is approached, small perforating vessels are found entering the muscle through the fascia. The assistant must now cauterize the vessels while the surgeon continues the dissection over the entire medial surface of the sternocleidomastoid muscle. The surgeon must be extremely careful at the upper half of this region, where the spinal accessory nerve enters the muscle, approximately at the junction of the upper and middle third of the muscle. The transverse process of the atlas serves as a useful anatomic landmark. After all the small vessels entering the sternocleidomastoid muscle have been cauterized a new avascular fascial plane is entered and the dissection continues posteriorly along the entire length of the muscle. The internal jugular vein can now be seen through the fascia of the carotid sheath. Wet surgical sponges are now introduced in the lower half of the sternocleidomastoid muscle, between the muscle and its dissected fascia to serve as a reference for the dissection of the fascia that still covers the posterior border of the sternocleidomastoid muscle. This fascia must be dissected posteriorly and slightly medially underneath the

Removal of the submental and submandibular lymph nodes (area I) comes next (Figure 5). From a technical standpoint, this maneuver may be accomplished without removing the submandibular gland. In fact, preservation of the submandibular gland was originally described by Osvaldo Suárez as one of the advantages of the functional approach to the neck. However, the surgical treatment of most primary tumors that require the inclusion of level I as part of the dissection, also requires the removal of the submandibular gland. On the other hand, those tumors in which the submandibular gland may be preserved without compromising the oncologic safety of the operation—such as cancer of the larynx, hypopharynx, or thyroid gland— usually do not require the dissection of level I. Thus, to avoid centering the controversy where it is less necessary, the following description will present the surgical details of

Figure 3 The sternocleidomastoid muscle is completely released from its fascia. The internal jugular vein (1) is still covered by the carotid sheath. The spinal accessory nerve (2) is identified as it enters the sternocleidomastoid muscle.

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Figure 4 Schematic view of the approach to the neck for a complete functional neck dissection. Above Erb’s point (ⴱ), the operation is performed anterior to the sternocleidomastoid muscle. The lower part of the posterior triangle (supraclavicular fossa) is approached posterior to the sternocleidomastoid muscle.

submandibular and submental lymph node removal including the resection of the submandibular gland. A fascial incision is performed along the upper boundary of the surgical field, from the midline to the tail of the parotid gland, preserving the marginal mandibular branch of the facial nerve. The nerve runs superficially in the submandibular gland fascia and its identification is usually tedious and unnecessary. Safe preservation of this branch of the facial nerve may be accomplished by using the facial vein as a landmark. After identification of the facial vein at the lower border of the submandibular gland, the vein is ligated and divided. The distal ligature is left long and reflected superiorly with a hemostat over the body of the mandible. This maneuver protects the marginal mandibular branch of the facial nerve from the dissection that follows. The submandibular gland is now dissected. The facial artery is ligated and divided thus freeing the superior border of the gland. At the anterosuperior border of the gland, the lingual nerve must be identified. This is accomplished by retracting the mylohyoid muscle medially and the submandibular gland in a posteroinferior direction. In so doing, the submandibular ganglion and its accompanying vein will bring the lingual nerve into the field. A hemostat is placed across the submandibular ganglion and vein, and both structures are ligated and divided. This frees the lingual nerve, which retracts superiorly, out of the field. The submandibular duct is identified inferior to the lingual nerve. After it has been ligated and divided, the gland is retracted inferiorly to identify the genioglossus and hyoglossal muscles. The dissection is continued inferiorly on the medial side of the submandibular gland to identify the digastric muscle and the

171 proximal end of the facial artery. The artery is ligated again immediately above the digastric muscle. The hypoglossal nerve is identified coursing in an anterosuperior direction just above and medial to the anterior belly of the digastric muscle. This completely frees the submandibular gland which is included in the specimen along with the fibrofatty tissue containing the lymph nodes from area I. The specimen is reflected inferiorly and the fascia over the digastric and stylohyoid muscles is incised from the midline to the tail of the parotid gland. Following the posterior belly of the digastric muscle the stylomandibular ligament is transected. At this level, the retromandibular vein, the posterior auricular vein and the external jugular vein are identified, ligated and divided according to their anatomical distribution. Depending on the lower extension of the tail of the parotid gland, part of the gland may also be included in the resection. This will facilitate the visualization of the upper jugular nodes as well as include in the specimen the infraparotid lymph nodes. The digastric and stylohyoid muscles are retracted superiorly exposing the hypoglossal nerve as well as the lingual veins that follow and cross the nerve in this area. The lingual veins should be carefully ligated since they may be a source of troublesome bleeding. When bleeding occurs in this area, bipolar coagulation may be used instead of clamps and ligatures to avoid injury to the hypoglossal nerve. The dissected tissue is finally pulled inferiorly and dissected free from the subdigastric and upper jugular spaces. At this moment, the specimen includes the submandibular and submental lymph nodes (area I), the uppermost jugular nodes (upper part of area II), and (optionally) the submandibular gland.

Figure 5 Dissection of the submandibular fossa. The anterior facial vein (1) has been ligated and the superior ligature is turned upwards to protect the marginal mandibular branch of the facial nerve. The stylohyoid (2) and digastric (3) muscles are retracted superiorly. The submandibular gland (4), along with the contents of the submandibular fossa (5), is dissected inferiorly, preserving the hypoglossal nerve (6). The sternocleidomastoid muscle (7) is retracted laterally, exposing the spinal accessory nerve (8) as it crosses the anterior wall of the internal jugular vein (9).

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Operative Techniques in Otolaryngology, Vol 15, No 3, September 2004 nerve maneuver.” Finally, a number 10 scalpel blade is used to make an incision into the tissue located below the entrance of the spinal accessory nerve into the sternocleidomastoid muscle. This cut is made just anterior to the sternocleidomastoid muscle and goes down to the level of Erb’s point following the medial border of the sternocleidomastoid muscle. The underlying levator scapulae muscle is identified and the tissue is slightly dissected forward and medially over its fascia. The rest of the dissection in this area will be completed later.

Dissection of the posterior triangle of the neck

Figure 6 Spinal accessory nerve maneuver. The tissue lying posterior and superior to the proximal part of the spinal accessory nerve is dissected inferiorly from the deep muscles of the neck (4). The tissue is then passed beneath the spinal accessory nerve (2) to meet the rest of the dissection. The sternocleidomastoid muscle (3) is retracted posteriorly and the internal jugular vein (1) is identified as it crosses the spinal accessory nerve.

The supraclavicular fossa constitutes the lower part of area V. The need to include this area in the dissection has become a controversial issues concerning FND. We remind the reader that this controversy is beyond the scope of this article. To facilitate the exposure of the supraclavicular area, the region is approached posterior to the sternocleidomastoid muscle (Figure 7). The loose fibrofatty tissue of the supraclavicular fossa and the absence of well-defined dissection planes within this area make knife dissection also ineffective here. Thus, for this step of the operation scissors and blunt dissection are also preferred. The sternocleidomastoid muscle is retracted anteriorly and the external jugular vein is divided and ligated low in the neck if this was not done at a previous stage of the operation. The

Dissection of the spinal accessory nerve and spinal accessory nerve maneuver The dissection of the spinal accessory nerve (Figure 6) is usually performed with scissors instead of scalpel. To approach this area, the sternocleidomastoid muscle is retracted posteriorly and the posterior belly of the digastric muscle is pulled superiorly with a smooth blade retractor. At this level the nerve runs within the “lymphatic container” of the neck, thus forcing the surgeon to cut across the fibrofatty tissue instead of following fascial planes as for the rest of the operation. In consequence, the tissue overlying the nerve is divided and the nerve completely exposed from the sternocleidomastoid muscle to the internal jugular vein. Usually, the internal jugular vein lies immediately behind the proximal portion of the nerve. However, in some occasions the nerve may go behind the vein or even across it. These anatomic variations should be kept in mind to avoid unintentional damage to the internal jugular vein when dissecting the spinal accessory nerve. Once the spinal accessory nerve has been completely exposed, the tissue lying superior and posterior to the nerve must be dissected from the splenius capitis and levator scapulae muscles. The occipital and sternocleidomastoid arteries must be ligated or cauterized. When the dissected tissue reaches the level of the spinal accessory nerve it must be passed beneath the nerve to be removed in continuity with the main part of the specimen. This step of the operation was called by Osvaldo Suárez the “spinal accessory

Figure 7 Dissection of the posterior triangle of the neck. The sternocleidomastoid muscle (1) is retracted anteriorly and the omohyoid muscle (7) is retracted inferiorly. The spinal accessory nerve (10) is identified as it leaves the sternocleidomastoid muscle. The fibrofatty tissue from the supraclavicular fossa (2) is dissected anteriorly and medially over the fascia of the levator scapulae (9) and scalene (6) muscles. The transverse cervical artery (5), the brachial plexus (8), the phrenic nerve (3), and the internal jugular vein (4) are clearly visible.

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173 shoulder function, the deep branches from the second, third, and fourth cervical nerves that may anastomose with the spinal accessory nerve should be preserved. In the same manner, the contribution to the phrenic nerve from the third, fourth, and fifth cervical nerves should also be preserved. This is best achieved by keeping the dissection superficial to the scalene fascia, where the branches of the cervical plexus usually lie. The dissection of the deep cervical muscles (Figure 8) must be stopped as soon as the carotid sheath is exposed. Continuing the dissection posterior to the carotid sheath carries a high risk of damage to the sympathetic trunk.

Dissection of the carotid sheath

Figure 8 Dissection of the deep muscles of the neck (surgeon’s view). Several branches of the cervical plexus (5) have been preserved to improve shoulder function. The phrenic nerve (2), the internal jugular vein (1), the sternocleidomastoid muscle (3), and the spinal accessory nerve (4) are identified and preserved.

dissection then proceeds from the anterior border of the trapezius muscle in a medial direction including the lymphatic contents of the supraclavicular fossa. At the upper margin of this area it is where there is greatest risk of damage to the spinal accessory nerve during the whole operation. The position of the patient’s head along with the traction exerted by the surgeon during the dissection may displace the nerve from its original course, creating a slight anterior curvature where the nerve may be inadvertently damaged. The omohyoid muscle is then identified and its fascia is dissected off the muscle to be removed with the contents of the posterior triangle. The muscle may be transected at this moment if this will be required for the removal of the primary tumor; otherwise it is preserved and retracted inferiorly with a smooth blade retractor. The transverse cervical vessels are identified deep to the omohyoid muscle. The deep layer of the cervical fascia over the levator scapulae and scalene muscles is now visible. The brachial plexus is easily identified because it appears between the anterior and middle scalene. Staying superficial to the scalene fascia prevents injuring the brachial plexus and the phrenic nerve. The dissection is continued medially until it reaches the level of the anterior border of the sternocleidomastoid muscle. The muscle is then pulled laterally with retractors and the contents of the supraclavicular fossa are passed underneath to meet the tissue previously dissected from the upper half of the neck. The sternocleidomastoid muscle is then retracted posteriorly and the dissection continues anterior to the muscle toward the carotid sheath.

This part of the dissection needs a new number 10 knife blade and adequate tension (Figure 9). The surgical specimen is grasped with hemostats and retracted medially, while the surgeon uses one hand with a gauze pad to pull laterally over the deep cervical muscles. An incision is made with the scalpel over the vagus nerve along the entire length of the carotid sheath. The fascia is then removed from the internal jugular vein. This is achieved by continuously passing the knife blade along the wall of the internal jugular vein up and down along its entire length. The scalpel must be moved obliquely with respect to the vein, with the blade pointing away from the vein wall. When this is properly done and the traction exerted on the tissue is adequate, this maneuver is extremely safe and effective. The fascia can be seen coming apart from the vein after each pass of the knife blade, until the internal jugular vein is completely released from its fascial covering. The facial, lingual, and thyroid veins

Dissection of the deep cervical muscles As the dissection proceeds medially toward the carotid sheath, several branches of the cervical plexus are found over the deep muscles of the neck. To achieve optimal

Figure 9 Dissection of the carotid sheath. The fascia (7) is removed from the internal jugular vein (1), carotid artery (2), and vagus nerve (3). The sternocleidomastoid muscle (4), omohyoid muscle (5), and sternohyoid muscle (6) are clearly visible.

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Figure 11 Anatomical boundaries of the central compartment of the neck. (1) Carotid artery, (2) internal jugular vein (3) hyoid bone, (4) suprasternal notch, and (5) thyroid gland

Figure 10 The strap muscles are released from their fascial covering. (1) Strap muscles, (2) thyroid cartilage, (3) thyroid gland, (4) fascia of the strap muscles, (5) stylohyoid muscle, (6) digastric muscle, (7) anterior facial vein, and (8) submandibular gland optionally preserved.

should be clearly identified, ligated, and divided to complete the isolation of the internal jugular vein. Other smaller branches can be cauterized, by means of bipolar cautery. The dissection of the carotid sheath has 2 danger points, one at each end— upper and lower— of the dissection. At these 2 points the traction exerted to facilitate the dissection of the fascial envelope produces a folding of the wall of the internal jugular vein that can be easily sectioned at the touch of the scalpel blade. The surgeon must be extremely cautious to avoid injuring the vein at these points. Lower in the neck, the terminal portion of the thoracic duct on the left side, and the right lymphatic duct—when present—also are within the boundaries of the dissection and must be preserved. Once the internal jugular vein is released from its covering fascia, the dissection continues medially over the carotid artery. The specimen is now completely separated from the great vessels and remains attached only to the strap muscles

is identified, ligated, and divided at both ends of the surgical field. The fascia is now dissected from the underlying strap muscles. The dissection starts at the upper part of the surgical field and continues in a lateral and inferior direction. The sternohyoid and omohyoid muscles are completely freed from their fascial covering. The superior thyroid artery can be identified coursing in an inferomedial direction toward the thyroid gland. Depending on the resection of the primary tumor, the

Dissection of the strap muscles Although this is described as the last step of the operation (Figure 10), it may be performed in a different order according to the needs of the surgery and the location of the primary tumor. The midline constitutes the medial border of the dissection for unilateral operations. Thus, a midline cut is made in the superficial layer of the cervical fascia from the upper border of the surgical field to the sternal notch. The anterior jugular vein

Figure 12 The neck after a right functional neck dissection for supraglottic cancer of the larynx. (1) Internal jugular vein, (2) carotid artery, (3) sternocleidomastoid muscle, (4) submandibular gland, (5) omohyoid muscle, (6) sternohyoid muscle, (7) levator scapulae muscle, and (8) anterior scalene muscle.

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superior thyroid artery can be preserved or should be ligated and divided. The common facial vein and a variable vein communicating the superficial and deep venous systems of the neck— ocher’s vein— usually are ligated and divided before the specimen is completely released from the strap muscles.

Dissection of the central compartment For some tumor locations the central compartment must also be included in the dissection (Figure 11). During the dissection of the central compartment, the recurrent laryngeal nerve must be identified and preserved in a patient with normal vocal cord function whose primary tumor does not require the removal of the ipsilateral larynx. Identification of the nerve should be attempted before further removal of lymphatic tissue from the central compartment to assure its preservation. The nerve is then followed upward toward the larynx and downward to the upper mediastinum. The inferior thyroid artery is ligated and divided when total lobectomy is planned, and the lymphatic tissue is removed from the central compartment of the neck. Adequate management of the parathyroids is also extremely important in all cases. At least one gland should be identified on each side and their blood supply must be preserved.

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Closure of the wound FND is now completed and the remaining neck structures are clearly visible (Figure 12). The neck is carefully inspected for bleeding points and surgical sponges. The entire field is thoroughly irrigated with normal saline. Finally, the skin is closed in 2 layers over a large suction catheter. The platysma is sutured with absorbable buried sutures, and the skin with skin clips. A moderately tight dressing is applied with special attention to the supraclavicular fossa since this is the area where most serohematomas develop.

References 1. Suárez O: El problema de las metástasis linfáticas y alejadas del cáncer de laringe e hipofaringe. Revista de Otorrinolaringología (Santiago de Chile) 23:83-99, 1963 2. Crile G: Landmark article Dec 1, 1906: Excision of cancer of the head and neck with special reference to the plan of dissection based on 132 operations. JAMA 258:3286-3293, 1987 3. Gavilán J, Herranz J, DeSanto LW, Gavilán C: Functional and Selective Neck Dissection. New York, Thieme, 2002