After general anesthesia, the patient is positioned supine with the head rotated to the contralateral side of the dissection. The operation can be greatly facilitated if the neck is relaxed by natural placement and not extended. A retroauricular incision is made around the retroauricular sulcus and along the hairline. The design for the skin incision is similar to the MFL incision for parotidectomy, but without the preauricular limb (Fig. 13.2). Sufficient skin flap elevation is mandatory for adequate working space creation. After skin incision, subplatysmal flaps are elevated above the SCM muscle preserving the external jugular vein and great auricular nerve (Fig. 13.3). The sub-SMAS (superficial musculoaponeurotic system) flap elevation should be performed until the platysma muscle is met. Then the subplatysmal flap is elevated medially over the midline, inferiorly to the clavicle, and laterally to the anterior border of the trapezius muscle (Fig. 13.3). After the flap elevation is performed, modified Chung’s retractor (Sangdosa Inc., Seoul, Korea) is placed to maintain the working space.

For the management of the papillary thyroid carcinoma with lateral neck metastasis, level II–V dissection is performed sparing level I. The inferior border of the submandibular gland is dissected and the posterior belly of the digastric muscle is identified. The inferior border of the parotid gland is dissected and retracted superiorly. The spinal accessory nerve (SAN) is sought near the internal jugular vein (IJV) using the transverse process of the second cervical spine as a landmark. The trapezius branch of the SAN is identified about 1 cm lower than the point where the greater auricular nerve crosses the posterior border of the sternocleidomastoid (SCM) muscle (Fig. 13.4). With the preservation of both the sternocleidomastoid (SCM) muscle branch and the trapezius branch, the whole course of the SAN is identified (Fig. 13.5). The SCM is skeletonized and elevated using Army-Navy retractors. The adipose tissues in levels IIB and VA are dissected and passed underneath the SAN, and the lymphofatty tissues in level IIA are then dissected carefully not to damage the IJV or the carotid artery (Fig. 13.6). The upper portion of level III can be also done under direct vision using conventional technique.

The approach from the axilla may be unfamiliar with most of head and neck surgeon. The operator will see the fat tissues immediately after incision in the anterior axillary line. With no guidance of plane, the operator may have hard times to find the pectoralis major fascia. After that, the dissection for the transaxillary flap elevation can be proceeded relatively quickly over the fascia of the pectoralis major muscle. The next obstacle is the clavicle. From the view point of axilla to neck, the clavicular head of the SCM muscle can be met after crossing over the clavicular eminence. Previously formed working space from the retroauricular approach can be reached from the transaxillary approach (Fig. 13.7). After finishing the flap elevation, self-retaining retractor (Chung’s retractor) is inserted through the axillary incision and is fixed firmly to the operation table. A face-down 30° endoscope is used for visualization of the surgical field. A 5 mm Maryland forceps and 5 mm Harmonic curved shears are equipped on either side of the endoscope (Fig. 13.8). The lower neck dissection procedure is started at levels IV and VB. With the preservation of the SAN, the inferior margin of the adipose tissues at level VB is dissected (Fig. 13.9). The omohyoid muscle is identified and cut using Harmonic curved shears. The brachial plexus and the phrenic nerve are identified beneath the fascial carpet and the transverse cervical vessels (Fig. 13.10). In level IV dissection, the transverse cervical artery and vein are verified and the phrenic nerve is preserved. Carotid sheath dissection is carried out using Harmonic curved shears with great caution, and the vagus nerve, carotid artery, and IJV are exposed in level IV (Fig. 13.11). The management of the thoracic or lymphatic duct is very important. For the prevention of chyle leakage, the sealing of the thoracic or lymphatic duct with the Harmonic curved shears is not enough. Those structures should be ligated with vessel clips or Hem-o-lok ligation system. Lymphofatty tissue in level Vb is dissected with the previously dissected level Va. Cervical plexus is ligated with the Harmonic curved shears (Fig. 13.12). The inferior-to-superior dissection over level III can be performed along the carotid sheath and internal jugular chain. The superior thyroid artery anterior to the carotid sheath is identified and preserved. After level III dissection, the axis of the robotic arms is realigned upward for level II dissection. The previously dissected specimen of level IIb is positioned medially, and the level IIa node dissection is performed in an inferior-to-superior fashion (Fig. 13.13). Careful dissection should be performed to identify the hypoglossal nerve in the area of the carotid artery bifurcation. The superior thyroid artery is identified close to the external carotid artery. With previously dissected upper neck dissection specimen, the whole neck dissection specimen is pulled out through the transaxillary incision (Figs. 13.14 and 13.15).