8-A837A-2017-Books-00129-029-060_Katz_Sec1_Ch02-ROUND-1

S E C T I O N I | T H Y R O I D

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Superior parathyroid gland

Superior parathyroid gland

Inferior thyroid artery (ligated)

Inferior thyroid artery (ligated)

Inferior parathyroid gland Right RLN

Inferior parathyroid gland Right RLN

Cervical thymus

Cervical thymus

FIGURE 2-7  Level VI lymph node dissection. RLN, recurrent laryngeal nerve.

by microscopic examination may help avoid inadvertent reimplantation of tumor or nodal metastasis. Addition of a CCND to total thyroidectomy has been shown to in- crease parathyroid reimplantation rates and temporary hypoparathyroidism but not permanent hypoparathyroidism. 52,77,99–103 At least an ipsilateral CCND should be performed in patients with lateral com- partment lymph node (levels II to V) involvement. In general, lymph node metasta- ses spread in a centripetal manner, and although “skip metastases” (no evidence of central compartment lymph nodes in the presence of lateral compartment nodal in- volvement) are described, their occurrence is atypical. Most patients with lateral com- partment nodal involvement will also have metastatic central compartment lymph nodes. 104–106 Level VII lymph nodes reside in the superior mediastinum caudal to the innominate artery on the right and the corresponding axial plane on the left. The level VII nodal basin is not typically involved in a CCND; however, lymph node involvement in this basin is not uncommon in patients whose lymph node metastasis is more extensive than usual. 107 Transcervical access to level VII is feasible in the initial and reoperative settings, and partial or complete sternotomy is rarely indicated. When central compartment lymph nodes encountered during thyroidectomy are suspected of harboring metastases, intraoperative pathology consultation can be help- ful in determining the presence of metastatic disease. 108 Visual inspection has been shown to have poor predictive value in central compartment nodal metastasis. 88,89 Sentinel lymph node biopsy for PTC has been described, but the practice has not been