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

C H A P T E R 2 | Oncologic Components of Lymphadenectomy

43

administering muscle relaxation during this portion of the procedure. As level V is dissected, the transverse cervical artery will be identified and can be ligated, if neces- sary. At the posterior aspect of the level V dissection, the spinal accessory nerve will be encountered, running laterally and diagonally entering the trapezius muscle. Injury to the spinal accessory nerve results in paralysis of the trapezius muscle, with shoulder drop and decreased abduction of the arm. A small plexus of nerve branches posterior and parallel to the spinal accessory nerve should be preserved; injury may cause sen- sory loss of the shoulder. 4.  MANAGEMENT OF EXTRANODAL EXTENSION IN THE LATERAL NECK Recommendation:  Lymph nodes with extranodal extension that involves the key structures of the lateral compartment should be resected to avoid leaving gross residual disease while attempting to preserve the integrity of the motor nerves. The internal jugular vein can be ligated if necessary. Type of Data:  Retrospective case series and observational data. Grade of Recommendation:  Strong recommendation, low-quality evidence. Rationale Extranodal extension of PTC is uncommon but is associated with an increased risk of recurrence. It can involve the surrounding soft tissue and internal jugular vein (IJV), sometimes in conjunction with intravenous tumor thrombus. The carotid artery and key nerves (vagus, phrenic, and spinal accessory) are rarely involved. Resection of gross disease should be performed, with attempts made to preserve the anatomic in- tegrity of the nerves and vascular structures. Intraoperative nerve monitoring can be helpful, particularly in the reoperative setting. Technical Aspects Intraoperative management of lateral compartment lymph node metastases with extranodal extension involving key structures should take into account the ability to resect completely all gross disease and to preserve the anatomic integrity of key nerves and vascular structures. In patients with extension into the IJV, with or with- out intravascular tumor thrombus, unilateral ligation of the ipsilateral IJV should be performed in an attempt to obtain a complete (R0) resection, as long as the con- tralateral IJV is patent. A staged procedure should be performed if bilateral venous involvement is known or suspected. If extranodal extension involves the nerves within the lateral compartment, attempts at anatomic and functional preservation of these nerves should be made, while resecting all gross disease, even if this achieves only an R1 resection. Resection of overlying muscle for direct extranodal extension can be performed but is rarely necessary in PTC. An attempt to preserve muscle volume should be made for cosmetic appearance and to enable coverage of key underlying structures.