Intraoperative Neuromonitoring in Selective Neck Dissection for Thyroid Cancer: SND (IIa–Vb) with Wu Gaosong's Procedure

Introduction:

Thyroid carcinoma is the most common endocrine malignancy and the ninth common malignancy in the United State, about 80% of thyroid carcinoma is papillary thyroid cancer.^1,2 The prognosis of most cases is excellent but local invasion, lymph node, or distant metastasis may happen in some cases. ³ The lateral neck compartmental lymph node dissection should be performed for patients with biopsy-proven metastatic lateral cervical lymphadenopathy. ⁴ Nowadays, the standard extent of neck dissection includes the lymph nodes at levels II, III, IV, and V. The dissection of levels IIb and Va should be based on an evident clinical metastasis on preoperative ultrasonography and nodal fine needle aspiration (FNA) cytology. Lymphadenectomy in patients with nodal metastasis lowered incidence of recurrence and improved survival.^5,6 However, complications might occur when patients selected unskilled or inexperienced surgeons. Potential complications from lateral neck dissection include chyle leak, hypoparathyroidism, injury to the internal jugular vein or carotid artery, and injury to nerves such as accessory nerve, sympathetic cervical plexus, and phrenic nerve. ⁷ Prof. Wu, the chief surgeon in this video and also the chief surgeon in the educational video of thyroid surgery in China, is a high-volume thyroid surgeon who has performed more than 1000 thyroid operations annually. The philosophies behind thyroidectomy with Wu Gaosong's procedure and central compartment lymph nodes dissection with Wu Gaosong's procedure have been published.^8,9 In this video, we show selective neck dissection (SND) for thyroid cancer: SND (IIa–Vb) with Wu Gaosong's procedure.

Materials and Methods:

The patient is a 57-year-old woman who was suffering from papillary thyroid carcinoma and underwent total thyroidectomy with bilateral level VI dissection 1 year ago. The recent ultrasonography reported left lateral neck nodal metastases and FNA cytology proved the metastases of papillary thyroid carcinoma. The patient had no symptoms at all and physical examination found no positive result. We performed a SND with Wu Gaosong's procedure. The sternocleidomastoid muscle, the external jugular vein, the internal jugular vein, the phrenic nerve, the accessory nerve, the cutaneous nerve, and the thoracic duct were preserved effectively. The dissection was restricted strictly within the “facial envelope,” which wrapped the lateral lymph nodes and comprised five boundaries, including the investing fascia laterally and anteriorly, the prevertebral fascia posteriorly, the carotid sheath medially, the digastric muscle superiorly, and the clavicle inferiorly. The lower jugular groups were connected loosely with carotid sheath and prevertebral fascia, and we used a peanut to dissect the fatty tissue in this area. Nerve monitoring (NIM-Response 3.0 System, Medtronic) was used in this case to help us identify various nerves in the lateral neck. One milli ampere electrical current was used to stimulate the target nerve.

Results:

Postoperative pathology analysis revealed 6/31 nodal metastases. The patient is discharged without any complication 5 days after operation.

Conclusions:

Nerve monitoring might have potential to be used in the lateral neck dissection and the procedure helps to decrease the incidence of potential complications during lateral neck dissection.

No competing financial interests exist.

Runtime of video: 7 mins 52 secs