Ultrasound-Guided Transoral Videolaryngoscopic Surgery for Retropharyngeal Lymph Node Metastasis of Papillary Thyroid Cancer

Endoscopic thyroidectomy versus traditional open thyroidectomy for identification of the external branch of the superior laryngeal nerve

AIM

To explore the anatomical features of the external branch of the superior laryngeal nerve (EBSLN) and determine an effective approach for its preservation during endoscopic thyroidectomy (ET).

METHODS

From January 2017 to December 2018, a total of 405 consecutive patients with thyroid disease were retrospectively analyzed. These patients were divided into the ET group and the open thyroidectomy (OT) group according to the surgical approaches. There were 195 cases in the ET group including 43 males and 152 females, and 210 cases in the OT group including 65 males and 145 females. The dissection process of EBSLN, detection rate, distribution of identification methods of the EBSLN and rate of voice change were recorded.

RESULTS

There were 205 EBSLNs detected under direct vision in ET group for a detection rate of 88.0%, while 158 EBSLNs were detected under direct vision in OT group for a detection rate of 58.1%. But with the assistant of intraoperative neuromonitoring (IONM), the number of EBSLNs detected visually reached up to 220 in ET group and 226 in OT group, respectively, for a visual detection rate of 94.4% and 83.1%, respectively. There were significant difference in the rate of direct visual identification, total visual identification with IONM. Stratified risk estimation indicated that the tumor size and location were risk factors for the direct visual dissection of EBSLN. Stratified analysis by tumor size indicated that when tumor diameter was ≤ 4 cm, the incidence of vocal cord fatigue and total vocal changes in ET group was significantly lower than that in OT group.

CONCLUSIONS

Recognition and exposure of the EBSLN can be facilitated by the magnification and focusing function of high-definition endoscopy and the advantage of a 30° variable angle. Full exposure of the sternothyroid-laryngeal triangle and fine dissection along the superior thyroid vessels is beneficial for recognizing the EBSLN.

Functional and oncological outcomes after retropharyngeal node dissection for papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma frequently metastasizes to central and lateral neck lymph nodes, but metastasis to retropharyngeal lymph nodes (RPLN) is rare.

PATIENTS AND METHODS

We retrospectively reviewed 16 patients with RPLN metastasis of PTC who underwent therapeutic dissection of RPLN metastases.

RESULTS

Among 16 patients, 7 patients underwent RPLN dissection with initial surgery and remaining 9 patients as salvage surgery. RPLN metastasis arose unilaterally in 15 patients and bilaterally in 1 patient. Eleven patients showed temporal dysphagia and four patients showed temporal vocal cord paralysis, but both symptoms eventually recovered in all cases. Two patients with salvage RPLN dissection died of distant metastasis and six patients survived with distant metastasis and/or persistent loco-regional disease. Other eight patients have been alive without disease.

CONCLUSIONS

Although transcervical approach for RPLN metastases of PTC provided acceptable functional and oncological outcomes, half of the patients with RPLN metastasis have had distant metastasis and/or persistent locoregional disease. Indications of surgery for patients with RPLN metastasis need to be performed carefully in consideration of patients' prognosis and quality of life.