Preoperative Laryngoscopic Exam Critical to Detecting Vocal Cord Paralysis in Patients with Thyroid Cancer with Recurrent Laryngeal Nerve Invasion

by Linda Kossoff •

What can be learned about the clinical presentation, surgical management, pathological characteristics, pre- and postoperative circumstances and therapies, and outcomes in patients with recurrent laryngeal nerve (RLN) invasion by thyroid cancer?

BOTTOM LINE

Among the highlighted findings in this analysis is the importance of laryngoscopic examination to detect preoperative vocal cord paralysis (VCP) and the value of a multidisciplinary team to achieve optimal survival and outcomes.

BACKGROUND: The location of the RLN places it at risk of thyroid malignancy invasion. Although VCP is indicative of this, a normal preoperative laryngeal exam does not preclude RLN invasion or electromyographic activity when applying intraoperative nerve monitoring (IONM). Accurate detection of RLN invasion impacts surgical decision making in invasive thyroid carcinoma.

STUDY DESIGN: Retrospective study.

SETTING: Department of Otolaryngology–Head and Neck Surgery, University of Rochester Medical Center, Rochester, N.Y.

SYNOPSIS: Researchers identified 65 patients with RLN invasion by thyroid carcinoma, nodal metastases, or both who were operated on at a single institution between December 1995 and December 2015. Of the 65 patients, 39.3% had preoperative voice complaints and 43.5% had preoperative VCP documented by fiberoptic laryngoscopy. Authors say these low percentages might suggest that nerve invasion by tumors is gradual, thus underscoring the importance of preoperative laryngoscopy in patients undergoing thyroidectomy and especially in patients with suspected RLN invasion. Absent a direct laryngeal exam, they note, surgeons risk missing the true functional status of the vocal cords in patients with invaded RLN who have unaffected preoperative vocal cord function. Findings showed that resecting an invaded RLN did not offer any statistically significant benefits on five-year recurrence-free survival (RFS) or five-year overall survival (OS). Radioactive iodine was the only statistically significant factor associated with improvement in both fiveyear RFS and five-year OS, regardless of RLN resection status during surgery. Study limitations included its retrospective design and sample size, which may not be adequately powered.

CITATION: Brooks JA, Abdelhamid Ahmed AH, Al-Qurayshi Z, et al. Recurrent laryngeal nerve invasion by thyroid cancer: laryngeal function and survival outcomes. Laryngoscope. 2022;132:2285-2292.