Recovery of Recurrent Laryngeal Nerve Function With Neoadjuvant Treatment: Neural Characterization

• Published in: The Laryngoscope 2024-07, Vol.134 (7), p.3415-3419
• Main Authors: Russell, Marika D., Abdelhamid Ahmed, Amr H., Feng, Zipei, Shonka, David C., Karcioglu, Amanda S., Iwata, Ayaka J., Kyriazidis, Natalia, Siddiqui, Sameer H., Athni, Tejas S., Park, Jong C., Wirth, Lori J., Zafereo, Mark E., Randolph, Gregory W.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Female; Humans; Male; Middle Aged; Morphology; neoadjuvant; Neoadjuvant Therapy; paralysis; recovery; Recovery of Function; recurrent laryngeal nerve; Recurrent Laryngeal Nerve - physiopathology; Recurrent Laryngeal Nerve - surgery; Retrospective Studies; surgery; thyroid; Thyroid cancer; Thyroid Neoplasms - pathology; Thyroid Neoplasms - physiopathology; Thyroid Neoplasms - surgery; Thyroid Neoplasms - therapy; Thyroidectomy - methods; Treatment Outcome; Vocal Cord Paralysis - physiopathology; Vocal Cord Paralysis - surgery; Vocal Cord Paralysis - therapy
• ISSN: 0023-852X; 1531-4995; 1531-4995
• DOI: 10.1002/lary.31304

Objectives Neoadjuvant targeted therapy has emerged as a promising treatment strategy for locally aggressive thyroid cancer. Its impact on tumor and adjacent tissues remains a nascent area of study. Here we report on a series of six subjects with locally advanced thyroid cancer and recurrent laryngeal nerve (RLN) paralysis who experienced recovery of RLN function with neoadjuvant treatment and describe the morphologic and electrophysiologic characteristics of these recovered nerves. Methods This is a multicenter retrospective review. Descriptive analysis was conducted to examine the following parameters for recovered nerves: (1) nerve morphology, characterized as Type A (involving epineurium only) versus Type B (extending beyond epineurium); (2) proximal stimulability (normal vs. abnormal vs. absent); and (3) surgical management (resection vs. preservation). Results Six subjects with unilateral VFP were identified. Median time to return of VF mobility was 3 months (range 2–13.5). All nerves (100%) were noted to have Type A morphology at surgery. Proximal stimulability was normal in four subjects (66.7%), abnormal in one (16.7%), and absent in one (16.7%). Nerves that had improvement of function through neoadjuvant therapy were able to be surgically preserved in five subjects (83.3%). Conclusions This represents the first characterization of RLNs that have recovered function with neoadjuvant treatment of locally advanced thyroid cancer. Although much remains unknown, our findings indicate carcinomatous neural invasion is a reversible process and recovered nerves may demonstrate normal morphology and electrophysiologic activity. Level of Evidence 4 Laryngoscope, 134:3415–3419, 2024