Intraoperative Monitoring and Preservation of Anatomic Integrity of Palsied Recurrent Laryngeal Nerve is Extremely Meaningful During Redo Thyroid Surgery

Redo thyroid surgery on patients with unilateral recurrent laryngeal nerve (RLN) palsy certainly poses a great surgical challenge. We present a case of a patient with unilateral vocal cord (VC) palsy who underwent redo thyroid surgery under intraoperative neuromonitoring. The patient's normal speaking voice was maintained after the primary surgery, even though preoperative laryngoscopy showed an immobile right VC with a normal structure. During reoperation, surgical exploration revealed the anatomical integrity of palsied RLN with extralaryngeal terminal bifurcation. The electrophysiological stimulation of the vagus nerve and palsied RLN generated wave amplitudes (V1: 242, R1: 347, R2: 352 and V2: 152 mu V). Despite positive amplitudes, postoperative laryngoscopy confirmed RLN palsy and corresponding VC paralysis but preserved the structure of the immobile VC. Even palsied RLN should be monitored during redo surgery. A positive signal delineates at least partial neural transmission despite VC palsy. The preservation of anatomical integrity of palsied RLN for eventual partial conductivity may be vital in preserving the normal structure of VC and maintaining the patient's voice despite its immobility.