A novel lateral-approach laryngeal ultrasonography for vocal cord evaluation

Abstract

Laryngeal ultrasonography (LUS) is a new method of vocal cord (VC) evaluation in patients with risk of vocal cord palsy (VCP). The previously described anterior-approach LUS reportedly, however, has high failure rate of VC visualization in male patients. We devised a novel lateral-approach LUS to overcome this limitation. A total of 382 (82 male, 300 female) consecutive LUS and direct laryngoscopy (DL) examinations were performed on perioperative thyroidectomy and parathyroidectomy patients. The anterior-approach LUS was used for female patients whereas the lateral-approach LUS was used for male patients. Findings were cross-validated independently with DL examinations. Both anterior and lateral LUS methods had 100% visualization rate (no failed visualization) with an overall sensitivity of 100% (23/23) and specificity of 99.2% (356/359) for VCP. Among the 300 female patients, 18 patients had VCP. Sensitivity and specificity of anterior-approach LUS were 100% (18/18) and 99.3% (280/282), respectively. Among the 80 male patients, 5 patients had VCP. Sensitivity and specificity of lateral-approach LU were 100% (5/5) and 98.7% (76/77), respectively. The new LUS approach significantly enhances the visualization of vocal cords and, therefore, overall diagnostic efficacy of LUS in male patients.