Transcutaneous Laryngeal Ultrasonography: Clinical Variables

Abstract

Transcutaneous laryngeal ultrasound (TLUSG) is a noninvasive and convenient method of assessing the function of both vocal cords (VCs) before and after thyroidectomy. It works by essentially relying on the propagation of ultrasound waves travelling from the anterior neck skin to the VCs and the arytenoids via the ventral window of the thyroid cartilage. As a result, the presence of ossification (i.e., turning from cartilaginous tissue to bone) in the thyroid cartilage is the major determinant of obtaining clear VC visualization by TLUSG. It is now clear that the process of ossification is an inevitable, age-related phenomenon and slowly begins from the posterior part of the thyroid cartilage toward an anteromedial direction. Numerous clinical studies have shown that male patients with advanced age are particularly prone to have a complete ossification of the cartilage rendering VC visualization by TLUSG almost impossible. However, despite this process, one should also realize that since the majority of patients undergoing thyroidectomy are young females, TLUSG should be highly applicable to many thyroid surgeons. With appropriate training, the skills of TLUSG could be quickly learned by surgeons who may or may not routinely perform ultrasound in their practice.