Cricothyroid Subluxation: A New Innovation for Enhancing the Voice with Laryngoplastic Phonosurgery

Abstract

Laryngoplastic phonosurgery has evolved to become a dominant treatment modality for paralytic dysphonia. Current surgical procedures have addressed primarily the position of the musculomembranous vocal fold and the arytenoid in the axial and vertical planes. However, dynamic range capabilities and vocal flexibility have been limited secondary to the flaccid, denervated vocal fold tissue. Therefore, a new procedure was conceived to enhance the acoustic vocal outcome from operations that reposition the vocal edge. Cricothyroid (CT) subluxation was designed as a technique to increase the distance between the cricoarytenoid joint and the insertion of the anterior commissure ligament. Cricothyroid subluxation was done without complication in 9 patients who underwent combined adduction arytenopexy and medialization laryngoplasty, and in 4 patients with medialization laryngoplasty alone. Postoperative stroboscopic assessment was done in all of the 13 patients, while complete analysis of vocal function was available in 10 of the 13 patients; this revealed improvement (as a group) on almost all objective measures over the preoperative state. All patients who underwent CT subluxation had a normal maximum frequency range (pitch variation of more than 2 octaves), as compared with 22% of a prior similar cohort of patients who did not undergo CT subluxation. All patients who underwent CT subluxation had normal glottal airflow and a normal noise-to-harmonics ratio. Cricothyroid subluxation is a relatively easily adjustable procedure that increases the length and viscoelastic tension of the denervated vocal fold. The modified biomechanical properties resulted in improved vocal outcome in all of our patients, which was most remarkable in terms of maximal range capabilities. Cricothyroid subluxation enhanced the postoperative voice of patients regardless of whether they required medialization laryngoplasty alone or whether they also required adduction arytenopexy.