Selection of surgical techniques for unilateral vocal cord paralysis and its validity

We perform vocal cord injection, thyroplasty type I, and arytenoid cartilage adduction as voice function improvement procedures for unilateral vocal cord paralysis. Each surgical technique is selected according to our criteria. Vocal cord injection is performed using atelo-collagen to increase the mass of the vocal cord. The selection between thyroplasty type I and arytenoid adduction is based on the size of the glottic space during phonation and the positional relationship between the right and left vocal cord processes. We compared the glottal area ratio during phonation on NIH images and the results of phonatory function tests using a PS-77E phonatory function analyzer before surgery and those after surgery in patients who underwent thyroplasty or arytenoid adduction, and evaluated the validity of the criteria for the selection of surgical techniques. In patients who underwent a surgical technique according to the selection criteria, improvement was observed in all items (glottal area ratio, maximum phonation time, expiratory aerodynamic power, and phonation efficiency). Patients who underwent a surgical technique not fulfilling the selection criteria also showed improvement in some items but fewer surgical benefits than those who underwent surgery according to the selection criteria. These results suggest the validity of our criteria for the selection of surgical techniques.