Fiberoptic laryngoscopy is a standard procedure for evaluation of vocal folds immobility. However, this method is invasive, requires special qualifications and technical equipment, which limits its routine use. Therefore, in daily practice, the vast majority of laryngoscopy are performed by an indirect way, the accuracy of which depends on the specialist experience and the patient compliance. On the other hand, a large number of patients require for a convenient, non-invasive and inexpensive approach to assess the vocal folds mobility. The transcutaneous laryngeal ultrasonography can be such a method. However, the disadvantage of this technique is low informative value.
OBJECTIVE
To increase the effectiveness of the diagnosis of laryngeal dysfunction using transcutaneous laryngeal ultrasonography.
MATERIAL AND METHODS
Patients underwent laryngeal ultrasonography and videolaryngoscopy before and after thyroid or parathyroid surgery. Ultrasound was performed polypositionally in the transverse and oblique planes. Functional tests with breathing and breath holding were used. Qualitative (the smile or flying bird signs, the vertical closing line of the vocal folds, synchronicity and symmetry movement of the arytenoid cartilages) and quantitative (the length contraction of the vocal cord, the rotation angle of the arytenoid cartilage) ultrasonic parameters determin the normal vocal folds mobility.
RESULTS
996 patients were included in the study. Vocal folds paresis was detected in 106 (10.6%) patients. In 72 (7.2%) cases partial impaired mobility of the vocal folds (laryngeal dyskinesia) were detected. The echographic patterns of these patients were analyzed. Qualitative ultrasound signs of laryngeal dysfunction were identified: a crooked smile or falling bird signs, a closing line deformation of the vocal folds, an arytenoid immobility. Quantitative ultrasound signs included: a decrease in the length contraction of the vocal cord and a reduction of rotation angle of the arytenoid cartilage. Unilateral laryngeal paresis was diagnosed in 101 (10.1%) patients. In unilateral disorders the rotation angle of the arytenoid on the affected side was 0-14° and the length contraction of the vocal cord was 0-1.8 mm. A crooked smile or falling bird signs, a closing line deformation of the vocal folds and immobility of the arytenoid cartilages were also determined. In 5 (0.5%) cases bilateral laryngeal paresis was revealed, in which on both sides the rotation angles of the arytenoid were 0—14°, and the length contraction of the vocal cords was 0—1.8 mm. At the same time there was no a smile or flying bird signs and a closing line of the vocal folds. Laryngeal dyskinesia was characterized by a crooked smile or falling bird signs and a closing line deformation of the vocal folds. At the same time, partial mobility of the arytenoid cartilage was noted in comparison with the contralateral side (there was a difference in the rotation angle of the arytenoid between the right and left sides of 15 ° or more degrees).
CONCLUSION
The sensitivity and specificity polypositional ultrasound of the vocal folds in women were 100% and 99.8%, in men — 85.7% and 99.2%, respectively.
