Transcutaneous intrafold injection for unilateral vocal fold paralysis: functional results

This paper presents the technique of transcutaneous intrafold silicone injection and the functional results of 44 procedures in 42 patients. The injection is given under local anesthesia with the patient in a supine position. The needle is inserted through the cricothyroid space. The location of the needle as well as the effect of injection is monitored by means of a fiberscope connected to a television camera and screen. The preoperative and postoperative vocal function was multidimensionally evaluated with the use of a test battery consisting of the maximum phonation time (MPT), mean airflow rate (MFRc), fundamental frequency (F0) range and sound pressure level (SPL) range of phonation, pitch perturbation quotient (PPQ), amplitude perturbation quotient (APQ), and normalized noise energy (NNEa). In the majority of the patients, MPT, F0 range, and SPL range increased and MFRc, PPQ, APQ, and NNEa decreased postoperatively. In the overall evaluation based on the test values of these parameters, the result was excellent for 16 procedures, good for 16, fair for 7, and poor for 5. The most frequent cause of failure was an insufficient amount injected.