[Functional results after type I thyroplasty with the Montgomery's prosthesis]

Between January 1999 and October 2000, 16 patients with glottic insufficiency of varying etiologies underwent Montgomery type I thyroplasty at the E.N.T. Department of the University of Brescia, Italy. In 2 cases revision surgery was required for the onset of delayed complication (cutaneous and endolaryngeal exposure of the prosthesis). All subjects underwent a battery of clinical-instrumental tests pre- and postoperatively as well as 2, 6 and 12 months after surgery. These tests included videolaryngostroboscopy, subjective perception analysis using the GRBAS scale proposed by Hirano on vowels, statements and songs, and, using the Multi-Dimensional Voice Program (MDVP), acoustic measurement of the following parameters: jitter (J), shimmer (S), noise to harmonic ratio (NHR) and maximum phonation time (MPT). The patients also filled out a self-evaluation questionnaire to judge the postoperative voice and this was used to calculate the "voice handicap index" (VHI). In order to make the study sample as homogeneous as possible, detailed pre- and postoperative functional data were studied only for the 11 patients with glottic insufficiency subsequent to monolateral vagal or recurrent paralysis. Analysis of these data revealed that, in these patients, postoperative perceptive and subjective evaluation was similar to that found in normal subjects. Videolaryngostroboscopy showed that the glottis closed completely in most cases and objective acoustic analysis parameters were significantly improved after surgery. Despite the small sample, our functional results confirm the validity of the cord medialization technique through an external approach in laryngeal hemiplegia. In cases of glottic insufficiency of various etiologies (trauma, scarring subsequent to external and/or endoscopic surgery and radiotherapy), more accurate selection of the patients is required to reduce the incidence of complications and to improve vocal results.