Role of medialization in the improvement of breath control in unilateral vocal fold paralysis.

A prospective study was performed on 18 adults to analyze disturbances of voice and respiratory function in unilateral vocal fold paralysis and the role of medialization in the improvement of breath control. In addition to physical examination, an acoustic and aerodynamic analysis, as well as patient self-assessment, were performed both before and after medialization (14 fat injections, 4 thyroplasties) to evaluate voice and both phonatory breath control and respiratory function outcome. Preoperative and postoperative results, at short, middle, and long term, were compared to data from 14 control subjects and evaluated by statistical analysis. Preoperative acoustic and aerodynamic parameters were significantly disturbed in comparison to controls. Independently of the pulmonary status, medialization induced an improvement in most of the parameters at short and long terms, whereas a diminished effect was observed at middle term. Phonatory breath control, as evaluated by maximum phonation time, mean flow rate, and expired volume, was statistically improved, with the best results being obtained in women. From the questionnaire, it was clear that voice, as well as phonatory breath control and respiratory function, showed considerable improvement, although some difficulties persisted during effort. This study demonstrates that there is a disturbance of phonatory breath control and respiratory function in adult unilateral vocal fold paralysis. Improvement following medialization supports the concept that the respiratory dysfunction seen beforehand is most probably the result of air escape rather than laryngeal obstruction. Although medialization may provoke an extrathoracic obstruction, its feature of variability appears to improve breath control.