title: The use of polydimethylsiloxane for injection laryngoplasty.
abstract: BACKGROUND
  Injuries of the recurrent laryngeal nerve with consecutive vocal cord paralysis is a typical complication in chest, esophageal, thyroideal, and neck surgery. Glottic insufficiency secondary to such a lesion can be treated by endolaryngeal vocal cord augmentation (injection laryngoplasty). Many different substances have been used, often showing complications or disadvantages. This study reports on the use of injectable polydimethylsiloxane (PDMS), with special regard to the long-term results.
  
  
  METHODS
  In this prospective study, 21 patients with unilateral vocal cord paralysis underwent injection laryngoplasty using PDMS at a volume of 0.5-1.0 ml. Preoperatively, 6 weeks and 12 months after the injection the following parameters concerning patients' voice were evaluated: Glottic closure by videolaryngostroboscopy, maximum phonation time, voice range, voice dynamic, jitter, shimmer, noise-to-harmonic-ratio, and roughness, breathiness, and hoarseness (RBH). In addition, patients were asked to give their own evaluation of how satisfied they felt with their voice and of the handicaps it caused them.
  
  
  RESULTS
  Postoperatively an improvement was evident in all the parameters that were investigated, and this significant improvement was still in evidence for most of the parameters more than one year after the injection. In our study no complications were observed more than one year after injection.
  
  
  CONCLUSIONS
  PDMS is a safe substance for injection laryngoplasty in unilateral vocal cord paresis. Objective and subjective parameters confirm its effectiveness. It is suitable for obtaining satisfying results in the reestablishment of the patient's voice and communication ability.
authors.affiliation: Division of Phoniatrics, ENT Clinic, Head and Neck Surgery, University of Berne, Inselspital, Berne 3010, Switzerland. matthias.hagemann@insel.ch
authors.forename: Matthias
authors.initials: M
authors.lastname: Hagemann
authors.forename: Eberhard
authors.initials: E
authors.lastname: Seifert
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D004129:Dimethylpolysiloxanes / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007267:Injections; D007830:Larynx / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010699:Phonation; D012009:Recurrent Laryngeal Nerve / Q000601:surgery*; D061226:Recurrent Laryngeal Nerve Injuries; D016896:Treatment Outcome; D014826:Vocal Cord Paralysis / Q000209:etiology / Q000601:surgery*
chemical_list: D004129:Dimethylpolysiloxanes; C013830:baysilon