title: Airway resistance and airflow dynamics after fat injection into vocal folds.
abstract: OBJECTIVE
  The aim of this prospective study was to verify whether vocal fold fat augmentation (VFFA) modifies upper airway patency. To the best of our knowledge, this is the first study analyzing the impact of VFFA on laryngeal resistance to airflow.
  
  
  METHODS
  Twenty-one consecutive patients 16 to 74 years of age underwent 24 VFFA operations because of glottic incompetence due to laryngeal hemiplegia (13 patients) or vocal fold tissue defects (8 patients). Flow-volume loop spirometry and body plethysmography were performed before and 1 to 6 months after surgery.
  
  
  RESULTS
  There were no significant differences between preoperative and postoperative pulmonary volumes (FVC and FEV1), expiratory flows (PEF, FEF50), or inspiratory flows (PIF, FIF50), although a slight increase in inspiratory flows meant that FEF50/FIF50 slightly decreased. Specific airway resistance (sRaw) increased after VFFA, but not in a statistically significant manner (p = .078). None of the patients experienced postoperative stridor. One obese woman with laryngeal hemiplegia had postoperative effort dyspnea; her respiratory studies showed a reduction in inspiratory flows and an increase in sRaw, and demonstrated progressive improvement.
  
  
  CONCLUSIONS
  Flow-volume loop spirometry showed that VFFA does not significantly modify respiratory airflows, although a slight increase of inspiratory airflows suggested an improvement in variable extrathoracic obstruction. Body plethysmography proved to be a sensitive procedure that highlighted the subtle increase in upper airway resistance. Hence, VFFA can be considered a relatively safe procedure for achieving vocal fold medialization, and spirometry and plethysmography can be useful for preoperative assessment and postoperative follow-up.
authors.affiliation: Department of Otolaryngology, Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Fondazione IRCCS (Istituto di Ricovero e Cura a Carattere Scientifica), Milan, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Cantarella
authors.forename: Valter
authors.initials: V
authors.lastname: Fasano
authors.forename: Barbara
authors.initials: B
authors.lastname: Maraschi
authors.forename: Riccardo F
authors.initials: RF
authors.lastname: Mazzola
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Sambataro
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000403:Airway Resistance / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology; D005931:Glottis / Q000294:innervation; D006801:Humans; D007267:Injections; D007818:Laryngeal Diseases / Q000150:complications*; D008875:Middle Aged; D010991:Plethysmography; D011446:Prospective Studies; D013147:Spirometry; D050507:Subcutaneous Fat, Abdominal / Q000637:transplantation*; D014182:Transplantation, Autologous / Q000379:methods; D016896:Treatment Outcome; D014826:Vocal Cord Paralysis / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery*; D014827:Vocal Cords