title: External nasal valve collapse - a case-control and interventional study employing a novel internal nasal dilator (Nasanita).
abstract: BACKGROUND
  Nasal alar collapse is a common problem and difficult to assess and treat.
  
  
  METHODS
  In 10 healthy controls and 10 patients with alar collapse, the size of the external nasal valve was analyzed on standardized nasal base photographs during quiet breathing and forced inspiration. A novel internal nasal dilator (Nasanita, Siemens & Co, Germany) was employed to assess the effects of a therapeutic intervention. In addition, active anterior rhinomanometry was performed.
  
  
  RESULTS
  During quiet breathing, the external nasal valves were significantly smaller in patients with alar collapse (0.3 +/- 0.08 cm2) than in controls (0.7 +/- 0.2 cm2; p < 0.001). In heal-thy controls, forced inspiration did not significantly alter the size of the external nasal valve (-1.8% +/- 27.5%; p = 0.84), whereas it significantly decreased the external valve area in patients with alar collapse (-42.1% +/- 26.4%; p = 0.001). The internal nasal dilator significantly increased external valve areas during quiet breathing and forced inspiration and completely abolished alar collapse. Nasal airflow at a transnasal pressure difference of 150 Pa was not correlated with external valve size. Nasal airflow increased significantly after inserting the internal nasal dilator to 1300 +/- 370 ml/s (p < 0.001) in controls and 1300 +/-300 ml/s (p < 0.01) in patients.
  
  
  CONCLUSIONS
  A small sized external nasal valve appears to be a major causative factor of alar collapse. A novel internal nasal dilator effectively enlarged the external nasal valve, abolished alar collapse and improved nasal airflow.
authors.affiliation: Department of Otorhinolaryngology, Medicial University Innsbruck, Innbruck, Austria. herbert.riechelmann@i-med.ac.at
authors.forename: H
authors.initials: H
authors.lastname: Riechelmann
authors.forename: E
authors.initials: E
authors.lastname: Karow
authors.forename: D
authors.initials: D
authors.lastname: DiDio
authors.forename: F
authors.initials: F
authors.lastname: Kral
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D004106:Dilatation / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009296:Nasal Cavity / Q000601:surgery*; D015508:Nasal Obstruction / Q000601:surgery*; D025363:Rhinomanometry; D012225:Rhinoplasty / Q000295:instrumentation*; D016896:Treatment Outcome