title: Computational fluid dynamic modeling of nose-to-ceiling head positioning for sphenoid sinus irrigation.
abstract: After sinus surgery, patients are commonly instructed to irrigate with saline irrigations with their heads over a sink and noses directed inferiorly (nose-to-floor). Although irrigations can penetrate the sinuses in this head position, no study has assessed whether sphenoid sinus penetration can be improved by irrigating with the nose directed superiorly (nose-to-ceiling). The purpose of this study was to use a validated computational fluid dynamics (CFD) model of sinus irrigations to assess the difference in sphenoid sinus delivery of irrigations after irrigating in a nose-to-floor vs nose-to-ceiling head position.
  
  
  
  Bilateral maxillary antrostomies, total ethmoidectomies, wide sphenoidotomies, and a Draf III frontal sinusotomy were performed on a single fresh cadaver head. CFD models were created from postoperative computed tomography maxillofacial scans. CFD modeling software was used to simulate a 120-mL irrigation to the left nasal cavity with the following parameters: flow rate 30 mL/second, angle of irrigation 20 degrees to the nasal floor, and either nose-to-floor or nose-to-ceiling head positioning.
  
  
  
  In the postoperative CFD models, the sphenoid sinuses were completely penetrated by the irrigation while in a nose-to-ceiling head position. However, no sphenoid sinus penetration occurred in the nose-to-floor position. Other sinuses were similarly penetrated in both head positions, although the ipsilateral maxillary sinus was less penetrated in the nose-to-ceiling position.
  
  
  
  CFD modeling demonstrated that the nose-to-ceiling head position was superior to the nose-to-floor position in delivering a 120-mL irrigation to the sphenoid sinuses.
authors.affiliation: Department of Otolaryngology, Henry Ford Hospital, Detroit, MI.
authors.forename: John R
authors.initials: JR
authors.lastname: Craig
authors.affiliation: Department of Otolaryngology, University of Pennsylvania, Philadelphia, PA.
authors.forename: James N
authors.initials: JN
authors.lastname: Palmer
authors.affiliation: Department of Otolaryngology, Ohio State University, Columbus, OH.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhao
mesh_terms: D004724:Endoscopy; D005626:Frontal Sinus / Q000601:surgery; D006801:Humans; D057446:Hydrodynamics; D008962:Models, Theoretical; D055556:Nasal Lavage / Q000379:methods*; D059747:Nasal Surgical Procedures; D011184:Postoperative Period; D011187:Posture; D013101:Sphenoid Sinus
keywords: chronic rhinosinusitis; computational fluid dynamics; endoscopic sinus surgery; sinus irrigation; sphenoid sinus; topical therapy for chronic rhinosinusitis