Unexpected consequences of transnasal balloon dilation of the maxillary ostium

Background Nasal irrigations and topical sprays have been demonstrated to have benefit in chronic sinusitis. Increasingly, it is evident that delivery system, patient anatomy, and inflammatory process have significant impacts on irrigant distribution. Methods Intrasinus endoscopy was performed during sinus irrigation of 5 thawed fresh frozen cadavers (10 sides) before and after transnasal dilation of the maxillary, frontal, and sphenoid ostia with a 5‐mm balloon. Results Guidewire insertion created false passages through maxillary fontanelle on all of 10 attempts; 1 of 10 frontal insertions entered the ostia in a submucosal plane, while all 10 sphenoid attempts were successful without complication (p < 0.0001). Average minimum ostial dimension increased from 1.73 mm to 3.6 mm (p < 0.0001) after dilation. Obtaining an ostial size of 5 mm was associated with significantly improved irrigation penetration relative to a minimum dimension of 4 mm or less (p = 0.019). After balloon dilation of the true ostia, irrigation of the sphenoid increased, irrigations into the frontal sinuses were unchanged, and irrigation into the maxillary sinuses decreased. Conclusion Guidewire insertion in this study was noted to frequently create a false passage during maxillary sinus ostial dilation. After balloon dilation, irrigant penetration was increased into the sphenoid sinus for heavy and mist irrigators whereas the maxillary sinus had diminished irrigant penetration for heavy and NetiPot irrigators. © 2011 ARS‐AAOA, LLC.† This article is a U.S. government work and, as such, is in the public domain in the United States of America.