Transnasal Endoscopic Repair of Unilateral Choanal Atresia in a Young Adult Using a Cross-Over Nasoseptal Flap Technique and a Bioabsorbable Mometasone-Furoate-Eluting Stent: A Case Report

Background and Clinical Significance: Choanal atresia is a rare congenital obstruction of the posterior nasal aperture, with an estimated incidence of one in 5000 to one in 8000 live births. Bilateral disease typically presents as a neonatal emergency, whereas unilateral disease is more frequent and may remain undiagnosed for years or decades, presenting in adolescence or adulthood with chronic unilateral nasal obstruction and ipsilateral mucopurulent rhinorrhoea. Optimal surgical management remains debated, particularly with regard to mucosal-flap reconstruction and the choice of postoperative stent. Case Presentation: A 22-year-old male was referred for chronic left-sided nasal obstruction, persistent ipsilateral mucopurulent rhinorrhoea and reduced ipsilateral olfaction. Nasal endoscopy and high-resolution computed tomography demonstrated an isolated, non-syndromic, mixed bony–membranous left choanal atresia. The patient underwent transnasal endoscopic choanoplasty with posterior septectomy and removal of the atretic plate and posterior vomer. An ipsilateral superiorly based septal mucoperichondrial flap was raised first and later transposed over the sphenoid rostrum; following drilling, the contralateral septal mucosa was approached and incised horizontally to generate a superior and an inferior leaflet, which were rotated to cover the corresponding portions of the residual posterior septal ridge. A bioabsorbable mometasone-furoate-eluting sinus implant (PROPEL®, Medtronic) was deployed across the neo-choana. The follow-up endoscopy at two months demonstrated a widely patent, well-mucosalized neo-choana with complete resolution of symptoms. Conclusions: Transnasal endoscopic posterior septectomy combined with mucosal-flap reconstruction and a bioabsorbable steroid-eluting stent is a technically feasible and biologically rational approach to adult unilateral CA. To our knowledge, this is among the first reports describing the off-label intraoperative use of a PROPEL® stent in a young adult with isolated unilateral choanal atresia.