title: Hematoxylin and eosin staining for detecting biofilms: practical and cost-effective methods for predicting worse outcomes after endoscopic sinus surgery.
abstract: OBJECTIVE
  Although biofilms have been implicated in poor prognosis after endoscopic sinus surgery (ESS), traditional methods detecting biofilm such as scanning electron microscope and confocal scanning laser microscope were rarely used in the practice. The aims of this study was to determine whether the presence or absence of a biofilm detected by hematoxylin and eosin (H&E) staining followed by light microscopy (LM) that is widely used in daily practice, predicts surgical outcomes after ESS.
  
  
  METHODS
  Retrospective analysis of prospectively collected data. Fifty-five consecutive adult patients (>18 years) who underwent ESS for chronic rhinosinusitis with a minimum of 12-months of follow-up were enrolled in this study. Random sinonasal mucosal samples were assessed for biofilm presence using H&E staining with LM. Three independent observers scored whether a biofilm was present or absent based on H&E staining/LM, and the interrater variability was calculated. Pre- and postoperative sinus symptoms and sinonasal mucosal grading were assessed.
  
  
  RESULTS
  Biofilms were present in 28 patients (51%), and the intraclass correlation coefficient according to H&E staining/LM was 0.731. The presence of a biofilm was associated with a higher preoperative Lund-MacKay computed tomography score (22.3 for biofilm-positive patients vs. 18.6 for biofilm-negative patients; P=0.021) and persistent inflammation (mucosal edema and discharge) after ESS (P<0.05).
  
  
  CONCLUSIONS
  The presence or absence of a biofilm based on H&E staining/LM is correlated with disease severity and surgical outcomes after ESS. H&E staining/LM for detecting biofilm could be practical and cost-effective methods for predicting prognosis of ESS.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Sang Duk
authors.initials: SD
authors.lastname: Hong
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hun-Jong
authors.initials: HJ
authors.lastname: Dhong
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Seung-Kyu
authors.initials: SK
authors.lastname: Chung
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hyo Yeol
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: JunOh
authors.initials: J
authors.lastname: Park
authors.affiliation: Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Sang Yun
authors.initials: SY
authors.lastname: Ha
keywords: Biofilms; Chronic rhinosinusitis; Endoscopic sinus surgery; Hematoxylin-eosin staining; Light microscope; Nasendoscopy; Postsurgical outcomes