Surgery
Surgery is an option after failure of appropriate medical therapy113,165. Modern endoscopic sinus surgery (ESS) relieves sinus outflow obstruction, debrides inflamed tissue and provides improved access for topical agents 166. Relief of obstruction is more relevant in mild to moderate CRSsNP4 and balloon dilation may be sufficient in selected cases 167. Mucus stasis from obstruction promotes microbial overgrowth and infectious inflammation predominantly in non-polypoid T1,3 inflammation. Relieving obstruction is of less value in CRS cases with diffuse inflammation as in CRSwNP and severe CRSsNP, in particular when associated with T2 inflammation168,169. Although high-level data is lacking, more extensive surgical procedures such as a ‘full house ESS’ are typically recommended for these cases 170-172. Maximum surgical approaches are reserved for the most severe cases and involve removal of the floor of the frontal sinus and in some cases sinus mucosa173-176. Surgical recurrence rates are generally correlated with the intensity of T2 tissue inflammation177-181. Systemic markers of T2 inflammation such as blood eosinophilia are associated with surgical failure even in the absence of a T2 signature in the tissue 182. In non-eosinophilic CRS, limited available data suggests that higher intensity of T1 and T3 inflammation also favors surgical failure182,183.