The contribution of flexible endoscopy for diagnosis of acute bacterial rhinosinusitis

This prospective controlled study ascertained the contribution of flexible endoscopy (FE) for diagnosis of acute bacterial rhinosinusitis (ABRS) in a group of consecutive adult patients who had symptoms suggestive of ABRS and in whom sinus radiography (SRG) and FE were accomplished. We adopted for analysis the 2007 updated European guidelines on rhinosinusitis and computed the sensitivity and specificity of FE against SRG. Positive diagnosis was entertained when FE showed purulent material within sinus drainage area and/or SRG demonstrated air-fluid level, complete opacification, or at least 6 mm mucosal thickening. Of a total of 179 patients initially included in this study, 104 had clinical criteria compatible with guidelines for ABRS. Of them, 43 (41.3%) had positive FE and SRG, 17 (16.3%) had positive FE and negative SRG, and vice versa in 9 (8.7%); both modalities were negative in 35 (33.7%). FE yielded sensitivity of 82.7 ± 5.24% (95% CI: 72.41-92.97%) and specificity of 67.3 ± 6.50% (95% CI: 54.56-80.06%). Age, gender, symptom duration, pre-referral antibiotics, and treatment by primary/secondary physician were not associated with positive or negative diagnosis of ABRS. Of 75 patients who were excluded from the analysis, 33 (44%) had positive diagnosis of ABRS established by FE and/or SRG. The finding that clinical criteria had moderate predictive value (66.3%) highlights the need for objective measures for diagnosis of ABRS. In absence of feasible gold standard and considering that guidelines do not recommend SRG for routine diagnosis, FE serves as an indispensable ancillary tool for establishing ABRS.