Impact of Paranasal Sinus Surgery in Granulomatosis With Polyangiitis: A Longitudinal Computed Tomography Study.

OBJECTIVES/HYPOTHESIS: Severe chronic rhinosinusitis (CRS) in patients with granulomatosis with polyangiitis (GPA) failing medical therapies can be treated with paranasal sinus surgery. Whether this surgery protects from progressive sinonasal damage remains unknown. Here, we aimed to analyze time-dependent relations between sinus surgeries and computed tomography (CT) imaging features in the CRS of GPA. STUDY DESIGN: Longitudinal observational study. METHODS: We assessed CRS features including bone thickening by global osteitis scoring scale, bone erosions, and mucosal thickening by Lund-Mackay scores in serial paranasal sinus CT scans (742 CT scans in total) from a cohort of 127 well-characterized GPA patients. Data on sinonasal surgical procedures were from a mandatory national registry and from chart review. We defined the time from baseline CT to last CT as the study observation period in each patient. Datasets were analyzed by linear mixed models. RESULTS: We found that 23/127 cohort patients had one or more paranasal sinus surgical procedures, and 96% of these (22/23) had osteitis by CT after surgery. In patients with nasal surgery alone or no surgery, we identified osteitis in 7/11 (64%) and 45/93 (48%), respectively. During the observation period of a median of 5 years, 38 patients had progression of their sinus osteitis, with the highest annual osteitis progression rates observed around the time of surgery. CONCLUSIONS: In this cohort, paranasal sinus surgery was associated with prevalence, severity, and progression rate of sinus osteitis, indicating that sinus surgery does not reduce the bone damage development in the CRS of GPA. LEVEL OF EVIDENCE: 4 Laryngoscope, 2020.