Methods: Patients with history of CRS with positive sinus CT and asthmatics without CRS were randomly identified via ICD-9 codes from Northwestern University’s data warehouse from 2002-2013. Chest CT scans were available in 187/516 (36%) patients with CRSsNP, 119/749 (16%) patients with CRSwNP and 288/316 (91%) asthmatics without CRS.
Results: Bronchiectasis was present in 16% (16/101) of patients with CRSsNP without asthma, 5% (1/20) of patients with CRSwNP without asthma, 24% (21/86) of patients with CRSsNP and asthma, 14% (14/99) of patients with CRSwNP and asthma and 11% (31/288) of asthmatics alone (p<0.005, CRSsNP with asthma vs. asthmatics alone). There was a trend towards higher prevalence of bronchiectasis in CRSsNP with asthma compared to patients with CRSwNP and asthma (p=0.08). Radiographic sinus severity and prior sinus surgery did not correlate with the presence of bronchiectasis.
Conclusions: We observed a significantly higher prevalence of bronchiectasis in CRSsNP (16-24%) than in the general population (estimated at ~1%). Coexistence of asthma in both CRSsNP and CRSwNP increased the prevalence of bronchiectasis. Patients with CRSsNP and asthma together had considerably higher prevalence of bronchiectasis than asthmatics alone, which suggests that asthma and CRSsNP have an additive effect. This association of CRS with bronchiectasis supports the unified airway concept and has clinical implications.