Impact of Serial Intralesional Steroid Injections on Idiopathic Subglottic Stenosis

Objectives Serial intralesional steroid injection (SILSI) has been increasingly used to treat idiopathic subglottic stenosis (iSGS). Prior studies have shown effectiveness, but not in all patients. This multi‐institutional study evaluates the effect of SILSI on time to recurrent operation, peak expiratory flow (PEF), and dyspnea. Methods Post‐hoc secondary analysis of the North American Airway Collaborative data were performed to evaluate the outcomes of iSGS patients undergoing and not undergoing SILSI. The primary outcome was time to recurrent operation, evaluated using Kaplan–Meier curves and Cox regression analysis. Secondary outcomes were change in PEF and clinical chronic obstructive pulmonary disease questionnaire (CCQ) score. Within patients undergoing SILSI, demographics, time from last procedure, and PEF at initiation of SILSI were evaluated to determine the effect on recurrence. Results Two hundred and ninety patients were included, 238 undergoing endoscopic dilation alone and 52 undergoing dilation and SILSI. No differences in baseline characteristics were observed. There was no difference in time to recurrence (hazard ratio: 0.64; p = 0.183). There were no differences in PEF or CCQ across the 2.5‐year study period. Among 52 patients undergoing SILSI, PEF at the time of starting SILSI did not affect recurrence ( χ 2 = 0.09, p = 0.77). Conclusion Patients undergoing and not undergoing SILSI had similar times to recurrence, PEF, and CCQ. Factors predicting recurrence among patients undergoing SILSI were not identified. These results support a randomized controlled trial with a uniform SILSI protocol to quantify the effects of SILSI on objective and subjective outcomes and help determine which iSGS patients benefit most. Level of Evidence 3 Laryngoscope , 133:2255–2263, 2023