Abstract

Background: Serial intralesional steroid injections (ILSIs) have been suggested to be an effective adjunct treatment for idiopathic subglottic stenosis (iSGS) by maintaining airway patency and extending inter-surgical intervals. However, evidence for the effectiveness of serial ILSIs remains inconclusive. The current study aimed to assess whether ILSIs reduce the risk of subsequent surgical dilation (i.e., recurrence) in a cohort of patients with iSGS.

Methods: Prospectively collected clinical data for 75 female iSGS patients with 1-4 years of follow-up were analyzed. To assess the effect of ILSI use on the risk of recurrence, we assessed both the time-to-first recurrence using a standard Cox proportional hazards model and all recurrences per patient using a recurrent-events model. Overall, there were 36 patients who had received ILSIs at any point in the follow-up period and 39 patients who had not.

Results: ILSI use was associated with a significantly reduced risk of recurrence in both time-to-first event (hazard ratio (HR) = 0.20, 95% confidence interval (CI) 0.08-0.49) and recurrent events (HR = 0.44, 95% CI 0.26-0.75) multivariate Cox proportional hazard models, along with older age at diagnosis and longer time since diagnosis (all p < 0.05). In the time-to-first event analysis, the median time to recurrence among those who had received ILSIs was 2.5 years compared to 1.4 years among those who had not. The number needed to treat with ILSIs to avoid one recurrence by 2 years follow-up was two.

Conclusion: Serial ILSIs were associated with reduced risk of recurrence, along with older age at diagnosis and longer time since diagnosis.

Level of evidence: 3 (non-randomized controlled cohort/follow-up study).

Keywords: cox regression; endoscopic surgical dilation; idiopathic subglottic stenosis (iSGS); recurrence; serial intralesional steroid injections.