Systemic Immunosuppression to Reduce Surgical Intervention in <scp>ANCA</scp> ‐Negative Subglottic Stenosis

ABSTRACT Objectives Idiopathic subglottic stenosis (iSGS) is a disease of unclear etiology and predictable phenotype. While surgical dilatation is the mainstay of management, a subset of patients experiences recurrent disease with minimal long‐term symptomatic relief. This study evaluates whether systemic immunosuppression alongside surgical management is an effective adjunctive treatment strategy in this patient cohort. Methods A retrospective study was conducted on patients at a tertiary airway center with isolated SGS. The cohort was categorized into idiopathic SGS and granulomatosis with polyangiitis SGS (GPA‐SGS). A sub‐cohort of iSGS patients with aggressive disease was classified as “atypical‐SGS.” Both atypical‐SGS and GPA‐SGS cohorts received systemic immunosuppression alongside surgery and disease activity was assessed before and after immunosuppression through the inter‐dilation interval (IDI). Results Sixty patients were included: 33 with iSGS, 20 with GPA‐SGS, and 7 with atypical SGS. The iSGS cohort had an indolent disease course, with a median IDI of 17.6 months (IQR 16.0–25.0); none received immunosuppression. GPA‐SGS patients demonstrated significantly shorter intervals prior to treatment (median 8.9 months, IQR 3.8–28.0), improving to 26.0 months (IQR 9.3–36.7) following immunosuppression ( p = 0.0027). Similarly, in atypical SGS, IDI increased from 7.6 months (IQR 6.8–12.0) to 27.8 months (IQR 12.0–49.0) post‐treatment ( p = 0.0496). No significant adverse events were observed. Conclusion Atypical SGS represents a diagnostically ambiguous yet clinically aggressive subset of SGS. Systemic immunosuppression, typically reserved for GPA, may prolong disease‐free intervals in both GPA‐SGS and atypical SGS. These findings support multidisciplinary evaluation and consideration of immunotherapy in frequently recurring, ANCA‐negative SGS. Level of Evidence 3