This study will examine the ability of steroid injections into the site of stenosis following surgical dilation to delay the need for repeated surgical dilations.

Inclusion Criteria:

• Have a life expectancy of ≥6 months; and,
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 - 1.

Exclusion Criteria:

• History of subglottic stenosis from identifiable cause (not idiopathic), including any of the below clinical criteria:
• Prolonged endotracheal intubation or tracheostomy (intervention greater than 7 days immediately prior to diagnosis of subglottic stenosis);
• External physical trauma (including but not limited to blunt, penetration, chemical, or thermal injury) that causes injury to the subglottis;
• Clinical diagnosis of granulomatosis with polyangiitis (GPA);
• Radiation exposure to the neck;
• Current or previous treatment with Serial Intralesional Steroid Injection (SILSI);
• Use of systemic corticosteroids (oral, intravenous, or intramuscular glucocorticoids), regardless of indication, within 7 days before triamcinolone administration;
• Local administration of corticosteroids (ophthalmic, intranasal, inhaled) is not prohibited. However, the administration of intraarticular corticosteroids during the treatment phase is not recommended due to potential increased risk of infection.
• Intralesional administration, in a site other than the subglottis, of corticosteroids should be discussed with the site PI before enrollment
• Intraarticular corticosteroids during the treatment phase due to potential increased risk of infection;
• Use of anticoagulants other than aspirin (aspirin dose should not exceed 81mg);
• Pulmonary disease including interstitial lung disease and Chronic Obstructive Pulmonary Disease (COPD)/emphysema;
• Systemic infection requiring treatment with antibiotics, antifungal, or antiviral agents within 21 days of enrollment;
• Poorly controlled diabetes as defined by a HbA1C value greater or equal to 8.0 in the last 180 days);
• Participants with active cancer or a history of cancer in the last 5 years, except for squamous or basal cell carcinoma of the skin;
• Participation in any clinical trial involving an investigational drug or device, within four weeks, or 5 half-lives of the investigational agent (whichever time point is longer) prior to enrollment or during this trial participation;
• Active autoimmune disease requiring systemic treatment;
• History of solid organ transplant due to use of immunosuppression;
• Contraindication to any aspect of the index endoscopic dilation procedure.
• Inability to tolerate in office SILSI procedure;
• Contraindication, hypersensitivity, or history of intolerance to oral or injectable steroids;
• Contraindication to intralipid including:
• Severe lipid metabolism disorders characterized by hypertriglyceridemia;
• Hypersensitivity to eggs, soybean, peanut protein, or any active ingredient in intralipid;
• History of intolerance to intralipid;
• Participants with known, suspected, or plan for becoming pregnant or breastfeeding;
• New York Heart Association (NYHA) class II-IV heart failure within the past 6 months;
• History of angioedema;
• History of subglottic stenosis from other causes, including prolonged intubation (intubation of >1 week immediately prior to diagnosis of subglottic stenosis, external physical trauma that causes injury to the subglottis);
• Lack of capacity to consent;
• Alcohol or substance abuse or dependence in the past 6 months;
• Participants who for any reason may not complete the study as judged by the PI;
• Participants planning to move to another city or state during the duration of the study;
• Not able to undergo phlebotomy as reported by the participant or determined by the study coordinator or physician.
• The presence of a medical condition, and/or use of a medication and/or any substance, individually or in aggregate, that in the judgement of the study team could impair study participation.