Variables Affecting Time to Airway Improvement After Endoscopic Management of Subglottic Stenosis.

Objectives: To determine time to maximal airway improvement in subglottic stenosis (SGS) patients after endoscopic surgery, measured by peak flow meter (PFM). Secondarily, to evaluate whether patient demographics, intraoperative treatments, or adjunctive medications influenced time to or change in maximal recovery.

Methods: We performed a retrospective and prospective analysis of 42 SGS patients undergoing endoscopic surgery at the UNC Voice Center. PFM measurements were taken once preoperatively and weekly for 6 months postoperatively. Patient demographics, comorbidities, diagnostic etiology, intraoperative treatments (steroid injection, Mitomycin C, none), and postoperative medications (oral steroids, antibiotics, none) were recorded. Primary outcomes included time to maximal postoperative PFM (tmPFM) and percent change in PFM (%∆PFM). Mann-Whitney U, Kruskal-Wallis, and linear regression were used to assess the influence of stratifying factors on outcomes.

Results: Average %∆PFM and increase in PFM following surgery were 98% (SD 69) and 164 L/min (SD 67). Mean tmPFM was 32 days (SD 17). Older age significantly impacted %∆PFM (coefficient of 1.713, p = 0.03) but not tmPFM. No statistically significant differences were found for %∆PFM or tmPFM vs. diagnostic etiology, comorbidities, BMI, intraoperative treatment, and postoperative medications, but the analysis was underpowered for subgroup analysis.

Conclusion: Time to maximal airway caliber following endoscopic airway surgery is not immediate; most patients reach maximal airflow between 18 and 39 days postoperatively, with an average 98% increase in PFM. Further study is needed to determine the impact of intraoperative medications (steroid injection and mitomycin C) and postoperative medications (steroids or antibiotics) on postoperative healing.

Level of evidence: 3: