Combined Optical Coherence Tomography and Endobronchial Ultrasonography for Laser-Assisted Treatment of Postintubation Laryngotracheal Stenosis

Abstract

We describe the use of combined optical coherence tomography (OCT) and endobronchial ultrasonography (EBUS) to identify the residual hypertrophic tissues and persistent inflammation that are known contributors to stricture recurrence after laser-assisted mechanical dilation (LAMD) oflaryngotracheal stenosis (LTS). Commercially available high-frequency EBUS (approximately 100-microm resolution) and time-domain OCT (approximately 10- to 20-microm resolution) systems were used to visualize airway wall microstructures in the area of hypertrophic tissue formation before and after LAMD in 2 patients with complex circumferential postintubation LTS. Before LAMD, EBUS revealed a homogeneous layer consistent with hypertrophic tissue overlying a hyperechogenic layer corresponding to tracheal cartilage. OCT revealed a homogeneous light backscattering layer and an absence of layered microstructures within hypertrophic tissue. Immediately after LAMD, OCT of the laser-charred tissue showed high backscattering and shadowing artifacts; OCT of noncharred tissue showed bright light backscattering regions that suggested acute inflammation. EBUS revealed thinner but persistent hypertrophic tissue overlying the cartilage. Stenosis recurred in both patients. Intraoperative use of EBUS and OCT could potentially identify residual hypertrophic tissues and persistent inflammation during or after LAMD. It might help physicians predict stricture recurrence, prompting alternative therapeutic strategies and avoidance of repeated endoscopic treatments for LTS.