ABSTRACT
SESSION TITLE: Technological Innovations in Imaging SESSION TYPE: Original Investigations PRESENTED ON: 10/17/22 1:30 PM - 2:30 PM PURPOSE: Central airway stenosis (CAS) is an important cause of pulmonary morbidity and mortality. Current grading and classification systems include subjective qualitative components, with limited data on reproducibility. We propose a novel radiographic segmentation approach to more objectively quantify CAS. Inter-rater reliability of this novel outcome, which is used in an ongoing randomized controlled trial (NCT04996173), has not been previously assessed. METHOD(S): Computed tomography (CT) scans demonstrating tracheal stenoses were identified in the Vanderbilt University Medical Center Benign Tracheal Stenosis registry. CTs were analyzed in OsiriX (Geneva, Switzerland) after upload via a secured cloud transfer service. Four independent readers with variable experience in CT interpretation were chosen (one chest radiologist, one pulmonary fellow, two internal medicine residents). Readers identified the point of nadir airway lumen, measured 1.5 cm above and below that point, then manually segmented visible tracheal lumen area on the soft tissue window of each axial CT slice within that 3 cm length. Missing ROI's were then generated in-between manual segmented areas. The Repulsor function was used to manually adjust the boundaries of the ROI to achieve fit. Intraclass correlation (ICC) was used to calculate the inter-rater reliability of the tracheal lumen volume of between readers. Other data collection variables included the type of CT scan, axial slice interval, the suspected underlying cause of CAS, and average stenotic volume. RESULT(S): Fifty CT scans from 38 individual patients identified in the registry from 2011-2021 were randomly chosen for inclusion. Most (22 of 38, 57.9%) had iatrogenic BCAS (either post-intubation or post-tracheostomy) and 10 (26.3%) had idiopathic subglottic stenosis. Half of the scans (n=25, 50%) were contrasted neck CT and half were non contrasted chest CTs. Scan slice thickness ranged 1 to 5 mm, median 2 mm (1.25-2.875). The median stenotic volume across all readers was 3.375 cm3 (2.52-4.51). The average ICC across all four readers was 0.969 (95% CI 0.944 - 0.982). CONCLUSION(S): Our proposed volume rendering and segmentation approach to BCAS proves to have substantial precision and agreement amongst readers of different skill levels. CLINICAL IMPLICATIONS: A NOVEL METHOD TO ASSESS SEVERITY OF BENIGN CENTRAL AIRWAY STENOSIS DISCLOSURES: No relevant relationships by Leah Brown No relevant relationships by Alexander Gelbard no disclosure on file for Robert Lentz;PI ofan investigator-initiated study relationship with Medtronic Please note: >$100000 by Fabien Maldonado, value=Grant/Research Support PI on investigator-initiated relationship with Erbe Please note: $5001 - $20000 by Fabien Maldonado, value=Grant/Research Support Consulting relationship with Medtronic Please note: $5001 - $20000 by Fabien Maldonado, value=Honoraria co-I industry-sponsored trial relationship with Lung Therapeutics Please note: $5001 - $20000 by Fabien Maldonado, value=Grant/Research Support Board of director member relationship with AABIP Please note: $1-$1000 by Fabien Maldonado, value=Travel No relevant relationships by Khushbu Patel No relevant relationships by Ankush Ratwani Consultant relationship with Medtronic/Covidien Please note: $1001 - $5000 by Otis Rickman, value=Consulting fee No relevant relationships by Evan Schwartz Copyright © 2022 American College of Chest Physicians
ABSTRACT
Introduction: In critically ill patients with SARS-CoV-2, risk factors for laryngeal complications after endotracheal intubation (ie, diabetes, obesity, prolonged intubation, hypotension, and large endotracheal tube [ETT] size) are common. Given the global impact of the virus, more information is needed regarding the long-term laryngeal effects on both breathing and voice. Method: A retrospective review of patients receiving laryngologic care at a tertiary academic center was compiled, and patient characteristics were abstracted. Postmortem analysis of subglottic tissue in 2 patients with SARS-CoV-2 was performed using in situ hybridization of SARS-CoV-2 RNA and immunohistochemistry (IHC) for CD4 and CD8. Results: Collectively, patients (n = 8) were 55.0 (SD ±14.3) years old with a body mass index of 33.7 (SD ±4.5). Most had type 2 diabetes mellitus (62.5%) and hypertension (50%). The average intubation duration was 15.1 days (SD ±5). Most patients were intubated with an 8.0 ETT. The level of laryngotracheal injury occurred within the posterior glottis (n = 6 [75%]) and subglottis (n = 2 [25%]). Both subglottic specimens tested for SARS-CoV-2 infection were positive for the virus within the mucosal epithelium. IHC demonstrated CD4+ and CD8+ cells indicating an abundant adaptive immune response. At our institution, 1.5% of SARS-CoV-2 patients required intubation. By extrapolating from these data, we estimate roughly 300,000 patients required intubation nationally in 2020 for SARS-CoV-2 infection with more than 225,000 survivors at risk for laryngotracheal complications. Conclusion: Laryngotracheal complications occur frequently after intubation for SARS-CoV-2. Earlier tracheostomy, use of smaller ETTs, and early injury identification through routine screening may limit the impact of functional laryngeal disability.