ENDOSCOPIC ARGON PLASMA COAGULATION FOR EXCESSIVE CENTRAL AIRWAY COLLAPSE: AN EXPERIMENTAL PILOT ANIMAL STUDY

Abstract

SESSION TITLE: Emerging Techniques for Interventional Pulmonary SESSION TYPE: Original Investigations PRESENTED ON: 10/20/2019 2:15 PM - 3:15 PM PURPOSE: Surgical stabilization of the airway through tracheobronchoplasty (TBP) is currently considered the treatment of choice for patients with symptomatic excessive central airway collapse (ECAC) despite optimal medical management (1–3). This highly invasive procedure is associated with a 3.2 % mortality rate and 40% morbidity (4). Bronchoscopic techniques hold potential as an appealing alternative for treatment of ECAC with less morbidity and mortality. Recently, we conducted an ex-vivo animal model showing that argon plasma coagulation (APC) produced preferable tissue effects (more pronounced thermal effect with avoidance of tissue erosion) at the posterior tracheal membrane as compared to electrocautery, radiofrequency ablation and potassium titanyl phosphate laser. METHODS: Two adult, sheep 35-40kg were used. Under flexible bronchoscopy an APC 2.3mm front firing probe was used to treat the posterior tracheal membrane. Precise effects 3, 5 and 7 were used. Posterior membrane was treated following a “dotted pattern”; the device was activated for 3 seconds at each treatment point. Four rows of three points with 1cm separation in between were created for each treatment effect. A margin of 2 centimeters was left in-between different effects. In the upper aspect of the trachea a single strafe for each effect was made activating the APC for 5 seconds. At day 3 post-procedure a chest CT-scan was performed. At 30 days, a flexible bronchoscopy was performed, the animals were sacrificed, and tissue was collected within 60 minutes, placed in formalin, and sectioned 24 hours later to evaluate histologic changes. RESULTS: Both animals tolerated the procedure without complications. Mean duration of the procedure was 28.5 minutes, with no technical difficulties. CT scans at day 3 showed no evidence of pneumomediastinum or pneumothorax. During the 30-day follow-up period, there were no signs of complications related to the procedure. Upon histological review, the, APC treated regions healed well, recapitulating near normal trachea, with significant coagulation effects and no evidence of erosion. However, compared to the untreated regions, APC treated regions demonstrated the following changes: squamous metaplasia within an attenuated epithelium, atrophy of the underlying seromucinous glands and superficial cartilaginous remodeling with chondrocyte injury. These distinct changes, while subtle, progressively worsened with each level increase of APC treatment. CONCLUSIONS: Bronchoscopic treatment of the tracheal posterior membrane with APC may be an effective alternative to TBP, with no short-term complications and adequate tissue regeneration observed. CLINICAL IMPLICATIONS: Additional assessment of the posterior membrane is ongoing to identify specific alterations in connective tissue which may be advantageous for tracheal stabilization in ECAC. DISCLOSURES: No relevant relationships by Jason Beattie, source=Web Response No relevant relationships by Fayez Kheir, source=Web Response Consultant relationship with Boston Scientific Please note: $1001 - $5000 Added 03/16/2019 by Adnan Majid, source=Web Response, value=Consulting fee Consultant relationship with olympus Please note: $5001 - $20000 Added 03/16/2019 by Adnan Majid, source=Web Response, value=Consulting fee Consultant relationship with pinacle biologics Please note: $1001 - $5000 Added 03/16/2019 by Adnan Majid, source=Web Response, value=Consulting fee Consultant relationship with cook medical Please note: $1001 - $5000 Added 03/16/2019 by Adnan Majid, source=Web Response, value=Consulting fee No relevant relationships by Daniel Ospina-Delgado, source=Web Response Advisory Committee Member relationship with Foundation Medicine Please note: $1001 - $5000 Added 03/15/2019 by Paul VanderLaan, source=Web Response, value=Consulting fee Consultant relationship with Gala Therapeutics Please note: $5001 - $20000 Added 03/15/2019 by Paul VanderLaan, source=Web Response, value=Consulting fee No relevant relationships by Barbara Vidal, source=Web Response