Hyperbaric oxygen therapy to prevent central airway stenosis after lung transplantation

• Published in: The Journal of heart and lung transplantation Vol. 40; no. 4; pp. 269 - 278
• Main Authors: Kraft, Bryan D., Mahmood, Kamran, Harlan, Nicole P., Hartwig, Matthew G., Snyder, Laurie D., Suliman, Hagir B., Shofer, Scott L.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2021
• Subjects: Adult; Aged; Airway Obstruction - diagnosis; Airway Obstruction - etiology; Airway Obstruction - prevention & control; Biopsy - methods; Bronchi - pathology; Bronchoscopy; cell hypoxia/genetics; Female; Follow-Up Studies; gene expression; Graft Rejection - complications; Graft Rejection - diagnosis; Humans; hyperbaric oxygenation; Hyperbaric Oxygenation - methods; lung transplantation; Lung Transplantation - adverse effects; Male; Middle Aged; post-operative complications; Postoperative Complications - diagnosis; Postoperative Complications - etiology; Postoperative Complications - prevention & control; Treatment Outcome; Young Adult; post-operative complications; lung transplantation; hyperbaric oxygenation; gene expression; cell hypoxia/genetics
• ISSN: 1053-2498; 1557-3117; 1557-3117
• DOI: 10.1016/j.healun.2021.01.008

Central airway stenosis (CAS) is a severe airway complication after lung transplantation associated with bronchial ischemia and necrosis. We sought to determine whether hyperbaric oxygen therapy (HBOT), an established treatment for tissue ischemia, attenuates post-transplant bronchial injury. We performed a randomized, controlled trial comparing usual care with HBOT (2 atm absolute for 2 hours × 20 sessions) in subjects with extensive airway necrosis 4 weeks after transplantation. Endobronchial biopsies were collected at 4, 7, and 10 weeks after transplantation for a quantitative polymerase chain reaction. Coprimary outcomes were incidence of airway stenting and acute cellular rejection (ACR) at 1 year. The trial was stopped after enrolling 20 subjects (n = 10 per group) after a pre-planned interim analysis showed no difference between usual care and HBOT groups in stenting (both 40%), ACR (70% and 40%, respectively), or CAS (40% and 60%, respectively). Time to first stent placement (median [interquartile range]) was significantly shorter in the HBOT group (150 [73–150] vs 186 [167–206] days, p < 0.05). HIF gene expression was significantly increased in donor tissues at 4, 7, and 10 weeks after transplantation but was not altered by HBOT. Subjects who developed CAS or required stenting had significantly higher HMOX1 and VEGFA expression at 4 weeks (both p < 0.05). Subjects who developed ACR had significant FLT1, TIE2, and KDR expression at 4 weeks (all p < 0.05). Incidence of CAS is high after severe, established airway necrosis after transplantation. HBOT does not reduce CAS severity or stenting. Elevated HMOX1 and VEGFA expressions appear to associate with airway complications.