D104-06 Extrinsic Airway Compression and Excessive Dynamic Airway Collapse (EDAC): Lessons From Two Lung Transplant Recipients

Abstract Tracheobronchial compression and EDAC secondary to pulmonary artery (PA) enlargement are rare but potentially life-threatening complications in patients with severe pulmonary hypertension (PH). Herein we present two patients cases, the first patient had mixed connective tissue disease (MCTD) associated interstitial lung disease (MCTD-ILD) and severe PH and underwent bilateral orthoptic lung transplant (BOLT) and in the post-operative period was found to have extrinsic compression of the left mainstem bronchus from native pulmonary artery. The second case is that of a patient with severe pulmonary arterial hypertension (PAH) who underwent BOLT and was found to have tracheal compression from enlargement of the main pulmonary artery. Case 1 A 61-year-old woman with MCTD-ILD and severe PH underwent BOLT. At post-operative day 6, surveillance bronchoscopy revealed healthy anastomotic sites bilaterally, and luminal narrowing with ∼75% collapse of left mainstem bronchus without an evidence of endobronchial mass (Figure 1). Chest computed tomography showed enlarged PA compressing on left mainstem. Subsequent surveillance bronchoscopy again showed narrowing of the left mainstem bronchus. Patient was put on non-invasive positive pressure ventilation (NIPPV) and positive end expiratory pressure was increased in increments of 2, from 2 to 10 cm H2O, which helped minimally with the diameter change of the left mainstem bronchus. Similarly, elevation of the head of the bed during bronchoscopy did not lead to a change in diameter of the left mainstem. Case 2 A 51-year-old female with severe PAH underwent BOLT. Post-operative course was complicated by excessive work of breathing post-extubation, requiring re-intubation and eventually requiring tracheostomy. Post-transplant surveillance bronchoscopy revealed healthy anastomotic sites bilaterally, and EDAC at the lower half of the trachea. After one of the surveillance bronchoscopies, the patient developed increased work of breathing and respiratory distress requiring intubation and admission to the intensive care unit. She was successfully extubated to NIPPV. She was started on nightly NIPPV to help decrease work of breathing while sleeping. Surveillance for rejection was subsequently conducted using cell-free DNA (cfDNA) testing. The first case highlights severe PA enlargement causing extrinsic airway compression and the second case highlights new diagnosis of EDAC post-lung transplantation. Use of NIPPV can be helpful. Careful review of prior imaging is helpful before performing bronchoscopy. Procedures in patients at risk of decompensation should be conducted in a controlled environment such as the operating room rather than the bronchoscopy suite. Noninvasive technologies like cfDNA may aid in post-transplant surveillance and warrant further evaluation in clinical studies. This abstract is funded by: None