(1696) Asymptomatic Pneumothorax and Pneumomediastinum in a Lung Transplant Patient: Watch or Act Now?

Introduction: Pneumothorax soon after lung transplantation (LT) is common and typically due to airway anastomotic complications leading to air leaks. However, spontaneous pneumothorax occurring long after LT is rare and less understood. Contributing factors include chronic lung allograft dysfunction (CLAD), infections, and mechanical stress on lung tissues. We present a case of pneumothorax with pneumomediastinum in an LT recipient several years after transplant presenting with ongoing gastrointestinal issues.

Description: A 73-year-old woman with hypersensitivity pneumonitis with history of bilateral LT 6 years prior, now with features of CLAD, presented to the ED with 3 days of intractable nausea, vomiting, and diarrhea. On admission, she was tachycardic, but her vital signs, physical exam, and lab tests, including an infectious work-up for C. difficile, were otherwise unremarkable. An abdominal/pelvic CT showed fluid-filled loops of the bowel, likely due to colitis. She was treated conservatively, improve, and was discharged. At her LT clinic follow-up 2 weeks later, she reported dry heaving and shortness of breath but denied violent coughing. A chest CT revealed a new pneumomediastinum and left pneumothorax with gas tracking into the left chest soft tissues, raising concerns of bronchial dehiscence. Bronchoscopy showed a normal airway and intact anastomoses, with washings indicating acute inflammation but no infection. Endoscopy to rule out Boerhaave syndrome (given gastrointestinal symptoms and new CT findings with no inciting factors) showed an unremarkable esophagus. With just close monitoring and oxygen supplementation, subsequent chest X-rays showed resolving pneumothorax and pneumomediastinum with no further intervention.

Discussion: Spontaneous pneumothorax is an uncommon late LT complication that can result from CLAD. CLAD phenotypes include bronchiolitis obliterans syndrome (BOS) and restrictive allograft syndrome (RAS). In BOS, airway obstruction and overinflation, and in RAS, fibroelastosis, causes localized areas of weakness and stiffening, leading to alveolar rupture. Small pneumothoraces may progress to pneumomediastinum as air migrates into subcutaneous tissue. Pneumothorax years after LT may be a manifestation of CLAD and necessitates further CLAD work-up.