Bronchoscopy is an important diagnostic and therapeutic tool in the management of the lung transplant patient. Surveillance bronchoscopy detects early rejection, airway colonization and airway infections, but does carry a risk of serious complications include bleeding and pneumothorax. Post biopsy fluoroscopic imaging is usually done to rule out pneumothorax. We hereby present two cases that developed a delayed pneumothorax despite negative fluoroscopic imaging. A 63 year old male status post bilateral lung transplant for idiopathic pulmonary fibrosis presented to the clinic with dyspnea on exertion and a 30 % drop in his FEV1. Two weeks prior to this presentation on post-op day 14 he underwent an uneventful surveillance bronchoscopy with transbronchial biopsies followed by a negative fluoroscopic check for pneumothorax. His chest x-ray at presentation to clinic revealed bilateral pneumothorax. Therefore a pleural pigtail catheter was placed and patient noted marked improvement in his symptoms. His donor records did not reveal any predisposing factors for a spontaneous pneumothorax. A 67 year old male status post bilateral lung transplant for pulmonary fibrosis presented to the lung transplant clinic with complaints of exertional dyspnea for 2 weeks following his bronchoscopy. He had a surveillance biopsy performed with negative fluoroscopic imaging following on post-op day 10. Upon presentation his home spirometry numbers were 20% lower than baseline and his chest xray revealed bilateral pneumothorax and pneumopericardium. A pleural pigtail was placed and his dyspnea promptly resolved. A 2D echo did demonstrate signs of tamponade. His donor\u27s records did not show any history of bullae or spontaneous pneumothorax. The risk of acute pneumothorax following transbronchial biopsies is reported between 8 to 61% and is described within the first four hours following bronchoscopy. Delayed pneumothorax is a very rare complication with an incidence of 1.4 to 4.5% with most cases reported within the first 24 hours. The proposed mechanism is secondary to fibrinolysis of blood clots that was sealing the biopsy site. Other postulated contributory factors include underlying infection or subpleural blebs. Our cases are unique with a long delay from the transbronchial biopsy time and clinical presentation. Whether there is a role of immunosuppression contributes to the delayed presentation deserves further study. These cases illustrate the need to still consider pneumothorax in the differential of dyspnea in a lung transplant patient irrespective of timing of the last lung biopsy
