Pneumothorax Ex Vacuo or Trapped Lung Associated With Hepatic Hydrothorax

Abstract

INTRODUCTION: We report six observations of pneumothorax ex-vacuo or "trapped lung" associated with hepatic hydrothorax in patients with end-stage liver disease (ESLD). In all cases, the diagnosis of "trapped lung" was made based on the presence of a pneumothorax or hydropneumothorax after evacuation of a long-standing hepatic hydrothorax and failure of the lung to re-expand after chest tube placement. While pneumothorax ex-vacuo is a known phenomenon in the setting of malignant effusions, to our knowledge, it has never been described in association with hepatic hydrothoraces. In one of our observed cases, the lung remarkably expanded without intervention after orthotopic liver transplantation (OLT). CASE PRESENTATION: A 24-year-old Hispanic male with hepatitis C contracted at birth subsequently developed ESLD complicated by variceal bleeding, portal hypertension, ascites, and a persistent right-sided hepatic hydrothorax requiring frequent thoracenteses. Given his refractory effusions, an indwelling Pleur-x catheter was placed at an outside institution 8 months prior to his OLT for self-drainage of the effusion at home. The Pleur-x catheter was removed 1 month after its placement, and he was managed with diuretics and therapeutic thoracenteses as needed. He subsequently underwent an uncomplicated OLT, and a pre-operative chest x-ray revealed a large, chronic, right-sided pleural effusion. He was successfully extubated after OLT, and thus, no intervention was performed on the effusion. However, on post-operative day 5, the patient developed respiratory distress with new, left-sided infiltrates consistent with pneumonia. He was placed on antibiotics, and a right-sided therapeutic thoracentesis was performed with removal of 1.3 liters of fluid. Post-thoracentesis, he had a large hydropneumothorax suspicious for a pneumothorax ex-vacuo. A small-bore chest tube was inserted and placed on suction without any additional re-expansion of the lung or any change in his respiratory status. The chest tube was removed 2 days later, and a subsequent chest CT confirmed the presence of a large, right hydropneumothorax with underlying visceral and parietal pleural thickening/fibrosis. This caused restriction and constriction of the underlying right lung, i.e. "trapped lung". His respiratory status fortunately improved with antibiotic treatment of his left-sided pneumonia. During the hospitalization, the thoracic surgery service was consulted for possible video-assisted thoracoscopic surgery (VATS), but the decision was made to defer the surgery until his immunosuppression was tapered. He was discharged home on post-operative day 20 without the need for supplemental oxygen. Repeat chest x-rays at 1 month showed improvement in the hydropnemothorax and at 6 months showed near-complete re-expansion of his right lung without any surgical intervention. Five other cases of pneumothorax ex-vacuo or "trapped lung" have been seen at our institution. DISCUSSIONS: We describe the first case series of pneumothorax ex-vacuo or "trapped lung" occurring in the setting of hepatic hydrothorax. Previously, this phenomenon has only been reported in the setting of malignant pleural effusions, which are associated with a poor prognosis. Similar to experiences seen with pneumothorax ex-vacuo in malignant effusions, chest tube placement in this setting does not result in lung re-expansion. Surgical intervention can carry significant mortality and morbidity in patients with ESLD due to their underlying coagulopathy, and the ideal management remains undefined. As described above, one patient remarkably had spontaneous resolution of his "trapped lung" after liver transplantation. CONCLUSION: To our knowledge, this is the first case series reported of the development of pneumothorax ex-vacuo in association with hepatic hydrothorax. Awareness of this phenomenon in ESLD patients with recurrent hepatic hydrothoraces and the various options for its management (including observation) are important for clinicians to be cognizant of.