Where is All This Air Coming from? A Rare Case of Pneumatosis Intestinalis with Extensive Pneumoperitoneum and Pneumomediastinum in Lung Transplant Patient Secondary to Mycophenolate Therapy

Abstract

<h3>Introduction</h3> Pneumatosis intestinalis (PI) is rare phenomenon following lung transplantation. Most common causes identified are bowel perforation and bowel ischemia. Here we present a case of PI likely secondary to mycophenolate mofetil (MFM). <h3>Case Report</h3> 60-year-old man 4 months post bilateral lung transplant for idiopathic pulmonary fibrosis, course complicated by primary graft dysfunction grade, vocal cord paralysis, gastroparesis status post percutaneous endoscopic transgastric jejunostomy 10 weeks prior, admitted with nausea, vomiting, and abdominal pain. His immunosuppressive therapy consisted of tacrolimus, mycophenolate, and prednisone. On presentation patient was hemodynamically stable and afebrile, lactic acid was normal. Imaging with computed tomography (CT) of the abdomen and pelvis, which was significant for extensive pneumoperitoneum, pneumatosis intestinalis (PI) of the ascending and transverse colon. Patient underwent diagnostic laparoscopy and primary repair of umbilical hernia; surgical exploration revealed no perforated viscous or bowel ischemia. He was treated with antibiotics prophylactically. Initial lab work showed no systemic signs of infection, he was afebrile, blood cultures and stool studies were negative. Mycophenolate was discontinued initially, and he was started on Azathioprine few days later. Given the CT findings in conjunction with surgical findings, no systemic signs of infection, clinical improvement after cessation of MFM, and repeat CT 5 days later showing significant improvement in pneumoperitoneum and pneumatosis intestinalis. <h3>Summary</h3> PI has an incidence of 0.03% in the general population and can be caused by various conditions. Clinical symptoms can range from benign to life threatening. Incidence of PI post lung transplant 2.68% mostly secondary to perforated viscus requiring surgical resection. MFM is an unusual cause of PI. The pathogenesis remains unknown.