Transient serosal enhancement mimicking pneumoperitoneum

Abstract

Sir, In a prior issue of this journal, we reported two cases of a novel enhancement pattern involving the pericardium, peritoneum and soft tissues seen on radiographs in the early post-cardiac catheterization period [1]. Knowledge of this phenomenon is clinically important because the enhancement pattern renders a relative lucency over the liver. We report a third case of this radiographic phenomenon that mimicked the appearance of pneumoperitoneum and led to an exploratory laparotomy. A baby girl with hypoplastic left heart variant including a double-outlet right ventricle and restrictive atrial septum was born by cesarean section at 37 2/7 weeks to a gravida I para I woman. Cardiac catheterization was performed on the day the child was born for stent placement into veins decompressing into the left atrium. At 5 days old, the newborn was taken for a Norwood/Sano procedure and atrial septectomy. A complicated post-operative course followed, including renal insufficiency, respiratory failure, poor cardiac function, acidosis and delayed sternotomy closure. The infant was taken back to the cardiac catheterization lab to evaluate the pulmonary veins. A radiograph of the chest and abdomen obtained within 24 h of completion of the cardiac catheterization suggested the presence of free intraperitoneal air, characterized by a conspicuous relative lucency over the right upper quadrant (Fig. 1). A left lateral decubitus view did not confirm the presence of pneumoperitoneum. However, given the suggestive findings of pneumoperitoneum on the supine radiograph and the infant’s clinical condition, the child was taken to the operating room. Findings during the exploratory laparotomy were negative. The classic findings of pneumoperitoneum on supine abdominal radiography include radiolucency over the liver [2].