Pneumothorax complicating laparoscopic ureterolysis

In a 71-year-old female marked left-sided ureteral stenosis secondary to retroperitoneal fibrosis was diagnosed. Since conservative therapy with cortisone had failed, laparoscopic ureterolysis was performed. Following tracheal intubation the lungs were ventilated with 40 vol% O2 in air and isoflurane 0.5-2%, using a positive end-expiratory pressure of 6 cm H2O. A CO2 pneumoperitoneum was established with a pressure-controlled high-flow insufflator; the intraabdominal pressure during the procedure was 14 mm Hg. Two hours after gas instillation, the peak airway pressure increased from 22 to 40 cm H2O, and the PaCO2 from 45 to 70 mm Hg. Breath sounds over the right lung were no longer heard, and subcutaneous emphysema was noted over the neck and face. An intraoperative chest X-ray confirmed a right pneumothorax. Following peritoneal gas evacuation, the PaCO2 returned to 35 mm Hg, the subcutaneous emphysema diminished, and a repeat chest X-ray showed complete resolution of the pneumothorax. The course of this event led us to the conclusion that the pneumothorax was due to diffusion of CO2 from the peritoneal to the pleural cavity through congenital defects in the diaphragm. Ureterolysis could be continued by laparotomy.