Abstract
During laparoscopic repair of massive hiatus hernia, surgical dissection can breach the parietal pleura allowing insufflating carbon dioxide to rapidly expand the pleural space, causing a tension pneumothorax. This extrapulmonary pneumothorax involves no damage to the lung parenchyma. Its rapid resolution is aided by the high solubility of carbon dioxide and it will not refill once the procedure is completed. In this series of 50 massive hiatus hernia repairs the incidence of pneumothorax was 22% (11/50), with two of these being bilateral. Cardiovascular compromise occurred in 91% of those (10/11). The aetiology, pathophysiology and management of this intraoperative capnothorax differ significantly from that of a pneumothorax secondary to lung trauma or occurring during other types of laparoscopy. Understanding the relevant pleural anatomy and pathophysiology of this condition allowed conservative management in all cases and avoided the need for chest drains, open surgery or abandonment of the procedure.