Pneumopericardium complicating pneumothorax therapy.

While complete absence of the pericardium is a very rare abnormality, which is sometimes found during a post-mortem examination, we believe that partial deficiency resulting in a pleuropericardial communication is probably not quite as uncommon as the meagre literature on the subject would indicate. Powell in 1869 first recorded a case of partial deficiency of the pericardium. In 1925 Moore found only sixty-four authentic cases of pericardial defect in the medical literature. Sixteen more examples have been noted by Grant (1926), Nicoli (1929), Watt (1931), Beck (1931), Egbert and Little (1935), and others. Diagnosis of this condition has been made during life on only three occasions. Ladd (1936), while operating for a diaphragmatic hernia in a two-year-old girl, found that her heart was devoid of its pericardium. Rusby and Sellors (1945) noticed a pneumopericardium when air was introduced in the left pleural sac as a preliminary to a thoracic operation, but "the full significance of this observation was not appreciated at the time," and the condition was elucidated on the operating table. Dahl (1937), while treating a case of pulmonary tuberculosis in a man aged 20, induced a left pneumothorax and on radiological examination found air in the pericardium as well as in the left pleural sac. He therefore concluded that there must have been a communication between the two cavities. This detection of a pneumopericardium during the course of artificial pneumothorax therapy is important, otherwise the possible existence of a pericardial defect remains unsuspected clinically. We report here two such cases. A third case, in which a pneumopericardium was simulated, is also described for purposes of discussion and differential diagnosis.