The presence of a mass in the cardiophrenic angle is almost always an incidental finding on an x-ray of the chest taken for another purpose. Special studies, i. e., laminagraphy and angiocardiography, usually do not reveal the nature of the mass, and exploratory thoracotomy is eventually performed. It has been possible to determine the nature of some of these lesions by the use of pneumoperitoneum.
The technique of inducing an artificial pneumoperitoneum has been described by several authors.1-4 In brief, the procedure we have used is described. The patient is placed in the supine position. The abdomen is prepared with benzal konium (Zepharin) and the left upper quadrant draped. A point midway between the left costal margin and the umbilicus is infiltrated with 2% procaine hydrochloride U. S. P.A 19-gauge needle 1½ in. long, attached to a 10 cc. syringe, is introduced into the abdominal wall to
BAKER DH, MAISEL B, GOLDBERG HP. Use of Pneumoperitoneum in Differential Diagnosis of Paracardiac Masses in Children. AMA Arch Surg. 1959;79(1):63–67. doi:10.1001/archsurg.1959.04320070067011