Manometric studies were performed in 1.2 unanesthetized dogs with the left sided esophagostomy and additional operative procedures of 3 different types; (A) division of the phrenico-esophageal ligament, (B) division of the phrenico-esophageal ligament and the modified Heller's esophago-cardiomyotomy (4 cm), and (C) intrathoracic lower esophagomyotomy (6 cm) just above the diaphragm. The resting pressure in the esophago-gastric junction were then measured.
After division of the phrenico-esophageal ligament, the resting pressure in the esophago-cardiac sphincter fell from 13.2 to 4.8 cm H2O. After lower esophagomyotomy no obvious changes were noted in the resting pressure.
The phrenico-esophageal ligament plays an important role in producing the high pressure zone in the esophago-gastric junctional area.