The E-G junction. Two Sphincters

I studied the esophagogastric junction in fresh and preserved cadaveric specimens in the infant, adolescent and adult as well as by reverse gastroesophagoscopy, both intraoperatively and postoperatively, on unanesthetized patients. Cut sections of fresh specimens of the lower esophagus consistently showed an increased thickness of the lower 2-3 cm of the inner circular muscle layer of the esophagus. The layers are more firmly fused at this level and a color change is evident. From the serosal surface, a slight whitish indenture marks this area. From the mucosal surface, this area is the level of the transition zone. This is the lower esophageal sphincter. Reverse gastroscopy performed via a mature gastrostomy enabled me to identify and photograph a diaphragmatic sphincter and a lower esophageal sphincter.