Defining The Position Of The Right Wall Of The Esophageal Hiatus To Identify The Circumferential Distribution Of Small Lesions Of The Lower Esophagus

Background: The reliability of methods for identifying the circumferential position of small lower esophageal lesions is unknown. We prospectively investigated a new method that presents lesion positions as times on a clock face.Methods: Eighty-seven patients were consecutively examined by endoscopy. After observing the esophagus, an endoscope was inserted into the stomach and fixed, and the greater curvature folds at the upper gastric corpus were set as horizontal on the endoscope monitor display. The scope was retrogressed into the lower esophagus. At this point, the right wall at the hiatus is at the 3 o'clock position (R-line). The scope was then retrogressed from the gastric angle to the cardia along the center of the lesser curvature in the retroflexed view to obtain the LC-line (the center of the lesser curvature at the cardia). The LC-line in the esophageal hiatus in the frontal view was then identified, and the angle between the R- and LC-lines (R-LC) was measured.Results: After excluding 7 patients with hernias >2 cm and 3 with esophageal stenosis, data from 77 patients were analyzed. The R-LC angle ranged from -38 degrees to +35 degrees. The mean R-LC angle was -0.3 degrees +/- 15.9 degrees, and its 95% confidence interval was [-4.0 degrees, 3.3 degrees] within [-15 degrees, + 15 degrees]. When indicating lesion locations as times on a clock face, there was an error of +/- 30 min (+/- 15 degrees); therefore, R- and LC-lines were shown to be identical on an equivalence test.Conclusions: This new method allows the circumferential position of small lower esophageal lesions to be reliably represented as a clock face.