Representation of the circumferential distribution of small lower esophageal lesions by defining the position of the right wall in the esophageal hiatus.

BACKGROUND: The reliability of methods to identify the circumferential position of small lower esophageal lesions remains unknown. We prospectively investigated a new method for distinctively presenting 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, setting the greater curvature folds at the upper gastric corpus horizontal on the endoscope monitor display. The scope was retrogressed into the lower esophagus. At this point, the right wall at the hiatus may be 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. The angle between the R- and LC-lines (R-LC) was measured. RESULTS: Seventy-seven patients were examined after excluding 7 with >2-cm hernias and 3 with esophageal stenosis. R-LC angles ranged between -38 degrees and +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 may be an error of +/-30 min (+/-15 degrees ); therefore, R- and LC-lines were demonstrated to be identical using an equivalence test. CONCLUSIONS: Using this method, the circumferential position of small lower esophageal lesions may be reliably represented as a clock face.