In vivo comparison of esophageal varices at and above the diaphragmatic high pressure zone using high resolution endoluminal sonography.

Our objective in this study was to use high resolution endoluminal sonography to compare the size of esophageal varices within 5 cm of and at the esophageal high pressure zone. We carried out the study in 36 patients with endoscopically proven esophageal varices. A 20-MHz 6.2F ultrasound catheter was passed through a 34F endoscope and used to image esophageal varices as it was slowly withdrawn through the high pressure zone (the level at which the diaphragm was imaged) and into the body of the esophagus approximately 5 cm above the high pressure zone. All images were captured on videotape and reviewed by one of the investigators. The mean, total, and percent cross-sectional surface areas occupied by varices were calculated and then compared within 5 cm and at the esophageal high pressure zone. Six of 36 (17%) patients had no varices imaged at the high pressure zone but did have varices imaged in the distal esophagus. The mean cross-sectional surface area per varix at the high pressure zone (0.036+/-0.006 cm2) was significantly less (p < or = 0.0001) than the mean cross-sectional area per varix 5 cm above the high pressure zone (0.142+/-0.018 cm2). The average total cross-sectional surface area occupied by varices at the high pressure zone (0.137+/-0.034 cm2) was significantly less (p < 0.0001) than the average cross-sectional surface area occupied by varices 5 cm above the high pressure zone (0.672+/-0.080 cm2). The mean percent esophageal wall cross-sectional surface area occupied by varices at the high pressure zone (16%) was significantly less (p < or = 0.0001) than 5 cm above the high pressure zone (49%). We conclude that the mean, total, and percent cross-sectional surface areas of esophageal varices at the high pressure zone are significantly less than those 5 cm above the high pressure zone.