Foreign body entrapment in the esophagus of healthy subjects--a manometric and scintigraphic study

Foreign body entrapment and mucosal injury caused by oral medications are increasingly reported to occur in the upper esophagus in apparently normal subjects. We performed esophageal manometry in 40 normal volunteers to determine whether a unique motility pattern in the upper third of the esophagus predisposes to entrapment of foreign bodies at this site; 18 normal volunteers also had transit scintigraphy of a gelatin capsule filled with a radionuclide. The esophageal body was divided into five consecutive segments starting proximally, with each segment corresponding to 20% of the total length. Amplitude, slope, and velocity of the esophageal contraction were markedly decreased in the second segment compared with the other segments. Entrapment and dissolution of a gelatin capsule occurred in 39% of volunteers in the proximal esophagus correlating to the second segment, i.e., the segment with the lowest amplitude, slope, and velocity of esophageal contractions. The observation that wet swallows have greater amplitudes (P less than 0.01) and steeper slopes (P less than 0.05) than dry swallows explains why the occurrence of pill entrapment was reduced when taken with sufficient water. However, even with a water chaser of 120 mL, pill entrapment occurred at the second segment of the esophagus in 1 of 18 volunteers. The observed motility pattern in the proximal esophagus provides a better explanation for the entrapment of foreign bodies at this site than compression of the esophagus by the left main stem bronchus, aortic arch, or left atrium as suggested by other investigators.