Warming barium sulfate improves esophageal leak detection in pig model.

BACKGROUND: Barium esophagograms have poor sensitivity in detecting leaks. We hypothesized that heating barium would decrease viscosity, facilitate extravasation, and enhance its sensitivity in detecting esophageal leaks.

METHODS: We characterized the viscosity of barium at increasing temperatures. We measured the radiopacity of barium at 25°C and 50°C. We determined the smallest diameter defect in esophagus that barium can detect by perforating a porcine esophageal segment with angiocatheters of various diameters, injecting barium at 25°C, and observing extravasation of contrast. We repeated this with barium heated to 30°C, 40°C, 50°C, and 70°C. To determine the ability of barium to detect a staple line leak, we perforated a stapled esophageal segment by air insufflation, injected barium at different temperatures, and monitored extravasation. We used Visipaque, a water-soluble contrast agent, for comparison in all experiments.

RESULTS: The viscosity of barium decreased with increasing temperature. The radiopacity of barium did not change with increasing temperature and was higher than that of Visipaque (P < 0.001). The size of the smallest detectable leak decreased from 2.1 mm with barium at 25°C to 1.3 mm at 40°C and 1.1 mm with Visipaque (P < 0.0001). The sensitivity of staple line leak detection increased from 0% for barium at 25°C to 80% (P = 0.02) with barium at 40°C. There was no significant difference in sensitivity between barium at 40°C and Visipaque.

CONCLUSIONS: Barium warmed to 40°C offers the best sensitivity of esophageal leak detection without compromising radiopacity. Barium at 40°C may be the optimum choice for swallow study to detect esophageal leaks.