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.