Air Bubble Sign: A New Screening Method for Anastomotic Leakage After Esophagectomy for Esophageal Cancer

Background: Contrast esophagography often is performed to screen for anastomotic leakage (AL) after esophagectomy. However, its sensitivity remains low. Adverse events also have been reported. This report describes a new screening method to detect AL on computed tomography (CT) after esophagectomy. Methods: From January 2012 to December 2015, 185 patients with esophageal cancer underwent surgical resection at the authors’ institution. The study comparatively reviewed patient characteristics, surgical outcomes, and findings from postoperative CT images and contrast esophagrams of 142 patients who underwent esophagectomy followed by primary gastric conduit reconstruction through a posterior mediastinum route. Results: In this study, 24 patients (15.5%) had AL (leakage-positive group), and 120 patients (84.5%) did not (leakage-negative group). Both groups had comparable backgrounds. The number of air bubbles around the anastomotic site and the mediastinal space on postoperative CT images were significantly greater in the leakage-positive group than in the leakage-negative group. The cutoff value for the number of air bubbles required for a positive diagnosis of AL (“air bubble sign”) was calculated to be 3 by receiver operating characteristic curve. Compared with contrast esophagography, the air bubble sign on CT demonstrated a significantly higher sensitivity (86.4 vs. 50.0%) and an equivalent specificity (95.8 vs. 100.0%). Contrast esophagography altered the postoperative management of only five patients (3.5%). Conclusions: A positive air bubble sign on CT is an objective and noninvasive screening method for AL after esophagectomy for esophageal cancer and may replace contrast esophagography as a screening test for AL.