Probe EUS for the diagnosis of invasion depth in superficial esophageal cancer: A comparison between a jelly-filled method and a water-filled balloon method

Background and Objective: Diagnostic accuracy of probe EUS depends on the constant maintenance of luminal medium for acoustic coupling. This study compared the accuracy of probe EUS by a jelly-filled method (EUS-J) and by a water-filled balloon method (EUS-W) for the assessment of invasion depth in superficial esophageal cancer. Design and Setting: A prospective, single-center study. Patients: Forty superficial esophageal cancers in 38 patients. Interventions: Patients were alternately assigned to EUS-J or EUS-W. The depth of invasion was classified into epithelium or lamina propria mucosae (D1), muscularis mucosae or superficial layer of the submucosa (D2), and deep portion of the submucosa (D3). Depiction rate, interobserver variation between 2 observers, and accuracy for the determination of invasion depth were compared between EUS-J and EUS-W. Main Outcome Measurements and Results: Eighteen cancers were examined by EUS-J, and 22 cancers were examined by EUS-W. The actual depth of invasion was D1 in 21 cancers, D2 in 9 cancers, and D3 in 10 cancers. Depiction rate (94.4% vs 77.2%, P = .14) and interobserver agreement of EUS determination (82.3% vs 58.8%, P = .13) was higher in EUS-J than in EUS-W. The overall accuracy for the diagnosis of invasion depth was 77.8% in EUS-J and 59.1% in EUS-W (P = .18). The sensitivity for the diagnosis of D1 cancer was significantly higher in EUS-J than in EUS-W (100% vs 50%, P = .03), while the specificity was not different between the 2 procedures (81.8% vs 87.5%). Conclusions: EUS-J is superior to EUS-W for the assessment of invasion depth in superficial esophageal cancer, especially for intramucosal cancer.