Bronchoscopic ultrasonography in the diagnosis of tracheobronchial invasion of esophageal cancer

Abstract

Objective: To study the usefulness of bronchoscopic ultrasonography in diagnosing tracheobronchial invasion of esophageal cancer and to compare it with endoscopic ultrasonography, bronchoscopy, and computed tomography.

Methods: We prospectively investigated 59 patients with newly diagnosed esophageal cancer located at or above the level of the tracheal bifurcation. A 20-MHz ultrasonic probe covered by a sheath with a balloon inflated with water was used for bronchoscopic ultrasonography. The presence of tracheobronchial invasion was diagnosed on the basis of an interruption in the most external hyperechoic layer of the tracheal bronchus.

Results: Bronchoscopic ultrasonography was completed without complications in all patients, but endoscopic ultrasonography was performed completely in only 44% of them. The overall accuracy rates for diagnosis of tracheobronchial invasion on the basis of bronchoscopy, bronchoscopic ultrasonography, endoscopic ultrasonography, and computed tomography were 78%, 91%, 85%, and 58%, respectively. Statistical examination showed that the accuracy of bronchoscopic ultrasonography and bronchoscopy was significantly greater than that of computed tomography, and the accuracy of bronchoscopic ultrasonography was greater than that of bronchoscopy.

Conclusions: Bronchoscopic ultrasonography is useful for evaluating cancer invasion into the tracheal bronchus. It is more accurate than the other methods and could be used to visualize the layered structure of the tracheal bronchus in all patients.