Endobronchial Ultrasound Application for Diagnosis of Tracheobronchial Tree Invasion by Esophageal Cancer

INTRODUCTION: Esophageal cancer staging has been performed through bronchoscopy, computerized tomography (CT), positron emission tomography (PET), and endoscopic ultrasound (EUS). Whereas CT and PET scan provide assessments of distant metastasis, bronchoscopy importantly diagnoses tracheobronchial involvement, complementing chest CT findings. EUS is the most accurate examination for T and N staging but is technically limited when tumoral stenoses cannot be traversed. Endobronchial ultrasound (EBUS) appears to present greater accuracy than EUS, CT, and bronchoscopy for assessing tracheobronchial wall involvement. EBUS has been recently associated with EUS for esophageal cancer staging in our unit. OBJECTIVE: To compare EBUS findings in esophageal cancer patients without evident signs of tracheobronchial invasion on conventional bronchoscopy with EUS and CT. METHODS: Fourteen patients with esophageal cancer underwent CT, conventional bronchoscopy, EUS, and EBUS for preoperative staging. All patients underwent EBUS and EUS with an Olympus® MH-908 echoendoscope at 7.5 MHz. Seven patients were eligible for the study according to the inclusion criteria. RESULTS: The echoendoscope could not traverse tumoral esophageal stenosis to perform EUS in two patients, and invasion was effectively diagnosed by EBUS. In 4 (57%) of 7 patients EBUS revealed additional information to staging. In the remaining 3 cases the invasion findings were the same under both EUS and EBUS. CONCLUSION: EBUS showed signs of tracheobronchial invasion not observed by conventional bronchoscopy, adding information to staging in most of the cases when compared with CT and EUS.