The Impact of Balloon Use during Endobronchial Ultrasound: A Randomized Pilot Study

Introduction: During endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA), a saline-filled balloon placed over the tip of the bronchoscope is used to improve coupling of the ultrasound transducer to the airway wall. However, it is unknown whether it objectively improves image quality or affects procedural outcomes. Our aim was to establish whether the use of a balloon during EBUS impacts image quality, diagnostic yield, procedure duration or complications. Methods: A pilot randomized control trial of patients undergoing EBUS-TBNA of mediastinal lymph nodes was performed at a single academic center. Patients were randomized to use a saline-filled balloon (versus no balloon use) during EBUS-TBNA of the right lower paratracheal lymph node (station 4R). The EBUS videos were recorded and scored on a 4-point Likert scale by three blinded external reviewers. The primary outcome of this study was ultrasound image quality. Secondary outcomes included diagnostic yield, procedure duration, and complications. Results: Forty-six patients were randomized. In the balloon group, 61% of patients had an image quality score of “excellent” or “good,” compared to 47% in the no balloon group (p = 0.009). There was no significant difference in diagnostic yield, procedure duration, or complications between the groups. Conclusion: Inflation of the balloon during EBUS-TBNA at the right lower paratracheal lymph node improves ultrasound image quality but does not impact diagnostic yield, procedure duration, or safety. This study provides a framework for additional studies with complete nodal assessment to determine if balloon use has a clinically meaningful benefit to procedural outcomes.