After general anesthesia, an 8.0 mm internal-diameter single-lumen endotracheal tube was inserted orally. An independent Coopdech bronchial blocker, which has a formed-curvature near the catheter tip, was directly inserted through the single-lumen endotracheal tube into right main bronchus. Chest inspection, auscultation, fiberoptic bronchoscopy confirmation, if necessary, by visualizing the blocker cuff located at right main bronchus just below the carina was performed firstly. After placing patients in left decubitus position, the position of BB was reconfirmed by auscultation firstly; then complete collapse of the right upper lobe was adjust, if necessary and reconfirmed on the video of thoracoscopy by both surgeon and anesthesiologists. The depth of BB and the need of fiberoptic bronchoscope were recorded. All the patients were extubated in operation room after completion of operation with optimal analgesia. Data collected included; age, sex, body height and weight and the depth of right-sided BB from incisor was then recorded.