General anesthesia
The patients’ were monitorisation was performed according to ASA standards. 0.03 mg/kg intravenous (iv) midazolam was given to the patients. After preoxygenation, 2 mg/kg propofol, 1.5 mcg/kg fentanyl, and 0.1 mg/kg vecuronium were administered for anesthesia induction. Intubation was performed with an appropriate-sized left double-lumen tube and the location of the tube was confirmed by fiberoptic bronchoscopy. Sevoflurane inhalation and remifentanil infusion (0.01–0.20 mcg/kg/min) were used for anesthesia maintenance. Sevoflurane inhalation and remifentanil infusion were adjusted to maintain the target heart rate and blood pressure within 20% from basal measurements. Biportal VATS was applied to the patients and a single chest tube was inserted.