Efficacy and Safety of the Visual Bronchial Blocker for Lung Isolation Surgery

This multicenter, prospective, randomized, controlled clinical trial is initiated by the First Affiliated Hospital of Zhejiang University School of Medicine, with participation from Peking Union Medical College Hospital, the Fourth Affiliated Hospital of Harbin Medical University, Harbin Medical University Cancer Hospital, and Shanxi Bethune Hospital. The study aims to compare the first-attempt placement success rate between visual bronchial blockers (VBB, test group) and conventional bronchial blockers (CBB, control group) during anesthesia for thoracic surgery, and to evaluate operational efficiency, lung isolation quality, and safety profiles. A total of 652 patients aged ≥18 years with ASA physical status I-III, scheduled for elective pulmonary, esophageal, or mediastinal surgery requiring lung isolation, will be enrolled in a 1:1 ratio (326 per group), with a 10% anticipated dropout rate. Key exclusion criteria include anomalous right upper lobe bronchial origin, severe airway anatomical abnormalities, bronchial sleeve resection, empyema, bronchopleural fistula, previous thoracic surgery altering bronchial anatomy, severe cardiopulmonary dysfunction (metabolic equivalent \<4), severe psychiatric disorders, and concurrent participation in other clinical trials. Following standardized anesthesia induction with rocuronium (2-3 × ED95), patients undergo tracheal intubation using a video laryngoscope. In the CBB group, placement is guided by blind probing and auscultation, with confirmation via fiberoptic bronchoscopy (FOB). In the VBB group, placement is performed under direct vision using the integrated camera, with FOB rescue allowed only if visualization fails (rescue cases are counted as failures). Placement success is defined as the cuff located in the ipsilateral main bronchus with the proximal cuff edge immediately below the carina. Primary endpoint: First-attempt placement success rate. Secondary endpoints: Time to successful first placement, lung collap