Safety and Feasibility of Medical Thoracoscopy Using Single-use Flexible Bronchoscope Versus SemiRigid Pleuroscope in Pleural Effusion

Inclusion Criteria: * Age \> 18 years * Patient presents with an undifferentiated pleural effusion with or without initial diagnostic thoracocentesis, thereby necessitating definitive pleural tissue sampling. * Demonstrated presence of a visually significant pleural effusion occupying at least one-third of the affected hemithorax on standard chest radiography, or a visually confirmed loculated effusion accessible via thoracic ultrasound mapping. * The patient has demonstrated full willingness to participate and has signed the formal written informed consent form approved by the institutional review board. Exclusion Criteria: * Age \< 18 years * Patients with contraindications to perform medical thoracoscopy, e.g.: * Uncorrectable coagulopathy (e.g., platelet count \<50,000/µL, INR \>1.5 despite correction) * Severe hypoxemia not correctable with supplemental oxygen * Hemodynamic instability * Extensive pleural adhesions or obliterated pleural space on imaging * Uncontrolled cardiac arrhythmia or recent acute coronary syndrome * Severe pulmonary hypertension with high procedural risk * Inability to tolerate lateral decubitus position * Refusal to provide informed consent * Pregnancy * Previous ipsilateral pleurodesis or thoracic surgery significantly altering pleural anatomy