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

Overview

Pleural effusion is a common problem in hospital patients. It may arise from a wide range of diseases. There is a multitude of recognised causes of pleural effusion, and in addition, other pleural conditions such as pleural thickening and pneumothorax represent a significant burden to the healthcare system and to patients. However, the diagnosis of this condition may sometimes be difficult. In pleural effusions undiagnosed by thoracocentesis, closed pleural biopsy provides limited yield, whereas the diagnostic yield of thoracoscopy is substantially higher for both malignant and tuberculous pleural effusions. Hence, medical thoracoscopy (MT) (pleuroscopy) is the gold standard in the diagnosis of pleural effusion and it is indicated when less invasive tests have failed. MT is a procedure in which the pleura is directly and visually examined. An endoscope is inserted into the intercostal space by creating a pneumothorax with an incision through the chest wall. The pleural space and its lining can be inspected and therapeutic interventions performed. There are two different techniques that can be performed for diagnostic and therapeutic thoracoscopy. One method recommends a single-entry site, the use of a rigid thoracoscope (or of a semi-rigid/semi-flexible pleuroscope) with a working channel for accessory instruments and an optical biopsy forceps, both performed under local anaesthesia. The other method requires two entry sites: one for a trocar for the examination telescope, and the second for accessory instruments including the biopsy forceps, and is usually performed with conscious sedation or general anaesthesia. In the trained hands of a pulmonologist, MT is a safe and effective procedure for diagnosing and treating multiple pleural diseases. The unfamiliarity of the pulmonary physician with rigid instruments and familiarity with the flexible bronchoscope has led various investigators to attempt thoracoscopy with flexible endoscopes. Flexible instruments allow concurrent suctioning to maintain a clear optical field, providing good views at the apex and paravertebral gutters. This method is considered useful for physicians with experience in chest drainage and flexible bronchoscopy, as well as safe and well tolerated with a minimal degree of discomfort and expense.

Research Question Can MT using a disposable flexible bronchoscope be used as an alternative method to a semi-rigid pleuroscope for diagnosis of pleural effusion with a comparable outcome? Research Hypotheses 1. Medical thoracoscopy using a single-use flexible bronchoscope is feasible, defined by successful entry into the pleural space, adequate pleural visualization, successful pleural biopsy acquisition, and completion of the procedure without conversion to conventional semi-rigid pleuroscopy. 2. There is no significant difference in the total duration of the procedure (in minutes) between medical thoracoscopy performed using the single-use flexible bronchoscope and the conventional semi-rigid pleuroscope. 3. Medical thoracoscopy using a single-use flexible bronchoscope is operationally feasible, showing no significant difference in procedural success rates-defined as successful entry into the pleural space, adequate visualization, and successful tissue collection without requiring device crossover-when compared to the conventional semi-rigid pleuroscope. 4. The immediate procedural cost-utilization and disposable hardware expenditures associated with the single-use flexible bronchoscope arm will be different from (or lower than) the conventional semi-rigid pleuroscope arm. 5. There is no significant difference in the preliminary baseline diagnostic yields or the 48-hour post-procedural complication rates and profiles between the single-use flexible bronchoscope group and the conventional semi-rigid pleuroscope group. Study Design This is a prospective, single-centre, open-label, two-arm parallel-group randomized controlled trial comparing disposable flexible bronchoscopy versus semi-rigid pleuroscopy among hospital patients with pleural effusion. Study Setting The study will be conducted in the Endoscopy Centre, Hospital Canselor Tuanku Muhriz UKM (HCTM UKM). Sample Size The target sample size for this pilot parallel-group study is 36 subjects in total, randomized in a 1:1 ratio into two comparative arms: the Flexible Single-Use Bronchoscopy Group (n=18) and the Conventional Semi-Rigid Pleuroscopy Group (n=18). Study Protocol All patients referred for medical thoracoscopy who fulfill the study inclusion and exclusion criteria will be screened for eligibility. Eligible patients will be approached by the study investigators and provided with detailed information regarding the study. Written informed consent will be obtained prior to enrolment. The decision to perform medical thoracoscopy will be made independently by the treating respiratory specialist based on routine clinical indications prior to study enrolment. The research intervention is limited to the allocation of the thoracoscopic device used during the procedure and does not alter the patient's standard clinical management. The study intervention consists solely of allocation to either the investigational device (UE Medical Single-Use Flexible Bronchoscope) or the standard-of-care comparator device (Olympus Semi-Rigid Pleuroscope), while all other aspects of patient management remain unchanged. Following consent, participants will be randomized in a 1:1 ratio using block randomization to either the Single-Use Flexible Bronchoscope Group or the Conventional Semi-Rigid Pleuroscope Group. Participants who decline the allocated intervention after randomization will be withdrawn from the study and managed according to standard clinical practice. Their withdrawal will be documented, and no further study-specific data will be collected. All procedures will be performed under local anaesthesia with conscious sedation according to institutional protocols. Procedures will be conducted by a respiratory specialist experienced in pleural interventions who has independently performed over fifty (50) medical thoracoscopy procedures. To ensure procedural consistency, standardization, and patient safety, an additional respiratory specialist will be present within the unit as an observer during the procedure. After establishment of pleural access and insertion of the trocar, the allocated endoscope will be introduced into the pleural cavity. A systematic examination of the pleural space will then be performed, including inspection of the parietal pleura, visceral pleura, diaphragm, and accessible pleural surfaces. To ensure adequate visualization, all four layers of parietal pleura (costal, mediastinal, diaphragmatic, and cervical pleura) must be visualized according to the standard reporting checklist. Any abnormal pleural lesions, nodules, thickening, adhesions, or suspicious areas will be identified and targeted for biopsy. Procedure duration will be measured from the time the endoscope enters the pleural cavity through the trocar until complete removal of the endoscope from the trocar at the end of the procedure. This duration will be recorded in minutes for subsequent analysis. Pleural biopsy specimens will be obtained using standard biopsy forceps through the working channel of the allocated device. To ensure uniformity of tissue sampling between both study arms, a minimum of ten (10) adequate pleural biopsy specimens will be obtained whenever technically feasible and clinically safe. An adequate pleural biopsy specimen is defined as a tissue sample deemed macroscopically satisfactory by the operator and suitable for histopathological assessment. Additional biopsies may be obtained at the discretion of the operator if clinically indicated. In the event of technical difficulties, inadequate visualization, inability to obtain satisfactory tissue samples, equipment failure, or any circumstance that may compromise patient safety, crossover to the alternative device will be permitted at the discretion of the operator. The reason for crossover will be documented and included in the final analysis. Upon completion of the procedure, a chest drain will be inserted according to standard institutional practice. Pleural fluid and biopsy specimens will be submitted for histopathological, microbiological, cytological, and other relevant investigations as clinically indicated. Patients will be monitored during the procedure and for at least 48 hours thereafter for any procedure-related complications. Data collected will include demographic characteristics, procedural duration, procedural success, need for crossover, diagnostic yield, complications, and immediate post-procedural outcomes. All data will be recorded using standardized case report forms and entered into a secure study database for analysis.