Single use and conventional bronchoscopes for Broncho alveolar lavage (BAL) in research: a comparative study (NCT 02515591)

BACKGROUND: Broncho alveolar lavage (BAL) is widely used for investigative research to study innate, cellular and humoral immune responses, and in early phase drug trials. Conventional (multiple use) flexible bronchoscopes have time and monetary costs associated with cleaning, and carries a small risk of cross infection. Single use bronchoscopes may provide an alternative, but have not been evaluated in this context. METHODS: Healthy volunteers underwent bronchoscopy at a day-case clinical research unit using the Ambu® aScope(TM) single-use flexible intubation bronchoscope. Broncho alveolar lavage was performed from a sub segmental bronchus within the right middle lobe; a total of 200 ml of warmed normal saline was instilled then aspirated using handheld suction. BAL volume yield, cell yield and viability were recorded. RESULTS: Ten volunteers, (mean age 23 years, six male) participated. Bronchoscopies were carried out by one of two senior bronchoscopists, experienced in the technique of obtaining BAL for research purposes. The results were compared to 50 (mean age 23, 14 male) procedures performed using the conventional scope by the same two bronchoscopists. The total volume yield was significantly higher in the disposable group median 152 ml (IQR 141–166 ml) as compared to conventional 124 ml (110–135 ml), p = <0.01. The total cell yield and viability were similar in both groups, with no significant differences. CONCLUSIONS: With single use bronchoscopes, we achieved a larger BAL volume yield than conventional bronchoscopes, with comparable cell yield and viability. Better volume yields can potentially reduce post procedure side effects such as pleuritic chest pain and cough. The risk of cross infection can be eliminated, providing reassurance to researchers and participants. Reduced maintenance requirements can be cost effective. These could potentially be used for early phase drug development studies. TRIAL REGISTRATION: This trial was registered prospectively in July 2015 with the National Clinical Trials register, with the following registration number assigned: NCT 02515591.