Initial Experimental Evaluation of Wireless Capsule Endoscopes in the Bladder: Implications for Capsule Cystoscopy

BackgroundCystoscopy remains one of the most important diagnostic procedures for the lower urinary tract. Wireless capsule endoscopy was introduced in the 1990s but use to date is limited to gastroenterology.ObjectiveWe evaluated the feasibility in the pig model of using wireless capsule endoscopes (WCEs) for cystoscopy.Design, setting, and participantsExperimental evaluation of capsule cystoscopy was performed in a 50-kg farm pig. The capsule was deployed into the bladder through a custom access sheath. Images were continuously transmitted at a rate of four frames per second to a laptop computer and processed using proprietary software. Manipulation of the WCE within the bladder was performed using a set protocol. The animal was then euthanized and gross inspection was performed.MeasurementsWe measured the ability to deploy and manipulate the capsule within the bladder. Feasibility of capturing and retrieving images in real time was also assessed.Results and limitationsThe WCE was efficiently deployed and manipulated within the bladder passively and with the use of external magnets. The entire bladder mucosa was visualized. Real-time image transmission and capture were successful. No complications were seen during capsule cystoscopy. Minor urethral bleeding was observed after the experiment, likely related to placement of the access sheath required for deployment of the WCE. Limitations are that the evaluation of WCE was performed in the pig model, in only one female animal, using a nonsurvival approach. Furthermore, the study was not designed to differentiate normal from abnormal mucosal findings and focused solely on inspection of the bladder.ConclusionsThis report suggests that cystoscopy with a WCE is feasible. With this device, all aspects of the bladder mucosa could be visualized, and ongoing technologic and procedural developments are warranted for this new approach.