Exploring the Entire Gastrointestinal Tract With Only 1 Capsule Endoscope by Using a Thin Catheter to Control the Capsule in the Stomach and Cleanse the Colon Efficiently

Introduction: Capsule endoscopes are designed for screening a particular region of the gastrointestinal tract (GT) such as the small bowel or the colon. Capsule endoscopy (CE) has many drawbacks compared to conventional endoscopy, particularly inadequate observation in the esophagus and stomach, an undesirable amount of preparation solution for screening the colon and long examination times. Magnetic navigation may be one of the solutions though it needs either an expensive magnetic unit or a lot of practice for the navigation. Our aim is to realize an entire GT examination with high accuracy, easy preparation and a short examination time. Methods: Our system was composed of a current PillCam Colon2 (CCE) (Covidien, USA), a flexible catheter with a tilting function at the tip, and a thin detachable carbon thread. After the subject ingested a CCE with the carbon thread attached to it, the examiner pushed a 4fr. thin catheter along the thread. In the stomach, the examiner used the catheter to navigate the capsule, control the volume of air and inject water through it if the stomach needed cleansing. After observing all parts of the stomach the CCE was navigated into the duodenum. The capsule was detached from the catheter by pulling hard on the end of the thread, After the detachment, the catheter was used to inject a large volume (over 2 liters) of preparation solution into the small bowel quickly to accelerate the movement of the CCE and to cleanse the colon easily. Results: By tilting and rotating the catheter we were able to observe all of the parts of the stomach and the images were not inferior to a conventional gastroscope. The examination time was quite similar to that of a conventional gastroscope. It took 200 seconds to inject 2 liters of preparation solution in to the duodenum at a speed of 10ml/sec. The average transit time (15 volunteers) for the small bowel was 12 minutes and 45 minutes for the colon and rectum. Conclusion: We have developed a simple, inexpensive and practical method for examining the entire GT. Even though it has made the procedure more invasive than the current CE, it could overcome some of the main drawbacks of CE such as more than one capsule is needed to screen the entire GI tract, capsule retention in the stomach and missing areas of the stomach. In addition, injecting the preparation solution through the catheter improved visibility in the colon because in Japan most patients do not drink enough of the preparation solution to cleanse the colon sufficiently.