ORLANDO, FLA. — A new diagnostic capsule can verify the presence of small bowel strictures seen on radiology and determine when it is safe to use video capsule endoscopy, Cristiano Spada, M.D., reported at the annual meeting of the American College of Gastroenterology.
Small bowel radiology is not always reliable in determining the presence of a stricture and the functional patency of the small bowel, so it is necessary to identify the presence of any stricture before using the Pillcam SB (formerly called the M2A video capsule) to perform capsule endoscopy. Both devices are manufactured by Given Imaging.
The investigational Patency Capsule contains a radiofrequency tag surrounded by a dissolvable lactose and parylene polymer coating.
A small window exposes the inside of the capsule to GI fluids to help digest the coating. A timing plug built into the capsule keeps the capsule intact for about 40-100 hours, after which it can pass through the small bowel if it encounters a stricture. At 8 and 24 hours after patients ingested the Patency Capsule, Dr. Spada and his colleagues identified the location of the capsule by using fluoroscopy and a device called the Patency scanner to locate the radiofrequency signal emitted by the capsule.
Overall, 46 of the 91 patients with radiologically confirmed or suspected small bowel stricture who ingested the Patency Capsule excreted the capsule intact. The other 45 patients excreted a partially intact or nonintact (dissolved) capsule. Most of the patients in the study had Crohn's disease, said Dr. Spada of Catholic University, Rome.
Overall, 22 patients reported abdominal pain after ingesting the Patency Capsule. The pain resolved within 24 hours in 17 patients, and 3 went to the hospital with severe pain that passed once the capsule was excreted.
Two patients underwent surgery for pain: One patient's stricture was so large that the intestinal lumen became completely occluded with the capsule while another underwent surgery for an unrelated problem. The Patency scanner failed to detect the capsule in two patients.
The transit time of the Patency Capsule was correlated with dissolving of the capsule. But the researchers could not find a correlation between the anatomical features of the stricture and the capsule's transit time. “In fact, in some patients with a tight stricture, the capsule was excreted intact after 2 hours,” Dr. Spada said.
These data suggested that the Patency Capsule could be used to confirm the functional patency of the small bowel and show that it is safe to use the Pillcam, he said.
In 67 patients with a small bowel stricture who excreted the capsule in 72 hours, 29 had a functionally patent small bowel and received the Pillcam video capsule.
The other 38 were not eligible to use the Pillcam. All 29 patients with small bowel strictures who used the Pillcam passed the capsule uneventfully in the same mean transit time that they had passed the Patency Capsule.