Indications and Limitations Associated with the Patency Capsule Prior to Capsule Endoscopy

The retention of the capsule used during small bowel capsule endoscopy (SBCE) is a serious complication that can occur in patients with known or suspected small bowel stenosis, and a prior evaluation of the patency of the gastrointestinal (GI) tract is therefore essential. Patency capsule (PC) is a non-diagnostic capsule the same size as the diagnostic SBCE. To date, there are no clear guidelines regarding the contraindications for undergoing a PC evaluation prior to SBCE. Each small bowel disorder has specific occasions to inhibit the progress of PC and SBCE, even though they do not have any stenotic symptoms or abnormalities on imaging. In this review, we summarize the indications and limitations of PC prior to SBCE, especially the contraindications, and discuss clinical scenarios in which even PC should be avoided, and therefore such areas of stenosis should be evaluated by alternative modalities. We thus propose this new algorithm to evaluate the patency of the GI tract for patients with suspected and known small bowel stenosis in order that they may undergo SBCE safely.