Clinical usefulness of transabdominal ultrasonography prior to patency capsule for suspected small-bowel strictures

Patency capsule (PC) examination has made it possible to perform capsule endoscopy (CE) in patients with a suspected small-bowel stricture. However, PC has some drawbacks, so we assessed the usefulness of transabdominal ultrasonography (TUS) prior to PC in patients with suspected small-bowel strictures to avoid unnecessary PC examination.

Fifty-two patients who underwent TUS prior to PC were enrolled in this study. TUS findings were classified as follows: intestinal narrowing and distension at the oral side (Type A); extensive bowel wall thickening (Type B); focal bowel wall thickening (Type C) or no abnormality detected (Type D). We evaluated the TUS and PC findings for the detection of small-bowel strictures.

Double-balloon endoscopy (DBE) revealed small-bowel strictures in 13 of 50 patients (26%). TUS yielded Type B or C findings in 12 of 13 patients (92%), while PC revealed strictures in all 13 patients. In Crohn's disease (CD) patients with Type B TUS findings, 8 of 9 (89%) had small-bowel strictures on DBE. However, only two of six non-CD patients (33%) with Type B TUS findings had small-bowel strictures. The incidence of Type B strictures was significantly higher in CD patients.

CD patients with Type B TUS findings should not undergo PC or CE because of the high rate of small-bowel strictures. Non-CD patients diagnosed with Type B TUS strictures, as well as patients diagnosed with Type C or D strictures should undergo CE after confirming small-bowel patency using PC.