Predictive value of patency capsule and magnetic resonance enterography for capsule endoscopy retention in patients with established Crohn?s disease

Introduction: retention is the most common adverse event of the small bowel capsule endoscopy procedure. Patency capsule (Medtronic, Dublin, Ireland) and magnetic reso-nance enterography are two diagnostic methods that can prevent small bowel capsule endoscopy retention. The aim of this study was to evaluate the predictive value of these two diagnostic methods.Material and methods: a prospective, comparative and observational study was performed in patients with estab-lished Crohn's disease. All patients had undergone mag-netic resonance enterography and patency capsule proce-dures. If the patency capsule was not retained, the patient underwent a small bowel capsule endoscopy; otherwise, double balloon enteroscopy was performed to locate the stenosis. Magnetic resonance enterography predictive cri-teria for retention were analyzed in all cases. Sensitivity, specificity, positive predictive value and negative predictive value of the patency capsule and magnetic resonance en-terography compared to small bowel capsule endoscopy or double balloon enteroscopy were calculated. Results: forty patients were included (24 female, 55 +/- 13 years old). Retention criteria with capsule endoscopy or double balloon enteroscopy were found in six patients, agreeing in five cases with patency capsule and in three cases with magnetic resonance enterography. Sensitivity, specificity, positive predictive value, negative predictive value and Kappa coefficient for predicting retention with the patency capsule were 83 %, 100 %, 100 % and 97 %, respectively, and 50 %, 91 %, 50 % and 91 %, respectively, with magnetic resonance enterography.Conclusions: patency capsule has a higher sensitivity and positive predictive value than magnetic resonance enterog-raphy for preventing small bowel capsule endoscopy reten-tion in Crohn's disease patients.