Small bowel capsule endoscopy and treat-to-target in Crohn's disease: A systematic review

Abstract

Background: Crohn's disease (CD) can affect the entire gastrointestinal tract. Proximal small bowel (SB) lesions are associated with a significant risk of stricturing disease and multiple abdominal surgeries. The assessment of SB in patients with CD is therefore necessary because it may have a significant impact on prognosis with potential therapeutic implications. Because of the weak correlation that exists between symptoms and endoscopic disease activity, the "treat-to-target" paradigm has been developed, and the associated treatment goal is to achieve and maintain deep remission, encompassing both clinical and endoscopic remission. Small bowel capsule endoscopy (SBCE) allows to visualize the mucosal surface of the entire SB. At that time, there is no recommendation regarding the use of SBCE during follow-up.

Aim: To investigate the impact of SBCE in a treat-to-target strategy in patients with CD.

Methods: An electronic literature search was conducted in PubMed and Cochrane library using the following search terms: "capsule endoscopy", in combination with "Crohn's disease" and "treat-to-target" or synonyms. Two authors independently reviewed titles and abstracts identified by the search strategy after duplicates were removed. Following the initial screening of abstracts, all articles containing information about SBCE in the context of treat-to-target strategy in patients with CD were included. Full-text articles were retrieved, reference lists were screened manually to identify additional studies.

Results: Forty-seven articles were included in this review. Two indexes are currently used to quantify disease activity using SBCE, and there is good correlation between them. SBCE was shown to be useful for disease reclassification in patients who are suspected of having or who are diagnosed with CD, with a significant incremental diagnostic yield compared to other diagnostic modalities. Nine studies also demonstrated that the mucosal healing can be evaluated by SBCE to monitor the effect of medical treatment in patients with CD. This review also demonstrated that SBCE can detect post-operative recurrence to a similar extent as ileocolonoscopy, and proximal SB lesions that are beyond the reach of the colonoscope in over half of the patients.

Conclusion: SBCE could be incorporated in the treat-to-target algorithm for patients with CD. Randomized controlled trials are required to confirm its usefulness and reliability in this indication.

Keywords: Inflammatory bowel disease; Monitoring; Mucosal healing; Post-operative recurrence; Prognosis; Treat-to-target; Wireless capsule endoscopy.

Figure 1

Small bowel capsule endoscopy findings associated with Crohn’s disease. A: Edema; B: Aphthoid erosion; C: Superficial ulceration; D: Deep ulceration; E: Stenosis.

Figure 2

Preferred reporting items for systematic reviews and meta-analyses diagram.

Figure 3

Potential usefulness of small bowel capsule endoscopy in a treat-to-target strategy for patients with Crohn’s disease. Small bowel capsule endoscopy (SBCE) should help physician classify disease location and make a prognosis regarding future course of Crohn’s disease (CD) according to the presence of proximal small bowel lesions. SBCE should also be useful in the assessment of mucosal healing in patients with CD under treatment, and in the post-operative setting to detect post-operative recurrence in a timely manner.