Capsule Endoscopy in Inflammatory Bowel Disease: When? To Whom?

Deep learning and minimally invasive inflammatory activity assessment: a proof-of-concept study for development and score correlation of a panendoscopy convolutional network

Background

Capsule endoscopy (CE) is a valuable tool for assessing inflammation in patients with Crohn's disease (CD). The current standard for evaluating inflammation are validated scores (and clinical laboratory values) like Lewis score (LS), Capsule Endoscopy Crohn's Disease Activity Index (CECDAI), and ELIAKIM. Recent advances in artificial intelligence (AI) have made it possible to automatically select the most relevant frames in CE.

Objectives

In this proof-of-concept study, our objective was to develop an automated scoring system using CE images to objectively grade inflammation.

Design

Pan-enteric CE videos (PillCam Crohn's) performed in CD patients between 09/2020 and 01/2023 were retrospectively reviewed and LS, CECDAI, and ELIAKIM scores were calculated.

Methods

We developed a convolutional neural network-based automated score consisting of the percentage of positive frames selected by the algorithm (for small bowel and colon separately). We correlated clinical data and the validated scores with the artificial intelligence-generated score (AIS).

Results

A total of 61 patients were included. The median LS was 225 (0-6006), CECDAI was 6 (0-33), ELIAKIM was 4 (0-38), and SB_AIS was 0.5659 (0-29.45). We found a strong correlation between SB_AIS and LS, CECDAI, and ELIAKIM scores (Spearman's r = 0.751, r = 0.707, r = 0.655, p = 0.001). We found a strong correlation between LS and ELIAKIM (r = 0.768, p = 0.001) and a very strong correlation between CECDAI and LS (r = 0.854, p = 0.001) and CECDAI and ELIAKIM scores (r = 0.827, p = 0.001).

Conclusion

Our study showed that the AI-generated score had a strong correlation with validated scores indicating that it could serve as an objective and efficient method for evaluating inflammation in CD patients. As a preliminary study, our findings provide a promising basis for future refining of a CE score that may accurately correlate with prognostic factors and aid in the management and treatment of CD patients.

Pan-Enteric Capsule Endoscopy: Current Applications and Future Perspectives

Background

The role of capsule endoscopy in the evaluation of the small bowel is well established, and current guidelines position it as a first-line test in a variety of clinical scenarios. The advent of double-headed capsules further enabled the endoscopic assessment of colonic mucosa and the opportunity for a one-step noninvasive examination of the entire bowel (pan-enteric capsule endoscopy [PCE]).

Summary

We reviewed the technical procedure and preparation of patients for PCE, as well as its current clinical applications and future perspectives. In non-stricturing and non-penetrating Crohn's disease affecting the small bowel and colon, PCE monitors disease activity by assessing mucosal healing, a major treatment outcome, with a higher diagnostic yield than cross-sectional imaging or conventional colonoscopy. Also in ulcerative colitis, double-headed capsules have been used to monitor disease activity noninvasively. Currently, validated scoring systems have been specifically devised for these double-headed capsules and permit a standardized assessment of the inflammatory burden. In suspected mid-lower digestive bleeding, some exploratory studies have demonstrated the feasibility and high diagnostic yield of PCE, which may work as a filter indicating which patients may benefit of further invasive procedures, namely, for planned hemostatic procedures. The possibility of using PCE is also discussed in the context of polyposis syndromes with simultaneous involvement of the small intestine and colon.

Key Messages

PCE is a feasible, effective, and safe diagnostic procedure to evaluate the small bowel and colon. It has been increasingly explored in the setting of inflammatory bowel diseases and, more recently, in suspected mid-lower digestive bleeding. PCE is expected to reduce the demand for invasive procedures and expand the scope of noninvasive intestinal evaluation in the coming future.

Reclassification of Inflammatory Bowel Disease Type Unclassified by Small Bowel Capsule Endoscopy

Background and Objectives: Ulcerative colitis (UC) and Crohn's disease (CD) are idiopathic inflammatory bowel diseases (IBDs) without a unique, gold standard diagnostic test. UC and Crohn's colitis are impossible to distinguish in approximately 10% of cases. The term IBD type unclassified (IBD-U) is recommended for cases of chronic colitis showing overlapping endoscopic, radiological, and biopsy histological features between UC and CD, while indetermined colitis is reserved for colectomy specimens. Our aim was to assess the role of small-bowel capsule endoscopy (SBCE) in the diagnostic work-up of IBD-U. Materials and Methods: We retrospectively studied the cases of IBD-U explored by SBCE in a tertiary referral gastroenterology center. Patients were investigated using SBCE after contraindications were excluded. Diagnostic criteria for small bowel CD consisted in more than three ulcerations, irregular ulcers, or stenosis, and the Lewis score was used for the quantification of inflammation. The immediate impact of reclassification and outcome data was recorded over a follow-up period of more than one year. Results: Twenty-eight patients with IBD-U were examined using SBCE. Nine patients had small bowel lesions that met the diagnostic criteria for CD, resulting in a reclassification rate of 32.1%. In five of these cases, the treatment was subsequently changed. In the remaining nineteen examinations, no significant findings were observed. There were no complications associated with SBCE. Median follow-up time was 32.5 months (range 12-60). During follow-up, twelve patients were classified as having UC, and seven remained as having an unclassified type; one case of colectomy, for medically refractory UC, was recorded. Conclusions: SBCE is a useful safe tool in the work-up of IBD-U, allowing reclassification in about one third of cases, with subsequent treatment modifications. SBCE may provide a definite diagnosis, enhance the comprehension of the disease's progression, and optimize the short- and long-term management strategy.

Is Panenteric PillcamTM Crohn's Capsule Endoscopy Ready for Widespread Use? A Narrative Review

Patients diagnosed with Crohn's disease are increasingly subjected to repeat colonoscopic and radiological examinations to assess the extent of the disease severity and the effects of treatment. Pillcam^TM Crohn's video capsule, a modified colon capsule, was developed to generate a minimally invasive mouth to rectum video of the gastrointestinal tract. The capsule provides a wide-angle panoramic mucosal view to assess inflammation, ulceration, stenosis, disease extent, and effect of treatment. This review summarizes the evidence of its utility in both adult and paediatric Crohn's disease and reviews the scoring systems used to quantify findings. The literature survey indicates that the Pillcam^TM Crohn's capsule offers high sensitivity and specificity for the detection of inflammatory lesions and the extent and distribution of disease, and it could be considered a reliable imaging modality in both adults and childhood with Crohn's disease.