Intestinal ultrasound to detect postoperative recurrence in patients with Crohn's disease: an international, multidisciplinary, RAND/UCLA appropriateness method study.

Abstract

Background: Intestinal ultrasound is a non-invasive method increasingly used to diagnose and monitor disease activity in patients with inflammatory bowel disease; however, there is no consensus on the appropriate implementation of intestinal ultrasound to assess postoperative recurrence in Crohn's disease. We aimed to develop expert-based recommendations for standardising intestinal ultrasound use for the detection and evaluation of postoperative Crohn's disease recurrence.

Methods: An international, multidisciplinary, modified RAND/University of California Los Angeles appropriateness method was used. Based on a systematic review and meta-analysis of the literature, expert opinion, and panellist feedback, a list of statements related to the use of intestinal ultrasound in this setting was generated. Panellists with expertise in Crohn's disease intestinal ultrasound, surgery, postoperative management, clinical trials, and outcome measures were invited. Panellists rated the appropriateness of each statement on a 9-point Likert scale in two rounds of voting, with statements classified as appropriate, inappropriate, or uncertain based on median panel rating and the presence of disagreement, then met in person to discuss the results and vote on the appropriate and inappropriate statements in a final round of ratification voting. Statements ratified by 75% or more of the panellists were incorporated into the final recommendations.

Findings: The first online survey was open to the panellists from June 21, 2024, to Aug 6, 2024, and the second survey round was available between Nov 1 and Nov 25, 2024. The in-person ratification meeting was held on Feb 21, 2025. The panel comprised 16 experts (12 [75%] men and four [25%] women) from nine countries (Brazil, Canada, Denmark, Germany, Italy, the Netherlands, Spain, the UK, and the USA) with specialties in gastroenterology (n=10), colorectal surgery (n=4), and radiology (n=2). The overall response rate was 100% (all 16 panellists) for the first round of voting and 94% (15 of 16) for the second round of voting, with 12 (75%) of 16 panellists participating in ratification voting. The first survey contained 116 statements, with 88 (76%) rated as appropriate, two (2%) as inappropriate, and 26 (22%) as uncertain. Of the 122 statements in the second survey, 97 (80%) were rated appropriate, two (2%) were inappropriate, and 23 (19%) were uncertain. 79 statements were voted on during the ratification meeting and 67 (85%) were ratified. Recommended anatomical components for sonographic evaluation were the colonic segment immediately distal to the anastomosis, the neoterminal ileum, neoterminal ileal inlet, colonic and ileal blind side of the anastomosis, sonographically visible colonic segments, and the surrounding mesentery. Recommended parameters for assessment were bowel wall thickness, bowel wall stratification, bowel wall vascularity; mesenteric inflammatory fat and lymphadenopathy; luminal narrowing; and the presence of complications (abscess, inflammatory mass, fistula or sinus tract, stricture and stricture length, and prestenotic dilation). Intestinal ultrasound findings in the neoterminal ileum and the inlet of the neoterminal ileum were considered most likely to reflect clinically meaningful disease activity. Waiting at least 4 weeks after surgery to perform intestinal ultrasound was recommended to avoid confounding the interpretation of sonographic findings with immediate postoperative complications or changes associated with surgical healing. The first assessment is recommended to be performed 3-12 months after surgery.

Interpretation: These multidisciplinary recommendations aim to standardise the application of intestinal ultrasound for assessing postoperative recurrence of Crohn's disease after surgical bowel ileocolic resection. Future development of a reliable, validated index for Crohn's disease postoperative recurrence is an important next step.

Funding: Johnson & Johnson Innovative Medicine.