TOPLINE

A meta-analysis of 11 studies showed that intestinal ultrasound (IUS) demonstrated high sensitivity of 87.6% and good specificity of 80.2% for detecting postoperative recurrence of Crohn’s disease, with diagnostic performance varying according to ultrasound techniques, bowel wall thickness (BWT) thresholds, and recurrence definitions.

METHODOLOGY

• Although IUS has emerged as an attractive noninvasive alternative for detecting postoperative recurrence of Crohn’s disease, its diagnostic performance has remained poorly understood because previous studies have used differing ultrasound techniques, diagnostic definitions, and recurrence assessment criteria.
• Researchers conducted a systematic review and meta-analysis of published English-language literature identified through searches of multiple databases through April 2025 to evaluate the diagnostic accuracy of IUS for detecting postoperative recurrence of Crohn’s disease.
• A total of 11 studies involving 25-108 participants were included in the meta-analysis; most studies were prospective, whereas the remainder used longitudinal and cross-sectional designs, and ileocolonoscopy served as the reference standard across all studies.
• Postoperative recurrence was evaluated using the Rutgeerts endoscopic scoring system, with recurrence defined as a score ≥ i2; severe recurrence was evaluated in a separate subgroup when available, using a Rutgeerts score ≥ i3 with BWT ≥ 5 mm on ultrasound.
• The timing of postoperative assessment varied across studies, ranging from scheduled evaluations at 6 months or 1 year after surgery to follow-up extending several years after resection.

TAKEAWAY

• Across all included studies, IUS achieved a sensitivity of 87.6% and specificity of 80.2% for detecting postoperative recurrence of Crohn’s disease (P < .001 for both); the false-negative rate was 12.4% (95% CI, 7.9%-19.0%) and the false-positive rate was 19.8% (95% CI, 8.5%-39.4%).
• Positive IUS findings increased the likelihood of postoperative recurrence by more than fourfold (positive likelihood ratio, 4.436; 95% CI, 2.070-9.505), whereas negative IUS findings lowered the likelihood of recurrence by 84.6% (negative likelihood ratio, 0.154; 95% CI, 0.101-0.236), underscoring the overall diagnostic performance of IUS for distinguishing patients with recurrence from those without recurrence (diagnostic odds ratio, 28.756; 95% CI, 11.175-73.994).
• A sensitivity analysis of nine studies found that a BWT threshold ≥ 3 mm detected recurrence with 88.9% sensitivity and 74.0% specificity.
• Diagnostic accuracy varied widely by ultrasound technique, BWT threshold, and diagnostic criteria used, with contrast-enhanced ultrasound, lower BWT cutoffs (≥ 3 mm vs ≥ 5 mm), and composite definitions generally improving sensitivity at the expense of specificity. Only the difference between contrast-enhanced and conventional ultrasound reached statistical significance; the BWT threshold and composite vs single-criterion comparisons did not.

IN PRACTICE

“IUS appears to be a clinically useful noninvasive tool for POR [postoperative recurrence] surveillance in CD [Crohn’s disease], with high summary sensitivity and good summary specificity. Its findings may help stratify patients according to the likelihood of endoscopic recurrence and guide the need for closer monitoring or ileocolonoscopy,” the authors of the study wrote.

SOURCE

The study was led by Viviana Parra-Izquierdo, MD, Translational Research Center for Gastrointestinal Disorders, KU Leuven, Leuven, Belgium. It was published online in the Journal of Crohn’s and Colitis.

LIMITATIONS

The available evidence remained limited, particularly for several subgroup analyses that included only a few studies. Differences in patient populations, timing of postoperative surveillance, ultrasound techniques, and recurrence definitions may have contributed to variation in diagnostic performance across studies. Positive and negative predictive values were not pooled because they depended on recurrence rates within individual study populations.

DISCLOSURES

Two authors disclosed receiving support from the Clinical Research Fund at University Hospitals Leuven and the Research Council at KU Leuven or the IOIBD-Helmsley fellowship at KU Leuven. Two authors disclosed receiving research support, consulting fees, or speaker’s fees from industry. One author disclosed holding stock options in two companies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.