Abstract
BACKGROUND & AIMS: Colonoscopy is recommended to monitor for Crohn's disease (CD) recurrence after surgical resection. However, repeated colonoscopy is invasive and resource-intensive. We conducted a systematic review and meta-analysis to evaluate the pooled diagnostic accuracy of noninvasive biomarkers and imaging measures for detecting endoscopic CD recurrence, as compared with colonoscopy. METHODS: A systematic review was conducted to January 31, 2024, to identify studies evaluating the diagnostic accuracy of C-reactive protein (CRP), fecal calprotectin, computed tomography and magnetic resonance enterography, or intestinal ultrasound (IUS) compared with colonoscopy for detecting CD recurrence. Estimates of sensitivity, specificity, and positive and negative likelihood ratios were pooled using a random-effects hierarchical summary receiver operating characteristic model. RESULTS: A total of 17 studies (N = 1080) evaluated inflammatory biomarkers and 20 studies (N = 1053) assessed imaging measures. The pooled sensitivity and specificity of CRP (threshold, 5.0 mg/L) were 0.45 (95% confidence interval [CI], 0.33-0.58) and 0.83 (95% CI, 0.68-0.92), respectively. Fecal calprotectin (threshold, 50 μg/g) was moderately sensitive 0.76 (95% CI, 0.70-0.82) but less specific 0.66 (95% CI, 0.56-0.75). Sensitivity for computed tomography enterography/magnetic resonance enterography and IUS was 0.89 (95% CI, 0.73-0.96) and 0.92 (95% CI, 0.75-0.96); specificity was 0.65 (95% CI, 0.43-0.82) and 0.76 (95% CI, 0.52-0.90), respectively. Using optimized radiographic parameters for IUS, specificity was improved to 0.85 (95% CI, 0.71-0.93). CONCLUSIONS: The high sensitivity of fecal calprotectin (<50 μg/g) and cross-sectional imaging can help reduce the need for invasive and costly colonoscopy monitoring for CD recurrence after surgery. Applying optimal definitions of sonographic recurrence by IUS parameters may further improve specificity for making therapeutic decisions without endoscopy.