Capsule Endoscopy, Magnetic Resonance Enterography, and Small Bowel Ultrasound for Evaluation of Postoperative Recurrence in Crohn's Disease: Systematic Review and Meta-Analysis

Background: Anastomotic recurrence is frequent in patients with Crohn's disease (CD) following ileocecal resection. The degree of endoscopic recurrence, quantified by the Rutgeerts score (RS), is correlated with the risk of clinical and surgical recurrence. Noninvasive modalities such as capsule endoscopy (CE), magnetic resonance enterography (MRE), and intestinal ultrasound (US) may yield similar information without the need for ileocolonoscopy (IC). The aim of our meta-analysis was to evaluate the accuracy of those modalities for detection of endoscopic recurrence in postoperative CD patients. Methods: We performed a systematic literature search for studies comparing the accuracy of CE, MRE, and US with IC for detection of postoperative recurrence in CD. We calculated pooled diagnostic sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curve (AUC) for each comparison. Results: A total of 135 studies were retrieved; 14 studies were eligible for analysis. For CE, the pooled sensitivity was 100% (95% CI, 91%-100%), specificity was 69% (95% CI, 52%-83%), DOR was 30.8 (95% CI, 6.9-138), and AUC was 0.94. MRE had pooled sensitivity of 97% (95% CI, 89%-100%), specificity of 84% (95% CI, 62%-96%), DOR of 129.5 (95% CI, 16.4-1024.7), and AUC of 0.98. US had pooled sensitivity of 89% (95% CI, 85%-92%), specificity of 86% (95% CI, 78%-93%), DOR of 42.3 (95% CI, 18.6-96.0), and AUC 0.93. Conclusions: CE, MRE, and US provide accurate assessment of postoperative endoscopic recurrence in CD. These modalities should gain wider use for detection of postoperative recurrence; the prognostic value of those diagnostic findings merits evaluation in further prospective studies.