Ultrasound vs Endoscopy, Surgery, or Pathology for the Diagnosis of Small Bowel Crohn's Disease and its Complications

Abstract

Background: In patients with inflammatory bowel disease, we strive to achieve mucosal healing, as this has been shown to decrease the risk of disease flares, hospitalization, and surgery. For this reason, we must use objective measures of mucosal healing to inform our clinical decision-making and can no longer rely on patient symptoms alone. Assessment of small bowel Crohn's disease (SBCD) is particularly challenging given its lack of accessibility via standard endoscopic techniques. Ultrasound (US) represents a readily available, cost-effective, minimally invasive, radiation-free alternative for the assessment of small bowel disease. In this study, we performed a systematic review to determine the accuracy of ultrasound in diagnosing SBCD and its complications as compared with endoscopic visualization, surgery, and/or pathology.

Methods: We searched MEDLINE, EMBASE, and CENTRAL. Prospective cohort studies published up to March 2017 were reviewed. References meeting all eligibility criteria were assessed at the full-text level by 2 independent reviewers. Sensitivity and specificity were collected where available.

Results: A total of 2817 unique references were identified. Twenty-two studies were included. All studies were at low-moderate risk of bias based on the Quality Assessment of Diagnostic Accuracy Studies criteria. Transabdominal US (TAUS) yielded moderately high sensitivity and specificity for the diagnosis of SBCD and its postoperative recurrence. Detection was more accurate for severe postoperative recurrence. The diagnostic accuracy of US in stricture and abscess detection was high. Contrast enhancement improved the detection of abscess. Diagnostic detection of fistulas was of moderate accuracy. Entero-enteric fistulization and entero-mesenteric fistulization were most clearly identified.

Conclusions: Ultrasound can be used to diagnose SBCD in those with known or suspected Crohn's disease. It can be used to detect postoperative recurrence and can accurately identify abscesses and fistulas, especially with the aid of contrast enhancement.

Keywords: Crohn’s disease; diagnosis; inflammatory bowel disease; systematic review; ultrasound.