Value of CT findings to predict surgical ischemia in small bowel obstruction: A systematic review and meta-analysis

Abstract

Purpose: Our aim was to assess the diagnostic performance in determining strangulation in small bowel obstruction (SBO) for five CT findings commonly considered in published small bowel obstruction (SBO) management guidelines.

Materials and methods: Medical databases were searched for "bowel obstruction", "computed tomography", "strangulation", and related terms. Two reviewers independently selected articles for CT findings investigated with surgical or histological reference standards for strangulation. Bivariate random-effects meta-analytical methods were used.

Results: A total of 768 patients, including 205 with strangulation from nine studies, were evaluated. The reduced bowel wall enhancement CT sign had the highest specificity (95 %, CI 75-99), with a positive LR of 11.07 (2.27-53.88) and DOR of 22.86 (4.99-104.61). The mesenteric fluid sign had the highest sensitivity (89 %, CI 75-96) with a negative LR of 0.16 (0.07-0.39) and a DOR of 13.9 (5.73-33.75). The bowel wall thickness had a sensitivity of 48 % (CI 41-54), a specificity of 83 % (CI 74-89), a positive LR of 2.84 (1.83-4.41) and a negative LR of 0.62 (0.53-0.72). The other CT findings had lower diagnostic performance.

Conclusion: Two CT findings should be used in clinical practice: reduced enhanced bowel wall is highly predictive of ischemia, and absence of mesenteric fluid is a reliable finding to rule out strangulation.

Key points: • Reduced bowel wall enhancement on CT increases the probability of strangulation 11-fold. • Absence of mesenteric fluid on CT decreases the probability of strangulation 6-fold. • The clinical reliability of other CT signs is doubtful for predicting strangulation.