The Safety of Expectant Management for Adhesive Small Bowel Obstruction: A Systematic Review.

BACKGROUND: Surgical training has long been to "never let the sun set on a bowel obstruction" without an operation to rule out and/or treat compromised bowel. However, advances in diagnostics have called into question the appropriate timing of non-emergent operations and expectant management is increasingly used. We performed a systematic review to evaluate the safety and effectiveness of expectant management for adhesive small bowel obstruction (aSBO) compared to early, non-emergent operation. MATERIALS &
METHODS: We queried PubMed, EMBASE, and Cochrane databases for studies (1990-present) comparing early, non-emergent operations and expectant management for aSBO (PROSPERO #CRD42017057676).
RESULTS: Of 4873 studies, 29 cohort studies were included for full-text review. Four studies directly compared early surgery with expectant management, but none excluded patients who underwent emergent operations from those having early non-emergent surgery, precluding a direct comparison of the two treatment types of interest. When aggregated, the rate of bowel resection was 29% in patients undergoing early operation vs. 10% in those undergoing expectant management. The rate of successful, non-operative management in the expectant group was 58%. There was a 1.3-day difference in LOS favoring expectant management (LOS 9.7 vs. 8.4 days), and the rate of death was 2% in both groups.
CONCLUSION: Despite the shift towards expectant management of aSBO, no published studies have yet compared early, non-emergent operation and expectant management. A major limitation in evaluating the outcomes of these approaches using existing studies is confounding by indication related to including patients with emergent indications for surgery on admission in the early operative group. A future study, randomizing patients to early non-emergent surgery or expectant management, should inform the comparative safety and value of these approaches.