Outcomes of Small Bowel Obstruction in Patients With No Prior Surgery: A Systematic Review

INTRODUCTION: Small bowel obstruction in patients without prior abdominal surgery (NPA-SBO) presents a diagnostic and therapeutic challenge. Although traditionally thought to require operative exploration, recent studies suggest that most patients may be managed nonoperatively. METHODS: We performed a systematic review and meta-analysis of studies reporting outcomes for adult patients with NPA-SBO published between 1996 and 2023. Databases were queried on September 30, 2024. The primary outcome was the proportion of patients successfully treated by nonoperative management. Secondary outcomes include complications, recurrence, rates of malignancy and adhesions. Pooled estimates were calculated using random-effects models. RESULTS: Fifteen studies encompassing 855 patients were included. Overall, 74% (95% CI, 66%-82%) of the patients were successfully managed nonoperatively. Complications occurred in 23% of the patients who underwent surgery (95% CI: 17%-28%) and in 10% of the patients who did not have surgery (95% CI: 0%-31%). Recurrence occurred in 7% for those treated without surgery (95% CI: 2%-11%). Malignancy was identified in 12% (95% CI, 6%-18%) of the cases, while adhesions accounted for 36% (95% CI, 22%-49%) of NPA-SBOs. Negative laparotomy occurred in 14% (95% CI, 8%-23%) of the patients, underscoring the diagnostic uncertainty in this population. CONCLUSIONS: Approximately three of four patients with NPA-SBO can be successfully treated with nonoperative management, with low complication and recurrence rates. While surgery remains essential for selected patients, an initial trial of nonoperative therapy in appropriately selected patients is warranted.