Non-operative management for small bowel obstruction in a virgin abdomen: a systematic review

BACKGROUND: Small bowel obstruction (SBO) is a common general surgical presentation and there has been a shift towards non-operative management (NOM) for patients with previous abdominal surgery. Historically, exploratory surgery has been mandated for SBO in patients with a virgin abdomen. However, there is increasing evidence for NOM in this group of patients. METHODS: A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A search was undertaken between 1995 and 2020 on Ovid MEDLINE, EMBASE and PubMed. Primary outcome measures were success and failure rates, whereas secondary outcome measures were morbidity, mortality rates and identifying underlying aetiologies. RESULTS: Six observational studies were included, with 205 patients in the NOM and 211 patients in the operative group. There was a high success rate of 95.6% and low morbidity rate of 3.1% in the NOM group compared to 88.6% and 26% in the operative group, respectively. Both groups reported no mortalities. The most common aetiologies for SBO in a virgin abdomen were adhesions (63%), malignancy (11%), foreign body/bezoar (5%), internal hernia (4%) and volvulus (4%). CONCLUSION: NOM for SBO is a safe and feasible option for a select group of clinically stable patients with a virgin abdomen without features of closed-loop obstruction. Adhesions are the most common cause of SBO in this group of patients. Further large-scale prospective clinical studies with standardized NOM modality, homogenous clinical resolution indicators and long-term follow-up data are warranted to allow for quantitative analysis to reinforce this evidence.