Aetiologies and prognosis of small bowel obstruction in virgin abdomen: a retrospective cohort study

Small bowel obstruction (SBO) in patients with a virgin abdomen (VA)-no prior abdominal surgery-remains understudied, with traditional assumptions favoring mandatory surgical exploration due to suspected non-adhesive etiologies like malignancy or hernias. However, emerging evidence suggests adhesions are also prevalent in SBO-VA, challenging this paradigm. This study investigates the etiologies, management outcomes, and prognostic factors of SBO-VA to guide evidence-based treatment strategies.

A retrospective analysis was conducted on 312 SBO-VA patients treated at a tertiary center from 2009 to 2020. Patients were categorized into immediate surgery (n = 124), delayed surgery (n = 45), or non-operative (n = 143) groups. Etiologies, imaging findings, surgical outcomes, and recurrence rates were analyzed.

Adhesions, luminal obstructions, and neoplasms were the leading causes of SBO-VA. The surgical group (n = 169) had a 7.1% mortality rate, highest with volvulus and mesenteric ischemia. Bowel necrosis occurred in 32.5% of adhesive SBO cases, associated with peritonitis or mesenteric edema on CT. The non-operative group had a 4.9% mortality rate, with inflammatory diseases as the predominant suspected etiology. CT accurately predicted surgical findings in 60.1% of cases, with closed-loop signs and ascites indicating necrosis. Recurrence occurred in 23.5% of conservatively managed patients, often within four years.

SBO-VA exhibits diverse etiologies, with adhesions being the most common. Conservative management is feasible in select patients, particularly those with inflammatory conditions, while early surgery is critical for cases with signs of strangulation or ischemia. CT imaging plays a pivotal diagnostic role. Incorporating water-soluble contrast agents may optimize non-operative management. These advocate for tailored treatment strategies based on etiology and clinical risk stratification.