No abstract

Computerized tomographic angiographic image of the right aortic arch with the aberrant subclavian artery as the fourth branch. Note the calcification and fibrosis at the site of attachment of the ligamentum on the left subclavian artery.

Background:The management of nonstrangulating small bowel obstruction (SBO) may require surgery, but the need for and timing of surgical intervention isn't always apparent. We sought to determine whether specific features on computed tomog raphy (CT) can predict the necessity for operative management.Methods: Two radiologists independently reviewed CT scans from all patients admitted to hospital with SBO between 2004 and 2006. We examined the associ ation between radiographic features and operative management by univariate analysis using the χ 2 or Fisher exact test. Significant factors with high concor dance between radiologists were entered into a multivariable stepwise logistic regression model. Results:There were 228 patients with SBO, 63 of whom met our inclusion criteria and had CT scans available for review. Three CT features were frequently associated with operative management and had good concordance between radiologists: com plete bowel obstruction, small bowel dilation greater than 4 cm and transition point. Transition point was the only significant factor predictive of operative management for SBO on multivariable logistic regression analysis (OR 19, 95% confidence interval 1.8-201, p = 0.014). Conclusion:In patients with nonstrangulating SBO, the presence of a transition point on CT scan should alert the surgeon to the increased likelihood that operative management may be required.