Prospective, observational validation of a multivariate small-bowel obstruction model to predict the need for operative intervention.

BACKGROUND

We published previously a model predictive of the need for exploration in small-bowel obstruction. We aimed to validate and refine the model, hypothesizing that the model would be predictive, would prevent delayed management of strangulation, and would be successfully improved.

STUDY DESIGN

Data from 100 consecutive patients with small-bowel obstruction and concurrent CT were collected prospectively. New features evaluated included obstipation and the absence of colonic gas on CT.

RESULTS

Overall mortality was 8%. Twenty-nine patients had all 4 clinical features, 22 of whom required operative exploration (concordance index = 0.75), confirming the validity of the old model. Intraperitoneal free fluid (odds ratio [OR]: 2.6, 95% CI: 1.0 to 6.9) and vomiting (OR: 1.5, 95% CI: 0.5 to 4.5) were not predictive of operative exploration; however, mesenteric edema (OR: 4.2, 95% CI: 1.1 to 15.8) and lack of the small-bowel feces sign were (OR: 3.5, 95% CI: 1.4 to 8.8). Obstipation was associated with the need for exploration (OR: 2.8, 95% CI: 1.2 to 6.6), but absence of colonic gas was not. A new model was equally predictive of the need for exploration: mesenteric edema (OR: 5.6, 95% CI: 1.5 to 20.7), lack of the small-bowel feces sign (OR: 5.1, 95% CI: 1.9 to 13.6), and obstipation (OR: 3.2, 95% CI: 1.2 to 8.3). The concordance index for this new model was 0.77.

CONCLUSIONS

Our current prospective study validated our original model and was successfully improved. Our new model demonstrated equivalent predictive ability and was simpler to use. When all 3 features of the new model are present, strong consideration for early operative exploration should be entertained and may decrease the rate of missed strangulation obstructions.