Recurrence After Operated Adhesive Small Bowel Obstruction: Development and Validation of a Predictive Model

Recurrence after operated adhesive small bowel obstruction (ASBO) is a threatening potentiality for patients and a therapeutic dilemma facing any surgeon. Yet, little is known about screening tools to identify patients at higher risk of recurrence. The present study aimed to determine the risk factors of recurrence in patients operated on for ASBO and to construct a reliable predictive model capable of quantifying the risk of recurrence, which will be a practical tool to guide individualized patient management.

We developed a best-fit nomogram using data from a training cohort of 454 patients with ASBO treated surgically at the Affiliated Hospital of Qingdao University from 2012 through 2021. The nomogram was developed based on variables independently associated with recurrent ASBO screened via multivariate logistic regression. This model was validated using data from an independent internal cohort of 194 patients at the same institution and an external cohort of 196 patients at Qilu Hospital of Shandong University. Both internal and external validation was performed with a bootstrap resampling method (1000 iterations). The predictive accuracy of the nomogram was evaluated using Harrell's concordance index (C index) and calibration curve.

Eight-one out of 648 (12.5%) patients experienced at least one ASBO relapse with a median follow-up of 37 (interquartile range, 18-70) months. Univariate and multivariate analyses identified the following independent predictive factors associated with recurrence: diabetes mellitus (P = 0.004), preoperative albumin levels (P = 0.002), omentectomy (P = 0.002), matted adhesions (P = 0.036), and the approach of surgery (P = 0.008). Incorporating these five predictors, our nomogram predicted recurrent ASBO with C-index scores of 0.932 (95% CI 0.867-0.996) in the training cohort, 0.874 (95% CI 0.706-1) in the internal validation cohort, and 0.852 (95% CI 0.667-0.920) in the external validation cohort. The predictive model showed a very good fitting degree.

The development of a practical, easy-to-use nomogram for calculating the risk of recurrence in patients with ASBO treated surgically will enable physicians to tailor therapeutic strategies and monitor disease in advance.