Surgical Outcomes in Patients with Malignant Small Bowel Obstruction: A National Cohort Study

Objective: The study objectives were to characterize surgical outcomes for malignant small bowel obstruction (MaSBO) as compared to other small bowel obstructions (SBO) and to develop a prediction model for postoperative mortality for MaSBO. Summary Background Data: MaSBO is a morbid complication of advanced cancers for which the optimal management remains undefined. Methods: Patients who underwent surgery for MaSBO or SBO were identified from the National Surgical Quality Improvement Program (2005-2017). Outcomes [30-day morbidity, unplanned readmissions, mortality, postoperative length of stay (LOS)] were compared between propensity score-matched MaSBO and SBO patients. An internally validated prediction model for mortality in MaSBO patients was developed. Results: Of 46,706 patients, 1612 (3.5%) had MaSBO. Although MaSBO patients were younger than those with SBO (median 63 vs 65 years, P < 0.001), they were otherwise more clinically complex, including a higher proportion with recent weight loss (22.0% vs 4.0%, P < 0.001), severe hypoalbuminemia (18.6% vs 5.2%, P < 0.001), and cytopenias. After matching (N = 1609/group), MaSBO was associated with increased morbidity [odds ratio (OR) 1.2, P=0.004], but not readmission (OR 1.1, P=0.48) or LOS (incidence rate ratio 1.0, P = 0.14). The odds of mortality were significantly higher for MaSBO than SBO (OR 3.3, P < 0.001). A risk-score model predicted postoperative mortality for MaSBO with an optimismadjusted Brier score of 0.114 and area under the curve of 0.735. Patients in the highest-risk category (11.5% of MaSBO population) had a predicted mortality rate of 39.4%. Conclusion: Surgery for MaSBO is associated with substantial morbidity and mortality, necessitating careful patient evaluation before operative intervention.