Risk factors and outcomes associated with postoperative ileus following ileostomy formation: a retrospective study

BACKGROUND: Postoperative ileus (POI) is associated with increased patient discomfort, length of stay (LOS), and healthcare cost. There is a paucity of literature examining POI in patients who have an ileostomy formed at the time of surgery. We aimed to identify risk factors for and outcomes associated with POI following ileostomy formation. METHODS: We included 261 consecutive non-emergent cases that included formation of an ileostomy by a board-certified colorectal surgeon at our institution from July 1, 2015, to June 30, 2020. Demographic, clinical, and intraoperative factors associated with increased odds of POI were evaluated. Post-procedure LOS, hospitalization cost, and re-admissions between patients with and without POI were compared. RESULTS: Out of 261 cases, 85 (32.6%) were associated with POI. Patients with POI had significantly higher body mass index (BMI) than those without POI (26.6 kg/m(2) vs. 24.8kg/m(2); p = 0.01). Intraoperatively, patients with POI had significantly longer procedure duration than those without POI (313 min vs. 279 min; p = 0.02). Patients with POI had a significantly higher net fluid balance at postoperative day (POD) 2 than those without POI (+ 2.65 L vs. + 1.80 L; p = 0.004), with POD2 fluid balance greater than + 807 mL (determined as the maximum Youden index for sensitivity over 80%) associated with a higher rate of POI (p = 0.006). This difference remained significant when adjusted for age, gender, BMI, pre-operative opioid use, procedure duration, and operative approach (p = 0.01). Patients with POI had significantly longer LOS (11.40 days vs. 5.12 days; p < 0.001) and direct cost of hospitalization ($38K vs. $22K; p < 0.001). CONCLUSIONS: Minimizing fluid overload, particularly in the first 48 h after surgery, may be a strategy to reduce POI in patients undergoing ileostomy formation, and thus decrease postoperative LOS and hospitalization cost. Fluid restriction, diuresis, and changes in diet advancement or early stoma intubation should be considered measures that may improve outcomes and should be studied more intensively.