Incidence and outcomes of postoperative paralytic ileus after cytoreductive surgery with HIPEC : A population‐based study

BACKGROUND: Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is standard treatment for peritoneal metastases in Sweden. Prolonged postoperative ileus (PPOI) is a common complication following major abdominal surgery and is associated with increased morbidity and prolonged hospitalization. The aim of this study was to evaluate the incidence of PPOI following CRS-HIPEC and to identify factors associated with its development, including its relationship to postoperative complications. METHODS: This retrospective, bicentre cohort study included patients undergoing CRS-HIPEC for peritoneal metastases between January 2012 and 2024. Patients were identified through the Swedish HIPEC Registry, with supplementary data obtained from medical records. PPOI was defined as delayed defaecation beyond postoperative day 5 and/or prolonged use or reinsertion of a nasogastric tube. Clinical, surgical and postoperative outcomes were analysed and risk factors for PPOI were assessed using a multivariable logistic regression model. RESULTS: A total of 982 patients were included, of whom 443 (45%) developed PPOI. Patients with PPOI had significantly longer hospital stays (median 11 vs. 9; p < 0.001) and delayed return of bowel function compared with patients without PPOI (median 6 vs. 3 days; p < 0.001). Major complications were more frequently observed in patients with PPOI (36% vs. 16%, p < 0.001). Independent risk factors for PPOI were major postoperative complications (aOR 3.74, CI 2.55-5.48), blood transfusion (aOR 1.70, CI 1.08-2.70) and omentectomy below the gastroepiploic arcade (aOR 1.51, CI 1.01-2.26). This association remained even after excluding patients with major postoperative surgical complications. Ileostomy formation was associated with a reduced risk of PPOI (aOR 0.51, CI 0.33-0.77). CONCLUSIONS: PPOI is a frequent complication following CRS-HIPEC and is associated with increased postoperative morbidity and prolonged recovery. Strategies aimed to optimize perioperative care and enhanced recovery protocols may help to reduce the incidence and the adverse effects of PPOI.