Anastomosis versus rectal stump procedure in cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for colorectal and appendiceal peritoneal metastases: A comparative study

Aim Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is the standard treatment for peritoneal metastases (PM) of colorectal or appendiceal origin. Rectal anastomotic leakage (RAL) or rectal stump blow‐out is a serious complication following rectal resection after CRS‐HIPEC. This study aimed to compare outcomes between ileo‐/colorectal anastomosis and rectal stump procedure and to identify risk factors for RAL and blow‐out. Method Data were retrospectively collected between 2012 and 2024 from a prospectively maintained HIPEC Registry and supplemented with the review of medical records. Postoperative complications and the prevalence of RAL or blow‐out were registered. Pearson's chi‐squared test was used to compare differences in categorical variables. Logistic regression was used to identify risk factors for RAL and blow‐out. Results Among 1271 CRS‐HIPEC procedures, 332 involved rectal resections. Patients received either an ileo‐/colorectal anastomosis ( n = 158) or had a rectal stump procedure ( n = 174). RAL occurred in 5.7% and blow‐out in 2.9% ( p = 0.201). In the rectal stump group, patients were older (65 vs. 59 years; p = <0.001), had higher PCI scores ( p = 0.031) and more often had received neoadjuvant treatment ( p = 0.025). Logistic regression showed no independent association between RAL and type of rectal reconstruction (OR 1.99; 95% CI: 0.61–6.51), low anastomotic level (OR 2.17; 95% CI: 0.50–9.42) or peritoneal cancer index >21 (OR 6.47; 95% CI: 0.84–50.1). Conclusion Both reconstruction strategies following rectal resection in CRS‐HIPEC were associated with low rates of RAL or blow‐out. No independent risk factors were identified, indicating that the choice of surgical approach should be individualized based on clinical context rather than presumed leakage risk.