Anastomotic Integrity in Colorectal Surgery for Colorectal Cancer: The Role of Protective Ileostomy and the Corner Effect

Anastomotic leakage is one of the most significant complications following low colorectal surgery for rectal cancer, with profound implications on morbidity, mortality, and long-term oncological outcomes. Protective ileostomy has been widely adopted to mitigate these risks by diverting fecal flow away from the anastomotic site, allowing it to heal without exposure to bowel contents. However, recent discourse challenges the routine use of protective ileostomies, suggesting a more selective approach based on patient-specific risk factors, surgical techniques, and intraoperative findings. This review examines the multifactorial nature of anastomotic failure, focusing on the impact of patient comorbidities, neoadjuvant therapies, surgical expertise, and technological advances, such as fluorescence angiography with indocyanine green (ICG), to assess tissue perfusion. The concept of the “corner effect” in low colorectal anastomoses, where tension and ischemia at stapled junctions predispose to leakage, is discussed. The review also explores the implications of long-term ileostomy use, including its association with Low Anterior Resection Syndrome (LARS) and delayed recovery. Further, we address gaps in the literature regarding the timing of ileostomy reversal, the influence of neoadjuvant therapy on anastomotic healing, and the potential role of bioabsorbable materials in reinforcing anastomoses. The review calls for a more personalized approach to protective ileostomy use, integrating patient characteristics, surgical expertise, and technological advancements to optimize outcomes in colorectal cancer surgery.