Local Methylene Blue Injection for Prevention of Anastomotic Leakage and Permanent Stoma After Low Anterior Resection for Rectal Cancer

Rectal cancer surgery has become increasingly effective, allowing many patients to avoid permanent colostomy. However, anastomotic leakage remains one of the most serious complications after rectal cancer surgery, especially in patients undergoing low anterior resection. Anastomotic leakage may lead to pelvic infection, prolonged hospitalization, additional treatments, and may affect the recovery of temporary diverting stomas. This investigator-initiated clinical study aims to evaluate the safety and potential effectiveness of local methylene blue injection around the pelvic floor after completion of colorectal anastomosis in patients with high-risk rectal cancer undergoing low anterior resection with a temporary diverting ileostomy. In this study, eligible patients will receive local injection of diluted methylene blue solution into the pelvic floor muscles surrounding the anastomosis after surgery. Participants will be followed for 12 months after surgery. The study will evaluate postoperative outcomes, including the occurrence of anastomotic leakage, complications related to the injection procedure, and whether the temporary stoma can be successfully reversed. The information collected in this study may help determine whether local methylene blue injection is a safe and feasible approach for reducing postoperative complications and improving recovery after rectal cancer surgery.