Safety of Mid and Low Rectal Cancer Surgery Without Dissection of the No.253 Lymph Node (S-M-O-O-T-H)

Prior treatment

• Extensive lesions not amenable to R0 resection.

Other illness

• Previous history of malignant colorectal tumors.
• Patients with complications such as intestinal obstruction, intestinal perforation, or intestinal bleeding requiring emergency surgery.
• Diagnosed with other malignancies within the past five years.
• Patients with severe liver, kidney, cardiac, pulmonary, coagulation dysfunctions, or serious underlying diseases that cannot tolerate surgery.
• History of severe mental illness.

Other

• Colonic biopsy pathology reveals mucinous adenocarcinoma or signet ring cell carcinoma.
• Imaging diagnosis of distant metastasis.
• Patients who have undergone multiple abdominal-pelvic surgeries or have extensive abdominal adhesions.
• ASA (American Society of Anesthesiologists) classification ≥ IV and/or ECOG (Eastern Cooperative Oncology Group) performance status score ≥ 2.
• Pregnant or breastfeeding women.

• Patient age between 18-75 years.
• Colonic biopsy pathology confirms adenocarcinoma.
• The inferior margin of the primary tumor is ≤ 7 cm from the anal verge, as confirmed by colonoscopy and baseline imaging at initial diagnosis.
• At initial treatment, imaging diagnoses the tumor T stage as less than or equal to 3.
• At initial treatment, imaging diagnoses no enlarged lymph nodes at the root of the inferior mesenteric artery.
• At initial treatment, imaging diagnoses the number of mesenteric metastatic lymph nodes as less than or equal to three.
• Strong willingness for surgery and signed informed consent.