Surgical treatment of colon cancer

Surgery is the preferred treatment for colon cancer. In most cases, local lymph nodes need to be removed at the same time as the primary tumor. Optional treatment options include: endoscopic polypectomy, laparoscopic colectomy (patients must be carefully selected), and combined treatment can be used for advanced malignant tumors.

1. Simple colonoscopic polypectomy is applicable to malignant polyps that are small and pedunculated, with cancer cells confined to the neck of the polyp and well differentiated. Before the operation, ink should be injected under the mucosa of the cancerous site for endoscopic observation or as an indication for resection. A follow-up examination should be conducted once 3 to 6 months after the operation, and subsequent follow-ups should be conducted in the first and third years respectively.

2. Radical surgery for colon cancer

(1) Bowel preparation: Preoperative bowel preparation includes mechanical catharsis and preventive antibiotics. Mechanical cleaning usually uses a hypertonic polyethylene glucose solution, such as oral sodium phosphate (rapid phosphate soda). There are two important principles for preventive antibiotic use: first, timely administration to ensure that there is sufficient antibiotic tissue concentration around the injured area when there is bacterial contamination; second, the dosage and range of administration should enable the antibiotic to directly act on Gram-positive bacteria, Gram-negative bacteria, aerobic bacteria and anaerobic bacteria. The dosage regimen is: neomycin 1g, erythromycin 1g, oral. Before the start of surgery, intramuscular and intravenous injections are added through parenteral routes.

(2) Laparotomy: A urinary catheter and a gastric tube are required. The peritoneal cavity is usually entered through a supraumbilical or subumbilical midline incision. Some surgeons also use a transverse incision, while the paramidline incision has been abandoned to a certain extent. During the operation, a comprehensive morphological examination and palpation of the entire peritoneal cavity should be performed, with particular attention to the liver, retroperitoneum, ovaries, omentum, large and small intestinal mesentery, and serosal surfaces. Intraoperative liver ultrasound can help detect suspicious liver lesions. During the operation, the staging of the primary tumor can be directly evaluated based on whether the tumor has infiltrated the intestinal wall, fixed and/or invaded adjacent structures.

(3) Principles of resection: Ligate the root of the lymphatic vessels that drain the intestinal segment where the tumor is located, and determine the scope of resection accordingly. Right hemicolectomy can be used for tumors located between the cecum and the colon. Transverse colon tumors can be treated with transverse colectomy or extended right hemicolectomy. Since the former may cause excessive tension on the anastomosis or insufficient blood supply during colon anastomosis, extended right hemicolectomy is a better choice. Left hemicolectomy can be used for tumors located in the splenic flexure, descending colon, and sigmoid colon. Partial intestinal resection is only used as a palliative surgery. In order to minimize the risk of transmission during the operation, before moving the intestine, the mesenteric vessels are separated and ligated, the intestine proximal and distal to the primary tumor is closed, and cytotoxic drugs are perfused, that is, tumor-free technology.

3. Laparoscopic colectomy As surgeons become more familiar with laparoscopic equipment and techniques, minimally invasive surgery has been used for a variety of abdominal organ surgeries, including the colon. The most direct benefits of this type of surgery are reduced postoperative hospital stays, reduced medical costs, shorter recovery time, higher quality of life, less impact on physiological and immune functions, and better appearance. However, its surgical equipment is expensive and time-consuming. In addition, laparoscopic surgery has its own special potential complications. For example, small intestine and ureteral injury, anastomotic leakage, CO2 embolism, hemodynamic effects, and arrhythmias. In oncology, there are still several problems, such as incomplete resection of the tumor base, recurrence at the surgical wound site, and accelerated tumor spread caused by pneumoperitoneum.