Surgical treatment of colorectal cancer

The surgical treatment of colorectal cancer can be divided into extensive radical surgery and palliative surgery according to the patient's condition. The former is to remove a part of the normal intestinal flexure and the mesentery and lymph nodes in the area that are more than 5 cm away from the upper and lower ends of the lesion. It is the most effective method to cure colorectal cancer. The latter refers to the patient's mesenteric root lymph nodes that cannot be completely removed, or there is distant metastasis, and only the primary cancer lesion can be removed, thereby relieving the patient's complications such as obstruction, ejaculation, and infection. Because the colon has a wide and long mesentery, it is easy to remove the entire related mesenteric lymphatic drainage system except for the cancer lesion, and the prognosis is better than that of rectal cancer. The specific scope of resection of colorectal cancer in different parts is: right hemicolectomy for cecum, ascending colon and hepatic flexure cancer, left hemicolectomy for splenic flexure and descending colon, complete resection of upper rectal cancer, and rectosigmoid anastomosis, Miles surgery for lower rectal cancer, and whether to perform Miles surgery or anus-preserving surgery for middle rectal cancer depends on the size and degree of differentiation of the tumor. In order to improve the 5-year survival rate after rectal cancer surgery, most people currently advocate extended radical rectal resection for Ducs B and C stage cancers to reduce local recurrence and improve survival rate.

There are four main techniques:

(1) Expand distally and perform lymph node dissection at the root of the inferior mesenteric artery anterior to the aorta.

(2) Expand to both sides and perform internal iliac lymph node dissection on the pelvic side walls. This is particularly suitable for rectal cancers in my country, especially since about 75% of rectal cancers are located below the peritoneal reflection plane and metastases to the lateral pelvic wall and inguinal lymph nodes account for about 30% of lower segment cancers. This type of extended radical surgery is definitely effective in improving the 5-year survival rate.

(3) Pelvic wall lymph node dissection with preservation of autonomic nerve plexus: Pelvic wall lymph node dissection can easily damage the pelvic wall autonomic nerves, which can lead to urinary retention (45%) and impotence (76%). Recently, it is advocated to perform a procedure that preserves the bladder and prostate branches of the pelvic wall autonomic nerve plexus and dissects one side to reduce complications. However, this procedure is only indicated for early rectal cancer.

(4) Expand forward and perform posterior pelvic resection (female) or total pelvic clearance (male). Most scholars believe that total pelvic resection should be considered for female patients with invasion of the anterior rectal wall and vaginal rectal septum, and male patients with invasion of the anterior rectal wall with prostate or bladder, and no obvious metastasis to the intrahip lymph nodes. In case of intestinal obstruction, a fistula should be made in the proximal intestinal flexure of the cancer first, and radical surgery should be performed after the general condition improves. If the cancer is extensively infiltrated and cannot be radically removed, palliative surgery can also be performed. Even if there is a small amount of metastatic cancer in the liver and the local cancer is not fixed, limited resection of the lesion and metastasis should still be performed, including: ① Left-sided colon cancer with complete intestinal obstruction: It is now advocated to perform a one-stage tumor resection and a one-stage colon anastomosis. The disadvantage is that the incidence of surgical death and anastomotic leakage is higher than that of staged surgery. However, as long as strict aseptic operation is performed during the operation, the intestinal tract is carefully washed and irrigated to reduce local tension and ensure good anastomosis. After surgery, the anal sphincter is expanded to reduce intestinal tension, which can completely replace the staged surgery. ② Anal preservation for lower rectal cancer: Recently, the surgery that was originally only applicable to the preservation of the anus after the resection of the middle and upper rectal cancer has also been applied to some lower rectal cancers, and the preservation of the anus is regarded as one of the important indicators of the quality of life of cancer. The indications for anal preservation are: middle and lower rectal cancer more than 5.5 cm away from the anal margin, early tumor diameter less than 3 cm, the lower edge of the tumor is resected 3 cm, the upper edge is resected 4 cm, the middle and lower rectum of the differentiated, ulcerative type, and the lower rectum should be resected 4 to 5 cm, poorly differentiated, invasive type, and the lower edge of the cancer is resected more than 5 cm.