Mr. Wang, 36 years old, went to the hospital for examination because of blood in the stool for 7 days. The doctor found a cauliflower-like mass 5 cm away from the anal opening and pathologically diagnosed as rectal cancer. The doctor told him that due to the low location of the tumor, it was difficult to keep the anus and it needed to be removed. Mr. Wang is usually in good health and is in his prime. He is not afraid of cancer and surgery, but he cannot accept the removal of the anus. He was referred to our hospital and we performed super-low rectal cancer resection and anal preservation surgery for him. Five years after the surgery, he is now working with great energy and outstanding performance, and his family life is also beautiful and happy. The new technology of low rectal cancer resection and anal preservation surgery has brought a resounding sound to patients and families like Mr. Wang.
The principle of ultra-low rectal cancer anus-preserving surgery
Traditionally, it is believed that any tumor within 5-6 cm from the anal opening should be removed and a colostomy (artificial anal surgery) should be performed. Recent clinical studies have shown that the lymphatic metastasis of lower rectal cancer is mainly upward, with a small amount of lateral spread, and the lateral spread is along the lateral rectal ligament rather than the upper edge of the anal raphe. Therefore, removal of lymphatic metastases is not necessary to remove the anal raphe and anal sphincter. The infiltration of rectal cancer into the distal rectum is usually within 1 cm, and resection of the distal 2 cm of the bowel wall is sufficient. It has been confirmed that the 5-year survival rate and local recurrence rate of rectal cancer with lower margin >2 cm from the dentate line are no different from those of Miles surgery (i.e. anal excavation); the 5-year survival rate and local recurrence rate of ultra-low rectal cancer with lower margin <2 cm from the dentate line are no different from those of Miles surgery (i.e. anal excavation) if total rectal resection and colon-anal anastomosis are performed. There is no difference. This is because recent clinical studies have demonstrated that normal anal defecation can be preserved as long as the external anal sphincter and anal levator muscle are preserved. The development of the anastomosis technique has provided the technical guarantee for ultra-low anal preservation surgery for rectal cancer. The anal levator and anal sphincter muscles are preserved, thus preserving the function of bowel control. Patients can resume normal defecation function 3 months after surgery, and the defecation control function will be even better if the colpotomy and super-low rectal anastomosis are used at the same time.
Low rectal cancer anal preservation surgery has the following advantages:
(1) It has the same good therapeutic effect as Miles excisional surgery;
(2) Preservation of normal bowel function improves the quality of life and enhances the patient’s self-confidence after surgery;
(3) good exposure of combined transabdominal and anal resection anastomosis with few complications.
Anal conserving surgery for ultra-low rectal cancer is suitable for the following cases.
Highly differentiated adenocarcinoma without peripheral infiltration.
Key points of anal preservation surgery for low rectal cancer.
The lymphatic tissue above the cancer must be thoroughly removed, including the resection of the superior rectal artery, the root of the sigmoid colon artery, and the removal of its lymphatic tissue, as well as the removal of the lymphatic tissue of the left colonic artery trunk and the root of the inferior mesenteric artery. At the same time, the clearance of lateral lymphatic tissues should not be neglected, including the excision of the lateral ligament and the fatty lymphatic tissues around the lower rectum, and the lymphatic tissues around the internal iliac artery if necessary. The upper part of the cancer must be resected >15cm intestinal canal, and the distal part must be resected 1cm normal intestinal canal. In practice, because the lower rectum is free and the intestinal canal is lengthened, the resection area of 2 cm from the lower edge of the tumor can often be ensured without pulling, and if necessary, the internal rectal sphincter can be partially or completely removed and a colon-anal skin anastomosis can be performed.
In order to ensure the blood flow of the left hemicolectomy, the left colonic artery should be preserved as much as possible, and if the main trunk of the left colonic artery is to be removed, care should be taken to protect the marginal arterial arch and the traffic branches between the superior and inferior mesenteric arteries. The descending colon and, if necessary, the splenic flexure of the colon should be free so that the proximal intestine can be retracted to the anal canal anastomosis without tension or torsion.
The anal levator and external anal sphincter muscles are preserved to ensure normal defecation control and sensory function after surgery.
Adequate exposure of the anal canal and surgical operation Adequate dilation of the anal canal and radiolucent suturing of the perianal skin with the distal skin to fully expose the anal canal for surgical operation.
Pay attention to preoperative intestinal preparation, ensure intestinal cleanliness, free the lower rectum and then block the intestinal canal below the tumor with upper clamp, irrigate the anal canal and lower rectum with saline and dilute iodophor to reduce contamination. The pelvic drainage through the paranal cavity was used to prevent pelvic infection and anastomotic leakage. In addition, intraoperative dilation must be sufficient to temporarily paralyze the anal sphincter for a few days after surgery to keep the anal opening open, reduce the contamination and pressure caused by fecal retention in the anastomosis, and ensure smooth healing of the anastomosis.
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Figure 1 End-to-end anastomosis of the colon with the rectum above the dentate line
Figure 2 “J-shaped” anastomosis of the colon with the rectum above the dentate line to improve defecation function after surgery
Figure 3 Longitudinal and transverse suture of the colon (A) and super-low suture of the rectum (B), with better defecation function
Figure 4 Comparison of different anastomoses: A – double anastomosis or triple anastomosis bowel anastomosis technique, the anastomosis is in the shape of: ” ” a “; B – double purse-string suture single anastomosis bowel anastomosis technique, the anastomosis is well aligned and round
Figure 5: The scope of surgical resection within the blue line, total mesorectal resection + total rectal resection + external sphincter preservation + colorectal anastomosis allows patients with low or ultra-low rectal cancer to preserve the anus; A – male pelvic anatomy; B – female pelvic anatomy