Since the nature of polyps is difficult to determine from the naked eye, they should generally be surgically removed or excised for pathological diagnosis after detection.
Surgical methods include endoscopic trapping, electrocautery (coagulation), or ligation of individual polyps. For those with larger size, it is not easy to perform trap resection or incisional removal, but the intestinal wall or intestinal segment can also be selected for resection. In cases without a tip or a wide tip (Figure 10), local excision is performed below the retroflexion of the abdomen, and above the retroflexion, the intestinal wall is excised, including the basal intestinal wall, or the intestinal segment is excised. Adenomatosis, including familial and non-familial, Gardner and Turcot disease both have numerous intestinal tumors that are prone to cancer and occur at an early age, such as familial adenomatosis are generally all cancerous before the age of 50, so it is advocated that those diagnosed with this disease have total colorectal resection and ileostomy, but it brings lifelong inconvenience to younger patients, so some advocate total colectomy ileorectal anastomosis. Whether the left rectum is the source of cancer, StMark data 25-year follow-up only 6.5% of rectal cancer, and most of them are early, so close postoperative follow-up is really necessary. Recently, some people advocate partial resection of the rectum plus mucosal peeling of the remaining rectum, preservation of the lower rectal muscle tube, and direct anastomosis between the ileum and the lower rectum. In conclusion, it is possible to avoid lifelong ileostomy and easy to be accepted by patients, although it adds some difficulty to the operation to preserve the anal function. Loop coagulation method: first aspirate the mucus and fecal water around the attached polyps, extract and inject air to replace the hydrogen and methane that may be contained in the intestine to prevent the explosion of electrocautery, near the polyp open the loop sleeve wire to avoid the loop too close to the intestinal wall, damage the intestinal wall to cause death perforation, sleeve into the tight sleeve wire, according to the thickness of the tip to choose a different current power, cutting not too fast, cutting slow hemostasis perfect (Figure 9). Biopsy forceps coagulation cut method: 0.5 cm wide based lesions, with biopsy forceps bite all, lifting the base is curtain-like narrow pseudo-tip, followed by current coagulation for a few seconds, the local is grayish white can bite the biopsy forceps pull off the tissue sent to pathological examination. Electrocoagulant cauterization method: mostly for lesions below 0.5 cm, mostly benign, can not be removed by forceps, can be removed by electrocoagulation hemostat contact after cauterization with coagulation current. However, do not go too deep to avoid perforation or delayed perforation, the latter can occur 2-7 days after surgery. Surgical treatment: Surgical treatment of polyps and polyposis generally includes: local excision, intestinal wall excision, intestinal segment excision, subtotal colon or total colorectal excision. Depending on the number of polyps, the presence or absence of the tip and the location: surgical options for carcinoma in situ limited to the mucosal layer: it is agreed that local excision is sufficient, but pathological confirmation is required. Malignant polyps: adenoma with cancer infiltration, invasion of mucosa and submucosa, colonoscopic excision is prone to residual and lymph node metastasis, therefore, it is advocated that those confirmed as malignant should be operated again. Small flat polyps can be removed first, and if they are suspected to be malignant during endoscopic examination, they need to be removed surgically, so Indiaink is injected locally during endoscopic removal to mark for further surgery after pathological diagnosis is confirmed. If there is recurrence, the intestinal segment will be surgically removed again. Infiltrating carcinoma: When the carcinoma penetrates the submucosa, the management opinions are different. The choice of surgical approach depends mainly on the risk of cancer metastasis and recurrence. 347 cases of infiltrating carcinoma in Nivation’s comprehensive literature had an overall lymph node metastasis rate of 9%, including a metastasis rate of 15% for malignant transformation of adenoma without a tip and 6% for cancer residual. The metastasis rate with tissues was 7.8%, of which 2.3% were cancer residuals. The rate of lymph node metastasis is 3% when the cancer is confined to the head of adenoma or adenoma, while the rate of lymphatic metastasis is 20% when the cancer enters the neck and base.
Local excision is feasible for adenoma with the following 4 features.
1. complete resection of adenoma confirmed by both colonoscopy and pathological examination
2, well differentiated cancer cells.
3, absence of cancer at the cut edge.
4. No vascular or lymphatic involvement. The rate of lymph node metastasis for those with these 4 items was <2% and was not higher than the mortality rate after bowel resection. The rate of lymph node metastasis was 41.7% if the opposite 4 characteristics were present. The majority of scholars now agree with the principle that invasive carcinoma confined to the head of a tipped adenoma with all of the above features does not require bowel resection, and that local excision with close follow-up is sufficient.
Those who have one of the following 4 items need to undergo intestinal resection.
1. Invasive carcinoma with poor differentiation in the head of the tipped adenoma.
2.Invasion of cancer cells into submucosal lymphatic vessels or veins.
3, cancer at the cut edge.
Morson et al. applied the above principles to perform complete adenomectomy for invasive carcinoma with 5 years of follow-up and no recurrence. A minority disagreed with the above principles and believed that all adenomas containing invasive carcinoma should undergo standard bowel resection. Adenoma carcinoma infiltrating into the muscularis: It is generally accepted that radical surgery is required regardless of differentiation. However, it has been reported that local resection plus radiotherapy for stage T2 rectal cancer in the lower rectum has satisfactory results. ＜If the polyp is less than 0.5 cm, all polyps can be removed by biopsy forceps coagulation method, and the specimen can be sent to pathology for examination; if the polyp is 0.5-1.0 cm, it can be removed by coagulation; if the polyp is multiple and it is not easy to be removed by forceps one by one, it should be removed by surgery; if the polyp is judged benign by naked eye, the lesion can be removed by electrocoagulation cautery. Endoscopic excision of polyps with and without a tip: polyps with a tip can be removed by coiling during colonoscopy, while small polyps without a tip can be removed by electrocautery and large polyps can be removed by submucosal injection of saline. The common complication after removal by electrocautery is postoperative bleeding, 0.1% to 0.2%.
Postoperative follow-up is 1 to 3 years, including for those with progressive adenomatous carcinoma in situ, or highly atypical hyperplasia. Because the lymphatic vessels of adenomatous polyps penetrate the mucosal muscle layer, those with severe atypical hyperplasia and carcinoma are limited to the mucosa without lymph node metastasis.
Tender polyps can be coiled and excised. The treatment of non-tipped polyps is: surgical resection: >2 cm of villous broad-based adenoma should not be removed by colonoscopy in blocks, and surgical resection is appropriate. For those who cannot be removed by endoscopy above the peritoneal reflex, they should be treated as colorectal cancer directly, so more than 1/3 of such patients have infiltrative carcinoma; for those who can be removed by endoscopy, careful pathological examination should be performed after resection, and radical surgery should be performed when infiltrative carcinoma is found. For those who are located below the peritoneal reflex, local excision can be performed via anus or sacrum. Principles of treatment of adenoma carcinoma.
Prognosis
Polyposis has an obvious tendency to become cancerous, and Lockhart-Mummcry predicted that “every polyp, left to its natural course, will eventually become cancerous. Simple polyposis is mainly found in the rectum and sigmoid colon, and the largest polyp is 4 cm in diameter and is cancerous. The cancer rate is 36% (Hullsiek) or 73% (Dukes) when patients are seen for symptomatic exacerbation. The propensity for carcinogenesis is thought to be related to the increased sensitivity of genetic variants to oncogenic factors.
In Muto, the cancer rate was 12.7% in 59 patients with a disease duration of less than 5 years, 41.8% in those with a disease duration of 5-10 years, and even higher in those with a disease duration of more than 10 years (45.4%). Four cases in this group were not found to be cancerous after 20 years.
Carcinoma is age-related. The disease mostly develops around 20 years of age, before 10 years of age, and less after 40 years of age. Dukes analyzed a large group of cases and concluded that the average interval between onset and diagnosis of cancer was 8 to 15 years (Table 6). Analysis by age group: the cancer rate was 29% for those under 19 years old, 38% for those 20-29 years old, 82% for those 30-39 years old, and 92% for those 50-59 years old.
There are more polyposis carcinomas, more multicentric ones, and more rectal and sigmoid colon carcinomas. These features should be noted during clinical biopsy.
In the follow-up of 56 cases, Jackman found that 70% of recurrent polyps could appear, and 12.5% of them developed into cancer. However, by 1962, there were 10 cases of spontaneous regression of simple polyposis reported in the world, the mechanism of which is unclear.
Prevention
The basic principle of management of familial adenomatous polyposis is to remove the diseased intestine before the polyp becomes cancerous, and to screen and follow up the family members. Careful genealogical registration this is very important to identify people at risk. For children in the family, regular colorectal examinations should be performed after the beginning of adolescence, usually about half a year for a sigmoidoscopy until the age of 40, if there are no polyps in the colorectum by then, the chance of having polyps again is less. However, it is worth noting that very few patients will develop polyposis after the age of 60. In addition, the upper gastrointestinal tract should also be examined periodically, especially around the duodenal potbelly, to exclude the possibility of duodenal and peri-potbelly polyps.
In recent years, many authors have found patients without clinical symptoms by testing for mutations in the APC gene with an accuracy of up to 100%. This approach avoids the pain of regular colonoscopy and provides 1 new avenue for early detection of patients with familial adenomatous polyposis.