I. Overview
Familial adenomatous polyposis (FAP) is characterized by multiple polyps in the colon and rectum, and the polyps that occur are precancerous and very prone to develop into cancer. It occurs in young people, and clinical symptoms usually start to appear at the age of 15-25 years old and are most obvious around 30 years old.
Classification
There are two types of FAP: typical FAP and mild FAP. Typical FAP is characterized by the presence of a large number of polypoid adenomas, usually thousands, spread throughout the colon. Mild FAP is characterized by a smaller number of colon polyps, usually less than one hundred, which are often flat and tend to be located in the right hemicolectum. Ninety-five percent of family members develop colonic adenomas at an average age of 35 years, with most members developing cancer around age 40. Small bowel adenomas occur in 80% of patients, small bowel adenocarcinomas in 5-10%, and gastric polyps in 50%. Some patients also have a combination of . Some patients have extra-gastrointestinal diseases, such as thyroid tumors, abdominal sclerofibroma, osteoma, epidermoid cysts and hepatoblastoma, as well as congenital retinal pigment epithelial hyperplasia, soft tissue tumors, osteoma and dental dysplasia, and central nervous system tumors.
Pathogenesis
FAP is caused by mutations in the adenomatous polyposis coli (APC) gene, which is located at 5q21-22 and is an oncogene with a variety of mutation patterns. The most common APC mutation is a change in gene sequence that results in the premature appearance of a termination code, producing a nonfunctional truncated protein. Mutations in the APC gene can be detected in more than 80% of FAP patients, but in about 20% of patients, mutations in the APC gene are not detected using available genetic testing techniques.
Pathological features
The clinicopathological features of FAP mainly show that gastrointestinal symptoms appear only after the growth of intestinal polyps, so patients usually develop symptoms around 15-25 years old. The common symptoms are vague abdominal pain, diarrhea, mucus and blood stool or small amount of blood stool, occasionally large amount of blood in stool, blood in stool is mostly intermittent, and the sensation of falling in the anus, which is often misdiagnosed as internal hemorrhoids or chronic colitis. The polyps gradually increase in size, and the above symptoms worsen. In individual patients, due to the large polyps, when intestinal entrapment occurs, patients have abdominal pain, abdominal distension, nausea, vomiting and other symptoms of intestinal obstruction, some intestinal entrapment can be reset by themselves and the symptoms can be relieved, but the entrapment can occur repeatedly. Due to long-term diarrhea and mucus and blood stool, patients may suffer from anemia, weakness, hypoproteinemia, etc.
V. Carcinogenesis rate
The larger the polyp, the more chance of cancer. If adenomas are found in the first examination, all of them should be biopsied electrically and confirmed to be adenomas, and colonoscopy should be performed after 3 years. If the first follow-up examination shows normal or a single small tubular adenoma is found, the next follow-up examination can be postponed to 5 years later; on the contrary, if the polyp is large in size and number, the interval of examination should be shortened.
6.Auxiliary examination
1.Anal finger diagnosis
Multiple polyps of grape bunch size can be palpated.
2.Barium meal examination of upper gastrointestinal tract
To detect polyps in the upper gastrointestinal tract and deal with them
3.Fiber colonoscopy
The easiest way to prevent colorectal cancer and improve the treatment effect of colorectal cancer. Multiple adenomatous polyps can be seen, and it is difficult to see the normal mucosa, and the polyps only involve the large intestine. Not only the size, distribution and morphology of polyps can be clarified, but also the nature of the polyps can be biopsied. endoscopically, most of the polyps in the large intestine are the size of a soybean, i.e. ≤12.5 px. hemispherical or broad basal, and it is difficult to see the normal mucosa in the intestinal segment where polyps are densely distributed. scattered short-tipped or broad basal-tipped polyps >25 px can often be seen between small polyps, which are lobulated or villi-like and often have congestion, edema The polyps are often congested, edematous, erosive, and bleeding. Small polyps are mostly non-congested and edematous. The distribution of polyps is most common in the rectum, followed by the sigmoid colon, descending colon, and transverse colon. Colonoscopy is needed for people who have some of the following symptoms or conditions.
aPatients with unexplained blood in the stool, especially dark red bloody stools or blood clots.
b atypical abdominal pain.
c unexplained diarrhea, pus and blood stools.
d unexplained constipation.
e those with a family history of tumor and over 35 years of age.
f patients in families eligible for familial polyposis (FAP) requiring regular colonoscopic follow-up after the age of 10 years.
g those eligible for hereditary non-polyposis colorectal cancer (HNPCC) in families over 18 years of age
h those without any symptoms over 45 years old need to have their first colonoscopy, and if there are no abnormal findings need to have a colonoscopy once every 3-5 years; colon polyps are found to be followed up according to the follow-up method for colon polyps.
4.Fecal occult blood test
Fecal occult blood or mucus blood is one of the characteristics of early colorectal cancer, but the false positive rate of this method is high, and not all colorectal cancers have bleeding.
5.Fundoscopy
Congenital hypertrophy of retinal pigment epithelium (CHRPE) is seen in more than 80-95% of FAP patients, and is visible in the fundus bilaterally, i.e. an oval flattened lesion with bounded pigment changes in the retina, surrounded by translucent rings. It is a specific manifestation of FAP, which is usually more than 4. As a sign, the suspect can detect clues of the disease by eye examination (fundoscopy). Since the disease is familial, if one member of the family is diagnosed, the other members should be examined (including fundoscopy). This method is a highly sensitive and specific FAP-assisted diagnosis, and is a safe and effective means of screening for family members.
VII. Treatment
1.Surgery.
Due to the large number of adenomas in FAP patients, it is impossible to remove them all together by colonoscopy, and 100% of patients will eventually transform into colorectal cancer, therefore, surgical resection of the entire colon is the only means to prevent adenoma carcinoma in FAP patients.
A. Total colonic resection and ileo-rectal anastomosis: This procedure is suitable for patients with few polyps, especially those with few rectal polyps.
B. Total colorectal resection: total colorectal resection is performed, with special emphasis on the removal of all rectal mucosa, as any remaining rectal mucosa may be the cause of postoperative polyp development and colorectal cancer.
C. Ileal and anal canal anastomosis (IAA). Patients undergoing this procedure have very poor stool control, with most of them having a dozen to dozens of bowel movements per day, and some patients have to switch to ileostomy because they cannot tolerate frequent bowel movements.
D. Ileal storage pouch and anal canal anastomosis (IPAA), this procedure is the most commonly used in clinical practice, but it should be applied with caution to patients who have developed cancer, especially those who have developed rectal polyps.
2.Drug therapy.
NSAID drugs such as – sulindac : a non-steroidal anti-inflammatory drugs and colonic polyps regression related. Oral administration of sulindac (150 – 200 mg/d) can reduce the size and number of intestinal polyps, so that the cell proliferation index is significantly reduced. Studies have shown that sulindac promotes the regression of polyps by inhibiting cyclooxygenase-2 (COX-2) and prostaglandin synthesis. Sulindac also inhibits the proliferation of cancer cells and increases the apoptosis of mucosal epithelial cells. Other drugs: aspirin, pyrrolizidine and indomethacin. Cilpro, etc.
Nursing diagnosis.
1. Anxiety: related to fear of cancer, surgery, and lack of knowledge about the disease.
2.Pain: related to surgical incision and nerve irritation by cancer.
3.Nutritional disorders lower than the body’s needs: related to surgical fasting and cancer depletion.
4.Cooperative problems: water-electrolyte disorders: related to postoperative fasting.
5.High body temperature: related to postoperative infection and anastomotic leak.
6.Self-image disorder: related to colostomy.
7.Limited self-care: related to stoma establishment.
Nursing care plan.
Preoperative care.
1, Diet: 3 days preoperative dregs-free semi-fluid, 1 day preoperative fluid diet.
2, intestinal preparation: 2 boxes of Hengkang Zhengqing orally 1 day before surgery, slag-free stools. Fasting after dinner and water fasting for 6 hours before surgery.
3, skin preparation: nipple line to the pubic symphysis, two symphysis to the axillary midline
4.Practice bed urination and defecation and effective coughing before surgery
5.Inform patients of the benefits of postoperative semi-recumbency, coughing to protect the wound, and the protection of the drainage tube and wound observation.
6.Psychological care: Patients with stoma can be introduced to the site, function and nursing knowledge of the stoma through pictures, models and food, explaining its significance and necessity.
7. Insert the gastric tube, wear clothes backwards, take off the dentures and jewelry on the body before sending to the operating room.
Postoperative care.
1, 6 hours after surgery to the pillow lying down, after the desirable semi-prone position (conducive to breathing and drainage). Fasting after surgery until the gastric tube is removed.
2. Closely observe the vital signs and record them every hour. Pay attention to the observation of postoperative complications, such as bleeding to see the amount, color, properties of drainage fluid and the presence of blood pressure and other vital signs of change.
3.Care of various drainage tubes: gastric tube, anterior sacral negative pressure, drainage tube, jejunostomy tube, abdominal drainage tube, keep the tube fixed, unobstructed, aseptic operation, observe the amount, color and properties of drainage fluid and record.
4.Observe the wound dressing dry, with exudation timely replacement.
5.Indwelling catheterization: clean the urethral orifice with potassium permanganate solution twice a day, and pay special attention to the observation of urine color within 24 hours after surgery. The catheter can be removed after the recovery of bladder function after the training of the clamped tube.
6, fasting: 3-5 days after surgery anal venting without abdominal distension can enter the liquid diet, no discomfort can enter the less residue diet, and later more high-calorie, high-protein, high vitamin diet. Do not eat greasy, unhygienic food to prevent diarrhea.
Care of human anal pouch.
1.Protect the patient’s privacy, understand the patient’s psychological changes, encourage and care for the patient.
2.Observe the stoma before it opens, and use petroleum jelly gauze or saline gauze for external dressing. Change the dressing promptly after it is wet to prevent infection. Observe the intestinal segment for retraction, bleeding, necrosis and stenosis.
3, protect the abdominal wall incision, the stoma is generally open 2-3 days after surgery, more lateral lying position to facilitate elicitation. Wash the skin around the stoma with neutral soap and then apply zinc oxide ointment to prevent rash.
4, the correct use of human anal pouch, full one-third to pour out, cleaned and can continue to use.
5, dietary guidance, light and easy to digest, should not be too dilute, avoid gas-producing food, moderate amount of fiber diet, prevent constipation.
Complications and care.
1, necrosis .
2.Stenosis.
3.Prolapse of the artificial anal colonic segment.
4.Artificial paranal hernia .
5.Anastomotic fistula.
1.Observe the color of the intestinal segment, whether there is black and purple.
2.After the stoma stitches are removed and healed, dilate the anus twice a day and observe whether there is intestinal obstruction (pain, vomiting, distension, closure).
3.If any stool is not relieved after 3-4 days of feeding, a low-pressure enema with paraffin oil or soap and water can be inserted with a catheter less than 10CM.
4, anastomotic fistula when the temperature, drainage fluid color, peritoneal irritation signs. Colostomy, saline continuous flushing.
Discharge instructions.
1, after discharge dilation once a day for 2-3 months, if there is obstruction promptly come to the hospital. 3 months to avoid labor that increases intra-abdominal pressure, such as mopping the floor, holding children.
2, dietary guidance, light and easy to digest, should not be too thin, avoid eating cold, greasy food, moderate amount of fiber diet, prevent constipation.
3.Regularly come to the hospital for review, carcinoembryonic antigen, colonoscopy.
4.Appropriate exercise, keep a relaxed mood, suggest patients to join the stoma association, mutual exchange of experience
5.Patients with chemotherapy should check blood picture every week and avoid catching cold. If patients have wasting, sacral pain, perineal swelling fast, abdominal swelling fast and liver enlargement, they should come to the hospital in time.