I. Introduction
Gastric polyps can occur singly or in multiple cases. The literature reports that gastric polyps are less common than colonic polyps, and mostly occur in men over 40 years old, often combined with the formation of chronic gastritis, single polyps account for the majority.
Second, the category characteristics
Pathologically, gastric polyps are divided into 2 categories.
1, proliferative or regenerative polyps.
2, adenomatous polyps.
Gastric polyps are mainly proliferative polyps, mostly located in the sinus and lower part of the gastric body, often less than 2 cm in diameter, with or without a tip, and generally without the tendency of malignant transformation. Hyperplastic polyps have been reported to be often associated with atrophic gastritis. 56 cases (93 sites) of hyperplastic polyps were followed by Kamiya for 5-12 years, and 2 cases had pathological changes of atypical hyperplasia. Zhang Yanxian reported 107 cases of gastric hyperplastic polyps, 23 of which were associated with grade 2-3 atypical hyperplasia.
Most of the adenomatous polyps were located in the gastric sinus, with or without a tip; the polyp surface was smooth or had a fine granularity resembling mulberry-like changes, and most of them had a redder surface than the surrounding mucosa. The pathology is divided into tubular adenoma, villous adenoma and tubular choroidal adenoma.
Symptoms
The disease is mostly asymptomatic in the early stage or without complications. When symptoms appear, they are often manifested as vague pain in the upper abdomen, abdominal distension, discomfort, and in a few cases, nausea and vomiting. In combination with erosion or ulcer, there may be upper gastrointestinal bleeding, mostly manifested by positive fecal occult blood test or black stool, and vomiting blood is rare. Polyps with tips located in the pylorus may dislodge into the pyloric duct or duodenum and present as pyloric obstruction. When the polyp grows near the cardia, it may have difficulty in swallowing.
Gastric polyps: Patients with gastric polyps are often accompanied by lack of gastric acid or low gastric acid, so they often have mild pain and discomfort in the upper abdomen, nausea, anorexia, indigestion, weight loss and diarrhea. If there is erosion or ulcer on the surface of polyps, intermittent or continuous bleeding may occur.
Etiology
The etiology is unknown. Gastric polyp is a bulging lesion originating from the epithelial cells of the gastric mucosa that protrudes into the stomach. Pathogenesis: Gastric polyps usually occur in the gastric sinus, but a few are also seen in the upper part of the gastric body, cardia and fundus. Pathologically, they are mainly divided into proliferative polyps and adenomatous polyps.
1.Proliferative polyps
This type of polyp accounts for about 75%-90% of gastric polyps, which are polyp-like objects formed by inflammatory mucosal hyperplasia, not real tumors. The polyps are small, generally less than 1.5cm in diameter, round or olive-shaped, with or without a tip, smooth surface, and can be accompanied by erosion. The epithelium is well differentiated and nuclear schizophrenia is rare. Inflammatory cell infiltration is seen in the lamina propria, and some polyps are accompanied by intestinal metaplasia. A small number of hyperplastic polyps can undergo heterogeneous hyperplasia or adenomatous transformation and produce malignant changes, but their cancer rate is generally not more than 1%-2%.
2.Adenomatous polyp
It is a benign gastric tumor from the epithelium of gastric mucosa, accounting for about 10%-25% of gastric polyps. They are generally large, spherical or hemispherical, mostly non-tipped, with smooth surface, and a few flattened, striped or lobulated. Histologically, they are mainly formed by surface epithelium, small concave epithelium and glandular hyperplasia. The epithelial differentiation is immature, and nuclear schizophrenia is common, which can be divided into tubular, villous and mixed adenomas, often accompanied by obvious intestinal hyperplasia and heterogeneous hyperplasia. The interstitium of the polyp was loose connective tissue with a small amount of lymphocytic infiltration. There was no obvious hyperplasia in the mucosal muscle layer and no dispersion of muscle fibers. The cancer rate of this type of polyp is high, up to 30%-58.3%, especially the malignant rate of tumor diameter greater than 2cm, villous adenoma and heterogeneous hyperplasia degree III is higher.
V. Laboratory tests.
1, combined with erosion or ulceration, mostly manifested as positive fecal occult blood test or black stool.
2.Other auxiliary examinations
(1) Endoscopic examination
The polyp is round or oval in shape, a few are lobulated, with or without a tip, most are between 0.5-1.0 cm in diameter, a few are larger than 2 cm in diameter. adenomatous polyps are often redder in color than the surrounding mucosa, while hyperplastic polyps are similar to the surrounding mucosa. Endoscopic biopsy and histological examination can clarify its nature and type, and treatment can be performed at the same time.
(2) X-ray examination
Barium X-ray examination shows filling defect, which has some value in diagnosing gastric polyp, but its detection rate is lower than that of gastroscopy, and is suitable for those who have contraindications to endoscopy.
VI. Treatment options
Endoscopic treatment
Endoscopic resection is the preferred method of gastric polyp treatment, mainly including high-frequency electrocoagulation resection, laser and microwave cauterization, nylon ligation and argon ion coagulation. Endoscopic treatment of polyps is simple, less damaging and less expensive, and most of them are one-time treatment, while a few need to be removed in stages. Regular follow-up by endoscopy can also detect the recurrence of polyps, and give timely treatment to prevent cancer.
1.High-frequency electrocoagulation method: It is the most widely used method, and its principle is to use the thermal effect generated by high-frequency current to cause tissue coagulation and necrosis to achieve the purpose of removing polyps. Generally, the current frequency is above 300 kHz and the output power is 30-80 W. Before the operation, the liquid in the stomach should be aspirated as much as possible, and the electrocoagulant or electrothermal biopsy forceps with a spherical front end should be preferred for polyps less than 0.5 cm.
When using the electrothermal biopsy forceps, the head should be bitten and gently lifted before cauterization. For tipped and non-tipped polyps larger than 0.5 cm, the trap should be selected as far as possible, but the spherical electrocoagulator or electrothermal biopsy forceps can also be used to cauterize them in stages. For tipped polyps, the trap should be placed over the tip and the residual tip should be kept for about 1 cm after electrification to avoid perforation due to deep tissue burn.
For non-tipped polyps, hypertonic saline or 1:10,000 epinephrine solution should be injected into the base of the polyp at 1-2 points, 1.0 ml per point, to avoid damaging the muscle layer and plasma membrane layer during trap resection, and then the head of the polyp should be lifted with double biopsy tube endoscope to form a pseudo-tip at the base before trap resection. The polyps can be treated in stages, i.e. the head of the polyp is first partially removed obliquely with a trap, and then the contralateral part is removed obliquely after an interval of 2 weeks, which can be repeated if not completely removed until all of them are removed.
The combination of attraction and electrocoagulation can also be used, i.e., the sleeve is placed in front of the endoscope, the trap for electrocoagulation is placed in the sleeve through the biopsy hole, the endoscope is sent to the gastric cavity, and the polyp is sucked into the sleeve under negative pressure after the head end of the sleeve is in close contact with the polyp, the sleeve is tightened, and the polyp is withdrawn for electrocoagulation.
For larger tipped or subtip polyps, metal clamps can also be used for ligation followed by coiling electrocoagulation, by placing a rotatable clamping device through the endoscopic biopsy hole, performing multiple cross metal clamps on the stem of the polyp, blocking the blood supply to the lesion, and then performing coiling electrocoagulation when the head end of the polyp is purple. When using trap electrocoagulation, we need to pay attention to the slow tightening of the trap loop before energization, and gently lift to avoid bleeding and deep tissue burns caused by mechanical cutting, after the tightening of the trap loop to first electrocoagulation and then electrocutting, repeatedly alternating, each energization time of a few seconds, but also available mixed current intermittent energization treatment.
2, microwave cautery method: the use of microwaves can make polar molecules vibrate to produce the principle of thermal effect, and the tissue coagulation and vaporization for polyp cauterization, and hemostasis, for polyps less than 2cm in diameter, the smaller polyps can be 1 time cauterization, the larger ones require multiple treatments. The output power is 30-40W, and the time of each cautery can be adjusted and fixed before treatment, usually 5-10s, or controlled by a foot switch.
Operation by biopsy mouth insert microwave coaxial cable (antenna), so that the spherical probe close contact with the lesion, or needle probe into the lesion after cauterization, should pay attention to control the depth of tissue burn, so as not to cause perforation. The method is simple, safe, low cost and easy to carry out.
3, laser method: the laser generated by the high energy laser, through the endoscopic biopsy hole into the optical fiber irradiation lesion site, through the transformation of light energy heat energy, so that its tissue protein coagulation, denaturation and destruction to achieve the purpose of treatment. It is mostly used for the treatment of wide-tipped or non-tipped polyps. At present, Nd:YAG laser is mostly used, and the power can be selected according to the size of polyps, generally ranging from 50-70 W. The head end of the optical fiber is about 1 cm away from the lesion, and each irradiation is 0.5-1 s. Excessive time may cause perforation, which should be noted.
Larger polyps can be treated in multiple stages. Alternatively, laser treatment can be used, which is characterized by small damage to the tissue around the lesion and shallow penetration depth. The laser should be directed at the lesion and irradiated quickly to avoid damage to the surrounding tissues by gastric peristalsis.
4.Nylon wire and rubber band ligation method: By ligating the root of polyps, it causes ischemic necrosis to achieve the purpose of treatment. Pathology confirmed that the ligated area was intact after treatment, and only the mucosa and submucosa were confined to produce local ischemic necrosis. Within 1-4 days after ligation, the local mucosa undergoes acute inflammatory reaction, granulation tissue proliferation and necrotic tissue shedding to form a superficial ulcer, which is gradually replaced by scar tissue and healed, so it has the advantage of avoiding perforation. Method: A clear suction sleeve is placed at the front of the endoscope.
The ligature is fed into the biopsy hole and probed from the front end, the nylon ligature sleeve or rubber band is placed in the groove of the sleeve, the endoscope is sent to the gastric cavity, the head end of the sleeve is in close contact with the polyp, the polyp is drawn into the sleeve by negative pressure, the handle of the ligature is pulled, and the nylon wire or skin band is ligated to the root of the polyp. The polyps fall off and form shallow ulcers within the first week after ligation, and heal with white scar formation in the 3rd-4th weeks.
5.Argon ion coagulation: Argon gas can conduct high-frequency electrical energy generated by tungsten electrode through ionization to make tissue coagulation effect, which has been applied to endoscopic treatment in recent years and received better efficacy. It is mainly applied to wide base without tip and the diameter is less than 1.5cm. Insert the argon ion coagulator catheter through the endoscopic biopsy hole, make the head end of the catheter 0.3-0.5cm above the lesion, start the foot switch for argon ion coagulation treatment, 1-3s each time.
6.Freezing method: The refrigerating gas is sprayed directly on the polyp surface through the endoscopic biopsy hole by a special catheter, or the lesion is frozen by contact with a special freezing rod to make the tissue necrotic and fall off. Therefore, it is difficult to cure a single large polyp in 1 time, so it is rarely used.
7, radiofrequency method: radiofrequency is a 200-750kHz electromagnetic wave, into the lesion tissue, local heat generation to make its water evaporation, drying and necrosis to achieve the purpose of treatment. Operation control RF treatment instrument output power of 23-25W, working time of 5-10s, the electrode through the endoscopic biopsy hole into the lesion for treatment.
8.Alcohol injection method: endoscopically inject anhydrous alcohol around the base of the polyp in a circle as a dot injection, 0.5ml per dot, and see the white mound-like elevation as degree. Generally, it is only used for the treatment of broad-based polyps.
Seven, the harm of gastric polyps
Many people who have gastroscopy found polyps, they often have such doubts: gastric polyp is this disease is not harmful? Will cancer occur?
Gastric polyps are divided into two types, one is called adenomatous polyps, is composed of densely arranged crowded proliferation of the gland, due to varying degrees of atypical hyperplasia, the cancer rate of up to 10%-30%, known as “precancerous lesions”; the other is called hyperplastic polyps, also known as inflammatory polyps or regenerative polyps, belong to the glandular proliferation extended The other type is called hyperplastic polyp, also called inflammatory polyp or regenerative polyp, which is a prolonged glandular proliferation, with disorderly arrangement, large gaps between glands, and immature cells in between. Most of them have no atypical hyperplasia, and the cancer rate is only 0.4%.
In addition, there are polyps that are different from gastric polyps, such as juvenile polyps, which do not have a tendency to become malignant; diffuse polyps, which can have a cancer rate of 20%; and hereditary polyps.
In general, gastric polyps grow very small, less than a centimeter, proliferative polyps are basically benign lesions, only a few people once the proliferative polyps grow, can cause indigestion, abdominal pain and discomfort and other symptoms, there will be upper gastrointestinal bleeding, but also cancer. Although adenomatous polyps are prone to cancer, they can also be prevented, such as epigastric discomfort, pain, nausea, loss of appetite or black stool and other symptoms, timely gastroscopy and electrodesection will be used to cut out the polyps.
In order to prevent gastric polyps from becoming cancerous, we should insist on doing gastroscopy once a year to remove the polyps. In addition, to strengthen self-care, to keep the food and drink, try not to burden the stomach. As long as everyone is vigilant, stomach cancer can be kept away from the door.