small bowel vascular malformation
Introduction
Introduction to small intestinal vascular malformation Small intestinal vascular malformation is one of the important causes of acute and chronic gastrointestinal bleeding. There are often no special clinical symptoms and signs. Early occult bleeding or chronic hemorrhage often occurs due to repeated gastrointestinal bleeding or massive gastrointestinal bleeding. Because of the routine examination and laparotomy, it is difficult to find the location of the lesion, so that it can not be cured, or given the wrong surgical treatment. In 1960, Magulis first reported the use of intraoperative angiography to confirm gastrointestinal vascular malformation. In 1965, Baum first applied percutaneous selective mesenteric angiography to diagnose this lesion, which led to an increase in the incidence of this disease, but it is also considered that endoscopy is The preferred method for the diagnosis of this disease. The etiology of this disease is complex, with congenital factors and acquired factors. Therefore, the naming and classification have not been unified. The names used in domestic and foreign literature reports include: intestinal vascular dysplasia (angiodysplasia), arteriovenous malformation, vascularectasia, telangiectasia, small intestine vasculature Hemangioma, etc., but most scholars believe that the name of vascular malformation can describe various lesions and is more commonly used, and it is easy to accept. basic knowledge The proportion of illness: 0.004%-0.007% Susceptible people: no specific population Mode of infection: non-infectious Complications: anemia, atrophic gastritis
Cause
Causes of small bowel vascular malformation
Causes:
The etiology of intestinal arteriovenous malformation is unknown, may be acquired acquired vascular degeneration, congenital vascular dysplasia and chronic mucosal ischemia, Boley et al considered a chronic, intermittent submucosal vein caused by mild obstruction Degenerative changes, this interpretation is more accepted, the disease with the increase of age and vascular degeneration, due to increased intestinal pressure, the muscles of the intestinal wall are tight and oppress the vein, so the venous return is blocked, venules and capillaries The blood vessels gradually become congested and dilated, which in turn affects the anterior capillaries of the capillaries, making the arteriovenous traffic branch open.
Pathogenesis:
1. Classification Currently, most agree with Moore's classification method, that is, according to the results of angiography, the intestinal vascular malformation is divided into three types: type I (isolated): the lesion is limited, the age of onset is often greater than 55 years old, good hair In the right colon, often not found during surgery, the lesions are acquired acquired; type II (diffuse type): the lesion is larger, and more extensive, the age of onset is less than 50 years old, can be located in any part of the intestine, even during surgery It can be found that the lesion consists of thick-walled and thin-walled blood vessels, which may be congenital lesions; type III (spot-like hemangioma): this type includes hereditary telangiectasia (Osler-Weber-Rendu syndrome), less common The lesion can be located anywhere in the gastrointestinal tract, with skin telangiectasia, with a genetic basis.
Dentuis proposed type IV, which believes that some vascular malformations are secondary to other lesions in the intestine, especially inflammatory bowel disease, caused by venous reflux caused by inflammatory fibrosis, and Lewislt changes type I according to histological changes. Divided into type Ia and type Ib, the former is a limited number of thin-walled blood vessels; the latter is limited, and a large number of expansion into thick-walled blood vessels, but the classification of these subtypes in the diagnosis and treatment does not have much significance.
2. Pathology
Gross specimens can be seen as single or multiple lesions, dark red, round or oval, slightly uplifted, clear border with surrounding gray-red mucosa, many superficial ulcers, with pseudopolyps; some Multifocal, segmental distribution or patch distribution, microscopically visible gastrointestinal submucosal malformation of thickening, increased, curved, but no aneurysm-like changes, accompanied by obvious expansion of the vein, congestion, blood vessel wall slightly thicker HE staining abnormal blood vessels showed no abnormal changes in histology. The inner and outer membranes and muscle layers of blood vessels were intact. Pathological examination showed no evidence of vascular inflammation or hardening of the arteries. Reticulum fibers and elastic fibers stained, and elastic tissues of deformed arteries. It is also intact, with a transverse diameter of 1.44 to 10.89 mm and an average of 3.46 ± 2.03 mm.
Prevention
Prevention of small bowel vascular malformation
Choose healthy foods and beverages instead of high-fat, high-sugar and high-calorie foods, eat different types of vegetables, fruits, whole grains and legumes, reduce the consumption of red meat (beef, pork and lamb), and avoid processed meat. Class, limit the consumption of high-salt foods. For cancer prevention, try not to drink alcohol. If you drink alcohol, you should limit your daily alcohol consumption. Men should not be more than 2 cups per day, and women should not be more than 1 cup.
Complication
Complications of small intestinal vascular malformation Complications anemia atrophic gastritis
Anemia caused by repeated bleeding, severe anemia can lead to anemia heart disease and atrophic gastritis, which in turn can be more anemia due to iron absorption disorders.
Symptom
Symptoms of small intestinal vascular malformation Common symptoms Chronic anemia, blood in the stool, gastrointestinal bleeding, intestinal vascular malformation, shock
Intestinal vascular malformation can be asymptomatic, the only clinical manifestation is gastrointestinal bleeding, usually intermittent intermittent blood in the stool, the amount is moderate, can present anemia, a small number of cases due to large amount of bleeding, can occur shock, symptoms can occur continuously, can also be intermittent Sex or phased.
The clinical features can be summarized as follows: (1) prolonged disease course, asymptomatic hemorrhage, vascular malformation does not involve intestinal function, no pain, clinical difficulty is not taken seriously, and diagnosis is difficult, so the medical history is lengthy, up to 20 years; 2 bleeding Mostly intermittent, small, self-limiting, bleeding often comes from dilated capillaries and venules, local pressure after bleeding is reduced and more likely to stop, a few may also have acute major bleeding; more than 3 with chronic anemia; 4 difficult to diagnose The rate of misdiagnosis is high, and the diagnosis is obtained after repeated clinical examinations.
Examine
Intestinal vascular malformation
1. Fecal occult blood test is positive.
2. Hemoglobin is reduced.
Film degree exam
1.X line
Gastrointestinal barium examination: regular barium meal and barium enema cannot be correctly diagnosed, but it can rule out other diseases, especially gastroduodenal ulcer disease, tumor or colon ulcer, and bleeding caused by tumor disease.
2. Endoscopy
Gastroscope and fiberoptic colonoscopy are especially suitable for gastric and colonic arteriovenous malformation. Moreto et al detected 49 cases in 46500 gastroscopes, the detection rate was 0.1%, and Riemann et al detected 24 cases in 1782 cases. The detection rate was 1.3%, and 31 cases were detected in 1368 colonoscopy. The detection rate was 2.4%. Ding Shigang et al. performed 52,247 endoscopy examinations from 1976 to 1993, and detected 123 cases of gastrointestinal vascular malformation. Endoscopy was detected. The rate was 0.24%, including 39207 cases of gastroscopy, 46 cases (0.12%) of vascular malformations, 3494 cases of total colonoscopy, 49 cases (1.4%) of vascular malformations, stomach and colonoscopy. The diagnosis of arteriovenous hemangioma of the colon is easy, but the lesion of the small intestine cannot be applied, so the enteroscopy is born. Han Guangyu uses small enteroscopy (propulsion type SIF-B and SIF-10) to examine 100 cases. There were 58 cases of occult bleeding in patients, and 3 cases were confirmed to be vascular malformations. In recent years, the use of enteroscopy can make occult bleeding in 26% to 77% of patients with gastrointestinal occult bleeding, and many diseases can cause intestinal bleeding. Among them, arteriovenous malformation is the most common, Lewislt applied probe-type enteroscopy in 33% (20/60) stomach Hemorrhagic foci were detected in the small intestine of patients with occult hemorrhage, 16 of them were caused by arteriovenous malformation, accounting for 80%, and 7 cases were located in the proximal jejunum. However, due to the limited depth of enteroscopy into the small intestine, Han Guangzheng enteroscopy The examination can only reach 50~60cm in the jejunum.
3. Angiography
It is currently considered that angiography is the most reliable method for diagnosing the disease, and the diagnosis rate can reach 75% to 90%.
(1) Contrast method: Selective mesenteric artery angiography can be performed on either side of the femoral artery. The Seldinger method is used to puncture the cannula, and the superior mesenteric and inferior angiography are performed separately. 12 images are taken in each 19s.
(2) angiographic signs: Boley, Fowler et al reported angiographic signs of vascular malformation: 1 increased density in the intestinal wall, delayed expansion of the emptying, twisted veins are the most common X-ray findings in the early stage of the disease, suggesting submucosal Venous dilatation; 2 arterial phase can be seen at the branch end of the blood supply artery is abnormal cluster-like blood vessels, shaped like a candlestick-like or oval, development can continue to the venous phase, the incidence rate is 70% to 80%, suggesting that the lesion range is expanded and involved Submucosal venules; 3 early filling of the vein (6 to 8 s), suggesting the presence of arteriovenous fistula; 4 contrast agent spillover persisted, showing the performance of acute bleeding.
Li Boqing and other reports of angiographic signs are more detailed, manifested as: 1 malformed blood vessels: irregular irregular stains, stained or vine-like small blood vessels, small arteries or small veins, arteriovenous fistula, unclear clustered blood vessels Group, 2 increased small blood vessels, arterial phase showed dense peripheral blood vessels, the blood vessels were chaotic when the intestines were distorted. The authors compared 31 mesenteric arteries with no history of intestinal vascular malformation or no blood in the stool. The number of small arterioles in the area to distinguish between intestinal vascular malformations, that is, the number of blood vessels walking in the same direction per 1cm2 is more than 5, continuous or discontinuous 5cm2 or more, it can be considered that there is vascular malformation, in the parenchymal stage, the lesions are stained in the intestine In the densely arranged fuzzy streaked vascular shadow, the increase of straight small blood vessels is often the only abnormal appearance of the diseased intestine during operation. 3 The parenchymal stage is densely stained: the diseased intestine is clearly contoured under the surrounding normal intestinal segment. In the stained area, the spotted in the abnormal blood vessels, the plaque contrast agent is more developed, the intestine is stained into a sheet or band, and the blood vessels on the edge are not pressed. Distinguishing tumor staining, suspicion of the disease should actively perform arteriography.
(3) angiographic indications: Li Boqing proposed angiographic indications: 1 repeated gastrointestinal bleeding without the exact cause; 2 no routine X-ray angiography findings, clinical diagnosis of hemorrhagic gastritis, tumors and other causes of gastrointestinal bleeding; 3 The endoscopic lesions were slightly inconsistent with the amount of bleeding or inconsistent with the bleeding site; 4 bleeding did not stop after surgery, and excluded anastomotic lesions.
Diagnosis
Diagnosis and diagnosis of small intestinal vascular malformation
diagnosis
At present, endoscopy and angiography are the basis for the diagnosis of this disease. The following clinical features are used to diagnose small intestinal vascular malformations.
Painless gastrointestinal bleeding
It can be expressed as recurrent hemorrhage, or acute massive hemorrhage; the course of disease can vary from several days to several years; some patients may be associated with iron deficiency anemia.
2. Fecal occult blood test is positive
Multiple fecal occult blood tests were positive, or continued positive.
3. Selective mesenteric angiography
The signs of development showed: early filling of the venous phase, abnormal vascular plexus, increased density in the intestinal wall, delayed distorted veins with delayed emptying, and contrast agent spillover during active bleeding (bleeding rate >0.5 ml/min) .
4. Enteroscopy
A vascular malformation under the small intestinal mucosa was found.
Differential diagnosis
The disease should be differentiated from peptic ulcer hemorrhage. The former is painless, intermittent, chronic and small. The peptic ulcer has a history of ulcer before hemorrhage, or pain in the upper abdomen.
