Ischemic colitis

Introduction to ischemic colitis Colonic ischemic injury caused by occlusion or insufficient blood perfusion in large and small arteries of the colon, common in hypovolemic shock, heart failure, mesenteric artery embolization or thrombosis, abdominal aortic reconstruction or arteritis, acute colon Ischemia is transient and reversible. In severe cases, necrosis of the entire intestinal wall, perforation or persistent intestinal ischemia occurs. basic knowledge The proportion of illness: 0.014% Susceptible people: no specific population Mode of infection: non-infectious Complications: hypertension, arteriosclerosis, heart disease, shock, intestinal obstruction, paralytic ileus, shock

Causes of ischemic colitis

(1) Causes of the disease

1. Vessel anatomy and physiology

The colorectal blood supply is mainly from the superior mesenteric artery, the inferior artery and the internal iliac artery. The artery of the right colon is from the superior mesenteric artery, the left colon and the upper part of the rectum are from the inferior mesenteric artery, and the arterial blood in the middle and lower part of the rectum is from the internal iliac artery.

(1) superior mesenteric artery: originated in the anterior wall of the abdominal aorta about the first lumbar vertebrae, located 1.0 to 1.5 cm below the starting point of the celiac artery, which is passed through the lower edge of the pancreatic neck and longitudinally spans the twelve rectum The transverse part enters the root of the small mesentery, and then the middle colon, the right colon and the ileal artery are separated, providing blood supply to the proximal transverse colon, ascending colon and ileocecal, respectively.

The middle colon artery originates from the superior mesenteric artery at the lower edge of the pancreas and enters the transverse mesenteric membrane after the stomach. It is divided into two left and right branches. It is consistent with the ascending branch of the right colon artery near the hepatic collateral of the transverse colon. The Riolan anastomosis is passed near the splenic flexion. The left colon artery is anastomosed, the anastomosis of the site is relatively small, and about 5% of the population is absent, making it the weakest part of the blood supply to the colon, prone to ischemic damage. In the normal population, there are about 20% of human colonic arteries are absent or stunted.

The right colonic artery starts from the superior mesenteric artery 1 to 3 cm below the starting point of the middle cerebral artery, and goes diagonally to the right through the retroperitoneum. It is divided into ascending and descending branches near the ascending colon, respectively, with the right middle branch of the colon and the ileocolonic colon. The anastomosis forms the vascular arch at the edge of the colon and branches along the way to the ascending colon to supply the ascending colon.

The ileal artery originates from the superior mesenteric artery below the starting point of the right colonic artery, and sometimes forms a trunk with the right colonic artery. It is obliquely descended to the right through the retroperitoneum, and is divided into upper and lower branches near the cecum, and the ascending branch and the right colon artery descending branch. The anastomosis, the reduction to the ileocecal part and the two branches with the superior mesenteric artery ileum anastomosis, supply the lower part of the ascending colon, the ileocecal and the end of the ileum.

(2) Inferior mesenteric artery: In the third lumbar vertebra, 3 to 5 cm below the horizontal part of the duodenum originates from the anterior wall of the abdominal aorta, and is arched obliquely to the left lower side. After 2 to 7 cm, the left colon artery is successively separated. And the sigmoid colon artery, and across the left common iliac artery, shifting behavior of the superior rectal artery.

The left colonic artery is divided from 2.5 to 3.5 cm from the root of the inferior mesenteric artery. The ascending and descending branches are divided into the upper left and lower left through the retroperitoneum. The ascending branch is anastomosed to the left branch of the spleen and the middle cerebral artery. The descending branch and the sigmoid colon Arterial anastomosis provides blood supply to the distal and descending colons of the transverse colon, respectively.

The starting point of the sigmoid colon artery varies greatly. About 36% of the population originates directly from the inferior mesenteric artery, and 30% originates from the left colon artery. The number is also quite different, generally 2 to 6. The sigmoid colon is obliquely to the lower left through the peritoneum. The square enters the sigmoid mesenteric and conforms to each other to form an arterial vascular arch and an edge artery. The upper artery and the left colon artery form an anastomosis branch, which supplies the blood supply to the distal side of the descending colon. There is no between the lowermost part and the superior rectal artery. The borderline arteries connect and become another weak point in the blood supply to the colon, also known as the Sudek point, which is prone to ischemic lesions.

The superior rectal artery originates from the lowermost sigmoid colon artery, and is divided into left and right posterior segments at the level of the second atlas. It supplies blood to most rectum.

The blood supply to the lower rectum is mainly supplied by the middle and middle rectal arteries from the internal iliac artery.

(3) Peripheral arteries: Each colonic artery is anastomosed near the intestinal wall, forming a plurality of continuous arterial arches parallel to the colon wall, called the marginal artery, also known as the Drummond vascular arch, and the marginal artery is distributed from the ileocecal portion to the rectosigmoid colon. The junction is connected by a single artery or by a grade 1, 2 arterial arch, and a small terminal blood vessel is distributed from the vascular arch closest to the intestinal wall to the intestinal wall.

These vascular arches have important clinical significance. In most cases, they constitute traffic between the various colonic arteries at different levels. When the trunk of a certain colonic artery is blocked, the colon in the blood supply area can pass. The vascular arch receives blood supply from other arterial trunks, and no ischemia occurs. However, if the occlusion occurs at the site of the vascular arch closest to the intestinal wall, the terminal artery supplying the intestinal wall is difficult to obtain blood supply through the collateral circulation. .

(4) Terminal arteries: small arteries that vary in length from the marginal artery to the intestinal wall. They are perpendicular to the colon and are responsible for supplying blood directly to the intestinal wall. There are two types of long and short branches in the terminal artery. After being separated from the marginal artery, it is divided into two branches at the mesenteric margin of the intestinal wall. The blood supply to the mesenteric 1/3 intestinal tube is supplied through the free edge between the serosa and the muscular layer to the intestinal wall. The terminal arteries have less anastomosis at the mesenteric margin of the intestine and at the margin of the mesentery, making the blood supply to the mesenteric margin of the colon susceptible to dysfunction; short branches from the long branch of the marginal artery or terminal artery, near The mesenteric margin penetrates into the intestinal wall and supplies 2/3 of the intestine of the mesenteric margin. The development and distribution of the terminal arteries are dense in the left colon. The right colon is relatively rare, and the distance from the marginal artery to the intestinal wall is also relatively high. Long, these terminal arteries are very sensitive to vasoconstrictors, and there are few collateral circulations between them. For the above reasons, when a long time of vasoconstriction occurs, it is difficult to obtain sufficient blood supply to the intestinal wall, which is prone to ischemia. This is more pronounced in the right colon.

There are vascular plexuses in the whole layer of the colorectal wall, but the vascular plexus of the mucosa and submucosa is the most abundant. The blood vessels supplying the mucosa gland are derived from the submucosal plexus. When the blood flow of the terminal artery is reduced by shock or hypotension, Arteriovenous shunt occurs in the intestinal wall, causing ischemia of the mucosa. The degree of ischemia depends on the collateral circulation of the intestinal wall and the site of vascular occlusion. When the vascular occlusion occurs at the root of the larger colonic artery, the edge of the vascular arch is passed. The collateral circulation, the colon in the relevant area does not necessarily have ischemia, but if accompanied by abnormal development of the marginal vascular arch, segmental intestinal ischemia or even necrosis occurs in the blood supply area, and the arterial occlusion is closer to the intestine Wall, the more likely to cause blood supply disorders of the intestinal wall, it has been reported that a long-branch vessel damage can cause the intestinal tube to necrosis about 2.5cm.

(5) Venous: The venous plexus in the colon wall is pooled into small veins, which are synthesized into larger veins at the mesenteric margin. Parallel to the colonic artery, it becomes the vein accompanying the colonic artery, the colonic vein, the right colon vein and the ileum. Intravenous synthesis of the superior mesenteric vein, into the portal vein, sigmoid colon vein, left colon vein and superior rectal vein synthesis of the inferior mesenteric vein, in the lateral direction of the inferior mesenteric artery, to the outside of the duodenal jejunum, through the back of the pancreas into the splenic vein, the final entry vein .

2. Etiology and pathogenesis

There are many causes of colonic ischemia, which can be roughly divided into two categories, one is vascular obstruction and the other is non-vascular obstruction.

(1) vascular obstructive colonic ischemia: In vascular obstructive colonic ischemia, the most common causes are trauma of mesenteric artery, mesenteric vascular thrombosis or embolism, and ligation of the inferior mesenteric artery during abdominal aortic reconstruction or colon surgery. .

In the case of blunt abdominal injury, if the mesenteric vessels are damaged and thrombosis or retroperitoneal hematoma is formed, it may cause colonic ischemia. Patients are often accompanied by extensive internal organs, limbs, heart and lung and nervous system damage. Dauterive et al. Of the patients with abdominal blunt trauma, 41 were associated with intestinal ischemic lesions.

Abdominal aortic angiography can induce thrombosis in the mesenteric artery, causing ischemic enteritis, but the incidence is relatively low, which may be caused by the stimulation of the inner wall of the blood vessel by the contrast agent or the damage of the blood vessel by the catheter during the examination.

A atherosclerotic shedding, or a left atrial embolus from a patient with atrial fibrillation, can also cause obstruction of the mesenteric artery, if only the inferior mesenteric artery is obstructed without collateral dysfunction, progressive emboli and Obstruction of the superior mesenteric artery roots, due to the presence of marginal vascular arches, the affected part of the colon can obtain blood supply through the collateral circulation, generally does not occur colonic ischemia, if the patient's colonic vascular arch congenital dysplasia or bilateral sacral If the artery is obstructed, the simple inferior mesenteric artery occlusion can also cause colonic infarction. Williams reported that the severity and survival rate of the disease are not directly related to the obstruction of the inferior mesenteric artery. The survival rate of the obstruction group is 65%, non-obstruction. The group was 60%, so the obstruction of the simple aorta did not seem to affect the clinical manifestations and prognosis of the disease.

In recent years, ischemic colitis associated with abdominal aortic surgery has attracted more and more attention. Bjorck et al. followed up 415 patients with abdominal aortic surgery and found that the incidence of ischemic colitis was 2.6. %, if there is shock during the operation, the incidence rate can reach 7.3%, the incidence rate after emergency surgery is significantly higher than the elective surgery, which occurs on the one hand related to intraoperative ligation of the inferior mesenteric artery in the root, on the other hand may also Other factors are related, such as the degree of openness of the internal iliac artery of the patient, the time of interruption of the intra-aortic aorta, the location of the inferior mesenteric artery, the degree of opening of the colonic vascular arch, the degree of arteriosclerosis, the time of hypotension, and the state of cardiac function. Whether accompanied by small blood vessel disease and so on.

More important than the obstruction of the inferior mesenteric artery is the obstruction of the surrounding small arteries, especially in young patients, which causes many causes of small arterial occlusion, including diabetes, vasculitis, systemic collagen disease, especially systemic lupus erythematosus, and knots. Segmental polyarteritis, allergic granulomatosis, Behcet syndrome, Buerger's disease, application of certain drugs, aplastic anemia, sickle cell disease, lymphoma, leukemia and tumor chemotherapy can also cause ischemic enteritis .

Colonic ischemia caused by venous return obstruction and venous thrombosis often occurs in the right colon. Studies have shown that venous obstruction can cause edema, infarction and fibrosis of the intestinal wall. Common causes are portal hypertension, pancreatitis with pancreatic abscess. And pancreatic pseudocysts, as well as long-term oral contraceptives, the mortality rate of pancreatitis with colon necrosis can reach about 50%.

The blood supply to the colon wall is affected by the diameter of the intestine, the muscle tension in the intestinal wall, and the pressure in the intestinal lumen. Saegesser reports that as the pressure in the intestinal lumen increases, the blood flow in the intestinal wall decreases, and the difference in arteriovenous oxygen content in the intestinal wall is also Reduced, at this time, the degree of intestinal mucosal ischemia is more obvious than the serosa layer, colonic expansion causes colonic ischemia, and colonic ischemia will further lead to colonic expansion, thus forming a vicious circle, in the case of intestinal obstruction, if the ileocecal valve Good function, almost all cecal perforation is caused by intestinal wall ischemia and necrosis. In addition to the effects of obstruction time, obstruction site, ileocecal valve closure function and degree of intestinal dilatation, tissue perfusion is insufficient due to various reasons. Such as shock, dehydration, acidosis, myocardial failure, etc. can also aggravate intestinal ischemia caused by colonic obstruction.

(2) Non-vascular obstructive colonic ischemia: mostly spontaneous, usually without obvious vascular occlusion, it is difficult to find a clear cause of colonic ischemia in the clinic. Most of the patients are elderly, and colonic deficiency occurs. After blood changes, vascular abnormalities revealed by mesenteric angiography may not be consistent with clinical symptoms.

Spontaneous colonic ischemia can be induced for a variety of reasons, including hypotension, which is most common in various causes, such as septic shock, cardiogenic shock, anaphylactic shock, neurological shock, etc., accompanied by heart disease, hypertension Diabetes and taking drugs that affect visceral blood flow (such as booster drugs) can significantly increase the chance of colonic ischemia, reduce mesenteric blood supply, and cause colonic ischemia; and a wide range of acute mesenteric blood supply disorders Causes significant irreversible cardiac output reduction, thus leading to a vicious circle of mesenteric ischemia.

(two) pathogenesis

Pathological classification

Ischemic colitis can be divided into vascular obstruction according to the cause; bald scorpion? ? stop There are two types of gangrene, of which non-gangrene can be divided into transient reversible and chronic irreversible.

2. Good hair

Ischemic colitis can occur in any part of the examination, but the incidence of left colon in the lower mesenteric artery is highest. Saegesser reported 112 cases, of which 37 were located in the descending colon, 33 were in the spleen of the colon, and 24 were located. The sigmoid colon, the right colon is less common in the right colon. The lesions in some patients can affect the whole colon. The location of the lesion is also related to the cause of ischemia. Ischemia is secondary to hypotension. Most of the lesions occur in the right colon, especially in the posterior wall of the colon, and in patients with abdominal aortic surgery, the lesions are mostly in the left colon.

3. Pathological changes

(1) Reversible colonic ischemia: most of them only involve the mucosa and submucosa, the lesions are relatively light, there is no obvious tissue necrosis, the intestinal wall becomes thicker, the mucosa is edematous, cobblestone-like changes, accompanied by mucosal linear ulcers and Hemorrhage, severe mucosal ulcers can be seen in severe cases, but there is little ischemic change in the mucosal muscle layer, the serosa layer is normal, and some patients may have mucosal shedding before tissue repair.

The typical histological manifestations are chronic submucosal inflammatory cell infiltration and granulation tissue formation. Visible mucosal islands can be seen between widely existing ulcers. Granulous tissue and inflammatory cells can be seen in the mucosal bed of the mucosal exfoliation site, sometimes Small arteritis and fibrin emboli can be seen in the submucosal artery. Capillary hyperplasia, fibroblasts and macrophages can be seen in the epithelial regeneration site. Eosinophils and hemoglobin-containing tissue cells can be found around the granulation tissue. Infiltration, the presence of these hemoglobin-containing macrophages suggests the occurrence of hemorrhagic intestinal infarction, which can be used to differentiate between ulcerative colitis and Crohn's disease. In addition, in ischemic colitis, about 80% of mucosa The lamina propria is hyaline-like and can be distinguished from pseudomembranous colitis.

(2) gangrene type: typical pathological manifestations are tissue necrosis of varying degrees in the lesions. In mild cases, intestinal lumen dilatation, mucosal hemorrhage, weak and thin intestinal wall, and depth and range can be seen. Mucosal ulcers and necrosis, the intestinal lumen is filled with blood, and the pathological changes of the naked eye are similar to fulminant ulcerative colitis. During the vascular regeneration period, the intestinal wall becomes thicker, and if the ischemic changes in the whole layer of the intestinal wall can cause intestinal stenosis, If the ischemia is light, only the pathological changes of the mucosa can be made, and the serosa layer is normal. In severe cases, the intestinal wall is black or green, the intestinal wall tissue is dissolved and thinned, the intestinal mucosa is shed, the muscle layer is exposed, and some patients have muscle layer. Necrosis and shedding, perforation of the intestinal wall.

Histological examination showed mucosal and submucosal hemorrhage, edema, and the surface layer of the intestinal gland first changed. The glandular tube was filled with inflammatory cells and red blood cells. The mucosal surface was covered with fibrin and necrotic tissue. The pathological changes of pseudomembranous colitis were sometimes difficult. The difference is that early lesions have a large number of inflammatory cell infiltration, followed by mucosal shedding, forming irregular necrotizing ulcers, typical fibrin emboli can be seen in the mucosa of the mucosa and submucosa, and Gram staining shows bacterial invasion under the mucosa. In patients with severe ischemic enteritis, normal tissue has rarely survived, and only necrotic mucosal and submucosal tissues are revealed.

(3) Chronic stenosis: the tissue structure is replaced by fibrous tissue in the process of chronic inflammation, and tubular stenosis is formed locally. The obstruction caused by stenosis is generally incomplete, the distance is relatively short, and it is most common in the sigmoid colon. The stenosis caused by disease and Crohn's disease is difficult to identify. The typical manifestation of histological examination is that the annular mucosa disappears. The ulcer area is covered by granulation tissue and newborn capillaries. The edge of the ulcer is accompanied by epithelial regeneration and the mucosal muscle layer is distorted. With extensive fibrosis, submucosa filled with granulation tissue, fibroblasts, plasma cells, eosinophils, and chronic inflammatory cells, scattered inflammatory changes in the serosal surface of the intestinal wall and fat around the colon.

Ischemic colitis prevention

For the prevention of this disease, middle-aged and elderly people should pay attention to regular living, avoid tobacco and alcohol, eat more vitamins and vegetables such as vegetables and fruits, try to avoid eating fat meat, animal internal organs and other high-fat foods. In addition, moderate participation should be taken. Some indoor and outdoor sports within reach.

Ischemic colitis complications Complications, hypertension, arteriosclerosis, heart attack, intestinal obstruction, paralytic ileus, shock

More with hypertension, arteriosclerosis, heart disease, shock and long-term medication, severe cases of intestinal wall necrosis, perforation or persistent intestinal ischemia.

1. Intestinal obstruction: In the early stage of gangrenous ischemic colitis, paralytic ileus may occur due to severe acute ischemia of the colon; and patients with chronic ischemic colitis due to fiber during chronic inflammation Tissue hyperplasia and scar formation, narrowing the intestinal lumen and incomplete intestinal obstruction.

2. Shock: In gangrenous ischemic colitis, due to the massive absorption of necrotic tissue and bacterial toxins, the microcirculatory vessels are widely open, the effective blood volume is insufficient, and patients may experience low volume and/or toxic shock.

Ischemic colonic symptoms common symptoms abdominal pain nausea colon expansion peritoneal irritation bloody peritonitis high fever colon obstruction intestinal hearing shock

The clinical manifestations of ischemic colitis are related to many factors, including etiology, mesenteric vascular occlusion, low blood flow, occlusion vascular caliber, time of colon ischemia and degree of ischemia, and how slow the ischemic process occurs. The compensatory function of the collateral circulation, the systemic circulation, the metabolism of the intestinal wall, the role of bacteria in the intestinal lumen, and whether it is accompanied by colonic expansion.

Abdominal pain, diarrhea and blood in the stool are the most common clinical manifestations. Most of the patients are older than 50 years old. There is no obvious predisposing factor. Most of the abdominal pain is consistent with the ischemic lesions of the colon. Most of them are sudden abdominal pains. Sexual seizures last for hours or days, followed by diarrhea, a small amount of blood in the stool, severe patients may have dark red or bloody stools, often nausea, vomiting and bloating, accompanied by body temperature and total white blood cell count and neutral Increased granulocytes, abdominal examination, smear and active bowel sounds in patients with early stage or non-gangrene type, tenderness in the abdomen of the lesion, and blood in the rectal examination.

In non-gang type patients, ischemic colitis is often self-limiting. Most patients with the establishment of collateral circulation blood supply, intestinal mucosal edema gradually absorbed, mucosal damage repair, symptoms improved within a few days, abdominal pain, diarrhea and bloody stool gradually Disappeared, if the intestinal wall is heavier, the ulcer will take a long time to heal. After the abdominal pain disappears, the diarrhea and blood in the stool can last for several weeks, but there is no tendency to aggravate. Because of the short course of the disease, the clinical manifestations of patients with transient ischemic colitis It is relatively light, many patients have no fiberoptic colonoscopy for various reasons at the time of onset, and the rate of misdiagnosis is very high. Most patients exclude other colonic diseases such as infectious colitis and Crohn's disease when reviewing their medical history. Ulcerative colitis, pseudomembranous colitis, and diagnosis of colonic diverticulosis.

Most patients with gangrenous ischemic colitis are elderly with poor general condition, often accompanied by other chronic diseases. Patients with ischemic colitis after abdominal aortic surgery can also be gangrenous due to early postoperative surgery. The clinical manifestations caused by itself and the clinical manifestations of ischemic colitis are difficult to distinguish, the diagnosis is difficult, the rate of misdiagnosis is high, most of the gangrenous ischemic colitis is acute, abdominal pain is severe, accompanied by severe diarrhea, blood in the stool and vomiting. Due to toxin absorption and bacterial infection, patients often have obvious fever and increased white blood cell count, and obvious peritoneal irritation can occur in the early stage. Patients with extensive lesions may also have obvious paralytic ileus, colonic swelling, and intestinal lumen. The internal pressure is increased, the intestinal wall is compressed, and the colonic ischemia is further aggravated. At the same time, the reduction of effective blood volume and the absorption of toxins can induce shock, further impede the blood supply to the intestinal wall, cause intestinal wall necrosis and perforation, and appear high fever. , persistent abdominal pain, shock and other manifestations of peritonitis, the diagnosis of most patients with gangrenous ischemic colitis is in the treatment of strangulated intestinal obstruction or peritonitis When a clear diagnosis of abdominal exploration.

40% to 50% of patients with intestinal obstruction caused by intestinal stenosis, most of the incomplete obstruction, some patients appear early after the onset, accompanied by other clinical manifestations of dangerous colitis, especially gangrenous colon Inflammation needs to be differentiated from colonic obstruction caused by colon tumor. Most patients with obstruction occur 2 to 4 weeks after onset. Due to fibrosis and scar formation in the lesion, clinical symptoms such as abdominal pain and diarrhea have gradually eased. Colonoscopy is very helpful for differential diagnosis.

Examination of ischemic colitis

There may be anemia and white blood cells increased, then see the red blood cells, colonoscopy can be seen intestinal mucosal congestion, edema and brown mucosal necrotic nodules, biopsy see varying degrees of submucosal necrosis, hemorrhage and granulation tissue, fibrosis or glassy changes, etc. Early barium enema can be seen in mild colon expansion, which can have typical finger pressure signs.

1. Blood routine: white blood cell count and elevation of neutrophils.

2. Histopathological examination : visible superficial necrosis and ulceration of the colonic mucosa, or full-thickness mucosal necrosis of the naked eye, microscopic examination of submucosal hyperplasia of capillaries, fibroblasts and macrophages; inflammation of the submucosal artery Changes and fibrin emboli; mucosal lamina propria can be hyaline-like degeneration; eosinophils and hemoglobin-containing tissue cells infiltrate around granulation tissue, and chronic phase manifests mucosal gland damage between lesions and normal mucosa And glandular regeneration, the reduction of the number of mucosal glands or the presence of fibrous tissue in the lamina propria of the mucosa suggests that the original lesions are more serious.

3. Digital rectal examination: often visible on the finger set with blood.

4. X-ray film : abdominal flat film can be seen in the colon and small intestine dilatation, colonic bag disorder, some patients can have intestinal fistula and stenosis, gangrenous ischemic colitis sometimes visible intraperitoneal free gas caused by colon perforation and due to the intestine Wall progressive ischemia, gas in the intestinal wall and gas in the portal vein caused by increased permeability of the intestinal wall.

5. Barium enema: This test can have a comprehensive understanding of the extent of the lesion, especially the extent of the lesion, but there is a risk of causing perforation of the colon. Therefore, patients with severe disease, accompanied by massive blood in the stool and suspected intestinal necrosis should be cautious. Typical image representations are:

1 thumb sign (pseudo-neoplastic sign): is the early manifestation of ischemic colitis in the double contrast examination of colonic gas, due to edema of the intestinal wall of the lesion, submucosal hemorrhage, the colonic mucosa unevenly protrude into the intestine, In the sputum angiography, the thumb-like filling defect is present due to the uneven distribution of the sputum in this part, which usually appears about 3 days after onset, lasting 2 to 4 weeks. This is the most common in the colon spleen, but it can also be Seen in other parts.

2 Colon polypoid changes: When inflammation develops further and many inflammatory polyps form, a typical colon polypoid change is seen in the lesion.

3 sawtooth sign: patients with extensive ulcers, barium enema examination showed irregularities in the edge of the intestine, a sawtooth-like change, similar to the performance caused by Crohn's disease, it is difficult to identify by simple barium enema examination, 4 colon stenosis : In patients with severe lesions, segmental colonic stenosis can also be seen in colonic barium examination. Some patients may be accompanied by cystic dilatation of the colon. In elderly patients, if the colonic stenosis is confined to only a certain part, the course of disease is shorter, accompanied by Abdominal pain, changes in bowel habits and blood in the stool, the stenosis found by barium enema examination needs to be carefully identified with the narrowing caused by malignant tumors. In this case, fiberoptic colonoscopy is helpful for the diagnosis.

6. Fiber colonoscopy : Fiberoptic colonoscopy is the most effective way to diagnose ischemic colitis. When patients are suspected of ischemic colitis, but without signs of peritonitis, abdominal X-ray film has no obvious colon. Endoscopic examination should be considered when imaging images of obstruction and colonic perforation.

Mucosal pale edema can be seen in the early stage of ischemia, accompanied by scattered mucosal hyperemia and punctiform ulcer. In the site with mucosal necrosis and submucosal hemorrhage, there is a change of blue or black under the mucosa or mucosa. Some patients can see the mucosa in the bulge. Hemorrhagic nodules, consistent with the thumbprint or pseudotumor signs seen during barium enema examination, continuous fiberoptic colonoscopy can observe the development of the lesion, mucosal abnormalities can be gradually absorbed and returned to normal; Or further aggravation of ulcers and inflammatory polyps, the endoscopic performance of the chronic phase is significantly different from the extent and severity of the early lesions. Patients with previous ischemic colitis may only show atrophy of the intestinal mucosa of the original lesion. , thinned and scattered granulation tissue.

7. Mesenteric angiography: Because most patients with ischemic colitis have arterial occlusion in the small arteries, mesenteric angiography is difficult to detect signs of arterial occlusion. In addition, because contrast agents may cause further thrombosis, caution should be used. .

8. CT scan : Some patients can see non-specific changes such as dilatation of the intestine and thickening of the intestinal wall caused by edema of the intestinal wall.

Diagnosis and diagnosis of ischemic colitis

diagnosis

1. History: elderly or young people, with transient hypotension, history of drug abuse, long-term medication history (contraceptives), or severe pancreatitis, history of aortic surgery and chronic diseases such as diabetes, rheumatoid arthritis, multiple Arteritis and so on.

2. Clinical manifestations: with colonic gangrene, stenosis or reversible ischemic manifestations.

3. Auxiliary examination: abdominal X-ray film, visible inflation of the large intestine, small intestine, colon spleen has a specific finger pressure sign, barium enema examination showed: intestinal wall edema, finger pressure and in the spleen, distal colon Intestinal stenosis of the descending colon, abdominal aorta angiography can be found in a blockage of the main blood vessels, can be diagnosed.

Differential diagnosis

In the acute phase of ischemic colitis, attention should be paid to the identification of infectious gastroenteritis, acute diverticulosis, acute ulcerative colitis, Crohn's disease and pseudomembranous colitis. With abdominal pain, changes in bowel habits and blood in the stool, it is necessary to carefully identify the narrowing caused by malignant tumors.

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