What Is Ischemic Colitis?

Ischemic colitis is a group of syndromes caused by insufficient blood supply to the colon due to occlusive or non-occlusive diseases of the colonic vessels. Ischemic colitis is mostly caused by non-occlusive ischemia of the superior mesenteric artery and right colon artery; a few are caused by occlusive ischemia due to microemboli or thrombosis. The age of onset of this disease is more than 50 years old, and half of the patients have hypertension, arteriosclerosis, coronary heart disease, and diabetes. Slightly more men than women, clinical features of acute abdominal pain, diarrhea and blood in the stool, divided into gangrene type, transient type and narrow type.

Basic Information

English name

ischemic colitis

Visiting department

Basic surgery

Multiple groups

Seniors over 50

Common locations

colon

Common causes

Trauma of mesenteric artery, thrombosis or embolization of mesenteric blood vessels, septic shock, cardiogenic shock, anaphylactic shock, neurological shock, etc.

Common symptoms

Abdominal pain, diarrhea, and blood in the stool, sudden severe abdominal pain, spastic seizures, diarrhea, blood in the stool, nausea, vomiting, and bloating

Causes of ischemic colitis

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

Vascular obstructive colon ischemia

In vascular obstructive colon ischemia, the more common causes are trauma to the mesenteric arteries, mesenteric vascular thrombosis or embolization, and ligation of the sub- mesenteric artery during abdominal aortic reconstruction surgery or colon surgery.

2. Non-vascular obstructive colon ischemia

Most of them are spontaneous, usually without accompanying obvious vascular occlusion, and it is difficult to find a clear cause of colonic ischemia clinically. Most of these patients are elderly. After the occurrence of colonic ischemic changes, vascular abnormalities displayed by mesenteric angiography may be inconsistent with clinical symptoms. Spontaneous colonic ischemia can be induced by a variety of reasons, of which hypotension caused by various causes is the most common, such as septic shock, cardiogenic shock, anaphylactic shock, neurotic shock, etc., accompanied by heart disease, hypertension , Diabetes, and taking drugs that can affect splanchnic blood flow (such as booster drugs) can significantly increase the chance of colon ischemia. Reduced mesenteric blood supply causes colonic ischemia; large-scale acute mesenteric blood supply disturbances can cause significant reductions in irreversible cardiac output, leading to a vicious cycle of mesenteric ischemia.

Clinical manifestations of ischemic colitis

Abdominal pain, diarrhea, and blood in the stool are the most common clinical manifestations. Most patients are older than 50 years of age, and there are no obvious predisposing factors. The site of abdominal pain is mostly the same as that of colonic ischemic lesions. Most of them are sudden and severe abdominal pain, which are spastic, lasting for several hours or days, and then diarrhea occurs, and the stool is slightly bloody. In severe patients, dark red or blood Stool, often with nausea, vomiting, and abdominal distension, accompanied by body temperature and an increase in total white blood cells and neutrophils.

Abdominal examination, early in the course of disease or non-gangrene-type patients can be heard and active bowel sounds, tenderness in the abdomen at the diseased site, digital rectal examination can often see blood on the finger sleeve.

In non-gangrene patients, ischemic colitis is usually self-limiting. With the establishment of collateral circulation blood supply, intestinal mucosal edema is gradually absorbed and mucosal damage is repaired. The symptoms improve within a few days, and abdominal pain, diarrhea and blood gradually become disappear. If the intestinal wall is ischemic, it will take a long time for the ulcer to heal. After the abdominal pain disappears, diarrhea and blood in the stool can last for several weeks, but there is no tendency to worsen. Because patients with transient ischemic colitis have a short course of disease and relatively mild clinical manifestations, many patients have not undergone fiber colonoscopy for various reasons at the time of onset, and the misdiagnosis rate is very high.

Most patients with gangrene-type ischemic colitis are elderly people with poor general condition, often accompanied by other chronic diseases. Patients with ischemic colitis after abdominal aortic surgery can also be of gangrene type. Due to the early clinical manifestations of the surgery itself and the clinical manifestations of ischemic colitis are difficult to distinguish, the diagnosis is difficult, and the rate of misdiagnosis is high. Most gangrene-type ischemic colitis has an acute onset, severe abdominal pain, severe diarrhea, blood in the stool, and vomiting. Due to toxin absorption and bacterial infections, patients are often accompanied by significant fever and increased white blood cell counts, and early signs of peritoneal irritation can occur. Patients with extensive lesions can also be accompanied by significant paralytic intestinal obstruction, colon swelling, increased pressure in the intestinal cavity, and intestinal wall compression, which further aggravates ischemic colitis by colonic ischemia. At the same time, the decrease in effective blood volume and the absorption of toxins can induce shock, further impair the blood supply to the intestinal wall, intestinal wall necrosis and perforation, and symptoms of peritonitis such as high fever, persistent abdominal pain, and shock.

40% to 50% of patients with intestinal obstruction caused by intestinal stenosis. Obstruction is mostly incomplete, and some patients appear early after the onset of the disease. At the same time, other clinical manifestations of dangerous colitis, especially gangrene colitis, need to be distinguished from colonic obstruction caused by colon tumors. The obstruction of most patients occurred 2 to 4 weeks after the onset of the disease, which was caused by fibrosis and scar formation at the lesion site. At this time, clinical symptoms such as abdominal pain and diarrhea have gradually eased. Fiber colonoscopy is very helpful for differential diagnosis.

Ischemic colitis examination

Blood routine

Leukocyte and neutrophil counts increased.

2. Histopathological examination

Superficial necrosis and ulceration of the colonic mucosa, or full-thickness necrosis of the mucosa were seen with the naked eye. Microscopic examination shows capillary, fibroblasts, and macrophages that proliferate submucosally; inflammation and fibrin emboli may be present in the submucosal artery; the lamina propria may be hyaline-like degeneration; eosinophils may be around granulation tissue And infiltration of tissue cells containing hemoglobin iron. The chronic phase is characterized by mucosal gland injury and gland regeneration between the lesion and normal mucosal tissue.

3. Digital rectal examination

Blood stains are often visible on finger cuffs.

4.X-ray plain film

The plain film of the abdomen shows the expansion of the colon and small intestine, the colonic bag is disordered, and some patients may have intestinal cramps and stenosis. Gangrene-type ischemic colitis sometimes shows free gas in the abdominal cavity caused by colon perforation, and gas in the intestinal wall and portal vein due to progressive intestinal wall ischemia and increased intestinal wall permeability.

5. Barium enema

This test can have a comprehensive understanding of the extent of the lesion, especially the extent of the lesion, but it has the risk of causing perforation of the colon. Therefore, it should be used with caution in patients with severe disease, a large amount of blood in the stool, and suspected intestinal necrosis.

6. Fiber Colonoscopy

Is the most effective test for the diagnosis of ischemic colitis. Endoscopic examination should be considered when the patient is suspected of having ischemic colitis but without signs of peritonitis, and plain radiographs of the abdomen do not show obvious signs of colonic obstruction and colonic perforation.

7. Mesenteric arteriography

Because the site of arterial occlusion in most patients with ischemic colitis is in the small arteries, mesenteric arteriography is difficult to detect signs of arterial occlusion. In addition, as contrast agents may cause further thrombosis, they should be used with caution.

8.CT scan

Some patients can see nonspecific changes such as dilatation of the intestinal cavity and thickening of the intestinal wall caused by intestinal wall edema.

Diagnosis of ischemic colitis

1. Patients 50 years and older. Accompanied by hypertension, arteriosclerosis, coronary heart disease, diabetes and other diseases, sometimes constipation, infection, taking antihypertensive drugs, arrhythmia, shock and other incentives.

2. Sudden abdominal pain, diarrhea and blood in the stool.

3. Anemia, colonoscopy with characteristic ischemic necrosis; barium enema X-ray examination, thumb prints can be seen in the acute phase, late intestinal narrowing signs; mesenteric arterial angiography can find signs of vascular stenosis or obstruction.

Ischemic colitis treatment

Treatment principle

Fasting, medium and high-flow oxygen supply; actively eliminating incentives and treating associated diseases; expanding blood volume, unblocking microcirculation, and improving intestinal ischemia; using antibiotics; improving systemic conditions, anti-shock, rehydration, and correcting heart failure; with Onset and comorbid treatment; surgical treatment if necessary.

Timely supportive treatment in the early pathology, including fasting, replenishing blood volume, maintaining water and electrolyte balance, and maintaining cardiac output. Antibiotics can be used to prevent infection. Severe patients with intestinal perforation or signs of peritonitis should undergo early laparotomy.

2. Treatment

(1) Conservative treatment The development of most non-gangrene lesions confined to the intestinal wall is self-limiting and can be gradually absorbed. Even if colon stenosis occurs in some patients, most of them are incomplete intestinal obstruction, which can be relieved by conservative treatment.

(2) Surgical treatment The mortality rate of gangrene ischemic colitis depends to a large extent on the promptness of diagnosis and surgical treatment, the general condition of the patient, and the occurrence of complications. Once severe complications such as respiratory distress syndrome, renal failure, and persistent infection occur, surgical mortality is mostly limited to gangrene patients with ischemic colitis. Once diagnosed, surgery should be performed as soon as possible. Patients with gangrene ischemic colitis with significant colonic dilatation should consider total colectomy. Surgical treatment should also be considered for patients whose condition persists for more than 2 weeks, although the disease has not significantly improved despite active conservative treatment. Colonic stenosis caused by most ischemic colitis is incomplete colonic obstruction, so surgery can generally be avoided. For patients with clinical symptoms of chronic colon obstruction, those who cannot be relieved by active conservative treatment or who have difficulty distinguishing from colonic malignant tumors should be treated with surgery to remove the narrow bowel segment, reconstitute the intestinal continuity by one-stage anastomosis, and remove the tissue for pathological examination. .

Ischemic colitis prevention

This disease is one of the senile diseases. The onset is sudden and the prognosis of the gangrene type is extremely poor, which has a significant impact on the success of the treatment. Regardless of internal medicine and surgical treatment, you should grasp the timing, observe closely, adjust the drugs in time, and first remove the inducements, such as constipation, infection, arrhythmia, unreasonable use of antihypertensive drugs, shock, etc. It is recommended to suffer from coronary heart disease, hypertension, arteries Patients with sclerosis and diabetes should adhere to treatment, exercise more, and promote blood return. If there is sudden abdominal pain of unknown cause and blood in the stool, they should be alert to this disease.