This disorder occurs when the intestine does not receive enough blood.

 

Ischemia can occur in the small intestine, large intestine, or both.
This is a very serious illness that can cause:

  1. Intense pain,
  2. Loss of bowel function.

Massive intestinal ischemia is very serious and causes death within a few days (on average, 24 hours).

Intestinal infarction may be of type:

  1. Embolic , if caused by a plunger , likely in patients with heart problems, eg cardiac arrhythmia ,
  2. Thrombotic (it is the most frequent), if it is caused by a thrombus that obstructs a blood vessel,
  3. Non-occlusive , during a hemorrhagic shock, a different distribution of circulating blood mass may occur. To bring blood to the brain and heart, the splanchnic vessels are sacrificed, so that the cells do not receive enough oxygen and nutrients. If ischemia is non-occlusive, some ischemic sections and other alternating healthy sections are formed in the intestine.

Older people (older than 50) are at greater risk of developing this problem than others.
Generally, this disease is very rare in the population.

Children
Intestinal ischemia mainly affects the elderly, but babies may suffer from necrotizing enterocolitis, usually if they are premature.

 

Pathologic anatomy

There are three major blood vessels to carry blood in the abdominal region and can cause an intestinal bowel ischemia:

  1. Celiac artery,
  2. Upper mesenteric artery,
  3. Lower mesenteric artery.

In the superior mesenteric artery there is the Reiter segment from which they originate:

  1. The colonic artery,
  2. A ileocolica,
  3. The average colic.

An obstruction in the Reiter segment can cause heart attacks throughout the gut.

Venous Ischemia
A blood clot can develop in a vein that carries blood out of the intestine.
When the vein is blocked, the blood returns to the intestine, causing swelling and bleeding.
This disorder is characterized by :

  1. Congestion of blood,
  2. Lack of oxygen,
  3. Changes in intestinal microcirculation,
  4. The intestinal loops are dilated and filled with blood.

Generally, infarction is said to indicate blockage of an artery, but in this case it is also used for venous obstruction because in both situations it occurs:

  • Deficiency of oxygen,
  • Damage to the endothelium (inner wall) of the blood vessels.

The causes can be:

  1. Compression caused by tumors or lymph nodes,
  2. Pancreatitis ,
  3. Abdominal infection,
  4. Intestinal disease, such as Crohn’s disease , ulcerative colitis and diverticulitis .
  5. Diseases that cause hypercoagulability,
  6. Trauma
  7. Important amounts of estrogen.

The symptoms are the same as the infarction or ischemia that originates in an artery.

 

Causes of intestinal ischemia

Obstruction of an artery can be caused by:

  • Atherosclerosis ,
  • Blood clots (which may form in the heart in the event of atrial fibrillation),
  • Aneurysms us blood vessels.

The venous occlusion can cause intestinal ischemia that  when:

  1. Hypertension of the portal vein (carries blood from the stomach and intestines to the liver) The portal vein originates from the conjunction of the superior mesenteric vein and the splenic vein (which collects blood from the inferior mesenteric vein).
  2. Deep venous thrombosis is more likely if the person has a hypercoagulable condition or in case of inflammation.
  3. because,
  4. Trauma,
  5. Surgery.

 

Causes of non-occlusive intestinal ischemia :

  1. Hypotension ( low blood pressure ), prolonged low blood pressure caused by heart surgery can cause intestinal ischemia and, in some cases, also an intestinal infarction.
  2. Spasm (contraction) of the arteries that go into the intestine,
  3. Cancer in the colon , which compress the blood vessels and can cause a blockage of the circulation,
  4. Heart failure ,
  5. Shock and bleeding – cause a reduction in circulating blood volume and blood pressure.
  6. Side effect of medications (vasoconstrictors, vasodilators and contraceptive pill ) and some drugs.

Risk factors include:

  1. Smoke ,
  2. Obesity,
  3. Very low pressure .

 

Signs and symptoms of intestinal ischemia

The symptoms are divided into two groups:

  1. Symptoms of acute myocardial infarction occurring suddenly,
  2. Symptoms of chronic ischemia that develop over time.

Acute Symptoms

  1. Sudden and severe belly pain, especially in one area of ​​the abdomen. The pain can be caused by chemical stimuli (ischemia and pH variations) or mechanical (distention of the bowel upstream of the obstruction of the artery or vein).
  2. Nausea ,
  3. Vomiting ,
  4. Blood in the stool ,
  5. Abdominal distension,
  6. Urgency to defecate,
  7. Fever .

In case of thrombosis or embolism, the following symptoms develop:

  1. At first , the person has a lot of pain, similar to a colic. Pain is widespread throughout the abdomen.
  2. After a few hours , the pain is concentrated in the area around the navel or on one side of the abdomen. This phase lasts 4-6 hours. The intensity of the pain decreases, but other symptoms worsen: rapid heart rate, low blood pressure, rapid breathing.
  3. At the end of the second phase , intestinal necrosis occurs, with peritonitisand shock.

Chronic symptoms

  1. Belly pain after meals,
  2. Nausea and vomiting
  3. Diarrhea or constipation ,
  4. Weight loss because the person does not eat to avoid the pain,
  5. Swelling in the belly .

 

Complications of intestinal ischemia

The consequences or complications of intestinal ischemia may be:

  1. Death of intestinal tissue
    If blood flow is stopped completely and suddenly, the intestinal tissue may die (gangrene).
  2. Perforation
    An injury to the wall of the intestine may occur. The consequence is the leakage of the contents of the intestine into the abdominal cavity, causing a serious infection (peritonitis).
  3. Fibrosis or shrinkage of the colon
    The process of curing ischemia causes the formation of fibrous scar tissue that restricts or blocks the bowel.
  4. Death

 

Diagnosis and exams for intestinal ischemia

According to the signs and symptoms, your doctor may recommend these tests:

  1. The angiography with computed tomography or magnetic resonance imaging to obtain detailed images of the blood flow in the small intestine and look for clogged arteries.
    Sometimes the doctor can treat obstructed arteries during angiography, in case of celiac or mesenteric artery insufficiency, the doctor may insert a stent through the catheters prior to the development of an intestinal infarct.
    Thus, the flow can be restored, for example, in a pathology that affects the celiac artery.
  2. The arteriography is the radiography of blood vessels.
  3. The ultrasound color Doppler shows whether the obstruction is venous or arterial.
  4. If the patient does not improve with the drugs, the doctor advises  exploratory  laparoscopic surgery  to locate and remove damaged tissue.
    Exploratory surgery allows diagnosis and treatment.

In laboratory blood tests we can note:

  1. Leukocytosis (elevated white blood cells) with neutrophils above 15 000 / mm³,
  2. Lactate dehydrogenase (LDH) high,
  3. Amylase high,
  4. High alkaline phosphatase,
  5. Increase in lactates.

 

Treatment and medication for intestinal ischemia

The treatment of intestinal ischemia involves restoring sufficient blood flow to the digestive system.
The options vary according to the type and severity of the disease

Medications
Thrombolytic medicines may be given to dissolve the thrombus or to prevent the formation of blood clots.
In addition, vasodilators are required to expand blood vessels in case of acute mesenteric ischemia.

In case of chronic mesenteric ischemia, the doctor may prescribe anticoagulants.

Mesenteric Venous Thrombosis
If the bowel has not been damaged, it is probably necessary to take an anticoagulant medication for about three to six months.
Anticoagulants prevent the formation of thrombi.

If the tests show a blood clotting disorder, you may need to take anticoagulants for the rest of your life.
If the parts of the large intestine are damaged, surgery may be needed to remove it.

Colon
ischemia Colon ischemia can heal itself without treatment, but the doctor may recommend antibiotics to treat or prevent infections .
Your doctor may recommend treatment for other related conditions, such as:

  1. Cardiac insufficiency,
  2. Irregular heartbeat ( arrhythmia ).

You must stop taking all medicines that cause vasoconstriction, for example, medicines to:

  1. Migraine ,
  2. Hormonal treatments,
  3. Heart disease.

If the colon is damaged, you may need surgery to remove the dead tissue or to skip the blockage in an intestinal artery.

Acute mesenteric ischemia (infarction)
Surgery is usually needed to:

  1. Remove a blood clot,
  2. Overcoming an arterial blockage,
  3. To repair and remove the damaged part of the intestine.

With an early diagnosis, if the disease affects a small part of the intestine, the surgeon can remove a segment of the intestine and make an anastomosis .

Treatment includes medicines for:

  • Prevent the formation of thrombi,
  • Dissolve the blood clots,
  • Dilate the blood vessels.

During angiography to diagnose the problem, it is possible to treat the disease with a simultaneous angioplasty.
The angioplasty involves insertion of a balloon in an artery swells to:

  1. Compress the fat deposits,
  2. Dilate the artery.

The consequence is an artery with a larger diameter that allows the blood to circulate freely .
The doctor may place a cylindrical metal stent (stent) in the artery to maintain the opening.

In the case of complete occlusion of the superior mesenteric artery, a massive infarction develops in the ileum, and in these cases the surgeon can not remove the entire ileum (part of the small intestine) because it is not compatible with life.
In this case, heparin is administered intravenously to the patient, waiting for the clot to disappear or to diminish.

Chronic mesenteric ischemia
Generally, surgery is needed to:

  1. Restore blood flow,
  2. Avoid the progression of acute mesenteric ischemia.

The surgeon can jump the blocked arteries or enlarge narrow arteries with:

  1. An angioplasty,
  2. The positioning of the stent.

In addition to angioplasty and coronary angioplasty , another method for the treatment of chronic mesenteric ischemia is called transaortic endarterectomy.
In this operation, the plaque that clogs the mesenteric artery is removed.

Convalescence after surgery
The postoperative course depends on the patient’s condition and the size of the intestine on necrosis.
The prognosis is poor in most cases, in case of venous obstruction the cure is more likely.

 

Prevention, diet and feeding for intestinal ischemia

It is possible to reduce the risk of intestinal ischaemia with some changes in lifestyle that help prevent atherosclerosis:
Choose a diet rich in fruits, vegetables, nuts and seeds.
Reduce the amount of added sugar, processed foods, cereals and dairy products.

Smoke. People who smoke should talk to their doctor to find out how to stop .
Counseling, medications and nicotine replacement products are some of the possible options.

Regular exercise
The goal is at least 30 minutes a day.
Maintain a proper height.
Treating other health problems.

We must prevent or treat the following disorders:

  1. High pressure ,
  2. High cholesterol,
  3. Diabetes or other diseases that increase the risk of atherosclerosis.

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