Intestinal Infarction

Intestinal infarction is a serious and life-threatening condition that occurs when blood flow to the intestines is severely reduced or completely blocked. Despite being uncommon, it has a very high death rate and requires immediate medical attention to prevent permanent damage or death.

Table of contents

• What Is Intestinal Infarction?
• Causes and Risk Factors
• Symptoms
• Diagnosis
• Treatment
• Complications and Outlook
• Prevention

What Is Intestinal Infarction?

Intestinal infarction, also known as bowel infarction or gangrenous bowel, represents an irreversible injury to the intestine that results from insufficient blood flow^[1]. It is a serious medical emergency because it can quickly result in life-threatening infection and death^[4].

The intestines need a steady supply of oxygen-rich blood to function properly. When blood flow is blocked or severely reduced, the affected intestinal tissue does not receive enough oxygen. This condition is called ischemia (pronounced “iss-key-me-uh”), which means parts of your body aren’t getting enough blood flow^[5]. If the ischemia is not corrected quickly, the tissue begins to die, leading to infarction^[2].

Intestinal infarction can affect the small intestine, the large intestine (colon), or both^[1]. The intestines are mainly supplied by two major arteries: the superior mesenteric artery (SMA), which supplies blood from the lower part of the duodenum to two-thirds of the transverse colon, and the inferior mesenteric artery (IMA), which supplies the large intestine from the distal one-third of the transverse colon to the rectum^[3].

This condition is uncommon, with an estimated incidence of 0.09–0.2% of all acute admissions to emergency departments^[12]. However, it has a high mortality rate. The death rate for acute cases ranges from 60-80%^[7], and without treatment, mortality can exceed 50%^[12].

Intestinal necrosis, Ischemic bowel – small intestine, Dead bowel, Dead gut, Infarcted bowel, Gangrenous bowel, Acute mesenteric ischemia

• Small intestine
• Large intestine (colon)
• Mesentery
• Superior mesenteric artery
• Inferior mesenteric artery
• Mesenteric veins

Causes and Risk Factors

Intestinal infarction occurs when blood flow to the intestines is interrupted or significantly reduced for an extended period. According to research, intestinal ischemia occurs when there is at least a 75% reduction in intestinal blood flow for more than 12 hours^[3].

There are several possible causes of intestinal ischemia and infarction^[2]:

Blood clots (embolus): Blood clots can block one of the arteries supplying the intestine. People who have had a heart attack or who have heart rhythm problems, such as atrial fibrillation (an irregular heartbeat), are at higher risk for this problem^[2].

Narrowing of the arteries: The arteries that supply blood to the intestine may become narrowed or blocked from cholesterol buildup, a condition called atherosclerosis. When this happens in the arteries to the heart, it causes a heart attack. When it happens in the arteries to the intestine, it causes intestinal ischemia^[2].

Narrowing of the veins: The veins carrying blood away from the intestine may become blocked by blood clots. This blocks blood flow in the intestine and is more common in people with liver disease, cancer, or blood clotting disorders^[2].

Low blood pressure: Very low blood pressure in people who already have narrowing of the intestinal arteries may also cause loss of blood flow to the intestine. This often occurs in people with other serious medical problems^[2].

Hernia: If the intestine moves into the wrong place or becomes tangled, it can cut off the blood flow^[2].

Adhesions: The intestine may become trapped in scar tissue from past surgery. This can lead to loss of blood flow if left untreated^[2].

Certain conditions and factors increase the risk of developing intestinal infarction. The condition is more common in people who are older, especially those with cardiovascular disease or blood clotting disorders^[5]. Risk factors include^[5]:

• Atrial fibrillation (a type of irregular heart rhythm)
• Coronary artery disease
• Diabetes
• Heart failure
• High blood pressure (hypertension)
• High cholesterol (hyperlipidemia)
• Conditions that make blood clot too easily (hypercoagulation disorders)
• Recent surgery
• Peripheral vascular diseases (such as peripheral artery disease)
• Tobacco use (past or present)

Symptoms

The main symptom of intestinal infarction is severe abdominal pain^[2]. Abdominal pain is the most common symptom in patients with intestinal ischemia^[3]. The pain is typically severe, even though the area may not be very tender when touched^[2].

Symptoms can come on suddenly, a condition called acute intestinal ischemia, which is a medical emergency. When this happens, the most common symptoms include^[1]:

• Sudden belly pain
• An urgent need to pass stool
• Forcefully passing stool often
• Belly tenderness or bloating

Other symptoms include^[2]:

• Diarrhea
• Fever
• Vomiting
• Blood in the stool

In older adults, mental confusion may also occur^[1]. Pain that feels so bad that you can’t sit still or find a comfortable position is a medical emergency^[1].

When symptoms develop more slowly over time, the condition is called chronic intestinal ischemia. Symptoms of chronic intestinal ischemia can include^[1]:

• Belly cramps or fullness, most often within 30 minutes after eating, that lasts 1 to 3 hours
• Belly pain that gets worse gradually over weeks or months
• Fear of eating because of pain after eating
• Weight loss without trying
• Diarrhea
• Nausea and vomiting
• Bloating

Diagnosis

Diagnosing intestinal infarction can be challenging because the symptoms may resemble those of other less serious gastrointestinal issues^[7]. If a healthcare professional suspects intestinal ischemia after a physical exam, several diagnostic tests may be performed based on the symptoms^[8].

Blood tests: Although blood tests alone can’t diagnose intestinal ischemia, certain blood test results might suggest the condition. Laboratory tests may show a high white blood cell count (a marker of infection)^[2]. There may also be increased acid in the bloodstream, a condition called lactic acidosis^[2].

Imaging tests: Imaging tests allow healthcare professionals to see internal organs and rule out other causes of symptoms. These tests may include^[8]:

• X-ray
• Ultrasound
• CT scan (computed tomography) of the abdomen
• MRI (magnetic resonance imaging)
• Doppler ultrasound of the abdomen

To look at blood flow in veins and arteries, healthcare professionals may use an angiogram using a certain type of CT scan or MRI^[8].

Angiography: During this test, a long, thin tube called a catheter is inserted into an artery in the groin or arm. A dye injected through the catheter flows to the intestinal arteries. The dye moving through the arteries allows narrowed areas or blockages to show up on X-rays^[8].

Use of a scope to see inside the digestive tract: This involves putting a lighted, flexible tube with a camera on its tip into the rectum to view the digestive tract. The scope can look at the last 2 feet of the colon (sigmoidoscopy) or the whole colon (colonoscopy)^[8].

However, these tests do not always detect the problem. Sometimes, the only way to detect intestinal ischemia is with a surgical procedure^[2]. In some cases, surgery is needed to find and remove damaged tissue. Opening the belly allows diagnosis and treatment during one procedure^[8].

Treatment

Intestinal infarction is a medical emergency that requires immediate treatment. Recognition of the condition before permanent tissue damage occurs is the best way to improve patient survival^[11].

In most cases, the condition needs to be treated with surgery^[2]. The only treatment for bowel infarction is immediate surgical repair and removal of the dead bowel segment^[4]. The section of intestine that has died is removed, and the healthy remaining ends of the bowel are reconnected^[2].

In some cases, a colostomy, ileostomy, or jejunostomy may be needed. This may be short-term or permanent^[2]. These are procedures where a portion of the intestine is brought through an opening in the abdominal wall to allow waste to leave the body.

The blockage of arteries to the intestine is corrected, if possible^[2]. Treatment approaches may include:

Initial stabilization: After diagnosis, immediate treatment may include dietary restrictions. A doctor may not allow foods or liquids by mouth and may put the affected person on bowel rest. During bowel rest, the person may receive nutrients through an intravenous (IV) tube^[7].

Medications: Inpatient medications that may be used include^[11]:

• Papaverine (a medication that helps widen blood vessels)
• Heparin or low-molecular-weight heparin (blood thinners)
• Warfarin (a blood thinner)
• Broad-spectrum antibiotics
• Pain medications
• Thrombolytics (medications that dissolve blood clots)

Endovascular approaches: Over the past two decades, the rapid development of endovascular techniques has made this approach an important alternative for patients with occlusion of the superior mesenteric artery. Angiography allows a healthcare professional to treat a blockage in an artery by removing a clot, putting in medicine, or using special tools to widen an artery^[8]. Some studies have shown that endovascular therapy is associated with lower rates of mortality and bowel resection than the traditional open approach^[12].

Second-look procedure: A second-look procedure is indicated whenever bowel of questionable viability is not resected during the initial surgery^[11].

After initial medical or surgical stabilization, patients with intestinal infarction typically have a prolonged recovery time in the hospital. Such patients may need to be kept on nothing by mouth status and may be maintained on parenteral nutrition (nutrition through a vein) for some time^[11].

Complications and Outlook

Damage or death of the bowel tissue is a serious condition that can result in death if not treated right away^[2]. The outlook depends on the cause, but prompt treatment can lead to a good outcome^[2].

What makes intestinal infarction so dangerous is that it affects the intestines, which contain trillions of bacteria. Normally, those bacteria are good for you and help digest food. But when the intestines start to die, those bacteria can spread to places they don’t belong and cause dangerous infections^[5].

Possible complications include:

Peritonitis: This is inflammation of the membrane lining the abdominal cavity and is common in cases of intestinal infarction^[2].

Sepsis: This is a life-threatening condition that happens when the immune system’s overwhelming reaction to an infection ends up damaging the body. Some people may become severely ill with fever and a bloodstream infection^[2].

Need for ostomy: Damage or death of the bowel tissue may require a colostomy, ileostomy, or jejunostomy. This may be short-term or permanent^[2].

Malabsorption: People who have a large amount of tissue death in the intestine can have problems absorbing nutrients. They can become dependent on getting nutrition through their veins^[2]. Patients who have undergone extensive resection of the small bowel may develop malabsorption, indicating the need for dietary supplements^[4].

Stricture: Less commonly, some people have repeat or chronic episodes of ischemic colitis in one area, which can cause scarring that narrows the colon^[23].

Early diagnosis and timely surgical intervention are the cornerstones of modern treatment to reduce the high mortality associated with this condition^[12]. The advent of endovascular approaches in parallel with modern imaging techniques provides new treatment options^[12]. A focused multidisciplinary approach based on early diagnosis and individualized treatment is essential^[12].

Prevention

Contact your healthcare provider if you have any severe abdominal pain^[2]. Seek medical care right away if you have sudden, severe belly pain. Pain that feels so bad that you can’t sit still or find a position that feels OK is a medical emergency^[1].

Preventive measures include^[2]:

• Controlling risk factors, such as irregular heartbeat, high blood pressure, and high cholesterol
• Not smoking
• Eating a nutritious diet
• Quickly treating hernias

During the inpatient stay, every effort must be made to find and, if possible, treat any predisposing cause(s) of intestinal infarction^[11]. Because timing is essential in preventing bowel necrosis with its severe complications and high mortality, patients should be transferred only if the primary hospital lacks adequate services for diagnosing and treating the condition. Patients should be optimally stabilized before transfer, and appropriate services must be available at the receiving hospital^[11].