Small bowel ischemia occurs when a blockage develops in the arteries that supply blood to the small intestine. It can come on suddenly or develop over time, and symptoms can be mild or severe. In some cases, it requires emergency surgery to remove the blockage.
If left untreated, the loss of blood supply can damage intestinal tissue and even lead to tissue death. People with existing blood-related conditions, such as abnormal blood pressure or a blood-clotting disorders, are at higher risk for small bowel ischemia.
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What Is Small Bowel Ischemia?
Small bowel ischemia is a group of conditions that reduces blood supply to the small intestine. It typically occurs when a blockage develops in the arteries that carry blood to the small intestine. The blockage may be a blood clot, a buildup of cholesterol, or scar tissue.
In some cases, low blood pressure or a hernia can cause small bowel ischemia.
The symptoms of the condition can be acute (they come on suddenly) or chronic (they develop over time). Acute intestinal ischemia needs immediate medical attention and often requires surgery to remove the blockage and restore blood flow. Chronic intestinal ischemia is less urgent but still requires treatment so it does not turn into an acute situation.
What are the types of small bowel ischemia?
Acute intestinal ischemia
Also known as acute mesenteric ischemia, acute ischemia occurs when blood flow to the small intestine is suddenly reduced or cut off, often without warning. It may be due to a blood clot, low blood pressure, or a blockage in an artery.
Symptoms include belly pain, bloating, and the urgent need to have a bowel movement. It is a medical emergency that typically requires surgery. If it is not treated, it can lead to irreversible tissue damage or death.
Chronic intestinal ischemia
Also known as chronic mesenteric ischemia, this condition is caused by a buildup of cholesterol in the blood vessels. Over time, that buildup causes the arteries to narrow, limiting blood supply to the small intestine. Symptoms include abdominal pain — especially after eating — vomiting, diarrhea, and weight loss.
Chronic intestinal ischemia can become acute if a blood clot forms or if a blockage becomes so severe that it cuts off the blood supply.
Mesenteric venous thrombosis
This type of small bowel ischemia is rare and occurs when blood can’t leave the small intestine due to a blockage in a vein. When that vein — which is supposed to carry oxygen-depleted blood back to the heart — is blocked, blood backs up in the intestines. This means less oxygen-rich blood can enter the small intestine.
Complications of mesenteric venous thrombosis include intestinal swelling and bleeding.
How common is small bowel ischemia?
Small bowel ischemia is rare: It accounts for 0.1% of all hospital admissions in the United States. Most of those cases are due to acute intestinal ischemia.
What causes small bowel ischemia?
Small bowel ischemia is caused by reduced blood flow to the small intestine.
Many conditions can contribute to a reduced blood supply, including:
- Atherosclerosis — When cholesterol builds up in the arteries, reducing blood flow to the small intestine.
- Blood clot — Can cut off the blood supply suddenly and often requires prompt surgery to correct.
- Hernia — A piece of intestine that gets stuck in the abdominal wall, which can result in strangulation, cutting off the blood supply. It’s a life-threatening condition that requires surgery.
- Low blood pressure — Makes it more difficult for oxygen-rich blood to reach the small intestine.
- Scar tissue — The buildup of scar tissue after a surgery or injury can lead to narrowed or blocked arteries.
Small bowel ischemia risk factors
Lifestyle, age, and preexisting health conditions can all raise your risk of developing small bowel ischemia.
Some of the most common risk factors include:
- Abnormal blood pressure — Blood pressure that is too high or too low.
- Age — People over 50 are more likely to develop small bowel ischemia.
- Atherosclerosis — The buildup of cholesterol in the arteries can lead to reduced blood flow to the small intestine.
- Blood-clotting disorders — Conditions like sickle cell anemia may increase your risk of blood clots, which can cut the blood supply to the small intestine.
- Heart and vascular conditions — Congestive heart failure or an abnormal heartbeat, especially atrial fibrillation, can increase your risk of small bowel ischemia, as can a previous stroke or heart attack.
- Illicit drug use — People who use cocaine and methamphetamine may be at higher risk of developing small bowel ischemia.
- Mechanical heart valves — Significantly increases the risk of clot formation in the heart, which almost always requires lifelong medications to thin the blood. During periods when these medications need to be held/stopped or if the levels aren't sufficient, you can become at increased risk of developing a clot, which can lead to stroke or bowel ischemia.
- Medications — People who take birth control pills or medications to control migraines, allergies, and blood vessel expansion and contraction are at higher risk.
- Tobacco use — Smoking increases your risk of developing small bowel ischemia.
Small bowel ischemia complications
Left undiagnosed or untreated, small bowel ischemia can lead to severe complications and even death. When blood flow to the small intestine is suddenly and completely cut off, it is robbed of oxygen. Without oxygen, intestinal tissue can be irreversibly damaged.
In some cases, small bowel ischemia can be fatal.
How can I prevent small bowel ischemia?
You may be able to prevent or reduce your risk of small bowel ischemia by making lifestyle changes, including:
- Not using illicit drugs.
- Lowering your cholesterol with diet, exercise, or medication.
- Seeking medical treatment for underlying cardiovascular conditions.
- Quitting smoking.
What Are the Signs and Symptoms of Small Bowel Ischemia?
The symptoms of small bowel ischemia can vary depending on whether your condition is acute or chronic.
Symptoms of acute intestinal ischemia:
- Bloody stool.
- Fever.
- Mental confusion in older adults.
- Nausea or vomiting.
- Sudden, severe abdominal pain.
- Sudden, severe bloating.
- Urgent need to have a bowel movement.
Symptoms of chronic intestinal ischemia:
- Abdominal cramps after eating.
- Abdominal pain that worsens over several weeks or months.
- Bloating.
- Diarrhea.
- Fear of eating because it will cause pain.
- Nausea or vomiting.
- Unintended weight loss.
When should I see a doctor about my small bowel ischemia symptoms?
If you have signs of acute intestinal ischemia, including sudden and severe abdominal pain and bloating, you need to go to the hospital right away. Acute intestinal ischemia is a medical emergency that can lead to irreversible intestinal damage or even death. You will likely require surgery to remove the blockage from your artery and restore blood flow.
Chronic intestinal ischemia is less urgent but still requires a visit to your doctor. Without treatment, the condition can worsen over time and lead to acute intestinal ischemia.
How Do You Diagnose Small Bowel Ischemia?
To diagnose small bowel ischemia, your doctor will need to get a view of your small intestine and the blood vessels leading to and away from the area. This view can be obtained with one of several imaging tests.
Tests to diagnose small bowel ischemia
- Angiogram — During an angiogram, your doctor will insert a long, flexible tube into the artery in your groin and push it up to the aorta, the largest central blood vessel in the body. Then the doctor will inject a dye into the bloodstream and follow its path through the arteries with a series of x-rays. This test can also be done with a CT scan, in which case it’s called a CT angiogram.
- CT scan — During a CT scan, technicians will take multiple x-rays of your abdomen. A computer will compile them together to create a three-dimensional image of your small intestine.
- Mesenteric duplex — An ultrasound study that evaluates the blood flow within the blood vessels of the bowel.
- MRI — An MRI uses a magnet and radio waves to create a detailed, three-dimensional image of your small intestine.
Small bowel ischemia outlook
If you go to the hospital right away, doctors can remove the blockage from your artery and restore blood flow to your intestine with surgery or medication, avoiding the most serious complications.
If you wait to seek medical care, the reduced blood flow can result in a lack of oxygen to your small intestine. This oxygen deprivation can cause irreversible damage to intestinal tissue or, in some cases, even death.
How Do You Treat Small Bowel Ischemia?
Lifestyle changes to prevent small bowel ischemia
These measures are not enough to treat small bowel ischemia, but they may reduce your risk of developing the condition:
- Not using illicit drugs.
- Lowering your cholesterol with diet, exercise, and medication.
- Quitting smoking.
Medicine to treat small bowel ischemia
If your chronic small bowel ischemia hasn’t damaged your intestine, you may be able to treat the condition by taking medication.
Common medications include:
- Antibiotics.
- Blood thinners.
- Clot-busting medication to break up blood clots.
Surgery for small bowel ischemia
Surgery may include:
- Angioplasty — An angioplasty can be performed if your ischemia is due to narrowed arteries. During this procedure, doctors will insert a balloon-tipped tube into the artery in your groin or arm and push it up to the affected area. They will then inflate the balloon to widen the artery and may place a stent — a small mesh tube — to keep it open.
- Laparoscopy — During this minimally invasive surgery, your doctor will make several small incisions in your abdomen and use tiny surgical instruments to restore blood flow to your small intestine. The procedure may include removing the blockage or creating a bypass to reroute blood flow around it. Laparoscopic surgery typically results in less pain and faster healing.
- Open surgery — In some cases, open surgery is required to remove dead tissue and restore blood flow. During open surgery, your doctor will make one long incision in your abdomen, remove dead tissue from the small intestine, and reconnect the healthy parts of the intestine to restore proper blood flow.
Why Choose UPMC for Small Bowel Ischemia?
If you need surgery, you can count on UPMC.
Here, you can expect:
- Access to new and innovative treatment — Nearly all of our surgeons participate in clinical or laboratory research. Their discoveries ensure that patients receive the latest treatments using the most advanced techniques.
- Top doctors — Our multidisciplinary team of surgeons and specialists is available around the clock to consult, diagnose, and treat patients. All of our surgeons are certified by the American Board of Surgery, and many are nationally renowned for the comprehensive care they provide.
- Care close to home — At UPMC, our 100,000 employees — including 5,000 doctors — provide care to patients at more than 40 hospitals and 800 outpatient care sites in Pennsylvania, New York, and Maryland. That means you never have to travel far to receive the world-class care you need.
