Mesenteric ischemia happens when blood flow to the intestines is reduced or blocked, causing tissue damage and, in severe cases, intestinal death. It can occur suddenly, called acute mesenteric ischemia, or develop gradually over time, known as chronic mesenteric ischemia.
Symptoms often include severe abdominal pain that feels worse than expected from the exam, along with nausea, vomiting, and unexplained weight loss. People with the chronic form may also feel pain after eating and avoid meals to prevent discomfort.
Treatment focuses on restoring blood flow through endovascular or surgical revascularization, along with medications that prevent clots. Managing risk factors like high blood pressure, high cholesterol, smoking, and atrial fibrillation helps prevent complications and improves recovery.
Main symptoms
The most common symptoms include:
-
Sudden or severe abdominal pain that seems out of proportion to exam findings
-
Pain that worsens after eating
-
Nausea and vomiting
-
Diarrhea or bloating
-
Unexplained weight loss
-
Loss of appetite or “food fear”
-
Abdominal tenderness in advanced stages
Symptoms of mesenteric ischemia depend on whether the condition is acute or chronic. In acute mesenteric ischemia, symptoms can appear suddenly and progress quickly, sometimes leading to shock. In chronic cases, symptoms develop more gradually and may include ongoing abdominal pain and weight loss.
Common causes
Mesenteric ischemia happens when blood flow to the intestines is reduced or blocked in the arteries or veins. The condition can have several underlying causes, which are generally grouped into four main types:
1. Arterial embolism
A blood clot that forms in the heart (often due to atrial fibrillation, a recent heart attack, or valve disease) can travel and block the superior mesenteric artery, cutting off blood flow to the intestines.
2. Arterial thrombosis
This type usually occurs in people with atherosclerosis, where fatty deposits narrow the arteries over time. When one of these narrowed arteries becomes completely blocked, it can lead to sudden or worsening symptoms of mesenteric ischemia.
3. Non-occlusive mesenteric ischemia (NOMI)
In this form, blood flow decreases because of vessel constriction rather than a physical blockage. It’s more common in people with heart failure, low blood pressure, or those taking high doses of medications that constrict blood vessels.
4. Mesenteric venous thrombosis
This occurs when a blood clot forms in the veins that drain the intestines. It’s often linked to conditions that increase the risk of clotting, such as inherited blood disorders, use of birth control pills, or inflammatory diseases.
Confirming a diagnosis
Diagnosing mesenteric ischemia involves a combination of medical history, physical exam, and imaging tests. CT angiography is the gold standard and can detect blockages, clots, or changes in the intestinal wall with very high accuracy.
Blood tests like lactate, D-dimer, and intestinal fatty acid–binding protein (I-FABP) can suggest intestinal injury but are not enough to confirm the diagnosis on their own. Other tests, such as duplex ultrasound or magnetic resonance angiography (MRA), may be used to identify chronic cases or track the disease over time.
Treatment options
Treatment for mesenteric ischemia includes:
1. Initial management
Immediate treatment focuses on stabilizing the patient with fluids, oxygen, and antibiotics to prevent infection. Anticoagulation with heparin is usually started right away, unless there’s a medical reason not to.
2. Endovascular revascularization
Minimally invasive procedures like angioplasty and stenting are often the first choice for restoring blood flow. These treatments have high success rates and lower mortality compared to open surgery, with most patients recovering well.
3. Open surgical revascularization
In more severe or complex cases, open surgery may be necessary to remove clots, bypass the blocked artery, or repair damaged blood vessels. Although this option carries more risk, it often provides the best long-term results for certain patients.
4. Bowel surgery
If part of the intestine has died due to lack of blood flow, surgery is needed to remove the affected section and prevent infection or sepsis. A second surgery is sometimes done within 24 to 48 hours to check how the intestine is healing.
5. Chronic mesenteric ischemia management
For long-term cases, the goal is to prevent acute attacks and relieve pain after meals. Treatments may include revascularization, lifestyle changes, and management of underlying cardiovascular risk factors.
Prevention measures
Preventing mesenteric ischemia mainly involves managing cardiovascular health and maintaining good blood circulation. Important preventive steps include:
-
Quitting smoking
-
Controlling blood pressure and cholesterol
-
Keeping blood sugar levels within a healthy range
-
Maintaining a healthy weight and exercising regularly
-
Taking anticoagulants if prescribed for atrial fibrillation to prevent blood clots
For people in critical care, doctors also aim to avoid high doses of medications that constrict blood vessels and to maintain stable blood flow to prevent non-occlusive mesenteric ischemia.
Prognosis and recovery
Mesenteric ischemia is a serious condition with a high risk of death if not treated quickly. Early diagnosis and prompt restoration of blood flow greatly improve survival and reduce complications like bowel necrosis. People with chronic mesenteric ischemia usually have a good outlook when treatment restores circulation and risk factors are well managed.