What Is Mesenteric Ischemia

Overview

Mesenteric ischemia refers to a condition where there is a lack of oxygen to the bowels. This occurs when restricted or obstructed arteries reduce blood flow to the small intestine. Reduced blood flow might cause lasting damage to the small intestine. There are two types: one that happens quickly and another that happens slowly.

Acute mesenteric ischemia is a sudden decrease of blood supply to the small intestine. The acute kind is frequently caused by a blood clot and needs prompt medical attention, such as emergency surgery.

Chronic mesenteric ischemia refers to mesenteric ischemia that develops over time. The chronic form is often caused by fatty deposits developing in the arteries. Chronic mesenteric ischemia is treated with planned open surgery or an angioplasty treatment.

If left untreated, chronic mesenteric ischemia can progress to acute mesenteric ischemia. It can also cause significant weight loss and malnutrition.^{1 2}

Mesenteric ischaemia can be misdiagnosed. It should not be confused with ischaemic colitis, which is when there is little blood supply to the large intestines. Thus having awareness about the symptoms related to the disease, and different treatment options depending on the severity of the disease, and what to look out for, is of great importance for early redressal and better outcomes.

Risk factors

This is mostly a disease of persons over the age of 50, but it can affect younger people with risk factors for mesenteric venous thrombosis (MVT), such as atrial fibrillation (AF). Overall, 0.09-0.2% of all hospital admissions are affected.

Risk factors for mesenteric ischaemia include:²

• Old age
• Blood pressure issues
• Heart disease (coronary artery disease, heart failure, valve disease)
• High cholesterol
• Smoking
• Blood that easily clots
• Kidney failure
• Cocaine addiction
• Recent procedure - catheter studies

Causes of mesenteric ischemia

Acute mesenteric arterial embolism is commonly caused by a cardiogenic event and mostly affects the superior mesenteric artery (SMA).  Heart arrhythmias, heart failure, heart attack, and aneurysm, which leads to a thrombus (clot) development that subsequently embolises (dislodges and moves to a narrower portion of the vessel) to produce ischemia, are all preceding events. Atherosclerotic disease is frequent in patients with acute mesenteric artery thrombosis. 

Non-occlusive mesenteric ischaemia (NOMI) is another presentation of mesenteric ischemia that is frequently accompanied by SMA vasospasm as a result of cardiac failure, low oxygen in peripheral blood vessels, or reperfusion damage.⁵ In rare cases, NOMI can be caused by vasopressors (e.g., cocaine and norepinephrine) and ergotamines. These are drugs that promote vasoconstriction and decreased blood flow to the mesentery, which can lead to intestinal ischemia. 

Embolic patients frequently have a history of cardiovascular illness, such as a recent myocardial infarction, congestive heart failure, or atrial fibrillation. Peripheral artery emboli, heart emboli, and an atheromatous plaque burst or released following surgery are all possible causes.³

Signs and symptoms of mesenteric ischemia

The signs and symptoms manifest similarly, with moderate-to-severe colicky or continuous and poorly localised discomfort. The physical findings are out of proportion to the level of discomfort, and in the early stages, there may be minimal or no tenderness or guarding. In the latter phases, classic peritonism symptoms such as rebound guarding and pain occur. A bulk can occasionally be felt. An examination may show linked causes (for example, cardiac arrhythmia).

Therefore, the signs and symptoms can be listed below:^{1 2}

Acute mesenteric ischemia:

The following are the symptoms:

• Sudden and intense abdominal discomfort
• Urgency of bowel movement
• Fever
• Vomiting and nausea

Chronic mesenteric ischemia:

The following are the symptoms:

• Pain in the abdomen begins around 30 minutes after eating
• Pain that intensifies over the course of an hour
• Pain that subsides in 1 to 3 hours

Diagnosis

A history and physical exam are used to diagnose this disorder. Your doctor will examine your tummy and ask you about your pain. They will also inquire about any smoking history, heart problems, or excessive cholesterol. The following tests may be used to diagnose the disease:⁴

• Angiography: A long, thin tube called a catheter is placed into an artery in the groin for this examination. The catheter is subsequently inserted into the mesenteric arteries. Images are captured when a dye that shows up on X-rays is injected. Once the obstruction has been identified, therapy may be administered using a catheter.
• Computed tomography angiogram (CTA): This technique, like angiography, employs a CT scan that uses X-rays at different levels of the body directed by a computer to construct a real-time 3-D picture.  
• Magnetic resonance angiography (MRA): This exam is similar to others in that 3-D pictures are formed using a computer and magnetic forces to align the water molecules in your body, which in turn helps create a picture of the inside of your body. This procedure does not involve your body being subject to any radiation.
• Ultrasound with Doppler: This test uses sound waves to make pictures of blood arteries in order to determine whether or not blood is flowing through them.
• Blood tests: Tests that evaluate the amount of white blood cells and the acidity level in the blood may aid in the diagnosis.

Angiography is the gold standard for investigating the severity, extent, and site of blockage.

Management and treatment for mesenteric ischemia

Acute mesenteric ischaemia:³

Medical treatment

• Initial resuscitation should be performed using intravenous fluids and oxygen.
• A Nasogastric tube (feeding tube through the nose) should be placed.
• Broad-spectrum antibiotics administered intravenously are advised.
• Intravenous unfractionated heparin (blood thinner) is also advised unless contraindicated.

Surgical treatment

• Patients with apparent peritonitis should have a laparotomy as soon as possible.
• The aims of surgery include restoring blood flow to the ischemic bowel, removing any non-viable sections, and preserving all viable intestines.

Endovascular revascularisation operations may be useful in the case of partial arterial blockage.

Chronic mesenteric ischaemia:²

Smoking cessation and antiplatelet treatment are used to treat asymptomatic people. The five-year mortality rate for these individuals is 40%, with the majority of fatalities being related to myocardial infarction or cardiovascular death.

Patients with untreated symptomatic chronic mesenteric ischaemia (CMI) have a five-year death rate close to 100%. Due to this, they require a stent to be placed to keep the vessel open; this procedure is called revascularization.

Because patients are frequently malnourished at the time of diagnosis, nutrition is critical in preoperative evaluation; complete intravenous nutrition may be required both pre-and postoperatively. The best revascularisation strategy is determined based on the patient's anatomy and pre-operative status. A frequent surgical consequence is renal failure.

Complications

Acute mesenteric ischemia, if not treated immediately, can result in:¹

• Bowel injury that is irreversible; Inadequate blood supply to the gut can cause sections of it to perish.
• Sepsis: The body releases chemicals into the circulation to combat infection, which causes this potentially fatal illness. Sepsis occurs when the body overreacts to substances, causing alterations that can lead to multiple organ failure.
• Death: Both of the aforementioned consequences are potentially fatal.

Chronic mesenteric ischemia can result in:²

• Eating anxiety: This happens as a result of the condition's after-meal soreness.
• Unintentional weight loss: This can happen as a result of eating anxiety.
• Mesenteric ischemia that is both acute and chronic; Chronic mesenteric ischemia symptoms might worsen, leading to it becoming acute all of a sudden.

FAQs

How can I prevent mesenteric ischemia?

The best way to prevent this disease is by making healthy lifestyle decisions:

• No smoking
• No drugs
• Eating healthy
• Exercise regularly
• Working with your doctor to manage problems you might have, like diabetes, heart disease, high blood pressure, and high cholesterol

How common is mesenteric ischemia?

Acute mesenteric ischemia only makes up 0.2% of admissions in hospital whereas, chronic mesenteric ischaemia makes up 0.001% of admissions, therefore its is rather rare. 

Who is at risk of mesenteric ischemia?

Usually, elderly people between the ages of 50 and 70 years of age have other health conditions like high cholesterol and artery disease, along with an unhealthy lifestyle like smoke and drinking.

What can I expect if I have mesenteric ischemia?

When you have mesenteric ischaemia, you will have problems eating, usually pain after eating, diarrhoea, nausea or vomiting. You might have blood in your stools, along with generalised weakness and fatigue.

When should I see a doctor?

Seek immediate medical attention if you experience severe, abrupt stomach discomfort that lingers. Make an appointment with your healthcare provider if you experience discomfort after eating.

Summary

Mesenteric ischaemia is a condition of the bowels in which the blood supply to the bowels is compromised. This leads to that part of the bowel being deprived of oxygen and thus going towards tissue death. Due to this, one experiences pain and all the other associated symptoms like diarrhoea, nausea, vomiting, blood in stools, loss of weight, etc.

When you experience such symptoms you should go see a doctor, they will examine you and order a few tests to rule out possible causes, mesenteric ischaemia being one of them. If your doctor thinks you have mesenteric ischaemia, they will talk to you about your treatment options.

Generally, in order to deal with this condition if it is acute, your doctor will examine you. This is because you may require surgery to remove the bowel that has become rotten. When you go home, you will be on medications and a new diet to make it easier for your bowel to heal. People who have chronic ischemia, can be treated with medication only up until they are not symptomatic, when they become symptomatic they will require a procedure that places a stent to open up their vessels, so that their bowels don't become rotten.