Intestinal ischaemia – Diagnostics – Overview of Information and Clinical Research

Intestinal ischaemia occurs when the blood supply to parts of the bowel becomes restricted or blocked, causing cells and tissues to become starved of oxygen. This serious condition requires prompt recognition and medical attention, as delayed treatment can lead to tissue death and life-threatening complications.

Introduction: Who Should Seek Diagnostic Testing

Anyone experiencing sudden, severe abdominal pain should seek medical attention immediately, especially if the pain seems out of proportion to physical examination findings. This is particularly important for people over 60 years of age, as intestinal ischaemia becomes more common with advancing age.^[1]^[3]

People with certain risk factors should be especially vigilant about seeking diagnostic evaluation when abdominal symptoms arise. These risk factors include irregular heart rhythms such as atrial fibrillation (a condition where the heart beats irregularly), heart failure, recent heart attacks, high blood pressure, diabetes, high cholesterol, and blood clotting disorders. Anyone who has undergone recent cardiovascular surgery or has a history of vascular disease should also consider prompt evaluation if abdominal pain develops.^[3]^[4]

For chronic forms of the condition, diagnostic evaluation is advisable when someone experiences repeated episodes of abdominal pain that occur within 30 minutes after eating and last for one to four hours. This pattern, sometimes called abdominal angina (pain in the belly similar to how chest pain relates to heart problems), often leads people to fear eating, resulting in unintended weight loss. If these symptoms sound familiar, a healthcare professional should be consulted for proper diagnostic testing.^[1]^[3]

⚠️ Important

Intestinal ischaemia is often deadly if not treated quickly. The mortality rate can reach 70% to 90% even with treatment in acute cases. Early diagnosis before permanent tissue damage occurs is the best way to improve survival, which is why seeking immediate medical care for sudden severe abdominal pain is critical, especially for older adults and those with heart or vascular conditions.

Symptoms that warrant immediate diagnostic evaluation include sudden belly pain accompanied by an urgent need to pass stool, forceful bowel movements, fever, vomiting, or blood in the stool. For chronic symptoms, repeating abdominal cramping after meals, fear of eating due to pain, unintended weight loss, diarrhoea, constipation, nausea, or bloating should prompt a visit to a healthcare provider.^[1]^[7]

Classic Diagnostic Methods

When a healthcare professional suspects intestinal ischaemia, the diagnostic journey typically begins with a thorough physical examination and review of medical history. During the examination, the doctor will check for abdominal tenderness and listen for unusual sounds in the abdomen. However, physical examination alone cannot confirm intestinal ischaemia, so additional diagnostic tests are necessary.^[6]

Blood Tests

Blood tests are usually among the first diagnostic tools employed, though they cannot diagnose intestinal ischaemia on their own. Healthcare professionals look for certain markers that might suggest the condition. A high white blood cell count can indicate infection or inflammation in the body. Laboratory tests may also reveal increased acid in the bloodstream, a condition called lactic acidosis, which occurs when tissues are not receiving enough oxygen.^[5]^[6]

Additional blood work helps assess overall health and rule out other conditions. Tests may examine liver function, kidney function, levels of inflammation markers, and blood clotting ability. These results provide healthcare professionals with a broader picture of what might be happening in the body, though they serve more to support other findings rather than definitively diagnose intestinal ischaemia.^[6]

Imaging Tests

Imaging tests allow healthcare professionals to see inside the body and are crucial for diagnosing intestinal ischaemia. These tests also help rule out other possible causes of abdominal pain. Several different imaging approaches may be used depending on the clinical situation.^[6]

Computed tomography, commonly called a CT scan, is one of the most frequently used diagnostic tools for suspected intestinal ischaemia. This test uses X-rays and computer technology to create detailed cross-sectional images of the abdomen. CT scans can reveal dilated loops of intestine with thickened walls, which are characteristic findings of ischaemic bowel. The test is particularly useful because it can be performed relatively quickly in emergency situations.^[2]^[4]

A special type of CT scan called CT angiography (CTA) provides even more detailed information about blood vessels. During this test, a contrast dye is injected into a vein, making blood vessels more visible on the images. This allows doctors to see narrowed or blocked arteries that supply blood to the intestines. CT angiography has become one of the cornerstones of modern diagnosis for intestinal ischaemia, as it can quickly identify the location and severity of blood vessel problems.^[4]^[13]

Magnetic resonance imaging (MRI) is another imaging option that uses powerful magnets and radio waves instead of X-rays to create detailed pictures of internal organs. Similar to CT, MRI can be combined with contrast dye in a procedure called magnetic resonance angiography (MRA) to visualize blood flow through vessels. While MRI provides excellent images, it takes longer to perform than CT and may not be available as quickly in emergency situations.^[6]

Plain X-rays of the abdomen may be taken as an initial screening tool. While they cannot definitively diagnose intestinal ischaemia, they can sometimes show signs of complications such as bowel obstruction or free air in the abdomen, which might indicate a bowel perforation. However, X-rays alone are not sufficient to confirm or rule out intestinal ischaemia.^[5]^[6]

Ultrasound uses sound waves to create images of internal organs. A special type called Doppler ultrasound can assess blood flow through vessels. While ultrasound is non-invasive and doesn’t use radiation, it may be less reliable than CT or MRI for diagnosing intestinal ischaemia because it can be difficult to see the mesenteric vessels clearly, especially in certain patients.^[5]^[6]

Angiography

Angiography is considered the best method for diagnosing intestinal ischaemia when it is available. During this procedure, a doctor inserts a long, thin tube called a catheter into an artery, usually in the groin or arm. A special dye is injected through the catheter, which flows into the intestinal arteries. X-rays taken during this process show the dye moving through the blood vessels, making any narrowed areas or blockages visible.^[4]^[6]

One advantage of angiography is that it serves both diagnostic and therapeutic purposes. If a blockage is found, the healthcare professional may be able to treat it immediately during the same procedure by removing a blood clot, administering medication to dissolve the clot, or using special tools to widen a narrowed artery. This dual capability makes angiography particularly valuable in managing acute intestinal ischaemia.^[6]^[8]

Endoscopic Procedures

Endoscopy involves using a flexible tube with a camera and light on its tip to view the digestive tract from the inside. For intestinal ischaemia, the scope is typically inserted through the rectum to examine the colon. When the examination focuses on the last two feet of the colon, it is called sigmoidoscopy. When the entire colon is examined, the procedure is called colonoscopy.^[6]^[8]

During these procedures, the doctor can directly visualize the intestinal lining and look for signs of ischaemia, such as inflammation, ulcers, or tissue damage. The doctor may also take small tissue samples, called biopsies, for examination under a microscope. Endoscopy is particularly useful for diagnosing ischaemia affecting the large intestine or colon.^[6]

Surgical Exploration

In some cases, particularly when intestinal ischaemia is suspected but cannot be confirmed with other tests, or when the situation is an emergency, surgery may be necessary for both diagnosis and treatment. During an operation, the surgeon can directly examine the intestines to look for areas of damage or tissue death. Opening the abdomen allows diagnosis and treatment to occur during the same procedure, which can be lifesaving when time is critical.^[6]^[8]

Sometimes a “second-look” operation is planned even after an initial surgery. This occurs when the surgeon is uncertain about whether all affected bowel tissue was removed or whether bowel of questionable health will recover. A planned return to the operating room allows the surgical team to reassess the intestines and remove any additional damaged tissue if necessary.^[12]

⚠️ Important

Some diagnostic tests for intestinal ischaemia do not always detect the problem immediately. The condition can be challenging to diagnose because symptoms often overlap with other, more common gastrointestinal disorders. This is why healthcare professionals rely on a combination of clinical judgment, medical history, risk factor assessment, and multiple diagnostic tests rather than depending on any single test result.

Diagnostics for Clinical Trial Qualification

While the sources provided do not contain specific information about diagnostic tests or criteria used to qualify patients for clinical trials studying intestinal ischaemia, the standard diagnostic methods described above would likely form the foundation of any trial enrollment process. Clinical trials typically require confirmed diagnosis through the accepted diagnostic standards discussed in this article, such as imaging studies showing reduced blood flow to the intestines or documented evidence of tissue damage consistent with ischaemia.

Prognosis and Survival Rate

Prognosis

The outlook for people with intestinal ischaemia depends heavily on how quickly the condition is diagnosed and treated, as well as which type of ischaemia is present. The chronic form of intestinal ischaemia, if left untreated, carries a very poor prognosis. Untreated symptomatic chronic mesenteric ischaemia has a 5-year mortality rate approaching 100%, which emphasizes why timely medical intervention is so critical.^[20]

For acute intestinal ischaemia, the prognosis is also serious, even when treatment is provided. The condition is often deadly because by the time symptoms become severe enough to seek emergency care, significant tissue damage may have already occurred. Several factors affect how well a patient might recover. These include how much of the intestine is affected, whether the blood flow can be restored quickly, whether any intestinal tissue has died and needs to be removed, and the patient’s overall health and presence of other medical conditions.^[3]^[9]

Patients who develop complications such as bowel death, infection spreading throughout the body (sepsis), or multiple organ failure face particularly grave outcomes. However, early diagnosis before permanent tissue damage occurs significantly improves the chances of recovery. This is why recognizing symptoms quickly and seeking immediate medical help is so important. Getting medical care early truly makes a difference in survival.^[1]^[9]

People who survive intestinal ischaemia may face long-term complications depending on how much bowel was affected or removed. Some patients may develop problems absorbing nutrients if a large portion of intestine was damaged or surgically removed, a condition called short bowel syndrome. These individuals might require long-term nutritional support, sometimes delivered through their veins. Others may develop narrowing of the intestine (strictures) at the site of healed ischaemic injury, or they may experience ongoing fear of eating due to remembered pain, leading to malnutrition.^[5]

Survival Rate

The survival rates for intestinal ischaemia vary considerably depending on the type and severity of the condition. For acute mesenteric ischaemia, which develops suddenly, mortality rates remain very high despite advances in medical care. Even with treatment, the risk of death ranges from 70% to 90% among those affected. This means that only 10% to 30% of patients survive acute mesenteric ischaemia even when they receive medical attention.^[3]^[4]

The mortality rate for all forms of intestinal ischaemia, considering different causes and severities together, ranges from 60% to 100%. This sobering statistic reflects how dangerous this condition can be. The high mortality occurs partly because intestinal ischaemia is uncommon, which can lead to delayed diagnosis. Additionally, many patients who develop the condition are already quite ill with other serious medical problems, which complicates their recovery.^[2]^[10]

Colonic ischaemia, which affects the large intestine, generally has a more favorable outlook than ischaemia affecting the small intestine. Many cases of colonic ischaemia resolve on their own within several weeks. However, about 20% of people with colonic ischaemia experience symptoms that become chronic or long-lasting rather than resolving quickly.^[21]

The timing of treatment dramatically impacts survival. When diagnosis occurs before bowel tissue dies, survival chances improve substantially. This is why healthcare professionals emphasize that recognition of acute mesenteric ischaemia before permanent tissue damage is the best way to improve patient survival. Unfortunately, the condition can be difficult to diagnose early because symptoms may initially seem similar to other, less serious abdominal problems.^[12]

#1 Clinical Trials Search in Europe