Definition and Overview
Every organ in the body, including the intestines, needs a steady supply of blood to remain healthy and function properly. The intestines receive blood from three main blood vessels called the mesentric arteries, which are composed of the superior and inferior mesenteric arteries and the celiac artery.
Like any other artery in the body, the mesenteric arteries are also prone to a variety of medical conditions that can cause them to narrow, preventing blood from passing through and reaching the intestines. When this happens, the tissues of the arteries will slowly die resulting in life-threatening conditions.
The narrowing of the intestinal arteries is a condition called intestinal ischemic syndromes, also known as mesenteric ischemic syndromes. Most conditions occur as a result of blood clots or plaque build up in the vessel walls causing a portion of the artery to narrow and significantly reduce or totally prevent blood from passing through.
Intestinal ischemic syndromes can appear suddenly (acute) or gradually develop over time (chronic). They can affect the colon and the small intestines, as such, the condition is categorized into three different types: colon ischemia, acute ischemia, and chronic ischemia. Acute intestinal ischemia usually affects the small intestines and requires immediate treatment. Chronic conditions that are still in the early stages may not require treatment, as it is possible for the condition to heal on its own by making a few lifestyle changes. However, chronic conditions that have already severely affected the intestinal tissues do require treatment that may involve surgery to remove the diseased portion of the intestine.
Although rare, another form of intestinal ischemia called mesenteric venous thrombosis involves the narrowing or blockage of the veins that deliver deoxygenated blood back to the heart. A blocked vein will result in blood flowing back to the intestine, which could then result in inflammation or bleeding. The condition can also be the cause of pancreatitis, cancer of the digestive system, blood disorders, or abdominal trauma.
Intestinal ischemic syndromes affect anybody of any age, but they are more prevalent in those above 60 years old.
Cause of Condition
The primary causes of intestinal ischemic syndromes are fat and plaque build-up on the artery wall or blood clots from the heart that has blocked at least two of the mesenteric arteries. Narrowed or blocked arteries prevent the cells from receiving oxygen, causing them to weaken and eventually die.
As more and more cells die, a portion of the intestine suffers damage. A severely damaged portion leads to infections or even a perforation of the intestinal wall. If this happens, the condition can be fatal if not treated promptly.
Colon ischemia is usually a result of a number of factors, such as cholesterol build-up in the arteries, medical disorders that affect the blood, medications that may constrict the blood vessels, use of illegal drugs, or even vigorous exercises.
Patients with intestinal ischemia will normally present a variety of symptoms depending on the exact type of the condition. Those with chronic ischemia usually experience diarrhea and abdominal pains, especially after a meal. Meanwhile, those with acute ischemia will likely to experience severe abdominal pain that manifests suddenly, diarrhea, and vomiting. Some patients have also experienced bleeding in the gastrointestinal tract. Other symptoms include fever, episodes of nausea, a bloated stomach, abdominal tenderness, and unexplained weight loss.
Who to See and Types of Treatment Available
Intestinal ischemia is a serious condition, thus, patients are encouraged to seek medical help once the symptoms mentioned above are experienced. During an initial consultation, the doctor will review the patient’s medical history, discuss the symptoms being experienced, and perform a physical examination. Several imaging tests such as CT-scan, MRI, X-ray, or ultrasound will also be performed. If the doctor begins to suspect intestinal ischemia, a magnetic resonance angiography (MRA) will also be conducted to examine the blood vessels. In some cases, a doctor may also request an arteriogram, a procedure used to examine the interior walls of the blood vessels.
Through these tests, the doctor will be able to diagnose the condition as well as assess its severity, which is the main consideration when deciding on the treatment method to be used. Early stages of intestinal ischemia may not require treatment. Making a few lifestyle changes, such as changing the diet or avoiding smoking and excessive alcohol intake, may reverse the condition.
Meanwhile, surgery will be recommended in cases where the condition has progressed and has severely affected the intestinal walls. The goal of the surgery is to remove blood clots, widen the arteries, or remove a diseased portion of the intestines.
A typical procedure used to treat this condition is called angioplasty where the doctor inserts a catheter with a balloon to the narrowed portion of the artery. The balloon is then inflated and deflated until the blockage has been cleared. To prevent the artery from collapsing and to keep it open, the stent will be placed.
If the artery is hardened and too narrow, widening it and placing a stent may no longer be beneficial. In such cases, the doctor will perform a bypass, which involves obtaining a blood vessel from other parts of the body and using it to bypass the blocked portion of the mesenteric arteries.
Treatment for chronic intestinal ischemia has a high rate of success. Most patients who undergo any form of treatment are able to recover and continue living a healthy life as long as they make some lifestyle adjustments.
Unfortunately, the same cannot be said for acute intestinal ischemia due to a high mortality rate. Statistics shows that more than 60% of acute intestinal ischemia patients eventually die from the condition. However, the primary reason for the high percentage is because many of the patients seek treatment for the condition too late. In most cases, a rather large portion of the intestinal tissue has already died, and the patient has already developed other complications.
- Hauser SC. Vascular diseases of the gastrointestinal tract. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 145.