Do you know that there are long networks of blood vessels in our human body? Despite being long and extensive, blood vessels that are damaged can cause health issues. Just imagine, when the blood vessels of the heart such as the coronary artery are dysfunctional, one can have a heart attack. This shows that even the smallest little thing called a blood vessel plays a great role in the human body. In this DoctorOnCall’s article, we will learn about chronic mesenteric ischemia, a condition where blood vessels are affected.
Before we go further on, you might want to understand more on mesenteric which is the structure affected by chronic mesenteric ischemia. Mesentery is the continuous set of tissue attached to the intestine of the abdominal wall. Mesentery also contains lymph nodes that regulate immune response. It also contains blood vessels and nerves that supply the intestines. There are 3 major mesenteric arteries that supply small and large intestines known as the celiac trunk, superior mesenteric artery and the inferior mesenteric artery.
When we talk about chronic mesenteric ischemia, we have to know that before a condition becomes chronic, there is usually a phase known as acute. Acute mesenteric ischemia is the interruption of the blood flow to the intestine. Ischemia in general is a condition where there is inadequate blood supply to an organ, which results in the organ unable to have sufficient blood and oxygen to function well. It can be caused by thrombosis, embolism or a low-flow state. These causes lead to inflammation that eventually causes ischemia to the intestine. Early symptoms for acute mesenteric ischemia is the severe abdominal pain. Patients may also have diarrhoea, bloody stool, bloating and history of postprandial pain (discomfort or pain after eating). The biggest differences between acute and chronic mesenteric ischemia is the pain in acute one is often described as “pain out of proportion to physical examination”.
Now, what is chronic mesenteric ischemia? Chronic mesenteric ischemia is the continuous low blood flow to the small intestine. It is also known as intestinal angina. Most cases are caused by atherosclerosis of the mesenteric vessels. This atherosclerosis typically refers to the narrowing of the celiac or superior mesenteric arteries. Mesenteric artery stenosis is common in almost 10% of those aged 65 years old and above. Despite this, the occurrence of chronic mesenteric ischemia is only responsible for less than 1 in 1000 hospitalisation due to abdominal pain. This makes this condition rare one. Most patients with chronic mesenteric ischemia are around the age of 50 to 70 years old and with history or evidence of atherosclerotic disease.
Symptoms for chronic mesenteric ischemia is often the abdominal pain that is vague, making it difficult to be diagnosed as it can be confused with other common causes of abdominal pain. The two common signs for chronic mesenteric ischemia are postprandial abdominal pain and weight loss. Abdominal pain starts around 15 to 30 minutes after a person has a meal. This abdominal pain can last up to 30 minutes. The pain will become dull as the obstructive progress. Weight loss is the result of the nutrition issue of malabsorption and low calorie intake. The nutrition issue is caused by the constant fear of abdominal pain that occurs after eating. Less specific symptoms are nausea, vomiting, diarrhoea, constipation and inability to eat a full meal or feeling full after only eating a small amount of food (early satiety). Patients with chronic mesenteric ischemia often have symptoms associated with atherosclerotic disease such as lower extremity claudication, angina or transient ischemic attacks/cerebrovascular accidents. Symptoms in general are only presented when there are two or three of the major mesenteric vessels affected.
Diagnosis is made with medical history and physical examination. History of weight loss, malnutrition and atherosclerotic disease should be indicative of chronic mesenteric ischemia on top of the abdominal pain. Physical examination may reveal abdominal tenderness and abdominal bruit apart from the atherosclerotic symptoms. Tests such as blood tests and imaging tests usually are needed to confirm diagnosis. Blood tests often show anaemia, low white blood cell count (leukopenia), electrolyte imbalances, low albumin and blood clotting issues. Imaging tests can be ultrasound and angiography. Computed tomography angiography (CTA) is the preferred imaging test to identify the condition.
Treatment for chronic mesenteric ischemia depends on the patient’s general condition. Those without symptoms are advised to stop smoking and prescribed with antiplatelet therapy. Surgery is often recommended in severe cases such as symptoms that persist more than 2 weeks, signs of peritonitis, massive gut bleeding and chronic malabsorption. Endovascular revascularization is the preferred initial surgery as it is less invasive with few complications.
Most patients with chronic mesenteric ischemia can be expected to have a poor quality of life. Beside the weight loss caused by the constant fear of abdominal pain, the malnutrition issue will lead to other problems such as metabolic and endocrine problems. Patients that have symptoms and go untreated may have an even higher risk for death in 5 years time compared to those who are treated and have no symptoms.
