What is Angiodysplasia?
The digestive system, also called the gastrointestinal (GI) tract, most often has various types of unusual blood vessels. These unusual blood vessels are irregularities in the standard form of the arteries, veins, or tiny blood vessels known as capillaries concerned. These irregular blood vessels can either be harmless or harmful, like in the cases of smooth, benign blood vessel tumors (hemangiomas) or malignant blood vessel tumors (angiosarcomas).
Furthermore, these blood vessel irregularities may be present from birth, such as in the case of hereditary hemorrhagic telangiectasia. Or, they can develop later in life, like in the case of angiodysplasia. Angiodysplasia refers to an abnormal, twisted, and enlarged small blood vessel located in the inner lining and layer below it (mucosal and submucosal layers) of the GI tract. These abnormal blood vessels have an inner lining of cells (endothelium) with few or no smooth muscle cells.
It’s important to mention that angiodysplasia is the most common cause of small intestine bleeding or what used to be called obscure gastrointestinal bleeding (OGIB) in people over 60 years of age. Angiodysplasia isn’t related to any genetic, skin or broader body diseases and can affect any part of the digestive system.
What Causes Angiodysplasia?
The precise cause of angiodysplasia, a condition related to abnormal blood vessels, is not entirely known. However, several possibilities are suggested in medical studies. These include age-related weakening of small blood vessels and certain heart and lung diseases. These conditions may reduce blood supply to tiny vessels, causing them to die off.
It’s also worth noting that angiodysplasia can be linked to aortic stenosis, a condition where the heart’s aortic valve narrows. Another cause that’s been mentioned is reduced blood supply to the mucus-lined tissue in the digestive system due to heart disease.
In the case of von Willebrand disease – a bleeding disorder – there have been reports of bleeding from angiodysplasia lesions in both the upper and lower parts of the digestive tract.
Risk Factors and Frequency for Angiodysplasia
Angiodysplasia, the most common blood vessel abnormality in the gastrointestinal (GI) tract, mainly affects people over 60 years old. The frequency of this condition tends to increase as people age. Some people might not experience any symptoms, while others suffer from GI bleeding. It’s responsible for non-variceal upper GI bleeding in around 5% to 10% of patients. In patients over 50, it is a leading cause of obscure GI bleeding. However, in those under 50, small bowel tumors are more commonly the cause. The most typical location of angiodysplasia in the GI tract is in the colon.
Some conditions have been found to be more commonly associated with angiodysplasia. These include end-stage kidney disease, Von Willebrand disease, issues with the left ventricular assist device, and aortic stenosis, also known as Heyde syndrome.
- In patients with end-stage kidney disease, while peptic ulcer disease is usually the primary cause of GI bleeding, angiodysplasia also contributes significantly (around 20% to 30%) to both upper and lower GI bleeding.
- For aortic stenosis (Heyde syndrome), it was first suggested in 1958 that there might be a link to GI bleeding caused by angiodysplasia. The link is still being researched, with various reports both supporting and challenging the connection.
- In systemic sclerosis, a disease that can cause changes to the blood vessels of the stomach, angiodysplasia could present as gastric antral vascular ectasia (also known as watermelon stomach). This condition affects about 5.7% of patients with systemic sclerosis.
While these associations have been observed, a direct cause and effect relationship between these diseases and angiodysplasia is yet to be established. The associations could be due to these groups of patients being more likely to undergo investigations for GI bleeding, which is common in these conditions due to other underlying causes, such as kidney disease-related blood clotting problems or issues related to aortic valve stenosis and left ventricular assist devices.
Signs and Symptoms of Angiodysplasia
Angiodysplasia is a condition that sometimes doesn’t show any symptoms, or it may cause mild to moderate unexplained lower gastrointestinal (GI) bleeding with no abdominal pain. When examining a patient’s history, doctors should consider all factors typically assessed when evaluating upper and lower GI bleeding. Some people with angiodysplasia may notice blood in their stool and may also have iron deficiency anemia due to the slow loss of blood.
During a physical examination, a patient who is stable might display signs and symptoms of anemia, like paleness or fatigue. Occasionally, a heart murmur heard during a cardiac examination can lead doctors to suspect aortic stenosis, a condition sometimes linked with angiodysplasia. Unexpected discoveries of these lesions can occur during endoscopy procedures initially performed for another reason. This condition can also cause a sudden drop in blood pressure or dizziness especially in severe or rapid instances of bleeding. While bleeding usually stops by itself, it might happen again. It’s important to note that angiodysplasia-related GI bleeding can occur anywhere in the GI tract, but is most commonly seen in the cecum (the beginning of the large intestine), rectosigmoid area (the meeting point of the rectum and sigmoid colon), the rest of the colon, small intestine, and stomach, in that order.
Testing for Angiodysplasia
Angiodysplasia is often discovered by chance during colonoscopies for colorectal cancer screening or during evaluations for sudden or chronic blood loss that could result in anemia. The initial diagnosis methods depend largely on how the bleeding presents and which part of the gastrointestinal system is likely to be the source.
Slow bleeding from the stomach or small intestine can show up as dark, tarry stools, while a source in the colon may result in bright red blood during bowel movements. One thing to be aware of is that heavy bleeding from the upper GI tract may also result in bright red blood. The patient’s vital signs are assessed to make sure they are stable. Initial tests will usually include a complete blood count, liver function tests, coagulation studies, and renal function tests. These will help assess the severity of anemia and identify any related medical conditions, such as end-stage renal disease or blood clotting disorders often seen in patients with cirrhosis.
Because angiodysplasia can occur anywhere along the GI tract, a combination of studies with endoscopy might be necessary. Both upper endoscopy (examining the upper part of the GI tract) and colonoscopies (examining the colon) are standard initial diagnostic tools. If visible during these exams, angiodysplasia will appear as small (5-10mm), flat, bright red, fern-like vessels that emerge from a central artery. These exams are estimated to diagnose angiodysplasia with about 80% sensitivity and a 90% predictive value.
If the angiodysplasia is in the small bowel and is a source of anonymous GI bleeding, it may need further investigation with wireless video capsule endoscopy or deep bowel enteroscopy, especially if the initial evaluations do not identify the source.
In cases of active bleeding, radionuclide scanning is the most sensitive radiological diagnostic tool, capable of detecting bleeding rates as low as 0.1 to 0.5 ml/min. This involves two types of nuclear scans, but the one with technetium red cells is commonly used because its longer half-life allows imaging up to 24 hours after the initial injection. However, the downsides of radionuclide scanning are that it only shows a general abdominal area of active bleeding, which may not correspond to the specific bleeding site due to the intestines’ moving nature.
CT angiography and magnetic resonance angiography are also valuable tools for further investigation if conventional methods did not identify the source of bleeding. Helical CT angiography has a sensitivity and specificity of 70% and 100%, respectively. However, it is more effective during active bleeding, with a minimum bleeding rate of 0.3 to 0.5 ml/min.
Angiography is generally needed for patients who are actively bleeding and unstable, or for those in whom the conventional diagnostic methods fail to identify the active bleeding source. Angiography requires a blood loss of 0.5 to 1 ml/min to pinpoint the active bleeding source but also offers the opportunity for therapeutic intervention simultaneously.
Intraoperative enteroscopy can be used when both an endoscopic examination and radiological investigation fail to find the source of bleeding. This involves inserting an endoscope during surgery through the mouth, rectum, or a surgical incision, and helps find the bleeding source in 60 to 88% of cases. It is rarely used and primarily chosen when an actively bleeding patient’s source has not been identified. Possible complications include perforation, tears in the lining of the abdomen, vessel tears, high blood levels of nitrogen compounds, and prolonged slow bowel movement.
Treatment Options for Angiodysplasia
Angiodysplasia, a condition affecting blood vessels, often gets diagnosed when doctors are performing an endoscopy for other reasons. The condition can present in three ways:
1. Incidental angiodysplasia: When there’s no history of bleeding in the gastrointestinal (GI) tract or unexplained iron deficiency, there’s usually no need for treatment. However, the risk of future bleeding isn’t clear.
2. Non-bleeding angiodysplasia in a patient with GI bleeding: If a patient experiences bleeding in their GI tract, but the angiodysplasia isn’t currently bleeding, treatment is usually recommended.
3. Actively bleeding angiodysplasia: If the angiodysplasia is currently bleeding, treatment typically involves the same methods used for other causes of GI bleeding such as blood transfusion or frequent monitoring of the patient’s blood count.
If a patient is unstable with active bleeding, doctors usually start with intravenous fluid immediately and might admit the patient to the intensive care unit. In this instance, doctors might decide for a surgical procedure if endoscopy or colonoscopy is not possible.
If the patient is stable, a colonoscopy or endoscopy is generally performed within 24 hours. Depending on the bleeding and the patient’s condition, various techniques can be used to treat angiodysplasia, such as argon plasma coagulation ablation, electrocoagulation, mechanical methods like endoscopic clips and band ligation, injection sclerotherapy, or other endoscopic methods.
If these methods fail, doctors may resort to angiography— a medical imaging technique to view blood vessels and organs of the body, particularly to reveal blockages or abnormalities like aneurysms in the blood vessels. The therapy involves temporary absorbable gelatin sponge, local infusion of vasopressin, or permanent embolization.
Surgical resection can be required in patients with heavy active bleeding who haven’t had success with the above methods. To decrease the chance of rebleeding, doctors often perform endoscopy, colonoscopy, or angiography before surgery.
In certain cases, drugs that inhibit the growth of blood vessels (angiogenesis inhibitors) such as thalidomide and bevacizumab have shown some success in treating angiodysplasia. However, these drugs can have serious side effects and should be used with caution.
Hormone therapy and a type of hormone therapy medication called octreotide have been explored as treatments as well, but there’s not enough evidence yet to show their effectiveness. In any case, medical professionals must make decisions based on the patient’s unique circumstances and response to previous treatments.
What else can Angiodysplasia be?
If you have angiodysplasia, a condition that affects your blood vessels, you might experience symptoms that are very similar to those of upper and lower GI (gastrointestinal) bleeding, such as blood in your stool or in your vomit. These can also be signs of unexplained iron deficiency anemia. There are many conditions that can cause the same symptoms, including:
- Peptic ulcer disease, which causes sores in your stomach lining
- Diverticulosis, a condition where small pouches form in the walls of your colon
- Various types of colitis, including ischemic colitis, inflammatory bowel disease, radiation-induced colitis, and infectious colitis
- Hemorrhoidal bleeding, which occurs when hemorrhoids (swollen veins in your lower rectum and anus) burst
- Certain cancers that affect the gastrointestinal tract, such as colon and rectal cancer.
It’s important to see your doctor if you’re experiencing any of these symptoms, as they will need to run tests in order to determine the correct diagnosis.
What to expect with Angiodysplasia
Patients with angiodysplasia, a condition where the small blood vessels in the digestive tract widen, generally have a positive outlook because the bleeding usually stops on its own. However, those with ten or more angiodysplasia lesions, or lesions larger than 10 mm, may face a more challenging outlook. These patients often have lower hemoglobin levels, which means there are fewer red blood cells to carry oxygen around the body. As a result, they may need more blood transfusions.
Possible Complications When Diagnosed with Angiodysplasia
Chronic hidden bleeding and low iron levels, resulting in anemia, are typically the major complications and first signs of symptomatic angiodysplasia. In rare instances, symptomatic angiodysplasia can cause severe bleeding that can disrupt the normal flow and supply of blood in the body.
Common complications of symptomatic angiodysplasia:
- Chronic hidden bleeding
- Iron deficiency anemia
- Severe bleeding
- Disruption to normal blood flow and supply
Preventing Angiodysplasia
Patients should be reassured in most cases when incidental angiodysplasia is discovered, as it often doesn’t cause any symptoms. Angiodysplasia is a condition where blood vessels in the digestive system enlarge, but it’s often discovered by chance and doesn’t always cause problems. The choice to treat it using endoscopy, a procedure where a long, thin tube is used to examine the inside of your body, is typically based on how the condition presents itself and whether it’s causing any gastrointestinal bleeding (bleeding from the digestive system) or unexplained iron deficiency anemia. Iron deficiency anemia is a condition where a lack of iron in the body leads to a reduced number of red blood cells, which can cause symptoms like tiredness and shortness of breath.
