Angiodysplasia is the most common vascular anomaly of the digestive system, responsible for about 6% of lower gastrointestinal bleeding cases and up to 8% of upper gastrointestinal bleeding.
It is caused by the formation of arteriovenous malformations between previously healthy blood vessels, most commonly in the cecum and ascending colon. Its prevalence is 1-2% and it is the second most common cause of rectal bleeding in individuals over 60 years old. It is the most common cause of bleeding from the small intestine.
Angiodysplasia can be classified as acquired or congenital, such as hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome) or Heyde syndrome.
Clinical Features
The main characteristics of angiodysplasia are rectal bleeding and anemia. This usually presents in one of three ways:
- Asymptomatic – diagnosis during colonoscopy (approximately 10% of cases)
- Painless microscopic bleeding (majority of cases)
- Acute bleeding (10-15% of cases)
Since lesions can occur throughout the gastrointestinal tract, the degree of symptoms will depend on the location and severity of the dysplasia. As with most cases of gastrointestinal bleeding, lesions in the upper gastrointestinal tract are more likely to present as hematemesis or melena, while lesions in the lower gastrointestinal tract (more common in angiodysplasia) are more likely to present as hematochezia. Clinical examination findings are usually minimal.
*Elderly patients with chronic undiagnosed angiodysplasia are often anemic and may present with symptoms of fatigue, weakness, or shortness of breath.
Differential Diagnosis
The differential diagnosis for painless gastrointestinal bleeding includes esophageal varices, gastrointestinal malignancies, diverticular disease, or bleeding disorders.
Laboratory Tests
Blood tests are usually ordered as part of the routine evaluation for any patient presenting with gastrointestinal bleeding. Depending on the clinical picture, there may be a potential need for blood transfusion.
*About 10% of patients with bleeding from angiodysplasias have iron deficiency anemia.
In patients presenting with symptoms of gastrointestinal bleeding, it is important to exclude any malignancy. Patients with possible angiodysplasias are likely to undergo gastroscopy and/or colonoscopy depending on the suspected site of bleeding.
Bleeding from the small intestine is more difficult to recognize; however, capsule endoscopy (Figure 2) is the preferred method (though deep enteroscopy is an alternative), with any significant bleeding being identified and treated by administering therapeutic agents during the endoscopy.
In the case of overt angiodysplastic bleeding, mesenteric angiography may be required to confirm the location of a lesion in order to plan for surgery as needed. Angiography may involve radionuclide scanning, CT scanning, or MRI scanning to visualize the vascular supply of the gastrointestinal tract after injecting a radiopaque contrast agent into the vessels.
Management
Approximately 10% of patients with angiodysplasia will experience significant gastrointestinal bleeding, for which patients should be treated accordingly. Risk factors associated with poor outcomes include age, liver disease, presentation with hypovolemic shock, and hospitalized patients (who have nearly four times the relative mortality compared to outpatients).
Patients admitted with angiodysplasia can be managed conservatively, especially if there is minimal localized bleeding in a hemodynamically stable patient. Rest and intravenous hydration, along with possible tranexamic acid, will provide adequate management due to the self-limiting nature of the condition.
In persistent or severe cases, when signs of bleeding are identified, there are two main treatment methods: endoscopic therapy and interventional radiology (mesenteric angiography):
- Endoscopy – typically the first line of management, with the most widely used technique being endoscopic argon plasma coagulation (APC). This involves applying electric current to the blood vessel, acting as a safe, cost-effective, and successful treatment option. Other endoscopic techniques include monopolar electrocoagulation, laser therapy, sclerotherapy, and ligation.
- Mesenteric Angiography – used for lesions of the small intestine that cannot be managed endoscopically. This procedure involves super-selective catheterization and embolization of the identified bleeding vessel. Mesenteric angiography may also be indicated for gastrointestinal bleeding from any other site when endoscopic treatment has failed (for therapy or localization) or when endoscopy is not an appropriate option (for example, in patients who are not candidates for endoscopy). The sensitivity of angiography ranges from 58-86% and increases depending on the rate of bleeding from the lesion.
Surgical Management
In a minority of cases, surgery is the only option, where resection and anastomosis of the affected segment of the intestine are required to control the bleeding. Intestinal resection in patients with angiodysplasia is associated with relatively high mortality, so it should only be considered if absolutely necessary.
Indications for intestinal resection in patients with angiodysplasia include:
- Continued severe bleeding despite angiographic and endoscopic management (or when treatments are not available)
- Severe acute life-threatening gastrointestinal bleeding
- Multiple angiodysplastic lesions that cannot be treated medically
Complications
The complications of angiodysplasia are mainly related to the treatment, as re-bleeding after treatment is relatively common. Endoscopic techniques have a very low risk of bowel perforation, whereas mesenteric angiography carries risks of hematoma formation, arterial dissection, thrombosis, and intestinal ischemia.
Source: https://teachmesurgery.com/general/small-bowel/angiodysplasia/
