Angiodysplasia

Angiodysplasia is a degenerative disorder of gastrointestinal (GI) blood vessels in which abnormal connections between veins and capillaries are formed, potentially leading to upper and/or lower GI bleeding of variable severity. The precise cause of angiodysplasia is unclear, but it is often linked to von Willebrand disease, end-stage renal disease, and the use of left ventricular assist devices. Diagnosis typically involves endoscopy or imaging studies such as angiography or CT angiography. Endoscopic hemostatic therapy is the first-line treatment, supported by pharmacotherapy (e.g., octreotide, bevacizumab) if lesions are persistent or endoscopic intervention is not feasible.

• Prevalence: increases with age; predominantly affects individuals > 60 years of age ^[1]
• Small bowel angiodysplasia is the most common cause of obscure GI bleeding in individuals > 50 years of age. ^[1][2][3]

Epidemiological data refers to the US, unless otherwise specified.

• The exact cause is unclear. ^[1][2]
• Associated with:
  • Von Willebrand disease (vWD)
  • End-stage renal disease
  • Heyde syndrome; : triad of aortic stenosis, acquired vWD, and GI bleeding due to angiodysplasia ^[4]
  • Left ventricular assist devices

• Most accepted hypothesis: Low-grade intermittent obstruction of submucosal veins associated with aging and other conditions leads to the formation of angiodysplasias. ^[1]
• Lesions consist of ectatic, thin-walled vessels that contain endothelium alone or small amounts of smooth muscle. ^[1][3]
• Veins are the most commonly affected vessel, but arteriovenous and arterial changes may also occur.

Presentation and severity vary from occult to life-threatening upper or lower GI bleeding.

• Clinical features of anemia
  • Fatigue
  • Weakness
  • Dizziness
  • Shortness of breath
  • Tachycardia
  • Pallor
• Clinical features of GI bleeding
  • Melena
  • Hematemesis
  • Hematochezia

Most patients with angiodysplasias present with chronic compensated episodic bleeding.

The diagnostic approach varies according to the severity and presentation of bleeding. See “Gastrointestinal bleeding” for an initial evaluation and diagnostic approach to overt GI bleeding.

Laboratory studies ^[1][5][6]

• Diagnostics of anemia: e.g., CBC, iron studies
• Coagulation studies: e.g., von Willebrand disease diagnostics (see also “Laboratory findings in bleeding disorders”)
• Pretransfusion testing: e.g., blood type and screen, crossmatching

Endoscopy ^[1][2]

Diagnostic confirmation with endoscopy is preferred.

• Modalities
  • Esophagogastroduodenoscopy
  • Video capsule endoscopy ^[2]
  • Colonoscopy
  • Intraoperative enteroscopy ^[1]
• Findings ^[2][3]
  • Lesion characteristics
    • Vessel: flat, cherry-red, and with a fern-like pattern
    • Size: < 10 mm
    • “Pale halo” sign: a ring of pale mucosa surrounding the angiodysplastic lesion
  • The most common locations: colon, duodenum, and jejunum ^[3]
  • Approx. 40–60% of patients have ≥ 1 lesion. ^[2]

Imaging ^[1]

• Indications
  • Recurrent bleeding and inconclusive results with all other techniques
  • Endoscopy is unavailable or contraindicated.
• Modalities
  • Angiography (gold-standard test)
  • CT angiography
  • MR angiography
• Findings
  • Simultaneous arterial and early venous filling (suggests early shunting)
  • Dilated vasculature
  • Contrast extravasation at the site of active bleeding

Angiodysplasias often occur in multiple locations in the GI tract. ^[1][3]

See “Differential diagnoses of upper GI bleeding” and “Differential diagnoses of lower GI bleeding.”

The differential diagnoses listed here are not exhaustive.

General principles ^[2][5][6]

• Approach to treatment depends on the severity of bleeding; see "Treatment of GI bleeding.”
• Consult specialists early (e.g., gastroenterology, interventional radiology).
• Hemostatic treatment is indicated for patients with overt GI bleeding or complications (e.g., severe anemia).
• For incidentally found lesions and other nonbleeding lesions, treatment is generally not required. ^[1]

Spontaneous cessation of bleeding from angiodysplasia occurs in approx. 90% of cases. ^[3]

Endoscopic therapy ^[1][3]

Initial treatment with endoscopic therapy is preferred.

• Indications: symptomatic or overt GI bleeding from lesions amenable to endoscopic therapy
• Techniques
  • Argon plasma coagulation
  • Electrocoagulation
  • Clipping
  • Laser ablation

Re-bleeding occurs in up to one-third of patients with angiodysplasia despite endoscopic therapy and is more frequent in small bowel lesions. ^[2]

Pharmacological therapy ^[1][3]

• Indications include:
  • Lesions refractory to, or inaccessible via, endoscopic therapy
  • Multiple lesions
  • High risk of complications with other therapies
• Agents ^[1]
  • Somatostatin analogues (e.g., octreotide)
  • Antiangiogenics (e.g., bevacizumab, thalidomide)

Angiographic therapy ^[1][3]

• Indications include:
  • Signs of hypovolemic shock
  • Lesions refractory to, or inaccessible via, endoscopic therapy
  • Endoscopy is contraindicated. ^[1]
• Techniques
  • Embolization of the vessel
  • Vasopressin infusion

Surgical therapy ^[1][3]

Surgical therapy is reserved for patients with a clearly defined source of bleeding.

• Indications include:
  • Severe active bleeding refractory to other therapies ^[1]
  • Recurrent chronic bleeding that requires multiple blood transfusions
• Technique
  • Intraoperative enteroscopy or guided endoscopic therapy
  • Partial surgical resection

Patients with aortic stenosis and multiple angiodysplastic lesions who do not respond to standard endoscopic treatment may require aortic valve replacement. ^[1][3]