II. Definitions
- Gastrointestinal Angiodysplasia or Arteriovenous Malformation- Abnormal vascular structures (arteries, veins, capillaries) in the Gastrointestinal Tract
 
- Dieulafoy Vascular Malformation- Tortuous arteriole in the submucosa of the Stomach which may result in upper gastrointestinal Hemorrhage
 
III. Epidemiology
- Relatively rare cause of Gastrointestinal Bleeding
- Most common in age over 60 years- Chronic Kidney Disease may predispose to earlier onset
 
IV. Pathophysiology
- Abnormal vascular structures form in response to chronic low grade intermittent submucosal vein obstruction
- Increased Vascular Endothelial Growth Factor dependent proliferation also contrubutes
V. Types
- 
                          Upper Gastrointestinal Bleeding
                          - Responsible for 4 to 7% of non-variceal Upper Gastrointestinal Bleeding
 
- 
                          Lower Gastrointestinal Bleeding (most common)- Cecum and ascending colon (>54% of lesions)
 
VI. Causes
- Aortic Stenosis (Heyde's Syndrome)
- Von Willebrand Disease
- Chronic Renal Failure
VII. Symptoms
- Recurrent painless Gastrointestinal Bleeding
- May present as acute Gastrointestinal Bleeding or chronic Gastrointestinal Bleeding
- May present as Upper Gastrointestinal Bleeding or lower Gastrintestinal bleeding
VIII. Diagnosis: Colonoscopy
- Abnormal ectatic, dilated or tortuous blood vessels lined by endothelium (but no Smooth Muscle)
- Vessels are small (typically <10 mm)
- Abnormal vessels lie within the intestinal mucosa and submucosa
- More than one lesion is seen in 40-60% of patients
IX. Management
- See Gastrointestinal Bleeding
- See Lower Gastrointestinal Bleeding
- Treatment of nonbleading lesions is not typically recommended
- Persistent bleeding- Endoscopic argon plasma coagulation (first-line)- Associated with 7-15% recurrence rate
 
- Endoscopic direct contact thermal electrocautery and possible endoclip placement
 
- Endoscopic argon plasma coagulation (first-line)
- Longterm bleeding prevention- Lanreotide (Somatuline)- Improves Hemoglobin, and decreases hospitalizations, transfusions and endoscopies
- Frago (2018) Scand J Gastroenterol 53(12):1496-502 [PubMed]
- Chetcuti (2017) Scand J Gastroenterol 52(9): 962-8 [PubMed]
 
- Hormonal management (e.g. Ethinyl Estradiol and norethisterone)- Does not appear to decrease bleeding episodes or transfusions
- Junquera (2001) Gastroenterology 121(5): 1073-9 [PubMed]
 
 
- Lanreotide (Somatuline)
X. Course
- Self-resolves in 40-45% of cases
