Angiodysplasia epidemiology and demographics
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief:
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Overview
Epidemiology and Demographics
AD is the most common vascular malformation of the GI tract in the general population.
United States statistics
The incidence of colonic diverticular and angiodysplasia bleeding per 100 000 person-years increased over time. Recent recorded drug intake showed an increased frequency of anticoagulants with colonic diverticular and angiodysplasia bleeding, whereas NSAID and low-dose aspirin use were more prevalent in peptic ulcer bleeding and colonic diverticular bleeding, respectively.
The prevalence of angiodysplasia is 0.8% in healthy patients older than 50 years who are undergoing screening colonoscopy.
Foutch et al noted the prevalence of angiodysplasia to be 0.83% from 3 prospective studies in which screening colonoscopies were performed in 964 asymptomatic individuals (mean age, 62 y). Angiodysplasia is the most common reason (50%) for occult GI bleeding. The pooled completion rate was 84%. The pooled retention rates were approximately 2%.
Angiodysplasia accounts for 20-30% of GI bleeding episodes in patients with end-stage renal disease and up to 50% of recurrent GI bleeding in this patient population. Patients with Von Willebrand disease may have an increased incidence of GI bleeding from colonic angiodysplasia.
International statistics
No widespread studies to determine the international incidence of angiodysplasia have been conducted, but the incidence probably is similar to that in the United States.
Colonic angiodysplasia in Japanese patients is predominantly located in the left colon, whereas in Western patients it is mainly located in the right colon.
The percentage of colonic lesions with a size of more than 5 mm or elevated type detected in Japanese patients was significantly higher than in Western patients.
No racial predilection exists in cases of angiodysplasia of the colon.
Angiodysplasia of the colon occurs with equal frequency in men and women.
Most patients found to have angiodysplasia are older than 60 years; of these patients, most are older than 70 years. However, case reports exist of occurrence in young people.
Location wise statistics:
Upper GI tract
AD is reportedly the cause in 4–7% of patients presenting with nonvariceal upper GI bleeding. In the largest study, 676 patients underwent endoscopy for suspected UGIB over a 40‐month period. AD was found in 4% of patients, of whom 77% had experienced at least one episode of overt upper GI bleeding (hematemesis or melena) and the rest had features of occult GI bleeding. Multiple lesions were found in 63% of cases and colonic AD was detected 50% of those who had a colonoscopy performed.
Small bowel
In patients under 50 years of age with obscure GI bleeding (OGIB), small bowel tumors are commonly identified as the cause in 5–7%. However, in patients older than 50 years, the source is likely to be small bowel AD.
Liao et al. performed a systematic review of all original articles relevant to wireless capsule endoscopy (WCE) for the evaluation of patients with small bowel signs and symptoms published between 2000 and 2008. A total of 227 studies involving 22 840 procedures were included. OGIB (overt and occult) was the most common indication (66.0%) and AD was the most common cause (50.0%) of bleeding in those patients. In another study, small bowel AD lesions were the most common cause of severe life‐threatening overt OGIB.
Colon
The colon is the most frequent site of AD in the GI tract. In western patients, lesions are predominantly located in the caecum and ascending colon (54–81.9%), while lesions diagnosed in Japanese patients are more likely to be in the descending colon (41.7%). The prevalence of colonic AD in healthy asymptomatic adults was estimated to be 0.83% and none of these individuals developed bleeding over a mean follow‐up duration of 3 years.
Therefore, treatment of nonbleeding lesions is generally not recommended. The frequency of colonic AD as a cause of lower GI haemorrhage varies between 3% and 40%. Bleeding from colonic AD can be mild, chronic, recurrent and can stop spontaneously in up to 90% of patients; nonetheless, it can also be life threatening.
Approximately 40–60% of patients with upper or lower GI AD have more than one lesion and 27% of patients with colonic AD had multiple lesions involving two or more segments of the large bowel.28 Moreover, while AD is usually present in the same part of the GI tract, synchronous lesions elsewhere can occur in approximately 20% of patients.
These findings suggest that local factors may be important in the pathogenesis of nonhereditary AD. It also highlights the importance of evaluating both the upper and lower GI tract in patients with symptomatic AD. AD can only be confidently diagnosed as the cause of blood loss if it was actively bleeding at the time of endoscopy.