Hemorrhagic angiodysplasia of the digestive tract: pathogenesis, diagnosis, and management.

GI angiodysplasia (GIA) is an acquired vascular superficial lesion, which presents typically as a bright red, irregular, round, slightly elevated lesion. GIAs are often seen in patients aged >60 years and are mostly located in the colon (cecum and ascending colon). The cause and mechanisms of GIA have yet to be completely understood. Small-bowel GIAs often are diagnosed in the setting of obscure GI bleeding. In some cases, GIAs are associated with aortic stenosis, von Willebrand’s disease, chronic renal disease, and liver disease. Endoscopic examinations are used as first-line diagnostic examinations. Video capsule endoscopy (VCE) is useful in patients with persistent obscure GI bleeding with negative gastroscopy and colonoscopy results. Enteroscopy also is used because it has cleansing and therapeutic abilities. Imaging techniques may be useful for diagnostic purposes, in cases of active overt GIA-related bleeding. Argon plasma coagulation (APC) is the reference standard treatment measure. Bipolar electrocautery probes seem to have similar efficacy. Endoclips and cryotherapy also may be used. As far as pharmacologic treatment is concerned, hormonal therapy has been tested, but studies are inconclusive. Somatostatin analogues such as octreotide may be useful in patients with chronic GIA-related bleeding when endoscopic treatment has failed. Anti-angiogenic drugs (thalidomide, lenalidomide) are being tested and seem promising. Percutaneous embolization is best suited for cases of active bleeding, if prior endoscopic treatment has failed. In summary, GIA is the most common vascular malformation of the digestive tract. Endoscopy is the cornerstone