Pharmacological Therapy of Vascular Malformations of the Gastrointestinal Tract

Abstract

Vascular malformation (AVM) in the gastrointestinal tract is an uncommon, but not rare, cause of bleeding and iron deficiency anemia, especially in an aging population. While endoscopic coagulative therapy is the method of choice for controlling bleeding, a substantial number of cases require additional therapy. Adjunctive or even primary phamacotherapy may be indicated in recurrent bleeding. However, there is little evidence-based proof of efficacy for any agent. The bulk of support is derived from anecdotal reports or case series. The present review compares the outcome of AVM after no intervention, coagulative therapy or focus on pharmacological agents. Most of the literature encompasses two common AVMs, angiodysplasia and hereditary hemorrhagic telangiectasia. Similarly, the bulk of information evaluates two therapies, hormones (estrogen and progesterone) and the somatostatin analogue octreotide. Of these, the former is the only therapy evaluated in randomized trials, and the results are conflicting without clear guidelines. The latter therapy has been reported only as case reports and case series without prospective trials. In addition, other anecdotally used medications are discussed.

Angiodysplasia as a Cause of Severe Hematochezia in a Child with End-Stage Renal Failure

“…The more serious side effects are development of gallstones, hypothyroidism, kidney stones, and pancreatic enzyme deficiency. 8 The relationship between octreotide therapy and cessation of bleeding is suggestive of a therapeutic effect in our case. We propose that octreotide may have a beneficial role in controlling massive GI bleeding due to angiodysplasia whenever endoscopic therapy is not promptly available or inapplicable.…”

“…6 Many therapeutic strategies have been used in patients with angiodysplasia such as endoscopic hemostatic therapy (EHT), surgical resection, and administration of estrogens, octreotide, thalidomide, tranexamic acid, epsilon amino caproic acid, or desmopressin. 8 In adults with active hemorrhage, EHT is generally the initial form of treatment. In adults, there are numerous reports about endoscopic treatment of vascular lesions by APC 9 whereas reports about APC used for treating vascular lesions in children are limited.…”

“…11 In children with other vascular malformation of GI tract, anecdotal use of octreotide in doses ranging from 4 to 8 mcg/kg have been reported. 8 However, in pediatric population, experience with octreotide therapy for angiodysplasia is very limited. The only published report on this topic was provided by Kaya et al 12 They reported a 14-year-old boy who presented with upper GI bleeding due to large gastric angiodysplasia in whom octreotide 0.1 mg, subcutaneously, two times per day arrested bleeding within 2 weeks and the effect was maintained for the next 16 months of octreotide therapy.…”

“…This drug induces a marked reduction of portal and mesenteric blood flow mediated through inhibition of vasodilator peptides. 8 It has also anti-angiogenetic activity in vitro, which might also be relevant, because angiogenesis seems to play a role in the pathogenesis of angiodysplasia. 13 Therefore, octreotide therapy was initiated in our patient.…”

Endoscopic evaluation of gastrointestinal tract in patients with hereditary hemorrhagic telangiectasia and correlation with their genotypes

“…patients improved in as little as 2 weeks, and the effect was sustained for a mean of 33 months. 29 Forsberg et al 30 recently reported prevalence data about colonic lesions in the normal population: one or more polyps were found in 27% of individuals, whereas at least one adenoma was found in 8% of cases, and patients in whom adenoma was found were significantly older than those with a negative CS. On the basis of similar evidence previously published, "European guidelines for quality assurance in colorectal cancer screening and diagnosis" suggest fecal occult blood test for colorectal cancer screening starting from 54 years.…”