title: Somatostatin analogues in the treatment of recurrent bleeding from gastrointestinal vascular malformations: an overview and systematic review of prospective observational studies.
abstract: Vascular malformation of the gastrointestinal tract is an uncommon cause for gastrointestinal bleeding. Traditionally, gastroenterologists prefer to use endoscopic modalities like argon plasma coagulation and electrocoagulation to treat accessible lesions. The role of somatostatin analogues (octreotide) in preventing recurrent bleeding in these patients is unclear. The use of pharmacological treatments would be useful especially in refractory bleeding, inaccessible lesions and in patients who are at high risk for invasive interventions.
  
  
  
  To systematically review pooled clinical response rates from prospective studies using somatostatin analogues for prevention of recurrent bleeding from gastrointestinal angiodysplasia and quantify the effects that therapy has on the use of blood transfusions.
  
  
  
  We searched several electronic databases including Pubmed for full journal articles published after 1966 reporting on the use of somatostatin analogues in the treatment of gastrointestinal angiodyplasia. We hand searched the reference lists of all retrieved articles. Prospective studies involving ten or more patients were included in the analysis. We calculated the pooled proportion of patients who had a clinical response to therapy in the selected studies and the weighted mean difference in transfusion requirements before and after therapy. Heterogeneity between the studies was assessed using the I2 statistic.
  
  
  
  A total of three studies involving 62 patients met the inclusion criteria. The proportional meta-analysis showed a clinical response to treatment of 0.76 (95% CI 0.64-0.85). The weighted mean difference in transfusion requirements before starting therapy (control group) and after treatment initiation (treatment group) was -2.2 (95% CI -3.9 to -0.5). No significant heterogeneity was seen between the studies.
  
  
  
  A significant number of patients with bleeding gastrointestinal angiodysplasia respond to treatment with octreotide by reducing the need for blood products. As all the included studies had small sample sizes, multicenter randomized trials are needed to confirm these findings. However, it seems reasonable to administer octreotide especially in patients with refractory bleeding, inaccessible lesions and in patients at high risk for other interventions.
authors.affiliation: Division of Gastroenterology and Hepatology, University of Alabama, Birmingham, AL, USA.
authors.forename: Colin
authors.initials: C
authors.lastname: Brown
authors.forename: Venkataraman
authors.initials: V
authors.lastname: Subramanian
authors.forename: C Mel
authors.initials: CM
authors.lastname: Wilcox
authors.forename: Shajan
authors.initials: S
authors.lastname: Peter
mesh_terms: D016888:Angiodysplasia / Q000188:drug therapy*; D005767:Gastrointestinal Diseases / Q000188:drug therapy*; D006801:Humans; D015282:Octreotide / Q000008:administration & dosage / Q000627:therapeutic use*; D013004:Somatostatin / Q000031:analogs & derivatives* / Q000627:therapeutic use*
chemical_list: D013004:Somatostatin; D015282:Octreotide
references.citation: J Clin Gastroenterol. 1988 Oct;10(5):482-4
references.pmid: 3263407
references.citation: Am J Gastroenterol. 1995 Apr;90(4):564-7
references.pmid: 7717311
references.citation: Gastroenterology. 2001 Nov;121(5):1073-9
references.pmid: 11677198
references.citation: Gastroenterology. 2000 Jan;118(1):201-21
references.pmid: 10611170
references.citation: Dig Dis Sci. 1989 Oct;34(10):1542-6
references.pmid: 2507262
references.citation: Int Clin Psychopharmacol. 2005 Jan;20(1):49-52
references.pmid: 15602117
references.citation: Gastroenterologist. 1997 Jun;5(2):148-56
references.pmid: 9193932
references.citation: Gut. 2004 Apr;53(4):609-12
references.pmid: 15016759
references.citation: Aliment Pharmacol Ther. 1999 Nov;13(11):1429-36
references.pmid: 10571598
references.citation: BMJ. 2003 Sep 6;327(7414):557-60
references.pmid: 12958120
references.citation: Aliment Pharmacol Ther. 2007 Sep 15;26(6):935-42
references.pmid: 17767478
references.citation: Hepatology. 1995 Jan;21(1):134-9
references.pmid: 7806146
references.citation: Am J Gastroenterol. 1993 Jun;88(6):807-18
references.pmid: 8389094
references.citation: Control Clin Trials. 1986 Sep;7(3):177-88
references.pmid: 3802833
references.citation: Gastroenterology. 1977 Apr;72(4 Pt 1):650-60
references.pmid: 300063
references.citation: Dig Dis Sci. 2008 Jun;53(6):1632-5
references.pmid: 17990111
references.citation: Aliment Pharmacol Ther. 1999 Aug;13(8):1119-29
references.pmid: 10468691
references.citation: Endoscopy. 2006 Oct;38(10):1036-9
references.pmid: 17058171
references.citation: Am J Gastroenterol. 1993 Sep;88(9):1424-7
references.pmid: 8362842
references.citation: Am J Gastroenterol. 2007 Feb;102(2):254-60
references.pmid: 17311647
references.citation: Transfus Med Rev. 2003 Oct;17(4):272-86
references.pmid: 14571395
references.citation: Neurol Res. 2008 Jun;30(5):518-22
references.pmid: 18953743
references.citation: Am J Gastroenterol. 1996 Nov;91(11):2329-32
references.pmid: 8931412
references.citation: CMAJ. 2009 Apr 14;180(8):833-5
references.pmid: 19364792
references.citation: Gut. 1993 Apr;34(4):470-5
references.pmid: 8491392
references.citation: Semin Gastrointest Dis. 1999 Apr;10(2):71-7
references.pmid: 10361898
references.citation: JAMA. 2000 Apr 19;283(15):2008-12
references.pmid: 10789670
references.citation: N Engl J Med. 1996 Jan 25;334(4):246-54
references.pmid: 8532003
references.citation: Gastrointest Endosc. 2004 Feb;59(2):233-8
references.pmid: 14745397
references.citation: J Clin Gastroenterol. 1992 Sep;15(2):99-103
references.pmid: 1328358
references.citation: Can J Gastroenterol. 2006 Mar;20(3):171-8
references.pmid: 16550261