Somatostatin Analogues in the Treatment of Recurrent Bleeding from Gastrointestinal Vascular Malformations: An Overview and Systematic Review of Prospective Observational Studies

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 I (2) 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.