balloon-occluded retrograde transvenous obliteration balloon-occluded retrograde transvenous obliteration balloon-occluded retrograde transvenous obliteration (brto) is an endovascular procedure used for the treatment of gastric varices. when performing the procedure, an interventional radiologist accesses blood vessels using a catheter, inflates a balloon (e.g. balloon occlusion) and injects a substance into the variceal blood vessels that causes blockage of those vessels. to prevent the flow of the agent out of the intended site (variceal blood vessels), a balloon is inflated during the procedure, which occludes. balloon-occluded retrograde transvenous obliterationother namesbrtospecialtyinterventional radiology medical uses brto is used for the treatment of bleeding from gastric varices. in addition to transjugular intrahepatic portosystemic shunt (tips), brto is a first line treatment for the prevention of recurrent bleeding from gastric varices (gov2 or igv1). brto may be used for the treatment of ectopic varices. complications as brto results in a blockage of a portosystemic shunt, the procedure may result in increased portal hypertension, which may worsen esophageal varices or ascites. history brto was developed as a procedure in the early 1990s. initially, the procedure was performed using ethanolamine oleate as a sclerosant. between 2006 and 2007, american physicians began using sodium tetradecyl sulfate (3% sts) as an alternative sclerosing agent.