RANDOMIZED, CONTROLLED-STUDY OF VARIOUS AGENTS FOR ENDOSCOPIC INJECTION SCLEROTHERAPY OF BLEEDING CANINE GASTRIC VARICES

The purpose of this study was to compare the relative efficacy and tec hnical ease of use of eight different agents for endoscopic hemostasis and obliteration of bleeding gastric varices in a canine model, as no comparative data are available on gastric variceal sclerotherapy. Lar ge bleeding gastric varices in 20 heparinized dogs were randomized to endoscopic injection treatment with one of the following agents: cyano acrylate; a 1:1:1 mixture of sodium tetradecyl sulfate 3%, ethanol 98% , and normal saline solution; ethanolamine oleate 5%; sodium morrhuate 5%; sodium tetradecyl sulfate 1.5%; polidocanol 1%; normal saline sol ution with epinephrine 1:10,000; or normal saline solution (control). The number and volume of injections and the time required to achieve c omplete hemostasis were evaluated; follow-up endoscopy was performed a t 1 month to assess gastric variceal obliteration. Cyanoacrylate was t he best agent overall in terms of immediate efficacy, low volume requi rement, time required for initial hemostasis, and reduction of gastric variceal size. Cyanoacrylate, tetradecyl sulfate, and polidocanol wer e the most effective agents for reducing gastric variceal size. Epinep hrine was effective for controlling induced or secondary bleeding caus ed by puncture of the gastric varices with the sclerotherapy needle du ring intravariceal injections. Ongoing studies are evaluating combinat ions of agents with different mechanisms of action, such as epinephrin e (for vasoconstriction to minimize secondary bleeding) plus alcohol, and/or tetradecyl sulfate (for variceal thrombosis and sclerosis). In addition, different concentrations of alcohol as a single agent or com bined with epinephrine should be evaluated because of the relatively l ow cost and wide availability of these substances.