Studies on Endoscopic Sclerotherapy Preparations for Esophageal Varices: Monoethanolamine Oleate Injection Containing Iomeprol

Monoethanolamine oleate injection containing 50% Iopamiron 370 (50% IP370-EO) has been previously prepared for endoscopic sclerotherapy of esophageal varices on X-ray TV monitor. However, the dischargeable pressure of this sclerosing agent was slightly insufficient during clinical use. We therefore prepared monoethanolamine oleate injection containing 50% Iomeron 350 (50% IM350-EO) or 75% Iomeron 350 (75%IM350-EO), and measured the physical characteristics such as viscosity and osmotic pressure of this agent. The time required to discharge a given volume of each agent through a syringe, a tube and a puncture needle under the pressure of 2kg/2.6cm2 was measured. The ability to visualize this process was observed in patients with esophageal varices by X-ray. The viscosity, which was inversely related to the injectability into varices, of 50% IM 350-EO was lower than that of 50% IP370-EO. The viscosity of 75% IM350-EO was also lower than that of 75% IP370-EO. The osmotic pressure ratio of 50% IM350-EO and 75% IM350-EO were lower than those of 50% IP370-EO and 75% IP370-EO, respectively. The time required to discharge 50% IM350-EO was the shortest. Good fluoroscopic visualization was obtained in all preparations. Better contrast was obtained in the cardiac zone with 75% IM350-EO than with 75% IP370-EO. These results suggest that 50% IM350-EO and 75% IM350-EO are more useful agents for endoscopic sclerotherapy of esophageal varices.