Effects of Sclerosing Agents on the Local Blood Flow of the Mesenteric Vein in Rabbits

Abstract

Abstract: To investigate the pathophysiology of scleroembolization as a treatment for esophageal varices, studies were made of the effects of the intravenous administration of Aethoxysklerol (AS), Ethanolamine Oleate (EO), ethanol and thrombin on the local blood flow of the mesenteric vein, the systemic hemodynamics and thrombus formation in blood vessels in rabbits.The dosages and concentrations of Aethoxysklerol used were from 0.5 to 2 ml and from 0.5% to 2%, respectively. This was done to ascertain the possible relationships of these variances of Aethoxysklerol on the local blood flow in vessels with a low‐flow and a high‐flow.99% ethanol, 50 U thrombin and 5% Ethanolamine Oleate were also administered into low‐flow and high‐flow vessels in doses of 0.5 ml and 1 ml, respectively.The increase in AS concentration from 0.5% to 2% caused no remarkable changes in the degree of blood flow inhibition in vessels with either a low‐or a high‐flow, but the time required for inhibition was 45–50 min in vessels with a high flow, which was longer than the 25 min necessary in vessels with a low‐flow. The increase in AS dosage from 0.5 to 2 ml was negligible for enhancing the inhibitory effect of the drug upon the blood flow, but the blood flow inhibition was significantly increased in the low‐flow vessels compared with the high‐flow vessels even when the AS was administered in the same volume and concentrations.The AS‐induced changes on the systemic blood pressure were minimal even with high dosages and high concentrations.99% ethanol and thrombin were less effective in blood flow inhibition in both the low‐and the high‐flow vessels. 5% Ethanolamine Oleate when administered in a volume of either 0.5 ml or 1 ml significantly inhibited the flow in the low‐flow vessels as compared to the flow in the high‐flow vessles.On the other hand, when AS was administered with thrombin, the inhibitory effects were accelerated to 88±26% in the low flow vessels and 44±16% in the high‐flow vessels as compared with administration of AS alone in both the low‐flow and the high‐flow vessels, respectively.We concluded that the embolizing effect of AS alone is rather weak, although it is a relatively safe drug. We consider it wise to combine it with thrombin.