Experimental Study On Embolization Of Superior Mesenteric Artery Branches

Transcatheter aiterial embolization is accepted as a safe and effective method for treating acute bleeding from the upper gastrointestinal tract. However, it was believed that the lower gastrointestinal tract was highly susceptible to ischemic injury after embolotherapy because the lower gastrointestinal tract has not the rich and overlapping arterial supply characteristic of stomach and duodenum. So hesitancy persists using this technique below the ligament of treitz. Recently anatomic studys have demonstrated that the lower gastrointestinal tract has the rich intramural network which may protect from ischemic if the plausible location and range of vessel occlusion and the appropriate size of embolic materials were selected. But regarding these problem there is no pertinent study. Therefore we designed this experiment. Purpose: To investigate the most plausible location and range of vessel occlusion and the most appropriate size of embolic material by observing the degree of ischemic changes of the intestine after embolization of superior mesenteric arteiy branches with absorbable gelatin sponge. Materials and Methods: Twenty cases of dogs were arranged randomly into four groups, in which superselective arterial embolizaion was performed using the modified 3F microcatheter. All dogs were embolized with absorbable gelatin sponge. The distal of secondary-order branches of SMA was occluded with GEF particles 5OO拁?1 OO(4tm and 1 X 2mm in group A and B, respectively. Two and three distal of secondary-order branches of SMA was occluded individually with (3EF particles 1 X 2mm in group C and D. all the animals were scarified 2 days after procedure, the intestinal segment corresponding to the embolized artey were removed and measured, gross and pathological histological examination were carried out to evaluate bowel wall ischemic changes. Results: The embolization were successful in all dogs. The angiography shows that the intestinal segment corresponding to the embolized aiteiy was not visualized after 3 embolization. In group A, Significant mucosal destruction,, inflammatoiy cell infiltration of the mucosa and submucosa, and diffuse swelling in all layers of the intestinal wall were found in all five dogs. In group B, all the layers of the intestine were intact and did not show any ischemic changes. In group C, mild ischemic changes were found, the chief findings were congestion and edema of the mucosa and submucosa, and minor inflammatory cell infiltration, and superficial ulcer. In group 0, the iransitional ischemic changes were found, the acute hemorrhagic infraction of intestine were showed in the center of ischemic region, the bilaterial ischemic degree were showed from mild to severe. There is no significant difference in embolic range between group A and B(P>O.05 ), and there is significant difference in embolic range between group B and C, and group C and D( P