Superselective mesenteric embolization with microcoils in a porcine model

PURPOSE: There is a lack of data regarding the degree of ischemic change that may occur in small and large bowel after superselective arterial embolotherapy with platinum microcoils. The purpose of this study, was to gain a clearer understanding of the ischemic complications of superselective embolization of peripheral mesenteric arteries with microcoils by gross and histologic examination of postembolectomy bowel specimens at several time intervals in an adult porcine model. METHODS: Two-millimeter platinum microcoils with fibrils were superselectively deployed into six isolated mesenteric branch vessels in each of nine adult pigs. The animals were observed for two days (n = 3), one month (n = 3), or three months (n = 3) and then killed. At necropsy, intestines were examined for gross abnormalities. Sections of bowel containing microcoils were identified under fluoroscopy, resected, and evaluated histologically. RESULTS: A total of 54 microcoils were deployed into the distal arterial mesentery supplying the jejunum (n = 14), ileum (n = 26), and colon (n = 14) of nine adult pigs. Each animal received six microcoils. There were no clinical complications, and all pigs gained weight during their observation periods. Gross examination of the intestines did not reveal any evidence of acute or chronic ischemia. The coils were found in the distal arterial vasculature of the intestine. Histologic examination revealed mild superficial necrosis of villous tips in several samples; however, this finding is likely related to a fixation artifact rather than ischemic injury. There was no other histologic evidence suggestive of ischemic injury. CONCLUSIONS: Gross and histologic findings after superselective arterial embolotherapy demonstrated minimal changes in the bowel, and there were no significant clinical consequences to the animals. We conclude that transcatheter arterial embolotherapy in pigs is safe and may be applicable in the control of massive lower gastrointestinal hemorrhage in humans.