Safety Profile of Imipenem/Cilastatin as an Embolic Agent for Intestinal Embolization: Preclinical Evaluation in a Swine Model.

PURPOSE: To evaluate the tissue effects of imipenem/cilastatin (IPM/CS) as an embolic agent on the intestine using a swine model with and without systemic heparin. MATERIALS AND METHODS: Six castrated male Landrace pigs were allocated to two equal groups based on the presence or absence of systemic heparin administration: the heparin group (n = 3) and the non-heparin group (n = 3). Transcatheter arterial embolization using IPM/CS (0.3 g / 3 mL) was performed in three nonadjacent primary branches of the mesenteric artery of the swine. Angiographic evaluations were conducted using a four-grade scale based on the findings at 1 and 3 h post-embolization. The tissue samples were collected from the area of maximum macroscopic ischemia within the perfusion territory of the embolized artery. Macroscopic and histopathological evaluations of the samples were performed. To investigate the organ-specific responses, renal embolization and evaluation were performed for comparison. RESULTS: Angiographic scores remained unchanged between 1 and 3 h post-embolization in 72.2% of all samples. Macroscopic and pathological evaluations confirmed intestinal ischemia in all samples, with comparable median grades between the non-heparin and heparin groups (macroscopic: 3 vs. 4; pathological: 3 vs. 3). In contrast, renal angiography frequently showed cortical perfusion defects; however, histological damage was minimal. CONCLUSION: Regardless of systemic heparin administration, transcatheter arterial embolization using IPM/CS causes heterogeneous intestinal ischemia in a swine model.