Renal artery embolization with diluted hot contrast medium: An experimental study

PURPOSE: To evaluate the safety and efficacy of diluted hot contrast medium to embolize the renal arteries in a canine model. MATERIALS AND METHODS: Transcatheter embolization was performed in 15 dogs (five dogs in each phase: I, II, and control). The diluted hot contrast medium was heated to 90°C-100°C and 30-60 mL were injected into a renal artery of each dog in phase I (optimization studies) and II (efficacy studies). In the control group, balloon inflation was performed without injection of diluted hot contrast medium. The temperature measurement was performed on one dog in phase I by temperature probe. Follow-up angiography was performed immediately (n = 15), at 1 week (n = 9), at 1 month (n = 9), and after 3 months (n = 5). All dogs were killed and kidneys were removed for histologic examination. RESULTS: The procedure was performed successfully in all dogs. Follow-up angiography showed complete obstruction of the injected renal arteries in phases I and II. The microscopic findings showed acute full-thickness necrosis of the renal cortex and renal artery in phase I, and complete coagulative necrosis of the cortex, medulla, and intrarenal blood vessels in phase II. There were no histologic changes of renal veins, inferior vena cava (IVC), and aorta. There were nonspecific findings in the control group. CONCLUSION: This preliminary experimental study suggests that diluted hot contrast medium may be a safe agent for renal ablation without thrombus formation in the renal vein or IVC.