Comparison of hepatic damage from direct injections of iodinated contrast agents and carbon dioxide

PURPOSE: This study guides the choice of contrast agent for localization of portal veins during transjugular intrahepatic portosystemic shunt (TIPS) p lacement or use in percutaneous transhepatic cholangiography (PTC) by provi ding gross anatomic and histologic comparison of effects from parenchymal i njections of iodinated contrast agents and carbon dioxide. MATERIALS AND METHODS: Eighteen New Zealand White rabbits received direct i njections of 2-5 mL of either the nonionic contrast agent iohexol 300 mgI o r the ionic contrast agent diatrizoate meglumine 60% into one lobe of the l iver and the same volume of CO2 into the other lobe. The rabbits were kille d at 2-7 days for gross and histologic evaluation of the livers. RESULTS: At the time of injection, the diatrizoate and iohexol sites showed persistent dark discoloration, whereas CO2 sites showed minimal visible ch anges. On gross examination at death, all diatrizoate sites showed severe s carring and also commonly showed areas of necrosis. CO2 and iohexol sites S howed only minimal discoloration and needle-puncture scars (P < .0001). The histologic grade for diatrizoate sites was significantly more severe than paired CO2 sites (P < .016). Iohexol sites showed mild histologic changes s imilar to paired CO2 sites (P = .375). CONCLUSION: Iohexol and CO2 produce less severe hepatic damage and are pref erred to meglumine diatrizoate for hepatic injection.