Ask Dr. Z

"Patient with hepatocellular carcinoma in for Y90 mapping. Microcatheter was advanced into right hepatic artery, arteriogram performed demonstrated a hyperenhancing mass in the inferior right hepatic lobe. A Dyna CT was then performed demonstrating a small branch of the right hepatic artery supplying the mass in addition to a major branch of the right hepatic artery supplying the majority of the mass. Microcatheter was used to select the small right hepatic artery branch and particle embolization using 100 to 300 um Embospheres was performed to near stasis. Post embolization arteriography demonstrated markedly decreased flow into the target. At this point, the microcatheter was retracted and a total of 2 mL of MAA were slowly injected into the right hepatic artery."

Is 37242 appropriate for the embolization since this was prior to Y90, or is 37243 more appropriate since he states this was a feeding vessel? I'm confused if this is to be interpreted as prophylactic embolization.