Ask Dr. Z

Our physician on one day embolized (with glue) the left MMA and the left occipital artery for an "infratentorial torcula AV fistula".  He noted that there was "persistent feeding from the right MMA and occipital arteries". Then, two days later, he went back in and embolized the right posterior branch of the distal MMA. Would I use 61624/75894 (75898 if done) and catheter placements the first day and then on day 3 for the second embolization use a -76 modifier on all my other codes since he repeated it? Or since it was "staged" do I use a different modifier? Or do I use no modifiers at all? Since he actually embolized a different artery (but for same fistula) would it even be considered a repeat embolization?