“…3,5,8 However, in some cases, the procedure is not as straightforward as expected because of difficulties in catheterizing the OA or because angiographic visualization of the OA fails altogether. 5,[7][8][9] Two alternative techniques have been previously proposed in such cases: The first one involves the superselective catheterization of the middle meningeal artery (MMA), provided that an anastomosis between this vessel and the OA allows an acceptable choroidal blush; the second one is to just reapply the balloon technique to the ICA. 5,9 Failure to catheterize or infuse the OA can be a temporary occurrence, and the procedure can be successfully performed sometime later 8 ; on the other hand, a successful procedure through the OA on 1 or Ͼ1 occasion does not guarantee the same achievement in the following scheduled sessions of IAC.…”