“…[ 20 ] However, when the IPS is inaccessible or it is difficult to treat the CSDAVF with TVE through the IPS route, various alternative access routes, such as the superior petrosal sinus,[ 16 ] the pterygoid plexus,[ 9 ] the facial vein (FV),[ 3 , 13 ] and the STV,[ 8 ] have been reported. The usefulness of direct puncture of the SOV,[ 2 ] FV,[ 1 , 15 ] STV,[ 11 ] and frontal vein,[ 19 ] and direct puncture of the Sylvian vein by craniotomy[ 14 ] has also been reported.…”