Yes, EXCISIONS is a Scrabble word!

Letter values in Scrabble US: E 1, X 8, C 3, I 1, S 1, I 1, O 1, N 1, S 1.

Is it a valid word?

EXCISIONS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

the omission that is made when an editorial change shortens a written passage
surgical removal of a body part or tissue
the act of banishing a member of a church from the communion of believers and the privileges of the church; cutting a person off from a religious society
the act of pulling up or out; uprooting; cutting off from existence

Also: cutting out.