Speaking alongside her partner Michael Douglas, she added: “I’m OK. It’s been up and down, obviously. We’ve been through a lot, yes.”
She said she expected to spend about nine days in hospital after the operation.
She told followers: “I don’t want you to worry about me. I’m doing that enough.
“But I’m not worrying too much and I am in a good space. I have all the faith in the world in my surgeon and his team, and I am handing the reins over to him.
“He knows what he’s doing, and I’m going to do the getting better bit after. I’ll see you on the other side.”
Douglas said he would temporarily take over her social media, and posted a message alongside her video on her Instagram account on Friday.
“Hey everyone. Michael here. @davinamccall will be ‘off grid’ for a bit while she recovers from this brain operation.
“She is in great shape and in very good hands. I’ll I do the odd update from her account here for anyone interested.
“I’m sure she’ll read all the comments when she’s able to so feel free to send love. The support of people is amazingly powerful. Have a great day everyone.”