If a loaded gun is held to your head, and someone intervenes so that your brains aren’t blown out, does that intervention “involve the blood supply to the brain”? I suppose it does “in the broader sense” ...
The way it was explained to me by the specialists was that the purpose of the intervention, and the way in which the intervention was carried out, was to avoid interference with the blood supply to the brain. That makes pretty good sense to me.
The advice to me was that if there had been no intervention or the intervention had gone wrong, lots of bad things could have happened. Fortunately, the advice to me was the intervention on 23 August was a success, confirmed by a subsequent dynamic CTA on 9 November and intravenous DSA on 30 November.
But I get it that even amateurs like you know better.