Himself actually got to see his consultant today - upshot is they are going to monitor his head through regular angiograms. If it re-fills too much then they will insert coils around the thing that is already in there. The consultant actually congratulated him on not being dead and for getting through the surgery/recovery without any obvious side effects :)
Thanks all, I've been so worried that they would just say 'sorry, but you're f***ed', hardly slept last night. Going to have a lovely sleep tonight, but shall still be watching him like a hawk, xxx