I am looking for a doctor who has experience with a blood clot in a 13 year old boy's left vertebral artery, which has already c

The 13 year old  child is a cousin of mine who lives in the UK and they have said they won't operate there because it's too risky on children. However, the risk of leaving it is that he can have another stroke at any time - so I am trying to find someone to treat him here in the U.S.

Thank you.