Hey,
I think suvan is right, Doctor will help you and also doctor goes according to your passport name. Yes they will try to match your name on cic file but you can always explain them what happened and what is correct. I n my case my wife has her last name before marriage in passport and also cic has taken that name instead of my last name. But when I asked doctor to put my last name he said we go according to what is on passport... :

So don't waste your time and go to see doctor everything will be corrected there...

Don't worry be happy ;D