I agree with Juliemn about going under GA, I personnally think sooner treatment the better but it really depends on the doctor and how agressive they are. No child wants to go thru what I have. If you do early intervtion your son can live a normal life if removed if not completely it will prevent less problems in the future. I can not for say if it would be it really depends on how deep and darkness of the PWS.
Always remember if you do not like the answer you get from the doctor you can always get a third opinion. I have many for my PWS in my life as technology gets better and the V-Beam Pulse Dye Laser is safe for infants and I have used it and I recommend it.
Hope this helps.