Thanks for your quick reply to my problem unfortunately i am getting no support from anyone here in australia i have phoned medtronic in sydney but they said they would discuss it with the neuro rep & get him to call me back once he had contacted my neoro surgeon it seems that i am going round in circles,the shunt i have is magnetic & is adjusted by a magnetic control unit placed on the side of your head ,it seems that my shunt is to unstable unfortunately they said they do not make a fixed valve with 2.5 setting,even trying to adjust it seems to be a problem sometimes.I will enquire about scar tissue issues. I would like to give this site 10 out of 10. Good luck to you all