Scar revision surgery is very restricted in the UK for people who self harm (probably bearing in mind the rates of relapse, etc.). It is however available privately (I know BUPA do it) and your doctor might be able to make an exception (or offer you other treatment, like silicone gel) if it is particularly affecting you.
You can remove hypertrophic scars, but there will be a (smaller) scar left in it's place.
There's an
old thread here about it.