I am not an expert, but a dermatologist was doing a workshop at the women's center here and I attended it.
My information is from her, plus I've never known anyone to get rid of stretch marks.
As to your scar, as I understand it, if the scar is wide, they can narrow it, but if it is a slice-mark, then all they would be doing is slicing into you to close the slice. Doesn't make sense. Do you see what I'm saying?
They can also do dermabrasion on things like acne scars and stretch marks, but the results on stretch marks are not too good.