I have the exact same thing as you...wow I've never met anyone with an abdominal nerve entrapement! I had my gall bladder removed 7 years ago, therefore leaving me with a nerve entrapement in the abdominal wall at T-10. I have done trigger point injections and many radio frequency procedures. Yes, they all do wear off eventually....sometimes people get more and more relief with each one...which I did for awhile until they no longer work much at all.
I've had this pain for over 7 years and am now on oxycodone daily. They have tried to go operate on 2 separate occasions to remove/tease out the nerve. Neither surgery worked due to it being very very difficult to just remove a nerve. It looks no different than any other nerves, so it is a bit of a hit or miss. Then you worry about the possibility of more scar tissue with each surgery. It is definitely worth exploring...I just wanted to give you my feedback and what I have gone through.
I truly hope this is not the case for you! If you find someone willing to operate or any other ideas they come up with...please please please let me know! I will do the same for you...dont give up hope!! Keep me posted and hugs to you