I had the Medtronics SCS for about three years and then it just sort of stopped woking. I swapped it out for the Nevro which also did nothing. The Nevro rep checked the electrode paddle and said some of the electrodes were burned out. So, I don't know if it's the unit or the electrode that was the problem. To your point regarding the pain pump... yes, it is a bit large, but you get used to it after a while and the body slowly closes tissue around it over time. You definitely want to do a trial with the pain pump. The one I did was just a shot using a catheter that was placed into the space around the spinal cord. The meds are injected and the catheter is removed and a band aid is placed on the site, I had to have two injections, as the first one did not provide any relief. So, no, there is no implanted device for the trial.