The only thing that I was ever told by my doctor was that if they helped then great and they would continue to do them. If they did not or there were other complications from the blocks then they would not do them anymore. Maybe if I had gotten significant relief there would have been a point where we discussed the long term plans...but sadly my RSD spread after my block in January and that put an abrupt stop to that. The plan though was to do a series of three with one every other week.