Second lumbar fusion or discectomy?

Just curious if anyone had advice on having a second fusion or microdiscectomy. I am a 44 yr old with a herniated disc at s-1. I had lumbar fusion in April 2008 for a herniated disc at L4-5. Now disc at S-1 is pressing on the same nerve causing pain in my back and right leg. Had epidurals with some success but not enough relief, so the pain center is reluctant to continue epidurals (they seem to last only 3-4 weeks). Just tired of hurting every day want to get back to my normally active lifestyle. My neurosurgeon wants to do the second fusion...saying I could have the microdisectomy..but since L4-5 is fused already..chances are that i will probably have to have fusion at a later date even if the microdiscectomy works for a while...but I am just not sure if thats my best choice. Thanks in advance for any advice you can share.