Transitional Vertebrae L5-s1

My last MRI has a diagnosis of a moderate degree of degenerative change seen at the L5_si disc with narrowing of the disc,.  marginal spurring, and a mild to moderate degree of diffuse disc bulging at this level.  In the past I have good results with nerve blocks, giving me relief for years.  I have just finished around of nerve blocks with only 3 mos of relief.  My pain management doctor is suggesting a procedure where they would  seal the nerve.  He said there is a medicine I would take before hand to see if  this procedure would work for me.  Any information would be helpful.

[squirtatious]

What is the procedure called?