Thank you, Karen. I followed the link and read the story. Then, I went to the Mayo Clinic Web Site and searched for "Matthew Callstrom." I found some news stories related to his work with cryoablation. I also searched clinical trials and found at least one active study (phase II) that seems related (but maybe not identical) at:
clinicaltrials.mayo.edu/clinicaltrialdetails.cfm?trial_id=541
As I recall, the study is seeking participants who have pain that is significant and hard to control but at only one or two sites. (That is my paraphrase, not the study wording -- the real wording should be able to be found by following the link).
in haste -- mssmr