Wow, it tells you something when you Google one word and only get
72 hits.
... and I wonder further when I don't find it mentioned at the big medical sites like webmd.com... and there's not even a definition of it in the dictionary.
... so maybe a new thing, this esclerotherapy? Is your doctor recommending someone who specializes in it?
Being that there is so little to be found about it, I'd be leery - unless the option is being recommended to you by someone you trust deeply.