"ESB (whether as ETS as ETSC or ELS) generally represents a substantial interference in regulatory processes of the body. Therefore decision for this operation requires that previously conservative treatments were made. An ESB is therefore at the end of a treatment history, and never at the beginning."
Dr. Christoph H. Schick, ETS surgeon, President of the International Society of Sympathetic Surgery (ISSS)
text has been translated by google from German
http://www.dhhz.de/index.php?page=8&subPage=§ion=32