Sympathectomy is accomplished by burning, cutting, or clamping the nerve tissue. The clamping method, aka ESB (endoscopic sympathetic blockade) employs titanium clamps around the nerve tissue, and was developed in an attempt to make the procedure reversible. However, reversal of the clamping procedure has a short time window (a few days or weeks at most) and may be incomplete.
ETS can alter many bodily functions, including sweating , heart rate , heart stroke volume , blood pressure , thyroid , baroreflex , lung volume , pupil dilation, skin temperature, goose bumps and other aspects of the autonomic nervous system . It can diminish the body's physical reaction to exercise and/or strong emotion, and thus is considered psychiatric surgery. In rare cases sexual function or digestion may be modified as well.
http://lvhyperhidrosis.com/treatment.html