Wikipedia
Sympathicolysis is a procedure for temporary or long-term elimination of sympathetic innervation. It is used to improve blood circulation in the legs or arms. The sympathetic nervous system causes the balance of the autonomic system to lean towards narrowing of blood vessels, with elimination of its function resulting in vasodilatation. Completely blocked arteries are not opened again, but the collaterals are better supplied with blood.
To improve the blood circulation to the upper extremities, an anesthetic block of the stellate ganglion is performed. Due to this blockage, in addition to vasodilatation, in the entire innervation area this leads to reduced sweating ( anhidrosis) and Horner's syndrome. The latter is a sign of successful blockade. A temporary blockade of the stellate ganglion is performed for e.g. the treatment of advanced complex regional pain syndrome. Surgical elimination of the stellate ganglion ( sympathectomy) is a treatment of last resort for Raynaud's disease.
The sympathetic plexus can also be blocked in other parts of the body. Lying on the major abdominal vessels sympathetic plexus may, for example, under local anesthesia guided by a CT scan it can be turned off by injection of concentrated alcohol ( interventional radiology).