The most invasive treatment for hyperhidrosis is the surgical interruption of the thoracic sympathetic chain, a procedure done with the goal of permanently stopping sweating in the area innervated by the involved ganglia. Sympathectomy has been shown to be very effective for palmar sweating, but is less effective for axillary symptoms. Although now done as a minimally invasive technique using video-assisted endoscopy, the procedure is still associated with complications that lead most clinicians to reserve this procedure for patients with severe symptoms who have failed to improve with more-conservative treatment.[95,145]
History of thoracic sympathectomy
Focal hyperhidrosis was first treated by sympathectomy in the 1920s and 1930s in several European countries,[2,72] and over the next 50 years different surgical approaches were advocated. These included the supraclavicular, the posterior, the axillary transpleural, and the anterior approaches. Although high rates of palmar anhidrosis were obtainable, there were with each of these procedures some common complications, such as Horner’s syndrome (ptosis, miosis, and facial anhidrosis) and hemothorax, and specific complications, such as brachial plexus injury and poor cosmetic outcome.
Open surgery became obsolete as endoscopy was perfected. Thoracoscopes were used as early as the 1940s and 1950s to perform sympathectomy, and were popularized by Kux, said to be the father of endoscopic sympathectomy. With the advent of video-assisted endoscopy, the procedure has become increasingly popular over the last decade.
Anatomy of the sympathetic chain
Preganglionic fibers from the spinal cord synapse in sympathetic ganglia at the segment from which they arise travel up or down the sympathetic chain to synapses in other ganglia. Postganglionic fibers join peripheral nerves to innervate the sweat glands.[106,118] The sympathetic outflow to the arm originates from the T2 to T6 ganglia, and for some patients T1 fibers (from the stellate ganglion, a fusion of T1 and C8) also innervate the arms. Fibers to the face come primarily from the stellate ganglia (C8 and T1), with some contribution from T2 and T3. Resection of the stellate ganglion is more likely to cause Horner’s syndrome than resection of T2 and T3 ganglia. In addition, there is an anatomical variation—the nerve of Kuntz—seen in 10% of patients. It arises from the T2 and T3 spinal segments and bypasses the cervical chain to join the brachial plexus. The feet are innervated by L2 to L4.
To affect palmar sweating, T2 and sometimes T3 ganglia must be ablated, and for axillary sweating, at least T3 and sometimes T4 and T5(Ahn, et al., personal communication, July 2003). For plantar sweating, the L2 to L4 ganglia should be ablated, but, because sexual side effects can occur with ablation at this level, sympathectomy for plantar symptoms is rarely done.[9,106] For facial hyperhidrosis, ablation of T2 and T3 can decrease sweating, as can sympathectomy of the lower third of the stellate ganglion.[26,89]
The aim of surgery is to interrupt the transmission of nerve signals from sympathetic ganglia that send fibers to the area involved in excessive sweating. This can be done by destroying the ganglia (sympathectomy) or by dividing the sympathetic trunk, including the postganglionic fibers (sympathotomy or sympathicotomy).[10,15,72] Destruction can be done with local excision of the ganglia or by ablation using electrocautery or laser. Sympathicotomy also can be carried out with electrocautery or laser; less frequently clipping is used.[72,151] If present, the nerve of Kuntz also needs to be severed, excised, or coagulated.[55,72] When performing the procedure for palmar hyperhidrosis, many surgeons assess the adequacy of sympathetic denervation by measuring temperature with a fingertip temperature probe, observing an increase in temperature after successful sympathectomy.[94,127] Another approach is to assess microcirculation with a laser Doppler perfusion unit, expecting an increase after the correct ganglia are no longer functioning. Many centers perform same-day outpatient surgery, while others keep patients overnight and discharge them the day after.[35,72,150]