The term sympathectomy implies destruction or excision (resection) of the ganglion. Any nerve fibers entering or exiting the ganglion, horizontally or vertically, as well as the nerve cells contained in the ganglion are eliminated, thus guaranteeing that nervous signals crossing the ganglion are definitively blocked. A spontaneous regeneration of the ganglion is not possible. The connections of the ganglion should be severed with cutting current in order to prevent neuroma formation.
A critical evaluation of most of the methods used to treat palmar hyperhidrosis surgically in the past 25 years has ended up with a clearcut preference for a few over others. The evaluation is not necessarily based on controlled studies, not performable in most cases, but on common sense and analysis of clinical results. Surgery to treat palmar hyperhidrosis has traditionally been performed by dividing the sympathetic chain over the 2nd and 3rd rib. Calling this method a "T2-Sympathectomy" is actually a misnomer, because it left the T2 ganglion intact, transecting only the interganglionic segments above and beneath the T2 ganglion. This procedure is still used by many surgeons around the planet to treat handsweat. In the author's opinion, based on years of experience with all methods used in the past 25 years, it has a series of shortcomings:
Versus the end of the 90ies, surgeons began to search for a method to reduce the frequency of unfavorable outcome, especially compensatory hyperhidrosis: a minority of patients, reacting in an abnormal way to T2-ETS, ended up with severe compensatory sweating. A small number seemed to have their thermoregulatory system seriously impaired. In the late 90ies, Prof. Lin (Taipeh) introduced the potentially reversible clamping method, using titanium clips.
Around the millennium shift, Prof. Lin (Taipeh) discovered that a T4 approach had the same success rate on palmar hyperhidrosis as T2 surgery, but did produce almost no compensatory sweating. When we however tried to reproduce his method, it did not deliver the same results. We found out that eliminating the T4 ganglion did have some effect, but in many cases not a sufficient one, and sometimes the outcome was assymmetrical. Further investigations showed that the reason for this discrepancy was the fact, that blocking the sympathetic chain at the level of the 4th rib (applying clips above and below), in reality did in most cases squeeze the T3 ganglion, but left the T4 ganglion unharmed.
These observations put the base for the T3 method, representing a good compromise to optimize the relationship between desired and undesired effects. Several authors have reported and most surgeons using this technique have found evidence for a significant decrease of heavy compensatory hyperhidrosis, along with very good long-term results. Therefore, the author advocates methods to neutralize/interrupt/block the nerve fibers crossing the T3 ganglion, avoiding the adjacent ganglia and any interruption higher than the lower edge of the T2 ganglion.