Endoscopic thoracic sympathectomy or ETS is a mechanical solution to a physiological / genetic problem. With this type of procedure clamps are applied on the sympathetic chain which causes cessation of sweating in the hands. Having said that the body needs some time to adjust this change. The impact of doing of ETS and ELS at the same time might produce physiological changes in the body that will be difficult to tolerate. This is why a decision was made to wait at least 4 months between these two operations. The surgeon can also monitor your reaction and make the best determination on the next procedure.