A very rare possibility exists with swelling in the eyelids after ETS. This is an unusual side effect and the most likely explanation for this is the fact that the sympathectomy procedure causes vessel dilatation. As a routine we give the patient a lot of intravenous fluids in order to maintain stable cardiovascular condition. As a result of the vessel dilatation as well as the increased amount of intravenous fluids a patient can develop temporary swelling in different areas of the body. This excessive amount of fluids is eliminated over about a 24 hour period through normal body functions.