- OBJECTIVES: To determine effect of sympathectomy for hyperhidrosis on sympathetic skin response (SSR) during long-term follow-up. Patient satisfaction was assessed and surgical complications noted. DESIGN: Prospective, Open, Non-randomised study. MATERIALS AND METHODS: Patients who had undergone bilateral thoracoscopic sympathectomy for hyperhidrosis underwent postoperative assessment of SSRs. A 15 mA stimulus was applied over the median nerve contralateral to the sympathectomy and evoked electrodermal activity was recorded from the sympathectomised palm using a Dantec Counterpoint Mk 2. Patient satisfaction with surgery was assessed by questionnaire and visual analogue score (0-1.0). RESULTS: Of 26 patients, 21 were female. Mean (range) age was 23 (9-36) years. Mean (range) follow up was 39 (4-138) months. 12% of cases had residual or recurrent symptoms. Median (range) patient satisfaction was 0.83 (0.06-1.0). In 7/52 palms recurrent SSRs were not detected. Repeated measures analysis of variance found amplitude of SSR to be of low significance with respect to time since surgery (F = 0.48; p = 0.49) and incidence of compensatory sweating (F = 2.38; p = 0.14). CONCLUSION: Thoracoscopic sympathectomy for hyperhidrosis is an effective procedure. Following sympathectomy SSRs are not permanently abolished, but return of SSRs does not correspond with symptom recurrence. As such, SSRs are a poor tool for objective assessment of long-term outcome following sympathectomy.