Effects of thoracoscopic upper dorsal sympathicolysis for essential hyperhidrosis on bronchial responsiveness to histamine: Implications on the autonomic imbalance theory of asthma

Abstract Autonomic nervous system abnormalities in airway control may contribute to the symptoms of asthma, and even to the pathogenesis of bronchial hyperresponsiveness (BHR). Partial pulmonary sympathetic denervation by means of bilateral upper dorsal thoracoscopic D₂–D₃ sympathicolysis (TS) is an accepted treatment in severe essential hyperhidrosis (EH). The effects of this intervention on BHR are unknown. The objective of this study was to evaluate whether partial pulmonary sympathetic denervation by means of TS has an effect on BHR. Bronchial challenge tests with histamine, enabling the calculation of the provocative dose causing a 20% reduction in FEV₁ (PD_{20 His}) were performed 1 day before, and 6 weeks and 6 months after TS in 35 patients with severe EH. In nine patients (including three patients with a previous history of asthma) with pre-operative BHR (defined as PD_{20 His} < 2 mg), mean PD_{20 His} did not change significantly at 6 weeks, nor at 6 months after TS (0.62 ± 0.33, 0.71 ± 0.42 and 0.93 ± 0.65 mg, respectively) although there was a non-significant trend towards an increase in PD_{20 His} at 6 months. Three of the 26 patients (12%) without pre-operative BHR became hyperresponsive after TS, whereas 1 of the 9 patients with pre-operative BHR lost hyperresponsiveness. No patient developed asthma symptoms after TS. Upper dorsal thoracoscopic D₂–D₃ sympathicolysis performed for the treatment of EH has no significant effects on mean PD_{20 His} and individual loss (11%) or development (12%) of BHR occurs only in a minority of patients.