Long-term pulmonary function after thoracic sympathectomy

Background The purpose of this study was to evaluate the long-term and midterm effects of thoracic sympathectomy on pulmonary function and to assess the influence of the sympathetic nervous system on bronchomotor tone. Methods Thirty-seven consecutive patients were diagnosed with primary hyperhidrosis requiring thoracic sympathectomy and were included in this study. Spirometry and methacholine challenge testing were performed before and 3 months after surgery. To assess the long-term effects of the intervention, another spirometric study was performed 1 year later. Results Spirometry 3 months after surgery showed a significant decrease in the forced vital capacity (−5.2%), the forced expiratory volume in the first second (−6.1%), and the forced expiratory flow between 25% and 75% of vital capacity (−5.1%). Whereas methacholine challenge testing before surgery was positive in 3 subjects (2 of whom were asthmatic), it was positive in 6 patients after the procedure; differences were not statistically significant. After 12 months, forced vital capacity started recovering, and forced expiratory volume in the first second and forced expiratory flow rate 25% to 75% showed a sustained and significant reduction (−2.8% and −11.2%, respectively); however, patients remained asymptomatic. Conclusions We conclude that thoracic sympathectomy generates a mild, although significant, impairment of the bronchomotor tone, with no clinical consequences. These results suggest that the sympathetic nervous system is involved in pulmonary bronchomotor tone.