Thoracoscopic sympathicolysis for essential hyperhidrosis: effects on pulmonary function.

Bilateral interruption of the upper dorsal sympathetic chain at the D2 and D3 level represents the only permanent cure for essential hyperhidrosis. Following surgical sympathectomy, significant and symptomatic changes in pulmonary function have been observed. Since functional effects of the surgical intervention cannot be excluded, we wondered whether such alterations also occurred after thoracoscopic sympathicolysis; these should then be attributable to the surgical denervation itself. Pulmonary function tests (PFTs), including spirometry and body plethysmographic measurement of lung volumes and airway resistance and conductance, were compared before and 6 weeks after thoracoscopic sympathicolysis in 47 patients. In order to virtually exclude any effects of thoracoscopy on the test results PFTs were repeated 6 months after thoracoscopic sympathicolysis in 35 patients. Essential hyperhidrosis was completely relieved in all patients, thereby confirming the interruption of the D2-D3 sympathetic chain. None of the patients developed respiratory symptoms after thoracoscopic sympathicolysis. Forced expiratory volume in one second (FEV1) (-3%), forced expiratory flow after exhaling 75% of vital capacity (FEF75) (-8%) and total lung capacity (TLC) (-3%) were slightly but significantly reduced at six weeks after thoracoscopic sympathicolysis; whereas airway resistance (Raw) had increased (+12%). After correction for the small decrease in lung volume (FEV1/forced vital capacity (FVC), specific airway resistance (sRaw), specific airway conductance (sGaw))significant changes in "volume-dependent" PFT parameters were no longer observed. Smoking status had no influence on the reduction in FEF75. At 6 months after thoracoscopic sympathicolysis, TLC had returned to preoperative values, whereas FEF75 remained decreased (-8.6%). The decrease in airway calibre was confirmed by small but significant changes in FEV1/FVC (-2%) and Raw (+29%). We conclude that thoracoscopic sympathicolysis in patients with essential hyperhidrosis causes only minimal and subclinical changes in pulmonary function secondary to a temporary small decrease in lung volume, which in turn is probably inherent to the thoracoscopic procedure. D2-D3 sympathicolysis, in itself, is responsible only for a small and permanent decrease in forced expiratory flow, which suggests that, at least in essential hyperhidrosis patients, airway bronchomotor tone is influenced by sympathetic innervation.