Long-term cardiopulmonary function after thoracic sympathectomy: Comparison between the conventional and simplified techniques

Objective We sought to compare the long-term effects of conventional and simplified thoracic sympathectomy on cardiopulmonary function. Methods We performed a prospective and randomized study of 32 patients with diagnoses of primary hyperhidrosis who were candidates for either conventional or simplified thoracic sympathectomy. Patients were randomized according to the type of procedure: conventional thoracic sympathectomy (18 patients) and simplified thoracic sympathectomy (14 patients). Before surgical intervention, forced spirometry, body plethysmography, measurement of the diffusing capacity of the lung for carbon monoxide (Dlco), and exercise tests were carried out in all patients. These evaluations were performed again 1 year after the procedure to assess the long-term effects of sympathectomy. Results Lung function tests revealed a significant decrease in forced expiratory volume in 1 second (FEV 1 ) and forced expiratory flow between 25% and 75% of vital capacity (FEF 25%–75% ) in both groups (FEV 1 of −6.3% and FEF 25%–75% of −9.1% in the conventional thoracic sympathectomy group and FEV 1 of −3.5% and FEF 25%–75% of −12.3% in the simplified thoracic sympathectomy group). Dlco and heart rate at rest and maximal values after exercise were also significantly reduced in both groups (Dlco of −4.2%, Dlco corrected by alveolar volume of −6.1%, resting heart rate of −11.8 beats/min, and maximal heart rate of −9.5 beats/min in the conventional thoracic sympathectomy group and Dlco of −3.9%, Dlco corrected by alveolar volume of −5.2%, resting heart rate of −10.7 beats/min, and maximal heart rate of −17.6 beats/min in the simplified thoracic sympathectomy group). Airway resistance increased significantly in the group of patients undergoing conventional thoracic sympathectomy (+13%). Despite all these changes, the patients remained asymptomatic. No significant differences were found between the conventional and simplified thoracic sympathectomy groups. Conclusions Simplified and conventional thoracic sympathectomy resulted in a long-term reduction in FEV 1 , FEF 25%–75% , Dlco, and resting and maximal heart rate, as well as a mild but significant increase in airway resistance in the conventional thoracic sympathectomy group, without any clinical consequence to the patient. These changes were unrelated to the level of transection of the thoracic sympathetic chain.