Reply by the Authors of the Original Article

First of all, thank you for providing the opportunity to respond to the letter entitled “Achievements of Unilateral Sympathectomy.” Also, we want to thank the authors for their valuable comments on the subject of unilateral sympathectomy for palmar hyperhidrosis.

After performance of dominant side sympathectomy on 52 patients with primary palmar hyperhidrosis, only 7 patients (13.4%) needed a contralateral surgery in our study.[1] It was concluded that if the stress caused by impairment in social relationships due to oversweating of dominant hand is reduced, the symptoms in nondominant hand start to disappear or alleviate. Similar findings had been shown by Wolosker et al when video-assisted thoracoscopic sympathectomy for palmar hyperhidrosis resulted in great alleviation of plantar hyperhidrosis in more than 80% of patients immediately and in 60% of patients during 1-year follow-up without any anatomical and physiological explanation. They attributed this alleviation to the reduction in emotional stress, which can lower the sympathetic nervous stimuli to the feet and break the negative feedback.[2]

Thoracic ganglia are in the direct pathway of sympathetic nerves to cardiopulmonary system. Sympathetic influence on cardiopulmonary function has been well addressed in other studies. In Long QT syndrome, with no evidence of heart disease, the symptoms including tachyarrhythmia have been attributed to the sympathetic system as the episodes mostly occur during exercise or emotional stress and sympathectomy results in good therapeutic outcomes when the patients do not respond to medical therapy.[3]

Other studies have shown the sympathetic effect on heart activity at rest and maximum activity and also on bronchomotor tone in hyperhidrosis patients. It was shown by Noppen et al that bilateral sympathectomy causes a significant reduction in total lung capacity (TLC), forced expiratory volume in one second (FEV1), and significant increase in airway resistance (Raw). These changes were attributed to volume-restrictive effect of thoracoscopy rather than sympathetic denervation effect, because after correction for lung volumes (FEV1/forced vital capacity [FVC], and specific airway resistance and conductance), they remained unchanged and TLC returned to normal range after 6 months after thoracoscopic sympathectomy. However, greater reduction in forced expiratory flow after exhaling 75% of vital capacity (FEF₇₅) was observed and remained unchanged after 6 months and this change was attributed to sympathetic denervation.[4] In another study by Noppen et al, bilateral sympathectomy causes a minimal reduction in resting and maximal heart rate.[5]

Since cardiopulmonary system is greatly innervated by thoracic sympathetic ganglia, which can influence the function especially in essential hyperhidrosis patients, we think that unilateral sympathectomy would result in less interruption with cardiopulmonary function, as this method needs less denervation. Also, as this method requires less manipulation compared with bilateral, it may lower the adverse volume-restrictive effect of thoracoscopy. These advantages are especially more pronounced in those patients who use the maximum capacity of their cardiopulmonary systems like athletes. These theories need further studies to be confirmed.

• References

• 1 Ravari H, Rajabnejad A. Unilateral sympathectomy for primary palmar hyperhidrosis. Thorac Cardiovasc Surg 2015;
• 2 Wolosker N, Yazbek G, Milanez de Campos JR, Kauffman P, Ishy A, Puech-Leão P. Evaluation of plantar hyperhidrosis in patients undergoing video-assisted thoracoscopic sympathectomy. Clin Auton Res 2007; 17 (3) 172-176
• 3 Hwang SW, Thomas JG, Whitehead WE , et al. Left thorascopic sympathectomy for refractory long QT syndrome in children. J Neurosurg Pediatr 2011; 8 (5) 455-459
• 4 Noppen M, Vincken W. Thoracoscopic sympathicolysis for essential hyperhidrosis: effects on pulmonary function. Eur Respir J 1996; 9 (8) 1660-1664
• 5 Noppen M, Herregodts P, Dendale P, D'Haens J, Vincken W. Cardiopulmonary exercise testing following bilateral thoracoscopic sympathicolysis in patients with essential hyperhidrosis. Thorax 1995; 50 (10) 1097-1100