Thoracoscopic sympathetic block to predict compensatory hyperhidrosis in primary hyperhidrosis.

Background: Compensatory hyperhidrosis is the main cause of patients' dissatisfaction following sympathectomy for primary hyperhidrosis. Therefore, thoracoscopic sympathetic nerve block before sympathectomy can be used to predict compensatory hyperhidrosis after sympathectomy. The objective of this study is to review our recent experience with the nerve block procedure, describing efficacy, safety and validity.

Methods: We retrospectively reviewed the medical records of 107 patients who underwent thoracoscopic sympathetic nerve block with a local anesthetic for primary palmar and craniofacial hyperhidrosis using a 2-mm needlescope from March 2017 to November 2019. A week later, the patients were interviewed, and a decision made as to whether to proceed with sympathectomy. We analyzed the perioperative data of patients who underwent the predictive procedure either followed, or not followed, by sympathectomy.

Results: Primary hyperhidrosis was relieved in all patients by the predictive procedure without severe complications. Compensatory hyperhidrosis happened to 32 patients (29.9%). Seventy-eight patients (72.9%) decided to undergo sympathectomy (group A) and 29 patients (27.1%) refused the sympathectomy (group B). Group B tended to have higher average body mass index (24.5 versus 23.2 kg/m, P=0.082) and compensatory hyperhidrosis rate after predictive procedure (37.9% versus 26.9%, P=0.269) compared to group A. The compensatory hyperhidrosis rate after sympathectomy in group A was 76.9%. The effective duration of sympathetic block was significantly longer in group A than in group B (33.5 versus 13.9 hours, P=0.001). The predictive procedure had 94.4% specificity and 33.3% sensitivity for prediction of compensatory hyperhidrosis.

Conclusions: Thoracoscopic sympathetic block may be safe and feasible as a procedure for predicting compensatory hyperhidrosis after sympathectomy, and beneficially, it allows the patients to experience the effect of sympathectomy on primary hyperhidrosis and occurrence of compensatory hyperhidrosis. However, a longer effective duration of sympathetic block is needed to help patients to decide whether to proceed with the surgery.