A prospective controled randomized multicenter study to evaluate severity of compensatory sweating after one-stage bilateral thoracic sympathectomy versus unilateral thoracic sympathectomy in the dominant side

2- AbstractO_ST_ABSOBJECTIVEC_ST_ABSTo compare, in a Brazilian population, the clinical efficacy and quality-of-life (QoL) impact of one-stage bilateral thoracic sympathectomy (BTS) versus unilateral sympathectomy on the dominant side (UniS), with additional analysis of patients who later underwent contralateral surgery (two-stage bilateral, 2stS). METHODSProspective, randomized, controlled, multicenter trial (11 centers) including 163 adults with primary palmar hyperhidrosis. Participants were randomized 1:1 to BTS or UniS. From 6 months onward, UniS patients could elect contralateral sympathectomy (2stS). Sweating severity was assessed using the Hyperhidrosis Disease Severity Scale (HDSS) across 18 anatomical sites at each visit. Compensatory sweating (CS) was defined as new sweating in previously unaffected areas (preoperative HDSS = 1) and graded by the magnitude of HDSS increase. QoL was measured with two complementary validated instruments: HidroQOL and the Horn questionnaire. RESULTSBaseline characteristics were similar between groups, with most participants presenting severe preoperative disease. Improvement in the operated (dominant) hand was comparable after BTS and UniS, whereas control of the non-operated hand favored BTS. In the UniS group, spontaneous contralateral improvement occurred in approximately one-seventh of untreated hands. The proportion of patients without CS was similar in both groups ([~]25%), but severe CS was more frequent after BTS (40.4% vs 21.0%, p = 0.0344). QoL improved in both groups, with larger and more sustained reductions in Horn and HidroQOL scores after BTS (p < 0.001). In the 2stS subgroup, contralateral surgery produced a consistent HDSS decrease and marked QoL improvement, with predominantly mild additional CS. CONCLUSIONSBTS provides more complete symptom control and greater QoL improvement, but at the cost of more severe CS. UniS offers excellent control on the treated side, may reduce severe CS, and supports a staged strategy in which some patients avoid a second procedure (requested by 22.5% in this study); when needed, contralateral completion tends to restore additional clinical and QoL gains.