Background/Objectives. Heart rate variability (HRV) is the variability in the beat-by-beat heart period. Primary focal hyperhidrosis (PFHH) is a disease characterized by excessive sweat production, strongly affecting social life. Several authors define this condition as a dysautonomic disorder, mainly driven by exaggerated sympathetic activity. The aim of the study was to demonstrate a possible cardiac involvement in the disease. Other outcomes were the occurrence of dysautonomic disorders after surgery and its possible correlation with baseline characteristics. Methods. This observational, controlled trial enrolled patients with a confirmed clinical diagnosis of severe PFHH candidates to thoracoscopic sympathetic chain clamping. Before and after surgery, ECG was obtained using KardiaMobile 6L (AliveCor^®, Mountain View, CA, USA) device with a five-minute recording and HRV was analyzed using Kubios HRV Premium (Kubios©) software. Results. 111 patients were compared to 222 healthy control subjects. No differences were seen in HRV analysis between the two groups at baseline (time-domain p > 0.05, frequency-domain p > 0.05, autonomic indexes p > 0.05). When comparing autonomic function indexes in patients before and after the surgical procedure, no differences were seen in frequency-domain HRV analysis, but a blunted increase in SNS index (0.2 vs. 1.38, p 0.02). No development of systemic dysautonomic disorders nor significant compensatory hyperhidrosis were seen after the surgery. Conclusions. This study shows that PFHH is a peripheral autonomic nervous system derangement, rather than central. Sympathetic chain clamping resulted safe and effective in improving patients’ conditions, with no risks of dysautonomic disorders.

Background: Primary plantar hyperhidrosis is a disabling condition characterized by excessive plantar sweating and impaired quality of life. Lumbar sympathectomy is reserved for patients with symptoms refractory to conservative treatment, but minimally invasive techniques remain technically heterogeneous. This study describes a modified retroperitoneoscopic lumbar sympathectomy and reports its preliminary perioperative outcomes. Methods: A single-center case series included consecutive patients who underwent modified retroperitoneoscopic lumbar sympathectomy for primary plantar hyperhidrosis between June 2019 and May 2024. The technique combined ultrasound-guided retroperitoneal access, indocyanine green (ICG)-assisted creation of the retroperitoneal working space, and temporary selective clamping of the lumbar sympathetic trunk with an intraoperative assessment of plantar temperature and perfusion before definitive clipping. Results: Forty-five patients underwent 81 procedures, including 35 bilateral procedures (70 sides), 10 unilateral procedures, and one unilateral reoperation for recurrent symptoms. All patients resumed oral intake and ambulation on the day of surgery and were discharged within 24 h according to institutional protocol. No intraoperative or postoperative complications were observed and resolution of plantar sweating in subsequent follow-ups was achieved. Conclusions: Modified retroperitoneoscopic lumbar Sympathetic Chain Selective Clamping appears to be a feasible and safe technique for the surgical treatment of primary plantar hyperhidrosis. These technical refinements may facilitate retroperitoneal access and intraoperative confirmation of the target sympathetic level. Larger comparative studies with standardized outcomes and longer follow-up are needed to confirm the durability and clinical value of this approach.