Compensatory hyperhidrosis following thoracic sympathectomy: a biophysical rationale

Area of Science:

• Physiology
• Thermoregulation
• Biophysics

Background:

• Compensatory hyperhidrosis (CH) is a common side-effect of endoscopic thoracic sympathectomy (ETS).
• The underlying physiological mechanism of CH remains unclear.
• CH involves excessive sweating from skin areas with preserved sudomotor function post-ETS.

Purpose of the Study:

• To investigate the physiological mechanism of compensatory hyperhidrosis (CH) following endoscopic thoracic sympathectomy (ETS).
• To explore the role of thermoregulatory physiology and heat balance biophysics in CH.
• To determine if CH requires a postoperative alteration in physiological control.

Main Methods:

• The study proposes a theoretical model based on evaporative heat balance requirements.
• It analyzes the relationship between metabolic heat production, skin surface area, and sweat rate.
• The model considers sweating efficiency and sweat dripping under varying evaporative demands.

Main Results:

• The total evaporative requirement to balance metabolic heat production remains constant pre- and post-ETS.
• Post-ETS, a smaller intact skin surface area necessitates a higher local sweat rate for thermoregulation.
• Increased sweating inefficiency and sweat dripping under high evaporative loads further exacerbate CH.

Conclusions:

• Compensatory hyperhidrosis (CH) post-ETS can be explained by fundamental thermoregulatory physiology and altered heat balance biophysics.
• The findings suggest CH does not necessitate a postoperative change in physiological control.
• Psychological stimuli may also contribute to increased sudomotor activity, alongside biophysical factors.