Selective block of grey communicantes in upper thoracic sympathectomy. A feasibility study on human cadaveric specimens.

Background: Sympathetic chain interruption is the gold standard treatment for essential hyperhidrosis. Postoperative compensatory hyperhidrosis, the main reason for patients' dissatisfaction, is reduced by selectively lesioning white and grey rami communicantes (ramicotomy).Objective: To develop an endoscopic surgical technique that interrupts only T3 and T4 grey rami communicantes to minimize compensatory hyperhidrosis.Material and Methods: T3 and T4 grey rami communicantes ramicotomy in fifteen cold-preserved cadavers through a uniportal axillary endoscopic approach. The sympathetic chain, its ganglia, and white rami communicantes were left intact. On opening the chest, the sympathetic chain, rami communicantes and ganglia were dissected, photographed, measured and excised for histological examination.Results: Dissecting the grey rami communicantes is feasible as they consistently lie between the intercostal nerve and the homonymous sympathetic ganglion. At some levels, Kuntz nerves, as well as more than one grey ramus communicans, can be found. White rami communicantes are more medial, therefore damaging them can be avoided. Intercostal veins can be obstructive, but these can be controlled via coagulation or clipping if necessary.Conclusion: Uniportal endoscopic selective excision of the T3 and T4 grey rami communicantes is feasible without damaging the white rami communicantes, the sympathetic chain or its ganglia. Clipping the grey rami communicantes is technically possible but not reliable due to their thin diameter. This study confirms that T3 and T4 grey rami sympathetic block is technically feasible. Its application might reduce compensatory hyperhidrosis, but clinical studies are needed.