Feasibility of endoscopic transumbilical thoracic sympathectomy in a porcine model

Abstract

Thoracoscopic sympathectomy is an effective treatment for palmar hyperhidrosis. Current methods are associated with risks of chronic neuropathic pain and a visible chest scar. We developed a novel surgical technique for the performance of sympathectomy by embryonic natural orifice transumbilical endoscopic surgery with a flexible endoscope in a porcine model. Transumbilical flexible endoscopic thoracic sympathectomies were performed in seven farm pigs (three acute and four 4-week survivals). Under general anaesthesia, animals were intubated and mechanically ventilated with a dual lumen endotracheal tube through tracheostomy. A newly developed long transabdominal trocar was placed through the umbilicus. After insertion of a gastroscope through this trocar, a small incision was created on both sides of the diaphragm by a needle-knife. Then the gastroscope was inserted into the thoracic cavity, and the sympathetic chain was identified at the desired thoracic level and ablated. Operation time, safety and feasibility were recorded in all animals. The transumbilical thoracic sympathectomies were successfully completed in all pigs with a mean operation time of 66.7 ± 9.4 min. Intraoperative bleeding occurred in one pig during the electrosurgical incision of diaphragm tissue, which was successfully controlled by hot biopsy forceps. No other acute intraoperative complications were observed in any cases. In the acute group, the length of the diaphragm incision ranged from 4 to 5 mm in three pigs. In the survival group, the animals recovered promptly from surgery. In three pigs, a small pneumothorax was found in the postoperative chest X-ray, but all of them were completely resolved with conservative treatment. Autopsy showed all bilateral T3 sympathetic chains were successfully ablated and no evidence of vital structure injury or diaphragmatic hernia. Transumbilical flexible endoscopic thoracic sympathectomy is technically feasible, simple and safe in a porcine model. This technique can be used as a novel experimental platform for studies of natural orifice transluminal endoscopic surgery (NOTES) for intrathoracic surgery.