Intraoperative Electromyographic Evaluation of Brachial Plexus Decompression During the Roos Surgical Procedure for Thoracic Outlet Syndrome.

Background and Objectives: The aim of this retrospective study was to assess brachial plexus decompression throughout the sequential stages of the Roos procedure and to elucidate the role of first rib resection in the surgical management of Thoracic Outlet Syndrome (T.O.S). Materials and Methods: A total of 34 patients with a mean age of 34.6 years were included in this retrospective analysis. All patients underwent transaxillary first rib resection following anterior scalenotomy, consistent with the Roos procedure. Intraoperative brachial plexus functionality was assessed using recording electrodes for sensory and motor stimulation on the deltoid, biceps, triceps brachii, and abductor digiti minimi muscles. Mixed linear models with log-transformed data were used to assess changes in muscle measurements across surgical stages, with statistical significance at p less than 0.05. Results: The electromyographic values of the deltoid, biceps brachii, triceps brachii, and abductor digiti minimi muscles were significantly higher in the final post-operative neutral position compared to both the post-anterior scalenotomy and initial preoperative neutral positions. No significant differences were observed between the initial preoperative neutral position and the post-anterior scalenotomy values for these muscles. However, the abductor digiti minimi muscle exhibited a trend toward decreased values following anterior scalenotomy in comparison to the initial neutral position. Conclusions: Intraoperative outcomes of brachial plexus decompression during the Roos procedure demonstrate that first rib resection contributes to complete decompression of the relevant anatomical structures in Thoracic Outlet Syndrome.