Iatrogenic Brachial Plexus Injuries Evaluated in an Electrodiagnostic Lab

Background/Objectives: Iatrogenic brachial plexus injuries (BPI) are known to occur following a host of surgeries, most often during procedures at the shoulder and cardiac procedures with a median sternotomy. The primary mechanisms include overstretching of the brachial plexus, direct trauma, or compression by hematoma or seroma. Our objective was to determine the pattern of iatrogenic BPI in patients referred to us for electrodiagnostic (EDX) evaluation. Methods: This is a review of 52 patients who were referred to our Neurodiagnostic Center for an iatrogenic BPI over a 16-year (9 July 2010-17 June 2026) period. All patients underwent a clinical examination and EDX studies. Results: The most frequent etiologies of the iatrogenic BPI were shoulder surgery in 28 [53.8%] patients and coronary artery bypass graft procedures with a median sternotomy in 13 [25.0%] patients. The topography of brachial plexus involvement was trunks in 22 (42.3%) and cords in 12 (23.1%). Ten (19.2%) patients had a pan-plexopathy, and the remaining eight (15.4%) patients had multiple sites involving the trunks, cords, and branches. The majority (48 [92.3%]) of patients sustained a stretch injury of the brachial plexus, and four (7.7%) sustained a direct injury. A total of 48 (92.3%) patients had reduced motor unit potential recruitment and/or increased polyphasic motor units on needle EMG, and a similar number had an absence of or low amplitude sensory nerve action potentials. Conclusions: Surgeons should take appropriate precautions to avoid BPI during many surgical procedures especially those of the shoulder and cardiac procedures with a median sternotomy. EDX studies are valuable in detecting and localizing an iatrogenic BPI as well as assessing reinnervation. Preoperative positioning limiting excessive shoulder abduction as well as intraoperative neuromonitoring are measures that may reduce the likelihood of an iatrogenic BPI.