Detection of evolving injury to the brachial plexus during transaxillary robotic thyroidectomy

Objectives/Hypothesis: Continuous intraoperative neuromonitoring (IONM) of transcranial electric motor evoked potentials (tceMEPs) and somatosensory evoked potentials (SSEPs) has gained universal acceptance as an efficacious method for detecting emerging positional brachial plexopathy or peripheral nerve compression during spinal and shoulder surgery. This has implications for transaxillary thyroid surgery. Study Design: Case report with literature review. Methods: The patient underwent robotic transaxillary thyroid surgery with continuous tceMEP and SSEP monitoring of brachial plexus function. We present detailed IONM data depicting the emergence of positional brachial plexopathy. Results: Significant amplitude loss of both IONM modalities were identified during an evolving positional plexopathy, which resolved upon upper extremity repositioning and conversion to an open procedure. No permanent nerve injury or deficit was noted following surgery. Conclusions: Given the potential for brachial plexus injury during robotic transaxillary thyroid surgery secondary to arm positioning, we recommend that continuous tceMEP and SSEP monitoring be considered during such procedures.