Accessory neuropathy after sternotomy: Clinico-anatomical correlation supporting an inflammatory cause.

Inflammatory etiologies are becoming increasingly recognized as explanations of some neuropathies, especially those occurring in the perioperative period. Although "brachial neuritis" is known to affect extraplexal nerves, accessory nerve palsy following median sternotomy has been attributed to stretch on the nerve. To better elucidate stretch as a potential cause, a cadaveric study was performed. Two patients who developed accessory nerve palsy following median sternotomy are presented to illustrate features consistent with the diagnosis of a perioperative inflammatory neuropathy. Five adult unembalmed cadavers underwent exposure of the bilateral accessory nerves in the posterior cervical triangle. A median sternotomy was performed and self-retaining retractors positioned. With the head in neutral, left rotation and right rotation, retractors were opened as during surgery while observing and recording any accessory nerve movements. The self-retaining sternal retractors were fully opened to a mean inter-blade distance of 13 cm. Regardless of head position, from the initial retractor click to maximal opening there was no gross movement of the accessory nerve on the left or right sides. Opening self-retaining sternal retractors does not appear to stretch the accessory nerve in the posterior cervical triangle. Based on our clinical experience and cadaveric results, we believe that inflammatory conditions, (i.e., idiopathic brachial plexitis) can involve the accessory nerve, and might be triggered by surgical procedures. Clin. Anat. 31:417-421, 2018.