Iatrogenic injury of the spinal accessory nerve in selective superficial parotidectomy

The spinal accessory nerve, also known as accessory nerve, is the eleventh cranial nerve. It is responsible for the motor innervation of the sternocleidomastoid and trapezius muscle. The sternocleidomastoid muscle tilts and rotates the head, while the trapezius muscle, connecting to the scapula, elevate the shoulder girdle and retract the girdle dorsally. Spinal accessory nerve injury commonly occurs during neck dissection surgery, either elective or therapeutic procedure, performed to treat head and neck carcinoma. The Authors described the case of a 50-year-old man who underwent surgery for a parotid neoformation. After the superficial left parotidectomy emerged neck pain, weakness of the trapezius muscle and functional impotence of the left shoulder. Following diagnostic tests, was properly diagnosed an iatrogenic accessory nerve injury. The main purpose is to determine possible predictive factors related to the occurrence of accessory nerve injury during superficial parotidectomy and the possibility to recognize the error immediately after surgery when surgical repair has the great chance of success. Probably the awareness of the possibility of a iatrogenic injury and its consequences, even during reconstruction using the SMAS flap after superficial parotidectomy, would avoid delays in diagnosis and treatment.