[Postoperative iatrogenic lesions of the external branch of the accessory spinal nerve].

Iatrogenic lesions of the spinal nerve are rare and generally occur during cervicotomy for aetiological assessment of adenopathy. The spinal nerve is essentially damaged at two sites: the supraclavicular fossa (where the nerve is very superficial) and in the antero-lateral triangle of the neck (where the nerve approaches the sterno-cleido-mastoid muscle). The lesion of the spinal nerve essentially presents in the form of paralysis of the trapezius; which should be examined systematically postoperatively and at subsequent consultations, as the clinical signs may only develop after a certain latency period. The spinal nerve lesion requires early surgical repair (graft, suture) which gives the best results when it is associated with long-term, patient physiotherapy. Legally, the practitioner is generally condemned due to failure to obtain informed consent, which emphasises the importance of preoperative consultations during which the patients should be warned of the possibility of a lesion to this nerve.