[Incidence of damage to the recurrent laryngeal nerve in surgical therapy of various thyroid gland diseases--a retrospective study].

UNLABELLED: We investigated the incidence of the recurrent laryngeal nerve (RLN) palsy after thyroid gland surgery in 725 cases. The incidence was correlated to the different diseases of the thyroid gland, to the operative procedure (subtotal resection, lobectomy, thyroidectomy), to the intraoperative exploration of the nerve and to the surgeons' state of training. RLN palsy was found in 7.6 per cent (4.8 per cent nerve at risk) five days after surgery. A permanent RLN damage was defined as a persisting paralysis of the vocal cord six months after surgery. Permanent nerve damage occurred in 2.1 per cent for euthyroid nodular goitre, for recurrent goitre in 11.7 per cent and for thyroid carcinoma in 10.1 per cent. There was a statistically significant difference between the number of RLN pareses occurring after nerve exposure with 4.2 per cent and that occurring after non-exposure with 1.1 per cent for subtotal lobectomy. 67.7 per cent of these pareses at day five were transient. The RLN palsy rate for Senior House Officers was 6.7 per cent but there where none for registrars and consultants.
CONCLUSIONS: The RLN damage five days after thyroid gland surgery is mainly caused by the great number of recurrent goitre and thyroid cancer (16.1 per cent), the rate of procedures performed by younger surgeons and the near total resection of euthyroid goitre. The exposure of RLN is important for the training to manage thyroid gland surgery.