Recurrent laryngeal nerve injury and preservation in thyroidectomy

OBJECTIVE: We aim to evaluate the rates of recurrent laryngeal nerve (RLN) injury after thyroidectomy and to put forward the factors influencing the risk of RLN injury during thyroid surgery.

METHODS: We retrospectively analyzed the records of 418 patients who underwent thyroid surgery for thyroid disease at the Turkish State Railway Hospital, Ankara and Gazi University Hospital between 1989-2003 for RLN injury and factors affecting this complication. Moreover, we evaluated 6 different types of operations used during surgical practice. Indirect laryngoscopy was performed preoperatively and was repeated postoperatively for all patients.

RESULTS: Three hundred and thirty-nine (81.1%) were females and 79 (18.9%) were male. Indications for surgery were multinodular goiter in 253 cases, solitary nodule in 69, hyperthyroidism in 68, thyroid carcinoma in 5 and recurrent goiter in 23 cases. Bilateral subtotal thyroidectomy was performed in 286 cases (68.4%), unilateral subtotal thyroidectomy in 52 (12.4%), unilateral total thyroidectomy in 25 (5.9%), bilateral total thyroidectomy in 22 (5.3%), nodule excision in 10 (2.4%) and completion thyroidectomy for recurrent goiter in 23 (5.5%) cases. Unilateral vocal cord problems occurred, 16 (3.8%) cases and in 6 (1.2%) cases it became permanent. The distribution of permanent RLN paralysis over the cases was 0.04% multinodular goiter, 2.9% hyperthyroidism and 8.7% recurrent goiter (p<0.05). Transient RLN paralysis rate was 2%, while permanent RLN paralysis rate was 0.03% for bilateral subtotal thyroidectomies. In addition, in unilateral total thyroidectomies, transient RLN paralysis was 12% while permanent paralysis was 4%. For bilateral total thyroidectomies, 13.6% was transient and 9% was permanent RLN paralysis and 13% was transient and 8.7% was permanent paralysis for completion cases (p<0.05).

CONCLUSION: We can avoid RLN injury during thyroid surgery by identifying the nerve and following its course carefully. Intraparenchymal dissection or subtotal excision can be performed if failure to identify RLN occur, and new operative techniques and medical management of benign thyroid diseases should be considered.