Recurrent laryngeal nerve injury after thyroid and parathyroid surgery: Incidence and postoperative evolution assessment

Recurrent laryngeal nerve (RLN) injury is a feared complication after thyroid and parathyroid surgery. It induces important postoperative morbidity. The present study aimed to assess the incidence of transient/permanent postoperative RLN injuries after thyroid and parathyroid surgery in the present cohort, to observe the timing of recovery, and to identify risk factors for permanent RLN injury after thyroidectomy. All consecutive patients operated on at our institution for thyroid and parathyroid pathologies from 2005 to 2013 were reviewed for vocal cord paresis. Vocal cord paresis was defined based on postoperative fiberoptic laryngoscopy. Demographics, intraoperative details, and postoperative outcomes were collected. Treatment types were assessed, and recovery times collected. Patients with vocal cord paresis on preoperative fiberoptic laryngoscopy were excluded from the analysis. The cohort included 451 thyroidectomies (756 nerves at risk) and 197 parathyroidectomies (276 nerves at risk). There were 63 postoperative vocal cord pareses after thyroidectomy and 13 after parathyroidectomy. Sixty-nine were transient (10.6%) and 7 permanent (1.1%). The main performed treatment was speech therapy in 51% (39/76) of the patients. Median recovery time after transient injuries was 8 weeks. In the group with vocal cord paresis, risk factors for permanent injuries after thyroidectomy were previous thyroidectomy and intraoperative RLN injury on univariate analysis. On multivariate analysis, only intraoperative RLN injury remained significant. Most of the patients with transient postoperative RLN injury recovered normal vocal cord mobility within 6 months. The most common performed treatment was in this cohort speech therapy. Permanent RLN injuries remained rare (1.1%).