Recurrent Laryngeal Nerve Palsy Is More Frequent After Secondary than After Primary Anterior Cervical Discectomy and Fusion: Insights from a Registry of 525 Patients

Abstract

Recurrent laryngeal nerve (RLN) palsy is a common complication after anterior cervical discectomy and fusion (ACDF) and usually manifests with dysphagia, hoarseness, and respiratory difficulties. Next to proven risk factors, such as age and multilevel procedures, RLN palsy has been speculated to occur more frequently after secondary ACDF procedures. We analyzed a prospective registry of all consecutive patients undergoing zero-profile ACDF for disc herniation, myelopathy, or stenosis. RLN palsy was defined as persistent patient self-reported dysphagia, hoarseness, or respiratory problems without other identifiable causes. RLN palsy was assessed at scheduled 6-week telephone interviews. Among 525 included patients, 511 primary and 40 secondary ACDF procedures were performed. Hoarseness was present in 12 (2.2%) cases, whereas dysphagia and respiratory difficulties both occurred in 3 (0.5%) cases. Overall incidence of RLN palsy was 2% after primary procedures and 8% after secondary procedures (P= 0.017). These rates are in line with the peer-reviewed literature, and the difference remained significant after controlling for confounders in a multivariate model (P= 0.033). Other reported risk factors, such as age, sex, surgical time, and multilevel procedures, had no relevant effect (P > 0.05). Based on our data and other published series in the literature, RLN palsy may occur more frequently after secondary ACDF procedures with a clinically relevant effect size. There is a striking lack of uniformity in methods and reporting in research on RLN injury.