The utility of intraoperative nerve monitoring in secondary and tertiary Hyperparathyroid surgery

Objectives Recurrent laryngeal nerve (RLN) injury is a well-known complication of parathyroid surgery. Despite ample data, there is still uncertainty about the role of intraoperative monitoring (IONM) in mitigating RLN damage. Study Design A retrospective review. Methods We included all patients presenting for total, subtotal, or completion parathyroidectomy at a tertiary referral hospital from 2013 to 2018. Information about demographics, previous neck surgery, perioperative data, pathology, and possible RLN injury was collected. Two groups were formed for analysis: IONM vs. nonmonitored (NM). Results 105 patients underwent 107 surgeries with IONM utilized in 71 cases. The groups were similar in demographics, but significantly differed (all P < 0.05) in preincision parathyroid hormone level (IONM = 2091.44 vs NM = 1334.87), surgery type (IONM = 62.9% vs NM = 27.8% subtotal), and surgery length in minutes (IONM = 155.21 vs NM = 182.22). We observed six cases (6/71 = 8.45%) of persistent RLN complaints (three or more weeks postoperatively) and four cases (4/71 = 5.63%) of temporary complaints with the use of IONM compared with only one temporary complaint (1/36 = 2.78%) in unmonitored procedures (P = 0.129). Conclusions These results suggest that the use of IONM does not provide a protective effect on the RLN in patients with secondary or tertiary hyperparathyroidism undergoing total, subtotal, or completion parathyroidectomy. Prospective, randomized studies with pre- and postoperative flexible laryngoscopy are needed to explore the use of IONM in this patient population further.