Proving the Superiority of Intraoperative Recurrent Laryngeal Nerve Monitoring over Visualization Alone during Thyroidectomy

Abstract

Vocal fold paralysis after thyroid surgery is still a dangerous complication that significantly reduces patients’ quality of life. Since the intraoperative neuromonitoring (IONM) technique has been introduced and standardized, the most frequently asked question is whether its use has significantly reduced the rate of RLN injury during thyroid surgery compared to visual identification alone (VA). The aim of this study was to attempt to prove the superiority of IONM over VA of the RLN during thyroid surgery in the prevention of vocal fold paralysis, taking into account risk factors for complications. The medical records of 711 patients (1265 recurrent laryngeal nerves at risk of injury) were analyzed retrospectively: in 257 patients/469 RLNs at risk, thyroid surgery was performed with IONM; in 454 patients/796 RLNs at risk, surgery was performed with VA. The statistical analysis showed that in the group of patients with IONM only one risk factor—the surgeon’s experience—proved statistically significant (OR = 3.27; p = 0.0478) regarding the overall risk of vocal fold palsy. In the group of patients where only visualization was used, 5 of the 12 factors analyzed were statistically significant: retrosternal goiter (OR = 2.23; p = 0.041); total thyroid volume (OR = 2.30; p = 0.0284); clinical diagnosis (OR = 2.5; p = 0.0669); gender (OR = 3.08; p = 0.0054) and risk stratification (OR = 3.30; p = 0.0041). In addition, the cumulative risk, taking into account the simultaneous influence of all 12 factors, was slightly higher in the group of patients in whom only VA was used during the procedure: OR = 1.78. This value was also considerably more statistically significant (p < 0.0001) than that obtained in the group of patients in whom IONM was used: OR = 1.73; p = 0.004. Conclusions: Risk factors for complications in thyroid surgery are not significant for any increase in the rate of vocal fold paralysis as long as surgery is performed with IONM, in contrast to thyroid surgery performed only with VA, thus proving the superiority of IONM over VA for safety.

Reoperative Thyroid Bed Surgery: An Evaluation of Complications and Outcomes

“…Wilhelm et al studied 5446 patients and found out that routine use of IONM reduced the long-term vocal cord dysfunction from 3.7% to 2.2% (p<0.01) [17]. Wojtczak et al studied 711 patients and concluded that the risk factors causing complications in thyroid surgery are not significant for any increase in the rate of vocal fold paralysis with IONM, as compared to direct vision [18]. But we at our institute do not use IONM for routine thyroid surgeries where the anatomy is usually constant.…”

Current Knowledge on the Use of Neuromonitoring in Thyroid Surgery

“…In 2023, Wojtczak et al proved the superiority of IONM over visualization alone during thyroidectomy by analyzing risk factors in thyroid surgery. The authors proved that risk factors for complications in thyroid surgery are not significant for any increase in the rate of vocal fold paralysis as long as the surgery is performed with IONM, in contrast to thyroid surgery performed only with visualization alone [ 47 ]. In the context of reducing RLN injury, it is worth noting that various nerve monitoring techniques influence the rate of complications.…”