Neuromonitoring in thyroidectomy: a meta-analysis of effectiveness from randomized controlled trials

Abstract

Neuromonitoring in thyroid surgery has been employed to make nerve identification easier and decrease the rates of laryngeal nerve injuries. Several individual randomized controlled trials (RCTs) have been published, which did not identify statistical differences in the rates of recurrent laryngeal nerve (RLN) or external branch of the superior laryngeal nerve (EBSLN) injuries. The objective of this report is to perform meta-analysis of the combined results of individual studies to measure the frequency of RLN and EBSLN injuries in patients who underwent thyroidectomy with routine neuromonitoring in comparison with common practice of search and identification. RCTs comparing routine neuromonitoring versus no use in patients who underwent elective partial or total thyroidectomy were evaluated. Outcomes measured were temporary and definitive palsy of the RLN and EBSLN. A systematic review and meta-analysis was done using random effects model. GRADE was used to classify quality of evidence. Six studies with 1,602 patients and 3,064 nerves at risk were identified. Methodological quality assessment showed high risk of bias in most items. Funnel plot did not reveal publication bias. The risk difference for temporary RLN palsy, definitive RLN palsy, temporary EBSLN palsy, and definitive EBSLN palsy were -2% (95% confidence interval -5.1 to 1); 0% (-1 to 1); -9% (-15 to -2) and -1% (-4 to 2), respectively. Quality was rated low or very low in most outcomes due to methodological flaws. Meta-analysis did not demonstrate a statistically significant decrease in the risk of temporary or definitive RLN injury and definitive EBSLN injury with the use of neuromonitoring. The neuromonitoring group had a statistically significant decrease in the risk of temporary EBSLN injury.

Management of the exterior branch of the superior laryngeal nerve among thyroid surgeons – Results from a nationwide survey

“…Similarly, a retrospective study on 308 patients found a lower upper aerodigestive (UADS) score, indicating fewer symptoms, in patients who had undergone thyroidectomy with IONM than those who had not [18]. Likewise, a meta-analysis of available randomised studies found a lower frequency of temporary EBSLN damage with use of IONM, and a nonsignificant tendency towards a lower rate of permanent EBSLN damage [10]. In this survey, endocrine surgeons reported a much lower frequency of pre-and postoperative laryngoscopy and voice recording, than H&N surgeons.…”

“…However, identification can be facilitated by using intraoperative neural monitoring (IONM) [8,9]. Furthermore, IONM significantly lowered the risk of temporary EBSLN paresis, and there was a non-significant trend toward a lower risk of permanent EBSLN damage with IONM in a recent meta-analysis [10].…”

Análisis económico de la neuromonitoría rutinaria del nervio laríngeo recurrente en tiroidectomía total

“…The data from the recent meta-analysis showed that the frequency of RLN injury was 1% in the neuromonitor group and 1.6% for the standard group, which was a no significant difference (6).…”

“…The probabilities of RLN injury were obtained from a previous meta-analysis (6). For loss of signal probability, we used information from a study by Sitges-Serra, et al (9) (table 1).…”

“…Recently, neuromonitoring has been recommended as a novel alternative to further decrease the rate of RLN palsy (4). Two published meta-analyses did not demonstrate a statistically significant difference in the rate of RLN injury (5,6). Nonetheless, some authors suggest that its use can be cost-effective based on the decrease of sequels (7), but this argument has not been tested in the literature or the Colombian health system.…”