Usefulness of neuromonitoring in thyroid surgery

Abstract

One of the most important complications during thyroid surgery is injury to the recurrent laryngeal nerve (RLN) which leads to dysfunction and palsy of the vocal folds. Adequate knowledge about the location of the RLN supported by neuromonitoring can help the operating surgeon to prevent this complication. Visualization of the nerve alone seems not enough. An estimation of the function of the RLN is very important. Recently, the use of neuromonitoring has been increasingly employed to predict and document nerve function at the end of thyroidectomy. The aim of the study was to verify the usefulness of neuromonitoring in identifying the recurrent laryngeal nerve and to predict postoperative outcome in patients undergoing thyroid surgery for different indications. Between March 2009 and October 2010, 91 patients (26 men, 65 women; mean age 53 (range 26-83) underwent thyroidectomy. Intraoperative neuromonitoring (IONM) was registered for 91 patients. Eighty-four total thyroidectomies and seven lobectomies were performed with IONM. Eight unilateral postoperative transient paresis were identified without any permanent paralysis. Intraoperative neuromonitoring has an excellent specificity and negative predictive value in which an unchanged positive signal is highly predictive of intact nerve function. Intraoperative neuromonitoring during thyroid surgery is a reliable tool for early recurrent laryngeal nerve localization and identification, certainly in complicated thyroid operations. The probability is high for correctly predicting an intact postoperative nerve function by neuromonitoring.

Narrative review of proving the causal link of recurrent laryngeal nerve injury and thyroidectomy: a medico legal appraisal

“…On the basis of literature review, the evidences supporting the role of routine RLN identification in injuries prevention are several (24,25). This prevention appeared also improved by the implementation of intraoperative neuromonitoring techniques (26)(27)(28)(29) even if, in complicated cases, it appeared to be useful in identification but not in eliminating the risk of nerve damage (25)(26)(27)(28)(29)(30). Authors stated to carefully consider justification if neural monitoring is not used in pre-operative predictable risk procedures (26)(27)(28)(29)(30)(31)(32).…”

“…This prevention appeared also improved by the implementation of intraoperative neuromonitoring techniques (26)(27)(28)(29) even if, in complicated cases, it appeared to be useful in identification but not in eliminating the risk of nerve damage (25)(26)(27)(28)(29)(30). Authors stated to carefully consider justification if neural monitoring is not used in pre-operative predictable risk procedures (26)(27)(28)(29)(30)(31)(32). One article reported that neural monitoring was subject of pleading in 57% malpractice litigations (32).…”

Intraoperative Evoked Potentials: A Review of Clinical Impact and Limitations

“…Effectively, majority demonstrated significantly lower RLN morbidity when assisted by IONM, partial or transient palsy but less difference in permanent injury. Nevertheless, it improved thyroid surgery outcome with excellent specificity and negative predictive value [42,[59][60][61][62].…”

Fluorescence Imaging of Peripheral Nerves by a Nav1.7-Targeted Inhibitor Cystine Knot Peptide

“…13 Clearly, these unintended side effects could be reduced if an operating surgeon were more aware of the exact location of these vital nerves. While preoperative technologies to improve delineation and planning for larger nerve bundles do exist, [14][15][16] a surgeon's intraoperative arsenal to avoid iatrogenic nerve injury during an operation consists mainly of loupes, surgical light microscopes, and electromyography electrodes which, though useful during some procedures, 17 require nerves to be close to the tissue surface for stimulation, and cannot be used for all types of interventions. 18 Intuitively, the development of a fluorescent nerve agent would ameliorate this situation, but despite the clear medical need and its importance, peripheral nerves have proven to be a difficult target.…”