Intraoperative Nerve Monitoring Research Articles

Intraoperative Spinal Accessory Nerve Monitoring During Neck Dissection Surgery as a Predictor for Shoulder Dysfunction.

Shoulder dysfunction is one of the most common complications seen in patients who have undergone neck dissection surgery. The prevalence of shoulder dysfunction increases depending on the type and extent of neck dissection surgery. We aim to study the relationship between changes in intraoperative neuromonitoring (IONM) threshold during SAN stimulation, ultrasonographic measurement of muscle size and shear wave elastography with shoulder dysfunction. This is a prospective study. All patients who have undergone neck dissection in our centre have been recruited. Analysis of demographic data, IONM threshold during exposure and pre-closure, shoulder function score, neck disability index score (NDII) and ultrasonographic parameters pre-op and during follow up was done. The cohort was divided into patients who suffered from shoulder dysfunction post op (Group A) and patients with normal shoulder function post op (Group B). Statistical significance were seen in IONM threshold during SAN stimulation and Constant shoulder score for 6 months follow up in Group A. IONM threshold difference during exposure and pre-closure could effectively prognosticate shoulder dysfunction post op. A return of shoulder function could be seen in patients who suffered from shoulder dysfunction if early physiotherapy could be commenced.

부갑상선 절제술에 있어 반회후두신경의 수술 중 신경감시술의 임상적 의의

Background and Objectives Intraoperative nerve monitoring (IONM) has been gaining acceptance as a formal practice of thyroid and parathyroid surgery. However, most studies of IONM for recurrent laryngeal nerve (RLN) primarily focused on thyroid surgery. In this study, we evaluated clinical implications of IONM solely in parathyroid surgery, by comparing results of parathyroidectomy in patients with or without IONM. Materials and Methods This study designed as a retrospective cohort study. Between 2010 and 2022, patients who underwent parathyroidectomy for the treatment of hyperparathyroidism were included. Patients were divided into the no IONM and IONM groups and compared clinicopathological and surgical parameters according to the use of IONM. Results A total of 107 patients involving 65 patients in the IONM group and 42 patients in the IONM group were included in the study. In the IONM group, proportion of surgical type of uni- and bilateral neck exploration was significantly higher in the IONM group than the no IONM group (35.7% vs. 6.2%, p<0.001). Rate of RLN identification during surgery was significantly higher in the IONM group than the no IONM group (81.0% vs. 43.1%, p<0.001). Operating time for minimal invasive/focused parathyroidectomy was significantly shorter in the IONM group than the no IONM group (61.8 min vs. 85.6 min, p<0.001). Vocal cord paralysis occurred only 1 case in each group without significant difference in the incidence. Conclusion Use of IONM would contribute to safe and faster parathyroidectomy, justifying its routine use in parathyroid surgery.

Cochlear implantation through retro-facial approach with congenital microtia malformation with facial nerve deformity: a case report

The difficulty of cochlear implantation in patients with congenital microtia is usually increased due to the vague anatomical marks and facial nerve malformation. The common types of facial nerve malformation include facial nerve bony cover loss, aberrant position, and bifurcation malformation. Bifurcation malformation may obscure the oval window, press against stapes, and bifurcate in the vestibular window while obscuring the round window. It is important to correctly identify the facial nerve and choose a reasonable surgical approach to avoid postoperative complications. This article describes a case of profound sensorineural hearing loss due to facial nerve malformation in our institution. The patient underwent cochlear implantation through the retro-facial approach. There was no facial nerve injury or dysfunction symptoms such as facial paralysis and hemifacial spasm 2 years after the operation, and the cochlear implant works well. The score of the categories of the auditory performance（CAP） questionnaire was 7, and the score of the speech intelligibility rating（SIR） questionnaire was 4. When the round window cannot be exposed through the facial recess approach during surgery, the retro-facial approach is a feasible method. To avoid facial nerve injury, a thin-section CT of the temporal bone should be performed before the middle and inner ear surgery for patients with facial nerve malformation, and the intraoperative facial nerve monitor should be used to clarify the course of the facial nerve to avoid injury.

Impact of Intermittent Intraoperative Neuromonitoring (IONM) on the Learning Curve for Total Thyroidectomy by Residents in General Surgery.

Recurrent laryngeal nerve (RNL) identification constitutes the standard in thyroidectomy. Intraoperative nerve monitoring (IONM) has been introduced as a complementary tool for RLN functionality evaluation. The aim of this study is to establish how routine use of IONM can affect the learning curve (LC) in thyroidectomy. Patients undergoing total thyroidectomy performed by surgery residents in their learning curve course in 2 academic hospitals, were divided into 2 groups: Group A, including 150 thyroidectomies performed without IONM by 3 different residents, and Group B, including 150 procedures with routine use of intermittent IONM, by other 3 different residents. LC was measured by comparing operative time (OT), its stabilization during the development of the LC, perioperative complication rate. As previously demonstrated, the LC was achieved after 30 procedures, in both groups, with no differences due to the use of IONM. Similarly, there were no significant differences among the 2 groups, and between subgroups independently matched, for both OT and complications, even when comparing RLN palsy. Direct nerve visualization and IONM assessment rates were comparable in all groups, and no bilateral RLN palsy (transient or permanent) were reported. No case of interrupted procedure to unilateral lobectomy, due to evidence of RLN injury, was reported. The study demonstrates that the use of IONM thyroid surgery, despite requiring a specific training with experienced surgeons, does not particularly affect the learning curve of residents approaching this kind of surgery, and for this reason its routine use should be encouraged even for trainees.

Techniques of detecting recurrent laryngeal nerve palsy in patients undergoing thyroid surgery: Pearls and pitfalls.

Though permanent vocal cord palsy consequent to recurrent laryngeal nerve (RLN) injury is rare following thyroidectomies, its consequences are grave enough for it to be the most feared complication postoperatively. Anesthesiologists and surgeons take various precautions to prevent its occurrence and employ various methods for its early detection. They include direct visualization of the nerve intraoperatively, use of intraoperative nerve monitoring, and post-extubation visualization of vocal cord mobility by use of direct or indirect methods. In the present narrative review, we aim to discuss the clinical evidence pertaining to the various methods adopted for the prevention and early detection of RLN palsy during thyroidectomy.

Intraoperative neuromonitoring in surgery of cervical neurogenic tumors

Objective: To investigate the application value of intraoperative motor nerve monitoring in cervical neurogenic tumor surgery. Methods: The efficacy of intraoperative neuromonitoring (IONM) was analyzed retrospectively in 18 patients, including 6 males and 12 females, aged from 15 to 74 years, treated in Affiliated Drum Tower Hospital, Medical School of Nanjing University from June 2019 to September 2022 who underwent total cystectomy of cervical neurogenic tumors under intraoperative nerve monitoring. Results: All 18 patients had complete tumor removal, including 8 patients with tumors from the vagus nerve and 10 patients with tumors from the brachial plexus nerve. Postoperative nerve functions were normal in patients with tumors from brachial plexus nerve, and incomplete vocal cord paralysis occurred in 2 patients with tumors from vagus vagus nerve. The total incidence of motor nerve injury was 11.1% (2/18). All patients were followed up for 6 to 45 months, with no tumor recurrence. Conclusion: Intraoperative neuromonitoring has significant values in surgery of cervical neurogenic tumors, which is helpful to remove completely the tumors on the basis of protecting the nerve functions to the maximum extent.

Impact of Surgeon's Experience and Tumor's Nature in the Use of Intraoperative Facial Nerve Monitoring in Superficial Parotidectomy. Preliminary Results from a Single-Center Retrospective Analysis.

To assess the effectiveness of intraoperative facial nerve monitoring (IFNM) compared to non-monitoring in the prevention of post-operative facial nerve palsy during superficial parotidectomy. Patients treated with curative intent for parotid gland tumors between January 2020 and January 2022 were included. The study population has been divided in 2 groups, based on IFNM: the group A included patients operated with IFNM, whilst group B was the non-monitoring group. A further classification focused on the pathologies and the surgeons' experience. The study group included 58 patients, 27 female and 31 male. The mean age was 45.7yr (range 36-78). No statistical difference has been found in post-operative HB grade between group A and B. The analysis of patients affected by pleomorphic surface lobe adenomas of the parotid did not show a statistical difference in HB outcome (p > 0.05). The analysis of the effect of surgeons' experience in IFNM advantage did not show statistical difference for superficial parotid tumors. The results of the present study suggest that the use of IFNM during parotid surgery is not mandatory to preserve the VII nerve function, both in case of primary tumor and in case of recurrence, and even when surgery is performed by less experienced surgeon compared to those cases treated by a more experienced surgeon.

Evaluation of the effect of prostate diameters on erectile dysfunction in patients who underwent low-anterior resection.

Male erectile dysfunction is an important complication of rectal surgery. In this research, the effect of prostate dimensions on the development of postoperative erectile dysfunction in patients diagnosed with mid-rectum adenocarcinoma who underwent low anterior resection (LAR) is examined. Thirty-one male patients diagnosed as mid-rectal adenocancer were included. The International Index of Erectile Function (IIEF) questionnaire was used to determine the patients' pre and postoperative erectile dysfunction levels, and the level of relationship between the change in these IIEF scores and prostate measurements determined by computed tomography were evaluated. There were statistically significant differences between IIEF index score and anterior posterior (AP) and transverse (TR) measurements (p≤0.001; p≤0.001), but no statistically significant difference was found between craniocaudal (CC) measurement values (p=0.169). The risk of nerve injury will be higher in those with a small prostate transverse diameter. Intraoperative nerve monitoring should be recommended primarily in younger patient groups.

Continuous Intraoperative Nerve Monitoring for Thyroid and Parathyroid Surgery

Continuous Intraoperative Nerve Monitoring for Thyroid and Parathyroid Surgery

Continuous Intraoperative Nerve Monitoring of a Non-Recurrent Laryngeal Nerve: Real-Life Data of a High-Volume Thyroid Surgery Center.

Thyroid surgery is associated with a risk of injury to the recurrent laryngeal nerve, especially in the presence of anatomical variants such as a non-recurrent laryngeal nerve (NRLN). Injury to the nerve leads to transient or permanent vocal cord palsy (VCP). A novel method to prevent VCP is continuous intraoperative nerve monitoring (cIONM), but less is known about the applicability of this method in patients with NRLN. The aim of this study was to evaluate our own data regarding feasibility and detailed characteristics of cIONM in NRLN patients. We performed a monocentric retrospective cohort analysis including clinical data and intraoperative nerve monitoring data (measured by Inomed Medizintechnik GmbH, Emmendingen, 'C2' and 'C2 Xplore' device) of all thyroid surgery patients, showing NRLN between 2014 and 2022. Of 1406 patients who underwent thyroid surgery with cIONM between 2014 and 2022, 12 patients (0.9%) showed NRLN intraoperatively. Notably, cIONM was feasible in eight patients (67%). In all cases the onset latency of the right vagus nerve was shorter (<3.0 ms) than usually expected, suggesting that a short latency might be suitable to distinguish NRLN. None of the patients had a post-operative VCP. Overall, cIONM appears to be feasible and safe in NRLN patients and provides helpful information to prevent VCP.

Krause approach to pineal tumour with intraoperative oculomotor nerve monitoring

BackgroundThe supra-cerebellar infratentorial approach to pineal region tumours is versatile and safe corridor to lesions located below the deep veins. Monitoring of the extra-ocular muscle pathways using the evoked compound muscle action potential can lead to safer resections. Technical noteTo describe the use of electrooculography and a three handed retractor less method for pineal region tumour surgeries. Material and methodsIntraoperative electrooculography uses recording done from two channels (horizontal and vertical)by inserting disposable subdermal needle electrodes along the periorbital area. The oculomotor nerve is being monitored as it exits the midbrain. Retractor-less three-handed-technique allows for minimal handling of the cerebellum while maximizing the operative corridor. ResultThe oculomotor nerve was stimulated post resection and correspondingly led to improved symptoms post-operatively. Discussion and conclusionWe demonstrate a method for the intraoperative monitoring of the continuity of the oculomotor tracts and a three handed retractor-less method of resection of pineal region tumours. The placement of electrodes and area of stimulation need sound knowledge of anatomy of the region. Haemostasis at every step is absolutely essential to be able to visualize in the narrow corridor.

Can nerve monitoring during radical prostatectomy improve functional outcomes? A randomised trial.

To explore how the use of the ProPep® Nerve Monitoring System (ProPep Surgical, Austin, TX, USA) for intraoperative specific sparing of the pudendal nerve fibres influences postoperative functional outcomes after unilateral nerve-sparing (UNS) or non-nerve-sparing (NNS) robot-assisted radical prostatectomy (RARP). We randomised 100 men undergoing UNS or NNS RARP to ProPep nerve monitoring during RARP (intervention) or standard of care RARP (control). Functional outcomes were assessed at 3, 6, and 12 months using the International Consultation on Incontinence Questionnaire Short Form (ICIQ-SF), the International Prostate Symptom Score, the Danish Prostate Symptom Score, the International Index of Erectile Function, the Erection Hardness Scale, and 24-h pad tests. The primary outcome was the difference in ICIQ-SF score between the groups at 12 months. Secondary outcomes included differences in the remaining outcome measures and continence rates at all time points. Continence was defined as the use of no pads and the answer 'Never' to the question: 'How often do you experience urinary incontinence?' or a urine loss of <8 g on the 24-h pad test. A total of 82 patients were included in the per-protocol analysis at 12 months with 41 in each group. At 12 months the mean ICIQ-SF scores were 5.37 (95% confidence interval [CI] 3.71-7.03) and 5.66 (95% CI 4.05-7.27) for the intervention and control groups, respectively (P = 0.8). There were no statistically significant differences in any of the remaining outcomes. However, the continence rate was higher in the intervention group at 6 months (63% vs 44%, P = 0.09). Intraoperative nerve monitoring did not result in better functional outcomes following UNS or NNS RARP. Larger studies are needed to explore if ProPep can reduce the time to continence after RARP.

Preserving vocal cord function: Continuous intraoperative vagus nerve monitoring in total thyroidectomy

A 42-year-old female patient who underwent left hemithyroidectomy for a benign thyroid nodule, was referred for further management, as histology revealed a minimally invasive follicular carcinoma requiring completion thyroidectomy as recommended by Oncologists. She had developed unilateral vocal card palsy following the initial hemithyroidectomy. Pre operatively vocal cord function was evaluated by fibre optic laryngoscopy, which confirmed a left vocal cord palsy. During the completion thyroidectomy, continuous intraoperative nerve monitoring was done using an electrode attached to endotracheal tube. A delta electrode was attached to the Vagus nerve and continuous monitoring of the Vagus nerve was done while performing intermittent monitoring of the Recurrent Laryngeal nerve. Stimulation was performed using a current of 1–2 mA. According to the International Nerve monitoring Study Group (INMSG) guidelines initial amplitude value of at least 500 μV was considered as the normal value.According to INMSG guide lines, change of EMG signal curve amplitude below 100 μV was considered as loss of signal during the operation. Post-operative period of the patient was uneventful and the right vocal cord function was confirmed as normal by fibre optic endoscopic examination. Even though intraoperative nerve monitoring is a useful procedure for all the thyroidectomy surgeries it is documented to be more beneficial during revision surgeries, thyroid malignancies and pre-operative unilateral nerve palsy patients.

A sampling survey of intraoperative facial nerve monitoring in China

Objective: This study aims to investigate the current application and the level of knowledge of intraoperative facial nerve monitoring among medical staff in China. Methods: A comprehensive online questionnaire was conducted among medical professionals across different regions in China from October 2022 to February 2023. The survey exclusively targeted departments specializing in otolaryngology, head and neck surgery, neurosurgery, and oral and maxillofacial surgery. The questionnaire covered various aspects including general information, intraoperative facial nerve monitoring practices, training history, indications for monitoring, parameters used during monitoring procedures, as well as factors influencing its implementation. Results: A total of 417 participants from 31 provincial, municipal, and autonomous regions were included. Intraoperative facial nerve monitoring was found to be implemented in 227 (54.4%,227/417) repondents of 53 institutions (24.9%, 53/213). The top three indications for implementing this technique were acoustic neuroma, parotid gland surgery, and modified middle ear surgery (mastoidectomy). Herein 81.1%(184/227) medical staff involved in intraoperative facial nerve monitoring had received relevant training, 57.3%(130/227)-92.1%(209/227) reported a lack of clear description regarding recording thresholds, stimulation currents/frequencies/wave widths. Conclusion: The majority of the institutions surveyed have not yet adopted intraoperative facial nerve monitoring. Furthermore, significant gaps concerning the procedure exist. It is imperative to establish standards or guidelines to promote its better development and application.

Differences in surgical outcomes between cervical goiter and retrosternal goiter: an international, multicentric evaluation.

Goiter is a common problem in clinical practice, representing a large part of clinical evaluations for thyroid disease. It tends to grow slowly and progressively over several years, eventually occupying the thoracic inlet with its lower portion, defining the situation known as retrosternal goiter. Total thyroidectomy is a standardized procedure that represents the treatment of choice for all retrosternal goiters, but when is performed for such disease, a higher risk of postoperative morbidity is variously reported in the literature. The aims of our study were to compare the perioperative and postoperative outcomes in patients with cervical goiters and retrosternal goiters undergoing total thyroidectomy. In our retrospective, multicentric evaluation we included 4,467 patients, divided into two groups based on the presence of retrosternal goiter (group A) or the presence of a classical cervical goiter (group B). We found statistically significant differences in terms of transient hypoparathyroidism (19.9% in group A vs. 9.4% in group B, p < 0.001) and permanent hypoparathyroidism (3.3% in group A vs. 1.6% in group B, p = 0.035). We found no differences in terms of transient RNLI between group A and group B, while the occurrence of permanent RLNI was higher in group A compared to group B (1.4% in group A vs. 0.4% in group B, p = 0.037). Moreover, no differences in terms of unilateral RLNI were found, while bilateral RLNI rate was higher in group A compared to group B (1.1% in group A vs. 0.1% in group B, p = 0.015). Wound infection rate was higher in group A compared to group B (1.4% in group A vs. 0.2% in group B, p = 0.006). Based on our data, thyroid surgery for retrosternal goiter represents a challenging procedure even for highly experienced surgeons, with an increased rate of some classical thyroid surgery complications. Referral of these patients to a high-volume center is mandatory. Also, intraoperative nerve monitoring (IONM) usage in these patients is advisable.

Expert consensus on intraoperative facial nerve monitoring

Expert consensus on intraoperative facial nerve monitoring

Artificial intelligence-powered intraoperative nerve monitoring: a visionary method to reduce facial nerve palsy in parotid surgery: an editorial

Artificial intelligence-powered intraoperative nerve monitoring: a visionary method to reduce facial nerve palsy in parotid surgery: an editorial

Application of Intraoperative Neurophysiological Monitoring (IONM) for Preventing Dysphagia After Anterior Cervical Surgery: A Prospective Study

ObjectiveTo evaluate the clinical value of intraoperative nerve monitoring (IONM) for dysphagia after anterior cervical surgery with and without IONM. MethodA prospective, randomized, controlled study was conducted on 46 patients who underwent anterior cervical spine surgery by an experienced orthopaedic surgeon. Twenty-three patients who underwent anterior cervical surgery did not undergo IONM (non-IONM group), while the other 23 patients who underwent anterior cervical surgery did ("IONM group"). The swallowing function of patients was evaluated using the EAT-10 and endoscopic evaluation of swallowing (FEES) after surgery. ResultsThere was no difference in the incidence of swallowing difficulties between the intervention group and the control group on the third day or sixth week after surgery. At the 12th week after surgery, the incidence of swallowing difficulties in the intervention group and the control group was significantly different (43.5% vs. 13.0%, P = 0.024). ConclusionIONM is a promising tool for identifying and protecting the spinal cord and nerves during anterior cervical surgery. Our research revealed that IONM significantly reduced the occurrence of swallowing disorders 12 weeks after surgery, but the effect was not significant at the third or sixth week after surgery.

Intradural Extramedullary Spinal Tumors: A Clinical Study and Management without the Aid of Nerve Monitoring

Abstract Background: The incidence of primary spinal cord tumors is less and the true incidence is still not known and various studies are still being done. These tumors are benign and slow growing, and they generally present with pain – either radiculopathy or axial back pain or focal neurological deficits due to the loss of roots, myelopathy from spinal cord compression, or cauda equina symptoms due to chronic compression. Early diagnosis and operation are gratifying as the lesions are mostly benign and can be completely resected as well as preservation of functionality if operated as early as possible. Although rare, an inadvertent neurological injury during surgery is a concerning complication that can potentially be prevented with the assistance of intraoperative nerve monitoring (IONM). This technology enables real-time assessment of spinal cord function by providing feedback from sensory tracts, motor tracts, and individual nerve roots. However, the definitive requirement for IONM in the treatment of a highly curable condition is still under consideration. Objective: our study aims at studying the clinical features of intradural extramedullary tumors and their operative management without nerve monitoring. Material and Methods: Patients with intradural extramedullary (IDEM) spinal cord tumors who fit the inclusion criteria and who were willing to investigations, surgical procedures, and follow up were enrolled in the study, and consent was obtained. Patient assessment was done clinically by McCormick’s Scale and radiologically by magnetic resonance imaging. Patients who underwent operation were followed up. The data was collected and analysed using SPSS software. Results: Nineteen patients were enrolled in the study. The age group ranged from 6 years to 79 years. There were 13 females and 6 males in the study group. The common presenting complaints were backache and upper and lower limb pain. Nine out of the 19 patients underwent operative procedures after thorough radiological and clinical evaluation. Histopathology showed five cases of schwannoma and four cases of meningioma. The mean McCormick’s Scale preoperatively was 4.11, whereas postoperatively, it was 3.10. The operative procedures were performed without the aid of IONM, yet there were no inadvertent intraoperative injuries and postoperative outcomes were good. Our study data were comparable with other studies. Conclusion: IDEM tumors, though technically challenging to operate, have excellent results in terms of outcomes due to their benign characteristics as well as complete resectability. Therefore, it is essential to conduct a comprehensive examination and imaging for patients experiencing backaches and weakness. Following a careful evaluation, early surgical intervention should be considered, as the timeliness of the surgery contributes to enhanced outcomes. The unavailability of nerve monitoring did not portend any added risk of surgery if done meticulously though its aid would make the operative procedure safer and gross resection better.

Effect of modified endotracheal intubation protocol combined with early oral intake on postoperative recovery quality in thyroid and parathyroid surgery at a tertiary hospital in China: a 2x2 factorial randomised controlled trial protocol

IntroductionEarly oral intake (EOI) is supposed to be safe and beneficial to patients’ recovery. However, the optimal timing of resuming oral intake has not been validated in thyroid and parathyroid...