Roles of multimodal intra-operative neurophysiological monitoring (IONM) in percutaneous endoscopic transforaminal lumbar interbody fusion: a case series of 113 patients

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

OBJECTIVE

To evaluate the clinical value of intraoperative nerve monitoring (IONM) for dysphagia after anterior cervical surgery with and without IONM.

METHODS

A 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.

RESULTS

There 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).

CONCLUSIONS

IONM 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.

Accuracy of Intraoperative Neuromonitoring in the Diagnosis of Intraoperative Neurological Decline in the Setting of Spinal Surgery-A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

In an effort to prevent intraoperative neurological injury during spine surgery, the use of intraoperative neurophysiological monitoring (IONM) has increased significantly in recent years. Using IONM, spinal cord function can be evaluated intraoperatively by recording signals from specific nerve roots, motor tracts, and sensory tracts. We performed a systematic review and meta-analysis of diagnostic test accuracy (DTA) studies to evaluate the efficacy of IONM among patients undergoing spine surgery for any indication.

METHODS

The current systematic review and meta-analysis was performed using the Preferred Reporting Items for a Systematic Review and Meta-analysis statement for Diagnostic Test Accuracy Studies (PRISMA-DTA) and was registered on PROSPERO. A comprehensive search was performed using MEDLINE, EMBASE and SCOPUS for all studies assessing the diagnostic accuracy of neuromonitoring, including somatosensory evoked potential (SSEP), motor evoked potential (MEP) and electromyography (EMG), either on their own or in combination (multimodal). Studies were included if they reported raw numbers for True Positives (TP), False Negatives (FN), False Positives (FP) and True Negative (TN) either in a 2 × 2 contingency table or in text, and if they used postoperative neurologic exam as a reference standard. Pooled sensitivity and specificity were calculated to evaluate the overall efficacy of each modality type using a bivariate model adapted by Reitsma et al, for all spine surgeries and for individual disease groups and regions of spine. The risk of bias (ROB) of included studies was assessed using the quality assessment tool for diagnostic accuracy studies (QUADAS-2).

RESULTS

A total of 163 studies were included; 52 of these studies with 16,310 patients reported data for SSEP, 68 studies with 71,144 patients reported data for MEP, 16 studies with 7888 patients reported data for EMG and 69 studies with 17,968 patients reported data for multimodal monitoring. The overall sensitivity, specificity, DOR and AUC for SSEP were 71.4% (95% CI 54.8-83.7), 97.1% (95% CI 95.3-98.3), 41.9 (95% CI 24.1-73.1) and .899, respectively; for MEP, these were 90.2% (95% CI 86.2-93.1), 96% (95% CI 94.3-97.2), 103.25 (95% CI 69.98-152.34) and .927; for EMG, these were 48.3% (95% CI 31.4-65.6), 92.9% (95% CI 84.4-96.9), 11.2 (95% CI 4.84-25.97) and .773; for multimodal, these were found to be 83.5% (95% CI 81-85.7), 93.8% (95% CI 90.6-95.9), 60 (95% CI 35.6-101.3) and .895, respectively. Using the QUADAS-2 ROB analysis, of the 52 studies reporting on SSEP, 13 (25%) were high-risk, 10 (19.2%) had some concerns and 29 (55.8%) were low-risk; for MEP, 8 (11.7%) were high-risk, 21 had some concerns and 39 (57.3%) were low-risk; for EMG, 4 (25%) were high-risk, 3 (18.75%) had some concerns and 9 (56.25%) were low-risk; for multimodal, 14 (20.3%) were high-risk, 13 (18.8%) had some concerns and 42 (60.7%) were low-risk.

CONCLUSIONS

These results indicate that all neuromonitoring modalities have diagnostic utility in successfully detecting impending or incident intraoperative neurologic injuries among patients undergoing spine surgery for any condition, although it is clear that the accuracy of each modality differs.PROSPERO Registration Number: CRD42023384158.

Predictive Factors for Dysphagia After Anterior Cervical Spine Surgery: A Prospective Multicenter Study

OBJECTIVE

To identify the incidence and predictors of postoperative dysphagia in patients who undergo anterior cervical spine surgery (ACSS) by utilizing the Eating Assessment Tool (EAT-10).

METHODS

A multicenter prospective study was undertaken at three hospitals to evaluate patients undergoing ACSS between January 2021 and January 2023. Included patients were aged 18-80 years and were undergoing primary or revision ACSS. Dysphagia was assessed using the validated EAT-10 questionnaire. Patients with dysphagia were included in the observation group, and those without dysphagia were included in the control group.

RESULTS

Of the 343 patients enrolled, 50 patients (14.6%) had EAT-10 scores of 3 or more at the 6-month follow-up. In the univariate analysis, patients with dysphagia at 7 days had a longer operative time, were current smokers, had involvement of vertebral bodies at C4 and above, and underwent intraoperative neurophysiological monitoring. Patients with dysphagia at 6 months had involvement of vertebral bodies at C4 and above and underwent intraoperative neurophysiological monitoring. In the multivariate analysis to determine associations with prolonged dysphagia, only the involvement of vertebral bodies at C4 and above (odds ratio 3.883, 95% confidence interval 1.847-8.165, P = 0.001) and intraoperative neurophysiological monitoring (odds ratio 0.273, 95% confidence interval 0.080-0.931, P = 0.038) remained significant.

CONCLUSIONS

Dysphagia is common after ACSS, affecting more than 67.5% of patients at 7 days postoperatively, but over time, the incidence of dysphagia gradually decreases. Involvement of the vertebral bodies at C4 and above is a risk factor for dysphagia after ACSS, and intraoperative neurophysiological monitoring is a protective factor.

Perspective: Can intraoperative neurophysiological monitoring (IONM) limit errors associated with lumbar pedicle screw fusions/transforaminal lumbar interbody fusions (TLIF)?

Background

We evaluated whether intraoperative neural monitoring (IONM), including somatosensory evoked potential monitoring (SEP), motor evoked potential monitoring (MEP), and electrophysiological monitoring (EMG), could reduce operative errors attributed to lumbar instrumented fusions, including minimally invasive (MI) transforaminal lumbar interbody fusion (TLIF)/open TLIF.

Methods

Operative errors included retraction/stretch or cauda equina neural/cauda equina injuries that typically occurred during misplacement of interbody devices (IBD) and/or malpositioning of pedicle screws (PS).

Results

IONM decreased the incidence of intraoperative errors occurring during instrumented lumbar fusions (MI-TLIF/TLIF). In one series, significant loss of intraoperative SEP in 5 (4.3%) of 115 patients occurred after placing IBD; immediate removal of all IBD left just 2 patients with new neural deficits. In other series, firing of trigger EMG's (t-EMG) detected intraoperative PS malpositioning, prompted the immediate redirection of these screws, and reduced the need for reoperations. One t-EMG study required a reoperation in just 1 of 296 patients, while 6 reoperations were warranted out of 222 unmonitored patients. In another series, t-EMG reduced the pedicle screw breech rate to 7.78% (1723 PS) from a higher 11.25% for 1680 PS placed without t-EMG. A further study confirmed that MEP's picked up new motor deficits in 5 of 275 TLIF.

Conclusion

SEP/MEP/EMG intraoperative monitoring appears to reduce the risk of surgical errors when placing interbody devices and PS during the performance of lumbar instrumented fusions (MI-TLIF/TLIF).However, IONM is only effective if spine surgeons use it, and immediately address significant intraoperative changes.

Application of Intraoperative Electromyography Intelligent Monitoring in Orthopedic Surgery under General Anesthesia

To study the application of intraoperative EMG intelligent monitoring in orthopedic surgery under general anesthesia, a total of 53 patients who underwent orthopedic surgery from February 2021 to February 2022 were selected. The combined monitoring of somatosensory evoked potential (SEP), motor evoked potential (MEP), and electromyography (EMG) was used to analyze the monitoring efficiency. In 38 of the 53 patients, the intraoperative signal was normal, and there was no postoperative neurological dysfunction; one case had abnormal signal, and the abnormality still existed after debugging, but no obvious neurological dysfunction was found after operation; the remaining 14 cases had abnormal signal. There were 13 early warnings in SEP monitoring; 12 early warnings in MEP monitoring; 10 early warnings in EMG monitoring. There were 15 cases of early warning in the joint monitoring of the three, and the sensitivity of the combined monitoring of SEP + MEP + EMG was significantly higher than that of the single monitoring of SEP, MEP, and EMG (p < 0.05). There was no significant difference in specificity, positive predictive value, and negative predictive value between combined monitoring and single monitoring (p > 0.05). The combined monitoring of EMG, MEP, and SEP in orthopedic surgery can significantly improve the safety of surgery, its sensitivity and negative predictive value were significantly higher than the monitoring effects of the two alone.