Intraoperative Spinal Cord Monitoring Research Articles

Changes in medical costs for adolescent idiopathic scoliosis over the past 15 years.

Use of instrumentation has become widespread in spinal surgery due to intraoperative spinal cord monitoring, navigation, and improvement and development of implant materials. However, recent advances in spine surgery may have also led to an increase in medical costs. The purpose of this study is to investigate the trends of operative resource utilization and the costs of surgery for adolescent idiopathic scoliosis (AIS) over 15 years. Surgery for AIS was performed for 118 patients from January 2004 to December 2019 at national University Hospital. Trends were examined through retrospective calculation of the costs for outpatient, inpatient, and surgical services, and changes over time and the characteristics of fees were examined. Differences between groups were analyzed by Mann-Whitney U test and Student t-test. During the 15-year period, the length of hospital stay decreased, but costs for scoliosis surgery increased by 1.6 times and the total cost increased by 1.3 times. The fee for intensive care per day per person increased by 1.5 times. There were slight increases in MRI and CT fees, but no changes in fees for radiography, rehabilitation, subsequent visits, and prescriptions. New charges for medical supervision, medical clerk support, medical safety measures, and prevention of infection were added at different times during the 15-year period. Itemized costs related to surgery have increased with technological advances. Although these results only show changes in costs for AIS surgery, the findings indicate the challenges faced by the healthcare economy and the need for spine surgeons to understand medical costs.

Stimulation parameters for motor evoked potentials during intraoperative spinal cord monitoring. A systematic review

ObjectiveThe aim of this systematic review was to find the optimal stimulation parameters for muscle recorded transcranial electrical stimulation motor evoked potential (mTc-MEP) and D-wave monitoring during spinal cord monitoring. MethodsA PRISMA systematic search in Medline and EMBASE and a QUADAS-2 quality evaluation was performed to identify studies that compared stimulation parameters consisting of stimulation location, number of pulses, pulse duration, interstimulus interval, double train (DTS) or recurrent train stimulation (RTS) and intertrain interval (ITI) for performing mTc-MEP and D-wave monitoring. Only studies that used total intravenous anaesthesia (TIVA) were included. ResultsTen studies that compared stimulation parameters for performing mTc-MEP monitoring (stimulation location n = 4, number of pulses n = 2, pulse duration n = 1, interstimulus interval n = 4, DTS n = 1, RTS n = 2, ITI n = 2) were included. No studies compared stimulation parameters (stimulation location and pulse duration) for performing D-wave monitoring. ConclusionsFew studies examined the optimal stimulation parameters for monitoring mTc-MEPs and no studies were included for D-wave monitoring. There is a need for prospective research to investigate the optimal stimulation parameters for mTc-MEP with the use of TIVA and D-wave monitoring. SignificanceFor mTc-MEP monitoring, a table is provided in which the recommended stimulation parameters are stated.

Current Trends in Intraoperative Spinal Cord Monitoring: A Survey Analysis among Japanese Expert Spine Surgeons.

Although intraoperative spinal neuromonitoring (IONM) is recommended for spine surgeries, there are no guidelines regarding its use in Japan, and its usage is mainly based on the surgeon's preferences. Therefore, this study aimed to provide an overview of the current trends in IONM usage in Japan. In this web-based survey, expert spine surgeons belonging to the Japanese Society for Spine Surgery and Related Research were asked to respond to a questionnaire regarding IONM management. The questionnaire covered various aspects of IONM usage, including the preferred modality, operation of IONM, details regarding muscle-evoked potential after electrical stimulation of the brain (Br(E)-MsEP), and need for consistent use of IONM in major spine surgeries. Responses were received from 134 of 186 expert spine surgeons (response rate, 72%). Of these, 124 respondents used IONM routinely. Medical staff rarely performed IONM without a medical doctor. Br(E)-MsEP was predominantly used for IONM. One-third of the respondents reported complications, such as bite injuries caused by Br(E)-MsEP. Interestingly, two-thirds of the respondents did not plan responses to alarm points. Intramedullary spinal cord tumor, scoliosis (idiopathic, congenital, or neuromuscular in pediatric), and thoracic ossification of the posterior longitudinal ligament were representative diseases that require IONM. IONM has become an essential tool in Japan, and Br(E)-MsEP is a predominant modality for IONM at present. Although we investigated spine surgeries for which consistent use of IONM is supported, a cost-benefit analysis may be required.

WE-228. Current status of intraoperative spinal cord monitoring and its optimization

WE-228. Current status of intraoperative spinal cord monitoring and its optimization

Thoracolumbar and Lumbar Posterior Vertebral Resection for the Treatment of Rigid Congenital Spinal Deformities in Pediatric Patients: A Long-Term Follow-up Study

ObjectiveWe sought to determine whether a posterior vertebral resection on congenital deformities of thoracolumbar and lumbar vertebrae leads to more complications and provides less correction.MethodsTwenty-three patients underwent a posterior vertebral resection for a rigid congenital spinal deformity, which included scoliosis (13 patients), kyphoscoliosis (6 patients), and pure kyphosis (4 patients). The surgeries involved removing 1 to 2 vertebrae using multiaxial pedicle screws in all but 2 of the patients. All surgeries were performed under intraoperative spinal cord monitoring. Thoracic curve, lumbar lordosis, focal kyphosis, shift, and sagittal vertical axis were collected at baseline and during the last follow-up (taking place after at least 3 years) and were then statistically analyzed.ResultsThe major curve correction was about 55% in cases of scoliosis, with focal kyphosis improving from 54.3 ± 19.1 degrees to 21.3 ± 15 degrees. Two patients experienced intraoperative neuromonitoring changes, with data returning to baseline without any surgical intervention. Sensory or motor palsy after the surgery was not reported in patients.Despite improving sagittal or coronal deformities, 8 patients experienced excessive sagittal decompensation during follow-up, 1 of whom underwent revision surgery. Sagittal decompensation was by far the most common complication. Larger kyphoscoliosis or focal kyphosis angles were preoperative risk factors for postoperative sagittal imbalance (P value < 0.05).ConclusionsUsing a lumbar or thoracolumbar posterior vertebral resection enables surgeons to correct rigid curves in the pediatric population without major risk to nerve roots. The primary complications would be sagittal decompensation and the likelihood of undercorrection, which requires mindful addressing during the preoperative planning stages.

Anterior Decompression via a Single Posterior Approach Using the Ultrasonic Bone Scalpel for the Treatment of the Thoracic Segmental Ossification of Posterior Longitudinal Ligament: A Report of Three Cases

Introduction Thoracic myelopathy due to ossification of the posterior longitudinal ligament (T-OPLL) is an indication for surgical treatment because the symptom is usually progressive. The surgery for T-OPLL is technically challenging for several reasons. Various operational procedures were developed for dealing with T-OPLL. The anterior decompression through a single posterior approach is a procedure to achieve the complete decompression via the direct resection of the ossified lesion, especially for the beak-type OPLL. Previous reports showed better postoperative outcomes using this method than using other procedures. However, the difficulty and risk of complications are also reported because of the blinded resection of the lesion positioning ventrally to the dura mater. Technical Note We describe a novel method using an anterior decompression through a single posterior approach using an ultrasonic bone scalpel. The following procedure is for a case of beak-type OPLL at the T5-6 level. The posterior elements at T2-9 were exposed after a median skin incision was created above a spinous process. First, pedicle screws were inserted bilaterally at T3-5 and T7-9. After the laminectomies and dekyphosis maneuver at T3-9, the spinal cord compression by OPLL was evaluated using intraoperative ultrasonography. After the slight medial facetectomy and pediclotomy at T5-6, the ultrasonic bone scalpel was inserted through the bilateral side of the spinal cord. The tip of the handpiece was angled to reach OPLL. The resection of OPLL was performed under intraoperative spinal cord monitoring. The intraoperative ultrasonography revealed the normal pulsation of the spinal cord and the space between the vertebral body and dura mater after completing the resection of OPLL. Posterolateral fusion was completed with local bone and harvested iliac crest. Conclusions The anterior decompression through a single posterior approach using an ultrasonic bone scalpel is a safe and effective treatment of thoracic OPLL.

Anesthesia and intraoperative neurophysiological spinal cord monitoring.

We will explain the basic principles of intraoperative neurophysiological monitoring (IONM) during spinal surgery. Thereafter we highlight the significant impact that general anesthesia can have on the efficacy of the IONM and provide an overview of the essential pharmacological and physiological factors that need to be optimized to enable IONM. Lastly, we stress the importance of teamwork between the anesthesiologist, the neurophysiologist, and the surgeon to improve clinical outcome after spinal surgery. In recent years, the use of IONM has increased significantly. It has developed into a mature discipline, enabling neurosurgical procedures of ever-increasing complexity. It is thus of growing importance for the anesthesiologist to appreciate the interplay between IONM and anesthesia and to build up experience working in a team with the neurosurgeon and the neurophysiologist. Safety measures, cooperation, careful choice of drugs, titration of drugs, and maintenance of physiological homeostasis are essential for effective IONM.

Spinal arteriovenous malformation in a pediatric patient with a history of congenital syphilis: a case report

BackgroundSpinal arteriovenous malformations in children are extremely rare and pose great risk for intraoperative hemorrhage. Congenital syphilis sometimes presents with vascular symptoms, however, there is little published on patients with a history of congenital syphilis presenting with spinal arteriovenous malformations.Case presentationA 15-month-old female with a history of congenital syphilis presented with urinary retention, fever, and subacute onset of paraplegia. MRI showed a lesion at T8-L1, angiogram was performed which confirmed the presence of a complex type IVc arteriovenous malformation and fistula from Artery of Adamkiewicz at L1-L2. It also showed peri medullary dilated veins and a pseudoaneurysm that compressed the spinal cord at T8-T10. Somatosensory evoked potentials and motor-evoked potentials were not recordable on the bilateral lower extremities prior to surgery. Once the patient was optimized for surgery, osteoplastic laminotomies from T6-T12 were performed. The dura was opened and the intradural, intramesenchymal hematoma was evacuated. There were two episodes of brisk arterial bleeding with hypotension during resection of the hematoma. The patient was taken to the angiography suite from the OR to successfully coil the large aneurysm. Intraoperative spinal cord monitoring remained undetectable in the bilateral lower extremities. The patient’s paraplegia remained unchanged from preoperative presentation.ConclusionCongenital syphilis may present with vascular changes that might impact surgical approaches and treatment outcomes in patients with spinal arteriovenous malformations. Preparation for massive transfusion and intraoperative monitoring are imperative in ensuring a safe perioperative experience.

術中脊髄モニタリングでFree run EMG波形異常の経時的な変化を観察することができた1例

術中脊髄モニタリングでFree run EMG波形異常の経時的な変化を観察することができた1例

Intraoperative Spinal Cord Monitoring: Focusing on the Basic Knowledge of Orthopedic Spine Surgeon and Neurosurgeon as Members of a Team Performing Spine Surgery under Neuromonitoring.

An intraoperative functional spinal cord monitoring system is a technology used by spine and spinal cord surgeons to perform a safe surgery and to gain further surgical proficiency. However, no existing clinical neurophysiological method used in the operating room can monitor all complex spinal cord functions. Therefore, by observing the activities of certain neural action potentials transferred via limited neural tissues, surgeons need to deductively estimate the function of the whole spinal cord. Thus, as the number of spinal cord functions that need to be observed increases, spinal cord monitoring can be more reliable. However, in some situations, critical decision-making is affected by the limited capability of these methods. Nevertheless, good teamwork enables sharing of seamless information within the team composed of a surgeon, anesthesiologist, monitoring technician and nurses greatly contributes to making quick and accurate decisions. The surgeon, who is the person in charge of the team, should communicate with multidisciplinary team members using common technical terms. For this reason, spine and spinal cord surgeons must have appropriate knowledge of the methods currently used, especially of their utility and limitations. To date, at least six electrophysiological methods are available for clinical utilization: three are used to monitor sensory-related tracts, and three are used to monitor motor-related spinal cord functions. If surgeons perform electrode setting, utilizing their expertise, then the range of available methods is broadened, and more meticulous intraoperative functional spinal cord monitoring can be carried out. Furthermore, if the team members share information effectively by utilizing a clinically feasible judicious checklist or tools, then spinal cord monitoring will be more reliable.

Surgeon-directed transcranial motor evoked potential spinal cord monitoring in spinal deformity surgery.

Spinal deformity surgery carries the risk of neurological injury. Neurophysiological monitoring allows early identification of intraoperative cord injury which enables early intervention resulting in a better prognosis. Although multimodal monitoring is the ideal, resource constraints make surgeon-directed intraoperative transcranial motor evoked potential (TcMEP) monitoring a useful compromise. Our experience using surgeon-directed TcMEP is presented in terms of viability, safety, and efficacy. We carried out a retrospective review of a single surgeon's prospectively maintained database of cases in which TcMEP monitoring had been used between 2010 and 2017. The upper limbs were used as the control. A true alert was recorded when there was a 50% or more loss of amplitude from the lower limbs with maintained upper limb signals. Patients with true alerts were identified and their case history analyzed. Of the 299 cases reviewed, 279 (93.3%) had acceptable traces throughout and awoke with normal clinical neurological function. No patient with normal traces had a postoperative clinical neurological deficit. True alerts occurred in 20 cases (6.7%). The diagnoses of the alert group included nine cases of adolescent idiopathic scoliosis (AIS) (45%) and six of congenital scoliosis (30%). The incidence of deterioration based on diagnosis was 9/153 (6%) for AIS, 6/30 (20%) for congenital scoliosis, and 2/16 (12.5%) for spinal tuberculosis. Deterioration was much more common in congenital scoliosis than in AIS (p = 0.020). Overall, 65% of alerts occurred during rod instrumentation: 15% occurred during decompression of the internal apex in vertebral column resection surgery. Four alert cases (20%) awoke with clinically detectable neurological compromise. Surgeon-directed TcMEP monitoring has a 100% negative predictive value and allows early identification of physiological cord distress, thereby enabling immediate intervention. In resource constrained environments, surgeon-directed TcMEP is a viable and effective method of intraoperative spinal cord monitoring. Level of evidence: III Cite this article: Bone Joint J2021;103-B(3):547-552.

Can increased stimulus intensity improve Anesthetic Fade and detect spinal cord injury in intraoperative cerebral spinal cord monitoring?

Can increased stimulus intensity improve Anesthetic Fade and detect spinal cord injury in intraoperative cerebral spinal cord monitoring?

Neurophysiological monitoring of spinal cord function during spinal deformity surgery: 2020 SRS neuromonitoring information statement.

The Scoliosis Research Society has developed an updated information statement on intraoperative neurophysiological monitoring of spinal cord function during spinal deformity surgery. The statement reviews the risks of spinal cord compromise associated with spinal deformity surgery; the statement then discusses the various modalities that are available to monitor the spinal cord, including somatosensory-evoked potentials, motor-evoked potentials, and electromyographic (EMG) options. Anesthesia considerations, the importance of a thoughtful team approach to successful monitoring, and the utility of checklists are also discussed. Finally, the statement expresses the opinion that utilization of intraoperative neurophysiological spinal cord monitoring in spinal deformity surgery is the standard of care when the spinal cord is at risk.

AB144. Intra-operative spinal cord monitoring during spinal cord surgery: does it have any clinical value?

Background: Spinal cord surgery is a technically challenging endeavour with potentially devastating complications for patients and surgeons. Intra-operative neurophysiological monitoring (IONM), or spinal cord monitoring (SCM), is one method of preventing and identifying damage to the spinal cord. At present, indications for its use are based more on individual surgeon preference and for medico legal purposes. Our study aimed to determine IONM’s utility as a clinical tool.

Adverse Events Related to Transcranial Electric Stimulation for Motor-evoked Potential Monitoring in High-risk Spinal Surgery.

Prospective multicenter study. The aim of this study was to study the incidence of nonneurologic adverse events related to transcranial electric stimulation (TES) for intraoperative spinal cord monitoring (IOM) with motor-evoked potentials (MEPs) (Tc(E)- MEPs) and determine the need for safety precautions. Tc(E)-MEPs monitoring requires high-voltage multipulse TES that causes widespread muscle contraction and movement. Improved awareness of TES-induced movement-related adverse events is needed. We analyzed data from 2643 patients who underwent high-risk spinal surgery with intraoperative Tc(E)-MEPs at 11 spinal centers from 2010 to 2016. Information about neurologic and non-neurologic postoperative complications was collected, including type of surgical procedure, operative time, estimated blood loss, and treatment for postoperative adverse events. A 70% drop in Tc(E)-MEPs amplitude, which was the alarm criterion to interrupt surgery, predicted postoperative motor deficits with 93.5% sensitivity, 91.0% specificity, a false-positive rate of 8.2%, and a false-negative rate of 0.3%. Non-neurologic adverse events developed in 17 (0.64%) patients and were most commonly because of bite injuries (0.57%), including 11 cases of tongue laceration, two cases of lip laceration, and two cases of tooth breakage. Four (0.15%) tongue lacerations required surgical repair with sutures and two tooth breakages required dental treatment. One patient had hair loss corresponding to the TES site. One patient, who underwent additional IOM with transpharyngeal stimulation, had severe nasal hemorrhage following electrode placement by nasal route, which resolved spontaneously. Non-neurologic adverse events did not significantly affect the accuracy of IOM assessment. Neither operative times nor blood loss significantly influenced the occurrence of adverse events. During TES-IOM, both the surgeon and monitoring team must consider the possibility-although rare-of non-neurologic adverse events, particularly bite injuries. Such complications can be minimized by using a soft bite-block and frequently evaluating the intraoral integrity of the anesthetized patient. 4.

Cervical spinal cord injury associated with neck flexion in posterior cervical decompression -Verification by intraoperative spinal cord monitoring

Some unexplained postoperative paralysis have reported in the cervical spine surgery.We experienced several cases of intraoperative monitoring (IOM) warnings because of neck flexion in posterior cervical procedure. We investigated to evaluate preoperative factors in patients with spinal cord disorder due to flexion of the neck during posterior cervical spine surgery by changes in waveforms in IOM. A retrospective analysis of 179 consecutive patients who underwent IOM during posterior cervical spine surgery. When warning alarms were set off by amplitude changes in the period between skin incision and exposure of the lamina, the neck position was changed from flexion to neutral, and patients whose electrical potentials were recovered by a change in cervical position were placed in the flexion-induced potential reduction group. We analyzed to extract risk factors for flexion-induced reduction in potentials. 156 patients were analyzed in this study. A warning alarm went off in 7 patients (4.5%) at the time of posterior cervical spine exposure. However, by changing their neck position from flexion to neutral, the electrical potentials recovered in all patients, with no postoperative adverse events such as paralysis (flexion-induced potential reduction group) and the remaining 148 patients were used as controls. Logistic regression analysis was performed to identify the risk factors affecting the reduction of TCE-MEP. The two factors that were significantly associated with the risk of reduction of TCE-MEP were the occupying rate of anterior compression component at the most compressed level and Kyphotic angle in the flexion position of anterior compression component at the most compressed level.

S9-4. The advantages and issues about the intraoperative spinal cord monitoring using muscle evoked potentials

S9-4. The advantages and issues about the intraoperative spinal cord monitoring using muscle evoked potentials

LC6. Current status of intraoperative spinal cord monitoring and its optimization

LC6. Current status of intraoperative spinal cord monitoring and its optimization

S9-5. Alert timing and corresponding intervention with intraoperative spinal cord monitoring for spinal surgery

S9-5. Alert timing and corresponding intervention with intraoperative spinal cord monitoring for spinal surgery

Multimodal Intraoperative Spinal Cord Monitoring during Spinal Deformity Surgery: Efficacy, Diagnostic Characteristics, and Algorithm Development

Objective: This study aims to present the diagnostic characteristics of multimodal intraoperative monitoring (IOM) in spinal deformity surgery and to define and categorise the neuromonitoring events, as well as propose an algorithm of action. Materials and Methods: We reviewed 1,155 consecutive patients (807 female, 348 male) who underwent deformity correction using standardised perioperative care, cortical/cervical somatosensory evoked potentials (SSEPs), and upper/lower limb transcranial electrical motor evoked potential (MEPs) by a single surgeon. The mean age at surgery was 13.8 years (range 10–23.3). We categorised IOM events as true, transient true, and false positive or negative. Diagnostic performance criteria were calculated. Results: The most common diagnosis was adolescent idiopathic scoliosis in 717 (62%) patients. We identified 3 true positive monitoring events occurring in 2 patients (0.17%), 8 transient true positive (0.69%), and 8 transient false positive events (0.69%). There were no false negative events and no patient had postoperative neurological complications. The multimodal IOM technique had a sensitivity of 100%, specificity of 99.3%, positive predictive value of 55.6%, and negative predictive value of 100%. Sensitivity was 100% for MEPs and multimodal monitoring compared to 20% for cortical or cervical SSEPs. The frequency of true or transient true positive events was higher (p = 0.07) in Scheuermann’s kyphosis (3/91 patients, 3.3%) compared to adolescent idiopathic scoliosis (6/717 patients, 0.84%). Conclusion: Multimodal IOM is highly sensitive and specific for spinal cord injury. This technique is reliable for the assessment of the condition of the spinal cord during major deformity surgery. We propose an algorithm of intraoperative action to allow close cooperation between the surgical, anaesthetic, and neurophysiology teams and to prevent neurological deficits.