Iatrogenic Neurological Injury Research Articles

Effect of propofol infusion vs ketamine plus dexmedetomidine infusion on the amplitude of motor evoked potential in pediatric patients undergoing tethered spinal cord surgeries; a randomized, double blind controlled study

Background & objective: The use of intraoperative neurophysiologic monitoring (IOM) has increased over the past two decades for the detection and prevention of iatrogenic neurologic injuries. Motor evoked potentials (MEP) are extremely sensitive to changes in physiological variables and inhalational agents reduce MEPs in a dose dependent manner. So IV anesthetics (propofol or ketamine) and opioids (fentanyl or remifentanil), are frequently used in spinal surgeries under MEPs monitoring. We compared the effects of propofol and fentanyl to those of ketamine, dexmedetomidine, and fentanyl in terms of minimizing their effects on MEP amplitude and hemodynamic stability during surgery Methodology: This double blind, randomized, prospective study was conducted on 46 children, who were randomly allocated into 2 groups Ketamine–dexmedetomidine group: (n = 23) Maintenance throughout the procedure, by infusing Dexmedetomidine (0.4 -0.6 μg/.kg /.hr) ketamine, (1 -2m/.kg/.hr.) and giving bolus of fentanyl, (1-2μg/.kg/ ). Propofol-group:(n = 23) Maintenance throughout the procedure, By infusing propofol (100 ug L/kg/min) and giving bolus of fentanyl, (1-2μg/.kg/ ), with keeping mean arterial blood pressure changes within 25% of the baseline in both groups. Results: Right and left quadriceps muscle measurements were insignificantly different between both groups at base line and were significantly higher in Group KD than Group P at skin incision, surgical manipulation and surgical closure. Right and left adductor hallucis muscle measurements were insignificantly different between both groups at base line and were significantly higher in Group KD than Group P at 5 mins, 10 mins, 15 mins, skin incision, surgical manipulation and surgical closure (P value <0.001). Intraoperative fentanyl consumption was significantly lower in Group KD than Group P. Conclusion: The combination of dexmedetomidine and ketamine infusion is efficacious, safe, and has minimal effect on evoked potentials compared with the propofol-based TIVA group during spine pediatrics surgery. In addition, this combination increases the reliability and accuracy of MEP monitoring with hemodynamic stability and adequate post-operative pain relief. Using dexmedetomidine and ketamine infusions during pediatric spine surgery might successfully replace the typical propofol-based TIVA, although more studies are required . Registration: ClinicalTrials.gov registration number NCT05591001. Keywords: Motor evoked potential, dexmedetomidine, ketamine, propofol. Citation: Saleh AH, Hammad SH, Hassan PF. Effect of propofol infusion vs ketamine plus dexmedetomidine infusion on the amplitude of motor evoked potential in pediatric patients undergoing tethered spinal cord surgeries; a randomized, double blind controlled study. Anaesth. pain intensive care 2024;28(4):692−699; DOI: 10.35975/apic.v28i4.2218 Received: May 08, 2023; Reviewed: February 02, 2024; Accepted: July 03, 2924

Evaluating the Long-Term Neurologic Sequelae Among Trauma Patients who Received Flexion-Extension Radiographs.

This study evaluated the presence of neurologic sequelae among trauma patients after flexion-extension (F/E) radiographs. Authors of the study conducted a retrospective review of patients (age ≥ 14 years) with a Glasgow Coma Score of 15 who sustained a blunt traumatic injury and received F/E radiographs. Radiographic scans were defined as positive, negative, inconclusive, or incomplete. The neurologic status of each patient was assessed before and after the F/E radiographs, and at discharge and follow-up. Of the 501 patients included in the analysis, 84.6% (n = 424) had negative F/E radiographs, and 3.2% (n = 16) had positive F/E radiographs. Ten percent (n = 51) of patients had incomplete F/E radiographs, and 2.0% (n = 10) were inconclusive due to the inability to rule out a ligamentous injury. Three patients (0.6%) had MRI-confirmed ligamentous injuries, all of which had initial incomplete F/E radiographs due to pain. No patient had a documented neurological deficit before or after the F/E exam. Three patients with an initial negative F/E radiograph returned to the clinic with symptoms of neurologic sequelae. Two of these patients had symptom resolution with no further issues at future follow-up appointments. The third patient was found to have chronic neurologic symptoms after further evaluation. The inclusion of F/E exams in cervical spine clearance protocols did not demonstrate any new long-term iatrogenic neurologic injuries. Consideration should be given to performing MRIs on patients with incomplete F/E radiographs that cannot rule out a ligamentous injury.

Incidence and degrees of neurologic decline following thoracic costotransversectomy

Background ContextThoracic costotransversectomies (TCT) are amongst the most invasive spine procedures performed. Of greatest concern to the patient and surgeon is the risk of iatrogenic neurologic injury associated with these procedures. Most available studies limit their assessment of neurologic function to nonspecific scales such as the broader ASIA scoring system of A to E and have not comprehensively described the rates of iatrogenic injury following these procedures by looking more precisely with ASIA motor scoring (0–100) which allows for more in-depth analysis. PurposeThe purpose of this study is to investigate the rates and degree of iatrogenic neurologic decline following TCT and subsequent rates and degree of motor recovery. Study Design/SettingRetrospective medical record review at a single institution. Patient SampleAround 116 consecutive patients undergoing TCT operations. Outcome MeasuresNeurological changes from preprocedure to final follow-up assessed by lower extremity motor score. MethodsA retrospective chart review of patients undergoing TCT between May 2008 and April 2018 was carried out. Clinical, surgical, and intraoperative neuromonitoring data were collected. Patients who demonstrated an initial postoperative decline in lower extremity motor scores (LEMS) were followed through their final follow up to assess recovery. ResultsAround 116 patients underwent TCT between T2 and T12 between May 2008 and April 2018. Seven (6.0%) patients demonstrated an immediate postoperative decline as defined by a drop of more than 4 points (mean 15.1; range 5–50) in motor score. All patients who demonstrated an initial postoperative motor score decline returned to within 4 LEMS points of their preoperative LEMS by final follow up. IOMN changes were noted only in half of all monitored patients who were noted to have a decline. ConclusionsIn our series, 6.0% of patients undergoing TCT experienced an initial decline in motor score with 94.0% demonstrating an unchanged or improved examination compared to preoperative exam. In our series, all patients who exhibited a decline recovered to within 4 points of the preoperative motor score within the first year postoperatively.

Crossed versus lateral K-wire fixation of supracondylar fractures of the humerus in children: a meta-analysis of randomized controlled trials

Supracondylar fractures of the humerus are common in children. Whether fixation should be performed with crossed or lateral wires remains controversial. We performed a meta-analysis of randomized controlled trials to evaluate both techniques in terms of the function of the elbow and the risk of neurologic injury and loss of reduction. We also assessed the quality of the evidence currently available. The MEDLINE, Embase, Cochrane Library, and LILACS (Latin American and Caribbean Health Sciences Literature) databases, as well as ongoing clinical trial databases, were searched until March 2020. The main outcomes were function, measured by the Flynn criteria, and complications (neurologic lesions and loss of reduction). A meta-analysis was conducted using relative risk (RR) analysis for dichotomous variables and difference in means for continuous variables. Heterogeneity was tested using the I2 statistic. Twelve trials, with a total of 930 patients, met the inclusion criteria. Both groups (crossed-wire and lateral-wire fixation) presented satisfactory functional results, with no difference between them (RR, 0.99; 95% confidence interval [CI], 0.96-1.02; P = .44). Patients undergoing crossed-wire fixation had a higher risk of iatrogenic neurologic injury (RR, 0.45; 95% CI, 0.21-0.99; P = .05). The crossed group showed greater fixation stability, with a lower incidence of loss of fracture reduction (RR, 1.39; 95% CI, 1.04-1.85; P = .03). The GRADEpro GDT (Guideline Development Tool) showed that the quality of evidence of the evaluated outcomes was low or very low. There is evidence of very low quality that fixation with lateral wires is safer regarding iatrogenic nerve lesions whereas fixation with crossed wires is more effective at maintaining fracture reduction.

Anatomic versus reverse shoulder arthroplasty, are nerve injury rates different?

BackgroundThe true incidence of iatrogenic neurological injury following total shoulder arthroplasty (TSA) surgery remains controversial at a cited rate of 1%-18.7%. Additionally, there is a reported incidence of new onset distal peripheral neuropathy (DPN) of 7.1% and 12.3%, for anatomic (aTSA) and reverse (rTSA) shoulder replacements, respectively. The purpose of this present study is to report on nerve injury rates of a large, consecutive series of primary TSA (ie, rTSA and aTSA) performed by one surgeon, utilizing intraoperative neuromonitoring and consistent implant design. MethodsA retrospective cohort review of consecutive patients who underwent primary TSA was performed from January 2016 to March 2020. Intraoperative neuromonitoring data included transcranial electrical motor evoked potentials (MEPs), somatosensory evoked potentials, and free-run electromyography. Motor alert threshold was set at ≥ 80% signal attenuation in any one or more peripheral nerves. Patients were screened for neurological deficits immediately following surgery and in the first 2 postoperative visits. Additional data collection included surgical indication, gender, laterality, age at surgery, procedure performed, body mass index, history of tobacco use, Charlson comorbidity index, past medical history and preoperative range of motion. ResultsA total of 290 consecutive shoulders in 270 patients were included. Ninety-one (31.4%) shoulders underwent aTSA, while 199 (68.6%) underwent rTSA. Patients in the rTSA cohort were significantly older (70.1 vs. 61.3 years; P < .001), had higher Charlson comorbidity index scores (4.3 vs. 3.0; P < .001), and shorter operative time (81.8 vs. 99.7; P < .001). A total of 96 MEP alerts occurred in 65 (22.4%) operations, with a significantly higher proportion of these occurring in patients undergoing aTSA. MEP alerts occurred in 28 (39.8%) aTSA versus 37 (18.5%) rTSA (P = .024). Logistical regression found operative time (P = .003, odds ratio = 1.020 [95%: 1.007-1.033]) was predictive of a MEP alert. The axillary nerve was the most commonly alerted nerve accounting for 61.5% of all alerts. Zero patients had a major or minor nerve injury in this large cohort. Nine patients (3.1%) had DPN in the postoperative period. ConclusionIn 290 surgeries, no (0%) patients had a postoperative major or minor nerve injury, and 9 (3.1%) patients complained of postoperative distal peripheral neuropathy. Patients that had MEP alerts had significantly longer operative times and were more likely to be in the aTSA group compared to the rTSA group. This may be attributed to longer exposure and implantation times on the glenoid side for an anatomic as opposed to a reverse arthroplasty. Level of evidenceLevel III; Retrospective Cohort study.

PD23-08 ENHANCED INTRAOPERATIVE NERVE VISUALIZATION: PROOF OF CONCEPT

INTRODUCTION AND OBJECTIVE:Iatrogenic neurological injury is a risk in genitourinary surgery. Herein, we present our experience with an in-house designed agent to enhance the visualization of nerve...

Posterior iliac screw rod for the treatment of unilateral unstable Denis I and II sacral fractures

Objective To explore the efficacy of posterior iliac screw rod for unilateral unstable Denis I and II sacral fractures. Methods Data of 50 patients with unilateral unstable Denis I, II sacral fractures treated from March 2016 to October 2018 were retrospectively analyzed. According to fixation methods, the patients were divided into posterior iliac screw rod group (Iliac screw rod group) and robot-assisted iliosacral screw group (Iliosacral screw group). There were 20 patients in the Iliac screw rod group, 13 males and 7 females, with an average age of 41.10±14.07 years (range, 22-76 years), and there were 5 cases of Denis type I and 15 cases of type II sacral fractures. All of them had anterior pelvic ring injuries, and according to pelvic Tile classification, there were 2 B1 type, 12 B2 type, 6 C1 type, and 3 cases of Gibbons grade II sacral nerve injuries. There were 30 patients in the Iliosacral screw group, 18 males and 12 females, with an average age of 44.70±13.35 years (range,16-78 years), and there were 6 cases of type I and 24 cases of type II sacral fractures. There were 2 cases of type B1, 20 cases of B2, 8 cases of C1 pelvic fractures, 4 cases combined with sacral nerve injuries including 3 cases of Gibbons grade II and 1 case of grade III. The patients’ age, operation time, amount of bleeding, times of fluoroscopy, postoperative Majeed score were compared by the independent t test. The quality of fracture reduction was compared by Chi-square test, and the postoperative Gibbons grade was compared by the rank sum test. Results All patients were followed up for 22.8 months (range, 12-40 months). In the Iliac screw rod group, the operation time was 41.40±7.30 min, intraoperative blood loss 105.00±61.94 ml, intraoperative times of fluoroscopy 19.10±7.33, and according to Mears and Velyvis valuation criterion, there were 9 cases of anatomical reduction, 10 cases of satisfactory reduction, and 1 case of unsatisfactory reduction, with the Majeed score of 84.25±8.29. There were 3 cases with Gibbons grade II sacral nerve injury, and 2 of them recovered to grade I. In the Iliosacral screw group, the operation time was 18.27±5.89 min, intraoperative blood loss 33.00±17.54 ml, intraoperative times of fluoroscopy 14.93±4.49, and according to Mears and Velyvis valuation criterion, there were 15 cases of anatomical reduction, 13 cases of satisfactory reduction and 2 cases of unsatisfactory reduction, with the Majeed score of 86.43±7.43. There were 3 cases with Gibbons grade II sacral nerve injury, and 2 of them recovered to grade I, and 1 case with grade III recovered to grade II postoperation. Compared to Iliosacral screw group, the Iliac screw rod group has longer operation time (t=-12.36, P<0.001), more blood loss (t=-6.04, P<0.001) and more intraoperative times of fluoroscopy (t=-2.50, P=0.016). There were no statistical differences for quality of fracture reduction (χ2=0.23, P=0.89), Majeed score (t=0.97, P=0.34), and the Gibbons grade (Z=-0.224, P=0.82) between the two groups. In the Iliac screw rod group, 1 patient had a unilateral superficial wound infection and 1 patient complained of discomfort because of the nail. In the Iliosacral screw group 1 patient had iatrogenic S1 neurological injury. Conclusion For the unstable sacral fractures, who are not suitable for iliosacral screw fixation, posterior iliac screw rod fixation is an effective alternative with similar clinical effect as robot assisted iliosacral screw fixation. Key words: Sacrum; Fractures, bone; Fracture fixation, internal; Surgical procedures, minimally invasive

Intraoperative neuromonitoring in spine deformity surgery: modalities, advantages, limitations, medicolegal issues - surgeons' views.

In spine deformity surgery, iatrogenic neurologic injuries might occur due to the mechanical force applied to the spinal cord from implants, instruments, and bony structures, or due to ischemic changes from vessel ligation during exposure and cord distraction/compression during corrective manoeuvres.Prompt reaction within the reversible phase (reducing of compressive/distractive forces) usually restores functionality of the spinal cord, but if those forces continue to persist, a permanent neurological deficit might be expected.With monitoring of sensory pathways (dorsal column–medial lemniscus) by somatosensory-evoked potentials (SSEPs), such events are detected with a sensitivity of up to 92%, and a specificity of up to 100%.The monitoring of motor pathways by transcranial electric motor-evoked potentials (TceMEPs) has a sensitivity and a specificity of up to 100%, but it requires avoidance of halogenated anaesthetics and neuromuscular blockades.Different modalities of intraoperative neuromonitoring (IONM: SSEP, TceMEP, or combined) can be performed by the neurophysiologist, the technician or the surgeon. Combined SSEP/TceMEP performed by the neurophysiologist in the operating room is the preferable method of IONM, but it might be impractical or unaffordable in many institutions. Still, many spine deformity surgeries worldwide are performed without any type of IONM. Medicolegal aspects of IONM are different worldwide and in many cases some vagueness remains.The type of IONM that a spinal surgeon employs should be reliable, affordable, practical, and recognized by the medicolegal guidelines.Cite this article: EFORT Open Rev 2020;5:9-16. DOI: 10.1302/2058-5241.5.180032

Role of intraoperative neuromonitoring in spine surgery: A retrospective study

Background: Iatrogenic neurological injury resulting during surgical intervention is a devastating complication not only for patient but also for the operating surgeon. Even with best efforts, the risk remains approximately 5%. Aims: This study aims to study the role of intraoperative neuromonitoring (IONM) in non-deformed spine surgeries and to find out the sensitivity and specificity. Settings and Design: Tertiary health-care centre. Retrospective study with data of the patients operated from January 2019 to January 2020 was reviewed and evaluated. Materials and Methods: Patients with spinal fractures, spondylodiscitis, bony tumours of spine and degenerative spinal disorders without neurological deficit were included. The patients with spinal deformity and with prior neurological deficits were excluded. Group A: the patients with no IONM signal drop during procedure, Group B: the patients who experienced significant drop in signal during surgery. Statistical Analysis Used: Data entry-MS Excel, Data analysis-SPSS 23.0 version for windows, descriptive statistics-mean ± numerical variable, null hypothesis-paired test-two sample for mean (

Intraoperative Multimodal Monitoring in Pedicle Subtraction Osteotomies of the Lumbar Spine: A Narrative Literature Review.

The use of intraoperative multimodal monitoring (IOM) in spinal deformity surgeries is well documented. In particular, pedicle subtraction osteotomy (PSO), a corrective procedure for sagittal deformity of the spine, often involves IOM usage. By providing immediate feedback to the operating surgeon, IOM has the potential to eliminate or at least minimize the risk of iatrogenic neurological injury. However, despite the widespread usage of IOM, there is currently no standardization of IOM usage in complex spine surgeries, including lumbar PSOs, and decisions concerning IOM utilization are often driven by surgeon experience and preference. This creates a state of clinical equipoise, which is further complicated by the varying degrees of benefit that IOM has on patient outcomes depending on the operation and spinal levels involved. For instance, while IOM use in thoracic PSOs has been shown to be effective, there is no established consensus on the net impact of IOM use in PSOs of the lumbar spine. Although IOM has the potential to mitigate neurological damage, it also increases operation time and cost; thus, it should only be used in operations where it will have a net positive impact on patient outcomes. The question thus becomes whether PSO of the lumbar spine is one such operation. To address this, we examine the most frequently used IOM modalities and evaluate their current usage and efficacy in lumbar PSOs. Furthermore, we will also examine the utility of IOM for other surgeries of the lumbar spine, including corrective procedures for idiopathic scoliosis and degenerative scoliosis, and routine lumbar procedures, such as discectomies and decompression surgeries for foraminal and canal stenosis.

Percutaneous pedicle screw fixation and minimally invasive decompression in the same incision for type A3 thoracolumbar burst fracture

To assess the effectiveness of percutaneous pedicle screw fixation and minimally invasive decompression in the same incision for type A3 thoracolumbar burst fracture. Between May 2014 and February 2016, 43 cases of type A3 thoracolumbar burst fracture with or without nerve symptoms were treated with pedicle screw fixation and neural decompression. Of them, 21 patients underwent percutaneous pedicle screw fixation and minimally invasive decompression in the same incision (percutaneous group), and the other 22 patients underwent traditional open surgery (open group). There was no significant difference in gender, age, cause of injury, fractures level, preoperative American Spinal Injury Association (ASIA) grade, thoracolumbar injury classification and severity (TLICS) score, load-sharing classification, height of injury vertebrae, kyphotic Cobb angle, and spinal canal encroachment between 2 groups ( P>0.05). The length of soft tissue dissection, operation time, intraoperative blood loss, postoperative drainage, X-ray exposure times, and incision visual analogue scale (VAS) score at 1 day after operation were recorded and compared. At last follow-up, Japanese Orthopaedic Association (JOA) score and low back pain VAS score were recorded and compared respectively. The ASIA grade recovery was evaluated; the height of injury vertebrae, kyphotic Cobb angle, and spinal canal encroachment were assessed postoperatively. Percutaneous group was significantly better than open group in the length of soft tissue dissection, intraoperative blood loss, postoperative drainage, and incision VAS at 1 day after operation ( P<0.05), but no significant difference was found in operation time between 2 groups ( P>0.05); however, X-ray exposure times of open group were significantly better than that of percutaneous group ( P<0.01). The patients were followed up 12 to 19 months (mean, 15.1 months) in 2 groups. All patients achieved effective decompression. No complications of iatrogenic neurological injury and internal fixation failure occurred. The height of injury vertebrae, kyphotic Cobb angle, and spinal canal encroachment of the fractured vertebral body were significantly improved at 3 days after operation when compared with preoperative ones ( P<0.05), but no significant difference was found between 2 groups ( P>0.05). At last follow-up, JOA score and low back pain VAS score of percutaneous group were significantly better than those of open group ( P<0.05). The neurological function under grade E was improved at least one ASIA grade in 2 groups, but no significant difference was shown between 2 groups ( Z=0.480, P=0.961). Percutaneous pedicle screw fixation and minimally invasive decompression in the same incision for type A3 thoracolumbar burst fracture has satisfactory effectiveness. And it has the advantages of minimal trauma, quick recovery, safeness, and reliableness.

A Possible Case of Neurogenic Pulmonary Edema in a Sheep following Intracranial Surgery

Abstract Objective: To describe presentation, treatment and outcome of a sheep that developed acute respiratory distress after intracranial surgery. Case summary: A 3-year-old female crossbred sheep weighing 64 kg was anaesthetized for intracranial surgery as a part of a research project. Premedication and induction of anesthesia were uneventful as well as tracheal intubation. Anesthesia was maintained with isoflurane in a 50% mixture of oxygen and air, fentanyl (5-15 μg kg-1h-1) and lidocaine (1.8 mg kg-1h-1). During anesthesia, an increased alveolar-arterial oxygen gradient was calculated on the basis of arterial blood gas analysis: inspiratory fraction of oxygen was increased and a recruitment manoeuvre was performed. After 210 minutes of anesthesia, the sheep was let recover with oxygen supplementation under monitoring of pulse-oxymetry, capnography, inspired and expired oxygen, temperature and invasive blood pressure. At tracheal extubation no signs of regurgitation or aspiration were noticed. Twenty-five minutes later, the sheep showed deterioration of neurological status and clonic seizure responsive to diazepam. After transient tachycardia, blood pressure rose acutely and sinus bradycardia followed. Severe tachypnea started in few minutes accompanied by loud respiratory noises and harsh diffuse crackles on both sides of the thorax. Foamy blood nasal exudates discharged from the nostrils. Neurogenic pulmonary edema as a sequel of increased intracranial pressure was suspected and treated with intravenous mannitol (0.5 gkg-1) and furosemide (4 mgKg-1). Hypoxemia was successfully managed with oxygen supplementation. Motor and cognitive functions improved progressively and were deemed normal within 12 hours from the episode, when arterial partial pressure of oxygen was 11.7 kPa (88 mmHg) at room air. New information provided: Severe pulmonary complications may be observed after iatrogenic neurological injury in sheep. Neurogenic pulmonary edema should be taken into account among the differential diagnoses of abrupt respiratory distress following seizure.

Percutaneous Screw Fixation of Crescent Fracture-Dislocation of the Sacroiliac Joint

Crescent fracture-dislocation of the sacroiliac joint (CFDSIJ) is a type of lateral compression pelvic injury associated with instability. Open reduction and internal fixation is a traditional treatment of CFDSIJ. However, a minimally invasive method has never been reported. The purpose of this study was to assess the outcome of closed reduction and percutaneous fixation for different types of CFDSIJ and present their clinical outcome. The authors reviewed 117 patients diagnosed with CFDSIJ between July 2003 and July 2013. Closed reduction and percutaneous fixation was performed in 73 patients. Treatment selection was based on Day's fracture classification. For type I fractures, fixation perpendicular to the fracture line were performed. For type II fractures, crossed fixation was performed. For type III fractures, fixation was performed with iliosacral screws. Forty-four patients were treated by open reduction and plate fixation. Demographics, fracture pattern distribution, blood loss, incision lengths, revision surgeries, radiological results, and functional scores were compared. All 117 patients were followed for more than 6 months (mean, 14 months [range, 6-24 months]). Blood loss, extensive exposure, duration of posterior ring surgery, duration of hospital stay, and infection rates were lower in the closed group (P<.01). Patients in the closed group achieved better functional performance (P<.01). There were no significant differences in reduction quality (P=.32), revision surgery rates (P=.27), and iatrogenic neurologic injuries (P=.2) between the 2 groups. The authors' results indicate that closed reduction and percutaneous fixation is a safe and effective surgical method for CFDSIJ.

Neuromonitoring in pediatric spine surgery

Intraoperative neurophysiologic monitoring has an integral role during pediatric spinal deformity correction to mitigate the risk of iatrogenic neurologic injury. This review describes the nuances of pediatric spine surgery as they relate to neurophysiologic monitoring, addresses how the advent of multimodal techniques has expanded the scope of management of complex curvatures, and discusses the role of neuromonitoring during contemporary pediatric spine procedures, including growing rod and vertical expandable prosthetic titanium rib implantation.

Surgical management of eloquent supratentorial low-grade gliomas with special emphasis on intraoperative imaging.

Eloquent diffuse low-grade gliomas (LGGs) threaten patients' neurologic function and are also associated with inferior survival. Many neurosurgeons still refrain from early resection due to the fear of iatrogenic neurologic injury. However, the perceived safety of expectant management strategies may soon be overshadowed by the progressive deficits of tumor growth in eloquent regions. It is also known that radical and successful surgery prolongs progression-free survival, overall survival, and may reduce seizure burden and also potentially neurocognitive functions. Thus early successful surgery with preservation of function has a significant impact on patients' health. In modern neurosurgery, safe resection is often possible with detailed knowledge of anatomy and function together with the active use of various intraoperative surgical tools. We present illustrative cases of eloquent LGGs treated with different intraoperative tools. An introduction to important intraoperative tools in LGG surgery is provided by experts in the field and described in five cases viewed in the context of the recent LGG literature. We present five cases with presumed eloquently located LGGs where extensive resection was offered using different intraoperative techniques. The clinical and radiologic outcomes are described. Correct use of intraoperative tools together with the surgeon's knowledge of anatomy and function will provide good functional and oncologic results in eloquently located LGGs. Watchful waiting or deferral of surgery due to tumor location (i.e., claiming inoperability) is very rarely good practice.

Interest of Electrostimulation of Peripheral Motor Nerves during Percutaneous Thermal Ablation

We present our experience of utilizing peripheral nerve electrostimulation as a complementary monitoring technique during percutaneous thermal ablation procedures; and we highlight its utility and feasibility in the prevention of iatrogenic neurologic thermal injury. Peripheral motor nerve electrostimulation was performed in 12 patients undergoing percutaneous image-guided thermal ablations of spinal/pelvic lesions in close proximity to the spinal cord and nerve roots. Electrostimulation was used in addition to existing insulation (active warming/cooling with hydrodissection, passive insulation with CO2 insufflation) and temperature monitoring (thermocouples) techniques. Impending neurologic deficit was defined as a visual reduction of muscle response or need for a stronger electric current to evoke muscle contraction, compared with baseline. Significant reduction of the muscle response to electrostimulation was observed in three patients during the ablation, necessitating temporary interruption, followed by injection of warm/cool saline. This resulted in complete recovery of the muscle response in two cases, while for the third patient the response did not improve and the procedure was terminated. No patient experienced postoperative motor deficit. Peripheral motor nerve electrostimulation is a simple, easily accessible technique allowing early detection of impending neurologic injury during percutaneous image-guided thermal ablation. It complements existing monitoring techniques and provides a functional assessment along the whole length of the nerve.

Intraoperative neurophysiologic monitoring during syringomyelia surgery: lessons from a series of 13 patients

Avoiding iatrogenic neurological injury during spinal cord surgery is crucially important. Intraoperative neurological monitoring (INM) has been widely used in a variety of spinal surgeries as a means of reducing the risk of intraoperative neurological insults. This study evaluates the benefits of INM specifically in spinal procedures for treatment of syringomyelia. Thirteen patients who underwent surgery for syrinx drainage with the assistance of INM were included in this study. In all patients both somatosensory-evoked potentials (SSEP) and motor-evoked potentials (MEP) were monitored. INM data and perioperative neurological evaluations were both recorded and analyzed. Eleven patients underwent syringo-subarachnoid shunt (SSAS) surgery. One patient underwent syrinx drainage and foramen magnum decompression (FMD). One patient underwent syringo-pleural shunt (SPA) surgery. Baseline MEP and SSEP were recordable at the beginning of surgery in 11 patients (>84 %). In the other two cases, baseline data from specific INM modalities were absent, correlating with the antecedent neurologic symptomotology. Two patients exhibited significant intraoperative changes in MEP data that influenced the course of surgery and prompted removal or re-insertion of the shunt. Mild and transient worsening of preoperative symptoms was reported in these instances. No new postoperative neurological deficits were reported in the other 11 patients in whom INM data were preserved throughout surgery. These data support routine use of INM in syringomyelia surgery. INM can alert the surgeon to potential intraoperative threats to the functional integrity of the spinal cord, providing a useful adjunct to spinal cord surgeries for the treatment of syringomyelia.

Percutaneous lateral Kirschner wire fixation in pediatric supracondylar fractures of humerus

Aim: This prospective study was conducted to know the outcome of percutaneous lateral pinning in the management of displaced supracondylar fracture of humerus in children. Settings and Designs: Prospective study. Materials and Methods: Eighty five patients with displaced supracondylar fractures admitted between July 2005 and July 2010 were recruited into the study. All patients were operated under general anesthesia within 24 h after trauma using the percutaneous 2-lateral pin fixation (n = 85). Results were analyzed using Flynn's criteria. All patients were followed up to 6 months post-operatively. Results: Eighty five displaced supracondylar fractures of humerus, aged between 1½ year and 13 years, were treated using close reduction and percutaneous Kirschner (K) wire fixation under the c-arm image intensifier. Above elbow plaster of paris back slab was applied in all cases for at least 4 weeks. The slab and K-wires were removed after 4 weeks and elbow range of motion exercise was started. 68.23% had excellent, 29.40% good, 1.17% fair and 1.17% had poor results at 8 th weeks, which was improved to 91.75% excellent, 7.05% good, 1.17% fair and no poor result at final follow-up. There was no iatrogenic neurological injury either for the ulnar or for the radial nerves. Five patients developed superficial pin tract infection post-operatively and were treated conservatively with good healing and no long-term sequelae. Conclusion: Closed reduction and percutaneous lateral pinning proved an efficient, reliable, and safe method in the treatment of displaced supracondylar fractures of the humerus in children.

The Usefulness of Intraoperative Neurophysiological Monitoring in Cervical Spine Surgery

The usefulness of intraoperative neurophysiological monitoring (IONM), including somatosensory-evoked potential (SSEP) and transcranial electrical motor-evoked potentials (TcMEPs) in cervical spine surgery still needs to be evaluated. We retrospectively reviewed 200 cervical spine surgery patients from 2008 to 2009 to determine the role of IONM in cervical spine surgery. Total intravenous anesthesia was used for all patients. IONM alerts were defined as a 50% decrease in amplitude, a 10% increase in latency, or a unilateral change for SSEP and an increase in stimulation threshold of more than 100 V for TcMEP. Three patients had SSEP alerts that were related to arm malposition (2 patients) and hypotension (1 patient). Five patients had TcMEP alerts: 4 alerts were caused by hypotension and 1 by bone graft compression of the spinal cord. All alerts were resolved when causative reasons were corrected. There was no postoperative iatrogenic neurological injury. The sensitivities of SSEP and TcMEP alerts for detecting impending neurological injury were 37.5% and 62.5%, respectively. The sensitivity of both SSEP and TcMEP used in combination was 100%. No false-positive and false-negative alerts were identified in either SSEP or TcMEP (100% specificity). The total intravenous anesthesia technique optimizes the detection of SSEP and TcMEP and therefore improves the sensitivity and specificity of IONM. SSEP is sensitive in detecting alerts in possible malposition-induced ischemia or brachial plexus nerve injury. TcMEP specifically detects hypotension-induced spinal functional compromises. Combination use of TcMEP and SSEP enhances the early detection of impeding neurological damage during cervical spine surgery.

Impact of Multimodal Intraoperative Monitoring During Surgery for Spine Deformity and Potential Risk Factors for Neurological Monitoring Changes

Retrospective review. To evaluate the efficacy of multimodal intraoperative neuromonitoring for predicting iatrogenic neurological injury during surgical correction of a spine deformity and evaluate the potential risk factors for neurological monitoring changes. Single modal intraoperative neuromonitoring is insufficient to predict neurological injury during surgical correction of spine deformity. Multimodal monitoring can provide more accuracy. Some risk factors were reported to be correlated with high rates of neurological deficits during scoliosis correction. But few studies have reported on the risk factors for neurological monitoring changes (NMCs). The records of 176 consecutive patients who underwent surgery for the treatment of spinal deformities were reviewed. The patients were monitored using transcranial electric motor-evoked potential (MEP) and/or somatosensory-evoked potential (SEP). Alterations with the MEP wave amplitude decreasing more than 75% and SEP amplitude decreasing more than 50%, as compared with the baseline, were diagnosed as positive changes. Risk factors related to NMCs were evaluated, in light of preoperative neurological deficits, comorbidity of spinal cord deformity, procedure of osteotomy, main curve Cobb angle, and a diagnosis of kyphosis. Combined MEP/SEP monitoring was successfully achieved in 175 of 176 cases. Eleven cases were presented with true NMCs according to MEPs. One patient had an irreversible neurological deficit and 4 patients had transient neurological deficits after waking up from the operation. SEP lagged MEP for an average of 15 minutes when both were presented with positive changes. The sensitivity and specificity of MEP were 91.7% and 98.8%, respectively. Solo SEP were 50% and 95.2%. Combined MEP and SEP were 92.9% and 99.4%. The procedure of osteotomy, curve Cobb angle more than 90 degrees, and preoperative kyphosis were correlated with a higher incidence of NMCs. Multimodal intraoperative monitoring provides higher sensitivity for monitoring during spine deformity surgery and can predict events of neurological injury. The detection of NMCs and adjustment of surgical strategy may prevent irreversible neurological deficits. The possible risk factors for NMCs during spine deformity surgery include an osteotomy procedure, kyphosis correction, and preoperative Cobb angle more than 90 degrees.