Conscious sedation with dexmedetomidine compared with asleep-awake-asleep craniotomies in glioma surgery: an analysis of 180 patients

Efficacy of intranasal dexmedetomidine-esketamine sedation for pediatric acceptance of facemask: single-center, double-blind, randomized, controlled trial

OBJECTIVE

We compare the efficacy of intranasal dexmedetomidine (DEX) and DEX-esketamine sedation on pediatric acceptance of face mask.

METHODS

This single-center double-blind randomized controlled study was conducted at a tertiary hospital affiliated with Shanghai Jiao Tong University. Ninety children aged 1 year to 6 years old and scheduled for elective surgery were randomly allocated in a 1:1 ratio into receiving DEX alone (n = 45) and DEX-esketamine (n = 45). DEX and esketamine were used intranasally at doses of 2 µg/kg and 2.0 mg/kg respectively. Children were assessed by an attending anesthesiologist with modified observer's assessment of alertness and sedation (MOAA/S), pediatric separation anxiety scale (PSAS) and mask acceptance scale (MAS). Perioperative adverse events (bradycardia, hypotension, hypoxia, emergence delirium etc.) were recorded.

RESULTS

Of 95 patients enrolled, 90 completed the study. The proportion of children who accepted facemask was significantly higher in the DEX-esketamine group compared to the DEX group (86.7% (39/45) vs. 62.2% (28/45), p = 0.008). Within 30 min after intranasal administration of agents, PSAS scores were similar between the two groups. Children in the DEX group were easily aroused when repositioned from the transferring bed to the operation table. In contrast, those in the DEX-esketamine group maintained a stable level of sedation (MOAA/S scores, median [25th- 75th interquartile range], 1 [1, 1] for DEX-esketamine vs. 2 [1, 4] for DEX, p < 0.001). Furthermore, subgroup analysis found that DEX-esketamine provided better facemask acceptance in children with high anxiety (PSAS ≥ 3). There were no significant differences in perioperative heart rate, noninvasive blood pressure and percutaneous arterial oxygen saturation between the two groups. Postoperative extubation time and perioperative adverse events were also comparable between the groups (all p > 0.05).

CONCLUSIONS

For preoperative sedation, combination of DEX with esketamine improved mask acceptance than dexmedetomidine alone, likely due to its superior anxiolytic effect in children with high anxiety.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trial Register (registration no. ChiCTR2400087873, registration date on 6/8/2024).

Efficacy and safety of anesthetic agents in awake craniotomy using monitored anesthesia care protocol: a systematic review and meta-analysis

Awake craniotomy (AC) facilitates real-time brain mapping, maximizing tumor resection while preserving critical neurological functions. This study systematically reviews the efficacy of several anesthetic protocols under Monitored Anesthesia Care (MAC) during AC, focusing on clinical outcomes. A systematic review and meta-analysis were conducted using data from observational studies and randomized trials involving AC under MAC. Databases searched included PubMed, Embase, and Web of Science. The analysis employed mixed-effects models to assess both the overall rate of the outcomes and the impact of anesthetic agents on clinical outcomes. The primary outcome was the rate of postoperative neurological deficits. Of 468 studies initially identified, 26 met the inclusion criteria. The overall adverse event rate was 23.7%. The pooled proportion of patients with postoperative neurological deficits and intraoperative seizures was 10.45% and 8.8%, respectively. Remifentanil use was associated with a lower risk of neurological deficits in mixed effects meta-analysis (6.9% vs 16.5%), while intraoperative seizure rate was slightly lower with propofol use (7.1% vs. 11.8%). Midazolam use was also associated with lower agitation (5.5% vs. 10.9%). The rate of secondary adverse outcomes other than hypertension (10.2%) and tense brain (10%) were below 10% and comparable to the previous literature. The findings highlight the variability in anesthetic protocols used in MAC for AC. Despite limited evidence regarding safety concerns and potential confounders, Remifentanil, Propofol, and Midazolam appear to be superior to other agents evaluated in these procedures. However, further research is required to draw definitive conclusions.

Dexmedetomidine inhibits the migration, invasion, and glycolysis of glioblastoma cells by lactylation of c-myc

BACKGROUND

Glioblastoma (GBM) is a brain tumor with poor prognosis. Dexmedetomidine (Dex) regulates the biological behaviors of tumor cells to accelerate or decelerate cancer progression.

OBJECTIVE

We investigated the effects of Dex on the migration, invasion, and glycolysis in GBM.

METHODS

The concentration of Dex was determined using the cell counting kit-8 assay. The impacts of Dex on biological behaviors of GBM cells were assessed using Transwell assay, XF96 extracellular flux analysis, and western blot. The expression of c-Myc was examined using reverse transcription-quantitative polymerase chain reaction. The lactylation or stability of c-Myc was measured by western blot after immunoprecipitation or cycloheximide treatment.

RESULTS

We found that Dex (200 nM) inhibited GBM cell viability, migration, invasion, and glycolysis. C-Myc was highly expressed in GBM cells and was decreased by Dex treatment. Moreover, Dex suppressed lactylated c-Myc levels via suppressing glycolysis, thereby reducing the protein stability of c-Myc. Sodium lactate treatment abrogated the effects of Dex on the biological behaviors of GBM cells.

CONCLUSION

Dex suppressed the migration, invasion, and glycolysis of GBM cells via inhibiting lactylation of c-Myc and suppressing the c-Myc stability, suggesting that Dex may be a novel therapeutic drug for GBM treatment.

Dexmedetomidine for awake craniotomy: Systematic review and meta-analysis

INTRODUCTION

For awake craniotomy, monitored anaesthesia care (MAC) had shown relatively lower failure rates. Nevertheless, the conclusion of the appropriate anaesthetic agents, and complications, has not been proposed. Therefore, the systematic review and meta-analysis was done to compare the clinical profile, surgical outcomes, and anesthesia-related complications between dexmedetomidine-based and non-dexmedetomidine regimens during monitored anesthesia care (MAC) for this procedure.

EVIDENCE ACQUISITION

Published clinical trials described MAC, including the amount of anaesthetic drugs, or the number of patients for awake craniotomy between January 1st, 2009 and March 31st, 2022 were reviewed through PubMed, Scopus, Google Scholar, and grey literature index. The standard methodological procedures were following the PRISMA statement with the PROSPERO registration. Twenty-two articles with 2,137 awake craniotomy patients identified as epilepsy surgery, deep brain stimulation procedure, and intracranial surgery closed to an eloquent area with intraoperative awakening for neuro-evaluation were included. The relative risk (RR) regarding surgical outcomes, and anaesthesia-related complications were compared.

EVIDENCE SYNTHESIS

Dexmedetomidine-based versus non-dexmedetomidine anaesthetic regimen revealed no statistically significant differences in surgical outcomes (RR 1.08, 95 %CI 0.94-1.24), conversion to general anaesthesia (RR 0.45, 95 %CI 0.05-3.83), respiratory complications (RR 0.4, 95 %CI 0.12-1.27), and intraoperative nausea and vomiting (RR 0.30, 95 %CI 0.08-1.14). However, the intraoperative seizure was higher in non-dexmedetomidine group (RR 4.26, 95 %CI 1.49-12.16).

CONCLUSION

MAC for awake craniotomy with dexmedetomidine seems to be effective and safe. Randomized controlled trials with standard protocol in specific group of patients and surgical interventions would further demonstrate a clear benefit of dexmedetomidine in awake craniotomy under MAC.

Successful Second Awake Craniotomy Reoperation With Dexmedetomidine After an Initial Abandonment Case Due to Restlessness

Awake craniotomy (AC) is sometimes aborted due to poor arousal and restlessness. Dexmedetomidine (DEX), an α2-adrenoreceptor agonist, has sedative, analgesic, and anesthetic-sparing effects, with a low risk of respiratory depression, making it effective for intraoperative pain and agitation during the awake phase. We report a case in which AC was successfully performed in combination with low-dose continuous administration of DEX during reoperation in a patient who experienced poor arousal and restlessness during their first surgery, leading to the abandonment of AC. The patient is a 48-year-old male who is scheduled for AC reoperation. Two years ago, the first AC was scheduled and performed under anesthesia with propofol and remifentanil. However, AC was abandoned due to poor intraoperative arousal and restlessness. At reoperation, general anesthesia was induced with propofol and continuous administration of remifentanil (0.1 µg/kg/min); following anesthesia induction (continuous infusion of propofol, remifentanil, and a bolus infusion of fentanyl), DEX was also administered (0.2 µg/kg/hour). We performed a scalp nerve block. Before the awake phase, the propofol dose was decreased as was DEX to 0.1 µg/kg/hour, and propofol and remifentanil were discontinued. The patient gradually awoke without any agitation and restlessness 24 min after stopping propofol and remifentanil and could perform language tasks without any complications. In this case, AC was successfully performed in combination with continuous low-dose administration of DEX at the time of reoperation in a patient who experienced poor arousal and restlessness during their first operation and had to discontinue AC.

Psychological Characteristics of Patients Undergoing Awake Craniotomy With Dexmedetomidine: A Retrospective Analysis

BACKGROUND AND OBJECTIVES

Only few studies have investigated the psychological profile of patient candidates for awake craniotomy (AC). The aim of this study was to describe the multidisciplinary clinical protocol adopted in our hospital and to retrospectively explore differences in psychological characteristic of 51 patients, analyzing association with the tolerability of the procedure.

METHODS

During the preoperative neuropsychological assessment, the Pain Anxiety Symptoms Scale was administered to assess pain-related anxiety. Clinical characteristics and anesthesiological management were retrospectively recollected. The AC procedure was classified as "optimal" or "suboptimal" based on administration of rescue sedative midazolam doses because of psychomotor agitation or emotional distress in excess with respect to our anesthesiological protocol.

RESULTS

The awake procedure was considered optimal in 33 cases (64.7% of total sample). General anesthesia was never required in our patients. No significant differences between optimal and suboptimal groups were found. No single variable was significant as a predictor of outcome on the univariate analysis, and no multivariate predictive model was possible.

CONCLUSION

Although in our experience the Pain Anxiety Symptoms Scale score was not useful in identifying candidates for AC procedures, our multidisciplinary approach provided good results with respect to the tolerability of AC surgery. However, more studies are required to identify psychological profiles and preoperative possible warning signs to find the best course of surgery for each patient.

Awake craniotomy for high-grade gliomas - a prospective cohort study in a UK tertiary-centre

BACKGROUND

Studies from the UK reporting on awake craniotomy (AC) include a heterogenous group of patients which limit the evaluation of the true impact of AC in high-grade glioma (HGG) patients. This study aims to report solely the experience and outcomes of AC for HGG surgery from our centre.

METHODS

A prospective review of all patients who underwent AC for HGG from 2013 to 2019 were performed. Data on patient characteristics including but not limited to demographics, pre- and post-operative Karnofsky performance status (KPS), tumour location and volume, type of surgery, extent of resection (EOR), tumour histopathology, intra- and post-operative complications, morbidity, mortality, disease recurrence, progression-free survival (PFS) and overall survival (OS) from the time of surgery were collected.

RESULTS

Fifteen patients (6 males; 9 females; 17 surgeries) underwent AC for HGG (median age = 55 years). Two patients underwent repeat surgeries due to disease recurrence. Median pre- and post-operative KPS score was 90 (range:80-100) and 90 (range:60-100), respectively. The EOR ranges from 60 to 100 % with a minimum of 80 % achieved in 81.3 % cases. Post-operative complications include focal seizures (17.6 %), transient aphasia/dysphasia (17.6 %), permanent motor deficit (11.8 %), transient motor deficit (5.9 %) and transient sensory disturbance (5.9 %). There were no surgery-related mortality or post-operative infection. The median PFS and OS were 13 (95%CI 5-78) and 30 (95%CI 21-78) months, respectively.

CONCLUSION

This is the first study in the UK to solely report outcomes of AC for HGG surgery. Our data demonstrates that AC for HGG in eloquent region is safe, feasible and provides comparable outcomes to those reported in the literature.

Predictors for delayed awakening in adult glioma patients receiving awake craniotomy under monitored anesthesia care

PURPOSE

Delayed awakening after anesthetic discontinuation during awake craniotomy is associated with somnolence during functional brain mapping. However, predictors of delayed awakening in patients receiving monitored anesthesia care for awake craniotomy are unknown.

METHODS

This retrospective cohort study analyzed 117 adult patients with supratentorial glioma in or near eloquent areas who received monitored anesthesia care for awake craniotomy between July 2020 and January 2023 at Linkou Chang Gung Memorial Hospital. These patients were divided into two groups according to their time to awakening (ability to speak their names) after propofol cessation: longer or shorter than 20 min (median duration). Because propofol was solely used anesthetic from skin incision to dural opening, parameters in Schnider model for propofol target-controlled infusion, such as age, sex, and BMI, were adjusted or propensity-matched to compare their anesthetic, surgical, and histopathological profiles.

RESULTS

After propensity-matched comparisons of age and BMI, significant predictors of delayed awakening included IDH1 wild-type tumors and repeated craniotomies. Subgroup analysis revealed that older age and larger T2 volume were predictors in patients undergoing the first craniotomy, while lower preoperative Karnofsky performance scale scores and depression were predictors in repeated craniotomy cases. Delayed awakening was also associated with somnolence and a lower gross total resection rate.

CONCLUSION

Our retrospective analysis of patients receiving monitored anesthesia care for awake craniotomy revealed that delayed awakening after propofol discontinuation occurred more often in patients with IDH1 wild-type tumors and repeated craniotomies. Also, delayed awakening was associated with somnolence during functional mapping and a lower gross total resection rate.

Anesthetic Management for Awake Craniotomy Applied to Neurosurgery

Our anesthetic technique proposed for awake craniotomy is the monitored anesthesia care (MAC) technique, with the patient in sedation throughout the intervention. Our protocol involves analgo-sedation through the administration of dexmedetomidine and remifentanil in a continuous intravenous infusion, allowing the patient to be sedated and in comfort, but contactable and spontaneously breathing. Pre-surgery, the patient is pre-medicated with intramuscular clonidine (2 µg/kg); it acts both as an anxiolytic and as an adjuvant in pain management and improves hemodynamic stability. In the operating setting, dexmedetomidine in infusion and remifentanil in target controlled infusion (TCI) for effect are started. The purpose of the association is to exploit the pharmacodynamics of dexmedetomidine which guarantees the control of respiratory drive, and the pharmacokinetics of remifentanil characterized by insensitivity to the drug. Post-operative management: at the end of the surgical procedure, the infusion of drugs was suspended. Wake-up craniotomy is associated with reduced hospital costs compared to craniotomy performed in general anesthesia, mainly due to reduced costs in the operating room and shorter hospital stays. Greater patient satisfaction and the benefits of avoiding hospital stay have led to the evolution of outpatient intracranial neurosurgery.

Technical Aspects of Motor and Language Mapping in Glioma Patients

Gliomas are infiltrative primary brain tumors that often invade functional cortical and subcortical regions, and they mandate individualized brain mapping strategies to avoid postoperative neurological deficits. It is well known that maximal safe resection significantly improves survival, while postoperative deficits minimize the benefits associated with aggressive resections and diminish patients’ quality of life. Although non-invasive imaging tools serve as useful adjuncts, intraoperative stimulation mapping (ISM) is the gold standard for identifying functional cortical and subcortical regions and minimizing morbidity during these challenging resections. Current mapping methods rely on the use of low-frequency and high-frequency stimulation, delivered with monopolar or bipolar probes either directly to the cortical surface or to the subcortical white matter structures. Stimulation effects can be monitored through patient responses during awake mapping procedures and/or with motor-evoked and somatosensory-evoked potentials in patients who are asleep. Depending on the patient’s preoperative status and tumor location and size, neurosurgeons may choose to employ these mapping methods during awake or asleep craniotomies, both of which have their own benefits and challenges. Regardless of which method is used, the goal of intraoperative stimulation is to identify areas of non-functional tissue that can be safely removed to facilitate an approach trajectory to the equator, or center, of the tumor. Recent technological advances have improved ISM’s utility in identifying subcortical structures and minimized the seizure risk associated with cortical stimulation. In this review, we summarize the salient technical aspects of which neurosurgeons should be aware in order to implement intraoperative stimulation mapping effectively and safely during glioma surgery.

Risk Factors and Characteristics of Intraoperative Seizures During Awake Craniotomy: A Retrospective Cohort Study of 562 Consecutive Patients With a Space-occupying Brain Lesion

INTRODUCTION

Intraoperative seizures (IOSs) during awake craniotomy (AC) are associated with significant morbidity. The reported incidence of IOS is between 3% and 30%. The aim of this study was to identify risk factors for IOS during AC for elective resection or biopsy of a space-occupying brain lesion.

METHODS

In this retrospective study, we reviewed the records of all awake craniotomies performed by a single neurosurgeon at a single university hospital between July 2006 and December 2018. IOS was defined as a clinically apparent seizure that occurred in the operating room and was documented in the medical records. Explanatory variables were chosen based on previously published literature on risk factors for IOS.

RESULTS

Five hundred and sixty-two patients had a total of 607 AC procedures during the study period; 581 cases with complete anesthesia records were included in analysis. Twenty-nine (5.0%) IOS events were reported during 29 (5%) awake craniotomies. Most seizures (27/29; 93%) were focal in nature and did not limit planned intraoperative stimulation mapping. Variables associated with IOS at a univariate P -value <0.1 (frontal location of tumor, preoperative radiotherapy, preoperative use of antiepileptic drugs, intraoperative use of dexmedetomidine, and intraoperative stimulation mapping) were included in a multivariable logistic regression. Frontal location of tumor (adjusted odds ratio: 5.68, 95% confidence interval: 2.11-15.30) and intraoperative dexmedetomidine use (adjusted odds ratio: 2.724, 95% confidence interval: 1.24-6.00) were independently associated with IOS in the multivariable analysis.

CONCLUSIONS

This study identified a low incidence (5%) of IOS during AC. The association between dexmedetomidine and IOS should be further studied in randomized trials as this is a modifiable risk factor.

Neurosurgical Anesthesia: Optimizing Outcomes with Agent Selection

Anesthesia in neurosurgery embodies a vital element in the development of neurosurgical intervention. This undisputed interest has offered surgeons and anesthesiologists an array of anesthetic selections to utilize, though with this allowance comes the equally essential requirement of implementing a maximally appropriate agent. To date, there remains a lack of consensus and official guidance on optimizing anesthetic choice based on operating priorities including hemodynamic parameters (e.g., CPP, ICP, MAP) in addition to the route of procedure and pathology. In this review, the authors detail the development of neuroanesthesia, summarize the advantages and drawbacks of various anesthetic classes and agents, while lastly cohesively organizing the current literature of randomized trials on neuroanesthesia across various procedures.

A Brief Explanation on Surgical Approaches for Treatment of Different Brain Tumors

The main goal of brain tumor surgery is to achieve gross total tumor resection without postoperative complications and permanent new deficits. However, when the lesion is located close or within eloquent brain areas, cranial nerves, and/or major brain vessels, it is imperative to balance the extent of resection with the risk of harming the patient, by following a so-called maximal safe resection philosophy. This view implies a shift from an approach-guided attitude, in which few standard surgical approaches are used to treat almost all intracranial tumors, to a pathology-guided one, with surgical approaches actually tailored to the specific tumor that has to be treated with specific dedicated pre- and intraoperative tools and techniques. In this chapter, the basic principles of the most commonly used neurosurgical approaches in brain tumors surgery are presented and discussed along with an overview on all available modern tools able to improve intraoperative visualization, extent of resection, and postoperative clinical outcome.

Monitored anesthesia care and asleep-awake-asleep techniques combined with multiple monitoring for resection of gliomas in eloquent brain areas: a retrospective analysis of 225 patients

BACKGROUND

Awake craniotomy (AC) has become gold standard in surgical resection of gliomas located in eloquent areas. The conscious sedation techniques in AC include both monitored anesthesia care (MAC) and asleep-awake-asleep (AAA). The choice of optimal anesthetic method depends on the preferences of the surgical team (mainly anesthesiologist and neurosurgeon). The aim of this study was to compare the difference in physiological and blood gas data, dosage of different drugs, the probability of switching to endotracheal intubation, and extent of tumor resection and dysfunction after operation between AAA and MAC anesthetic management for resection of gliomas in eloquent brain areas.

METHODS

Two-hundred and twenty-five patients with super-tentorial tumor located in eloquent areas underwent AC from 2009 to 2021 in Xijing Hospital. Forty-one patients underwent AAA technique, and the rest one-hundred eighty-four patients underwent MAC technique. Anesthetic management, dosage of different drugs, intraoperative complications, postoperative outcomes, adverse events, extent of resection and motor, and sensory and language dysfunction after operation were compared between MAC and AAA.

RESULT

There was no significant difference in gender, KPS score, MMSE score, glioma grade, type, and growth site between the patients in the two groups, except the older age of patients in MAC group than that in AAA group. During the whole process of operation, there were greater pulse pressure difference (P = 0.046), shorter operation time (P = 0.039), less dosage of remifentanil (P = 0.000), more dosage of dexmedetomidine (P = 0.013), more use of antiemetics (81%, P = 0.0067), lower use of vasoactive agent (45.1%, P = 0.010), and lower probability of conversion to general anesthesia (GA, P = 0.027) in MAC group than that in AAA group. Blood gas analysis showed that PetCO2 (P = 0.000), Glu concentration (P = 0.000), and PaCO2 (P = 0.000) were higher, but SPO2 (P = 0.002) and PaO2 (P = 0.000) were lower in MAC group than that in AAA group. In the postoperative recovery stage, compared with that of AAA group, the probability of dysfunction in MAC group at 1, 3, 5, and 7 days after operation was lower, which were 27.8% vs 53.6% (P = 0.003), 31% vs 68.3% (P = 0.000), 28.8% vs 63.4% (P = 0.000), and 25.6% vs 58.5% (P = 0.000), respectively.

CONCLUSION

Compared with AAA, it seems that MAC has more advantages in the management for resection of gliomas in eloquent brain areas, and MAC combined with multiple monitoring such as cerebral cortical mapping, neuronavigation, and ultrasonic detection is worthy of popularization for the resection of gliomas in eloquent brain areas.

Combined Fluorescence-Guided Resection and Intracavitary Thermotherapy with Superparamagnetic Iron‐Oxide Nanoparticles for Recurrent High-Grade Glioma: Case Series with Emphasis on Complication Management

Simple Summary

Recurrent high-grade gliomas are difficult to treat. Here, we report on our single-center experience in combining fluorescence-guided tumor resection with 5-ALA and local thermotherapy with superparamagnetic iron nanoparticles. In total, 18 patients were operated on and received thermotherapy with or without additional radiotherapy. The median progression-free survival was 5.5 months and median overall survival was 9.5 months. Although no major side effects were observed during active treatment, 72% of the patients developed cerebral edema requiring steroid treatment or even surgical removal of the nanoparticles. In conclusion, the combination of fluorescence-guided resection and intracavitary thermotherapy provides a novel and promising treatment option for improving local tumor control in recurrent high-grade gliomas, but further refinements of the treatment protocol are needed to decrease major side effects.

Abstract

Background: Concepts improving local tumor control in high-grade glioma (HGG) are desperately needed. The aim of this study is to report an extended series of cases treated with a combination of 5-ALA-fluorescence-guided resection (FGR) and intracavitary thermotherapy with superparamagnetic iron oxide nanoparticles (SPION). Methods: We conducted a single-center retrospective review of all recurrent HGG treated with FGR and intracavitary thermotherapy (n = 18). Patients underwent six hyperthermia sessions in an alternating magnetic field and received additional adjuvant therapies on a case-by-case basis. Results: Nine patients were treated for first tumor recurrence; all other patients had suffered at least two recurrences. Nine patients received combined radiotherapy and thermotherapy. The median progression-free survival was 5.5 (95% CI: 4.67–6.13) months and median overall survival was 9.5 (95% CI: 7.12–11.79) months. No major side effects were observed during active treatment. Thirteen patients (72%) developed cerebral edema and more clinical symptoms during follow-up and were initially treated with dexamethasone. Six (33%) of these patients underwent surgical removal of nanoparticles due to refractory edema. Conclusions: The combination of FGR and intracavitary thermotherapy with SPION provides a new treatment option for improving local tumor control in recurrent HGG. The development of cerebral edema is a major issue requiring further refinements of the treatment protocol.

Awake craniotomy in brain tumors - Technique systematization and the state of the art

The anesthesia for awake craniotomy (AC) is a consecrated anesthetic technique that has been perfected over the years. Initially used to map epileptic foci, it later became the standard technique for the removal of glial neoplasms in eloquent brain areas. We present an AC anesthesia technique consisting of three primordial times, called awake-asleep-awake, and their respective particularities, as well as delve into the anesthetic medications used. Its use in patients with low and high-grade gliomas was favorable for the resection of tumors within the functional boundaries of patients, with shorter hospital stay and lower direct costs. The present study aims to systematize the technique based on the experience of the largest philanthropic hospital in Latin America and discusses the most relevant aspects that have consolidated this technique as the most appropriate in the surgery of gliomas in eloquent areas.

Clinical Pearls and Methods for Intraoperative Awake Language Mapping

Intraoperative language mapping of tumor and peritumor tissue is a well-established technique for avoiding permanent neurological deficits and maximizing extent of resection. Although there are several components of language that may be tested intraoperatively (eg, naming, writing, reading, and repetition), there is a lack of consistency in how patients are tested intraoperatively as well as the techniques involved to ensure safety during an awake procedure. Here, we review appropriate patient selection, neuroanesthetic techniques, cortical and subcortical language mapping stimulation paradigms, and selection of intraoperative language tasks used during awake craniotomies. We also expand on existing language mapping reviews by considering how intensity and timing of electrical stimulation may impact interpretation of mapping results.

Experience with awake throughout craniotomy in tumour surgery: technique and outcomes of a prospective, consecutive case series with patient perception data

BACKGROUND

Awake craniotomy is the standard of care in surgery of tumours located in eloquent parts of the brain. However, high variability is recorded in multiple parameters, including anaesthetic techniques, mapping paradigms and technology adjuncts. The current study is focused primarily on patients' level of consciousness, surgical technique, and experience based on a cohort of 50 consecutive cases undergoing awake throughout craniotomy (ATC).

METHODS

Data was collected prospectively for 46 patients undergoing 50 operations over 14-month period, by the senior author, including demographics, extent of resection (EOR), adverse intraoperative events, surgical morbidity, surgery duration, levels of O₂ saturation and brain oedema. A prospective, patient experience questionnaire was delivered to 38 patients.

RESULTS

The ATC technique was well tolerated in all patients. Once TCI stopped, all patients were immediately assessable for mapping. Despite > 75% of cases being considered inoperable/high risk, gross total resection (GTR) was achieved in 68% patients and subtotal resection in 20%. The average duration of surgery was 220 min with no episodes of hypoxia. Early and late severe deficits recorded in 12% and 2%, respectively. No stimulation-induced seizures or failed ATCs were recorded. Patient-recorded data showed absent/minimal pain during (1) clamp placement in 95.6% of patients; (2) drilling in 94.7% of patients; (3) surgery in 78.9% of patients. Post-operatively, 92.3% of patients reported willingness to repeat the ATC, if necessary.

CONCLUSIONS

The current ATC paradigm allows immediate brain mapping, maximising patient comfort during self-positioning. Despite the cohort of challenging tumour location, satisfactory EOR was achieved with acceptable morbidity and no adverse intraoperative events.

A novel online calculator predicting short-term postoperative outcomes in patients with metastatic brain tumors

Purpose

Establishing predictors of hospital length of stay (LOS), discharge deposition, and total hospital charges is essential to providing high-quality, value-based care. Though previous research has investigated these outcomes for patients with metastatic brain tumors, there are currently no tools that synthesize such research findings and allow for prediction of these outcomes on a patient-by-patient basis. The present study sought to develop a prediction calculator that uses patient demographic and clinical information to predict extended hospital length of stay, non-routine discharge disposition, and high total hospital charges for patients with metastatic brain tumors.

Methods

Patients undergoing surgery for metastatic brain tumors at a single academic institution were analyzed (2017–2019). Multivariate logistic regression was used to identify independent predictors of extended LOS (> 7 days), non-routine discharge, and high total hospital charges (> $ 46,082.63). p < 0.05 was considered statistically significant. C-statistics and the Hosmer–Lemeshow test were used to assess model discrimination and calibration, respectively.

Results

A total of 235 patients were included in our analysis, with a mean age of 62.74 years. The majority of patients were female (52.3%) and Caucasian (76.6%). Our models predicting extended LOS, non-routine discharge, and high hospital charges had optimism-corrected c-statistics > 0.7, and all three models demonstrated adequate calibration (p > 0.05). The final models are available as an online calculator (https://neurooncsurgery.shinyapps.io/brain_mets_calculator/).

Conclusions

Our models predicting postoperative outcomes allow for individualized risk-estimation for patients following surgery for metastatic brain tumors. Our results may be useful in helping clinicians to provide resource-conscious, high-value care.

Dual labeling with 5-aminolevulinic acid and fluorescein in high-grade glioma surgery with a prototype filter system built into a neurosurgical microscope: technical note

OBJECTIVE

Recent efforts to improve visualization of 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PPIX) fluorescence resulted in a dual-labeling technique, combining it with fluorescein sodium in a prototype setup. Fluorescein identifies regions with blood-brain barrier breakdown in gliomas. However, normally perfused and edematous brain fluoresces unselectively, with strong background enhancement. The aim of this study was to test the feasibility of a novel, integrated filter combination using porphyrins for selective tumor identification and fluorescein for background enhancement.

METHODS

A microscope with a novel built-in filter system (YB 475) for visualizing both fluorescein and 5-ALA-induced porphyrins was used. Resection limits were identified with the conventional BLUE 400 filter system. Six patients harboring contrast ring-enhancing lesions were analyzed.

RESULTS

The complete surgical field could now be illuminated. Fluorescein was helpful for improving background visualization, and enhancing dura, edematous tissue, and cortex. Overlapping regions with both fluorophores harbored merged orange fluorescence. PPIX fluorescence was better visualized, even in areas beyond a normal working distance of approximately 25 cm, where the BLUE 400 filters recognized no or weak fluorescence.

CONCLUSIONS

The novel filter system improved general tissue brightness and background visualization, enhancing fluorescence-guided tumor resection. Furthermore, it appears promising from a scientific perspective, enabling the simultaneous and direct observation of areas with blood-brain barrier breakdown and PPIX fluorescence.

5-Aminolevulinic Acid Fluorescence-Guided Resection of 18F-FET-PET Positive Tumor Beyond Gadolinium Enhancing Tumor Improves Survival in Glioblastoma

BACKGROUND

The value of early postoperative ¹⁸F-FET-PET in patients with glioblastoma (GBM) is unclear. Five-aminolevulinic acid (5-ALA) is used for fluorescence-guided resections in these patients and previous data suggest that fluorescence and ¹⁸F-FET-PET both demarcate larger tumor volumes than gadolinium enhanced magnet resonance imaging (MRI).

OBJECTIVE

To correlate fluorescence with enhancing volumes on postoperative MRI and ¹⁸F-FET-PET tumor volumes, and determine the value of postoperative ¹⁸F-FET-PET for predicting survival through observational study.

METHODS

GBM patients underwent fluorescence-guided resection after administration of 5-ALA followed by early postoperative MRI and ¹⁸F-FET-PET for determination of residual tissue volumes. All patients were treated with standard temozolomide radiochemotherapy and monitored for progression-free and overall survival (PFS, OS).

RESULTS

A total of 31 patients were included. For functional reasons, residual 5-ALA derived fluorescent tissue was left unresected in 18 patients with a median ¹⁸F-FET-PET volume of 17.82 cm³ (interquartile range 6.50-29.19). In patients without residual fluorescence, median ¹⁸F-FET-PET volume was 1.20 cm³ (interquartile range 0.87-5.50) and complete resection of gadolinium enhancing tumor was observed in 100% of patients. A ¹⁸F-FET-PET volume of above 4.3 cm³ was associated with worse OS (logrank P-value ≤ .05), also in patients with no residual contrast enhancing tumor on MRI. More patients in whom fluorescencing tissue had been removed completely had postoperative ¹⁸F-FET-PET tumor volumes below 4.3 cm³.

CONCLUSION

Postoperative ¹⁸F-FET-PET volumes predict OS and PFS. Resection of 5-ALA derived fluorescence beyond gadolinium enhancing tumor tissue leads to lower postoperative ¹⁸F-FET-PET tumor volumes and improved OS and PFS without additional deficits.

Anesthesia considerations of magnetic resonance imaging-guided focused ultrasound thalamotomy for essential tremor: a case series

PURPOSE

Essential tremor (ET) is a common movement disorder with disability in voluntary actions such as eating and writing. First-line treatment involves pharmacological agents, although efficacy is limited by side effects. In these patients, functional neurosurgery can be considered. Magnetic resonance imaging-guided focused ultrasound (MRgFUS) thalamotomy offers a non-invasive solution for treatment. This paper examines an original cohort of ET patients undergoing MRgFUS thalamotomy and discusses the anesthetic management of these cases.

METHODS

We retrospectively reviewed the anesthetic records of all MRgFUS thalamotomy cases from 15 May 2012 to 16 July 2015 at our centre (Sunnybrook Health Sciences Centre, Toronto, Canada) to expand a data set provided by the focused ultrasound system manufacturer (Insightec, Tirat Carmel, Israel) from a prior phase-II regulatory approval study. Specific drug and procedural details were listed including aspects of the patients' experience.

RESULTS

A total of 82 patients were included in the analysis, 78 from a phase-II trial (16 were from the local site) and four local non-trial cases. No patient required general anesthesia and only 29% of cases required sedation to tolerate the procedure. The most frequent medications required were antiemetics and analgesics. Headache (31%) was the most frequent perioperative symptom. Transient intra-procedural paresthesia symptoms were a common occurrence (32%).

CONCLUSIONS

The use of MRgFUS for thalamotomy provides a non-invasive and well-tolerated method for treating ET, which usually only requires monitored anesthesia care sedation. Nevertheless, there are several predictable side effects that require contingency planning including the personnel and means to resolve them.

Successful Anesthetic Management Using Dexmedetomidine Sequentially with Propofol in the Asleep-Awake-Asleep Technique for Elderly Patients Undergoing Awake Craniotomy

Anesthesiologists should supply proper sedation and high-quality awakening in awake craniotomy anesthesia. At our institution, we perform an asleep-awake-asleep technique for awake craniotomy anesthesia by using short-acting anesthetic drugs, such as propofol and remifentanil. However, elderly patients do not wake adequately in our normal protocol and hence are unable to complete the required neurological tasks. In this case series, we present the anesthetic management of three elderly patients with sequent use of propofol and dexmedetomidine as sedative agents for awake craniotomy. We hypothesized that this anesthetic protocol is advantageous in awake craniotomy management. For the awake phase, all patients were adequately awake and performed neurological tasks without adverse events and agitation. The use of dexmedetomidine sequentially with propofol in an asleep-awake-asleep technique for awake craniotomy in elderly patients might shorten the time to awakening and provide clear awakening.

Awake glioma surgery: technical evolution and nuances

INTRODUCTION

Multiple studies have demonstrated that improved extent of resection is associated with longer overall survival for patients with both high and low grade glioma. Awake craniotomy was developed as a technique for maximizing resection whilst preserving neurological function.

METHODS

We performed a comprehensive review of the literature describing the history, indications, techniques and outcomes of awake craniotomy for patients with glioma.

RESULTS

The technique of awake craniotomy evolved to become an essential tool for resection of glioma. Many perceived contraindications can now be managed. We describe in detail our preferred technique, the testing paradigms utilized, and critically review the literature regarding functional and oncological outcome.

CONCLUSIONS

Awake craniotomy with mapping has become the gold standard for safely maximizing extent of resection for tumor in or near eloquent brain. Cortical and subcortical mapping methods have been refined and the technique is associated with an extremely low rate of complications.

Dexmedetomidine Compared to Remifentanil Infusion as Adjuvant to Sevoflurane Anesthesia during Laparoscopic Sleeve Gastrectomy

Objectives

Evaluation of postoperative (PO) analgesic effects of intraoperative (IO) Dexmedetomidine (DEX) compared to remifentanil (REMI) infusions during sevoflurane anesthesia for laparoscopic gastric sleeve surgery.

Patients and Methods

One hundred and thirty-two patients with body mass index >35 kg.m^-2 and ASA Grades II or III were randomly divided into group R received REMI infusion (6-18 μg.kg^-1.h^-1) and Group D received DEX infusion (0.2-0.5 μg.kg^-1.h^-1) after tracheal intubation till before stoppage of inhalational anesthetic. Heart rate and mean arterial pressure were noninvasively monitored during and after surgery. Emergence time, time until postanesthetic care unit transfer, and total operating room (OR) time was recorded. PO shoulder-tip pain and wound pain scores were recorded and rescue analgesia was provided as 50 mg pethidine intramuscular injection. Occurrence of PO nausea and vomiting (PONV) and frequency of the need for antiemetic therapy were recorded. Primary study outcome was the ability of the study infusions to reduce consumption of PO pethidine down to one dose during 24-hr PO.

Results

IO use of REMI or DEX infusion allowed hemodynamic control to surgical stresses with nonsignificant difference between both infusions. REMI infusion insured significantly rapid recovery and short OR times but required larger volume of sevoflurane during surgery and proper PO follow-up for pain and PONV. DEX infusion significantly improved control of PO pain with a larger number of patient requested rescue analgesia only once, reduced the dose of PO analgesia, reduced the frequency of PONV, and the need for antiemetic therapy.

Conclusion

REMI or DEX infusion as IO adjuvant to general anesthesia is appropriate option to achieve hemodynamic control of surgical stresses and to improve perioperative outcomes. REMI infusion may be preferred for its induced rapid recovery and short OR time, whereas DEX infusion may be chosen for its improved control of PO pain and reduction of PO analgesia and frequency of PONV.

Dexmedetomidine vs propofol as sedation for implantation of neurostimulators: A single-center single-blinded randomized controlled trial

BACKGROUND

During the lead implantation of most spinal cord neurostimulators, the patient has to be comfortable and without pain. However, the patient is expected to provide feedback during electrical mapping. Titrating sedatives and analgesics for this double goal can be challenging. In comparison with our standard sedative agent propofol, the pharmacological profile of dexmedetomidine is more conducive to produce arousable sedation. The latter, however, is associated with hemodynamic side effects. We investigated whether dexmedetomidine is preferable over propofol during neurostimulator implantation.

METHODS

This single-center single-blinded randomized controlled trial included 72 patients with an indication for a neurostimulator, randomized to sedation with either propofol (0.5 mg/kg for 10 minutes, followed by 2.0 mg/kg/h) or dexmedetomidine (1 μg/kg for 10 minutes, followed by 0.6 μg/kg/h). The primary outcome was patient satisfaction with the sedation. The secondary outcomes were patient's and operator's comfort, number of titration adjustments, standard intraoperative hemodynamic and respiratory parameters and side effects.

RESULTS

Data of 69 patients (dexmedetomidine n = 35; propofol n = 34) were analyzed. Those receiving dexmedetomidine were more satisfied with the sedation than those receiving propofol; i.e. with sedation delivery (median 100.0 vs 83.3, P < .01), procedural recall (median 95.8 vs 83.3, P = .03), and sedation side effects (median 90.0 vs 83.3, P = .01). Fewer changes in the dexmedetomidine titration were necessary to maintain arousable sedation. Over time, mean arterial pressure and heart rate were significantly lower in the dexmedetomidine group. Hemodynamic side effects were comparable across groups.

CONCLUSIONS

Dexmedetomidine sedation resulted in higher patient satisfaction and allowed for better arousable sedation than sedation with propofol. Although differences in hemodynamic parameters were found between the groups, these differences were not regarded as clinically relevant.

Survey on sedation-analgesia regimens, in particular the use of dexmedetomidine, among Dutch implanters of spinal cord neurostimulators

Background and aims

During implantation of most spinal cord neurostimulators, patients need to be cooperative to give feedback during lead placement, and also be comfortable. Sedation and analgesia can support these conditions. This survey aimed to provide an overview of the sedation-analgesia regimens currently used among Dutch pain specialists. The survey focused on the sedative agent “dexmedetomidine” due to its attractive pharmacological profile and its promising results during awake procedures.

Methods

A 27-item survey was sent to the 65 pain specialists involved in neurostimulation in the Netherlands. The survey consisted of questions related to different aspects of sedation and analgesia during neurostimulation, e.g. the current regimen, the opinion on and experience with dexmedetomidine as a sedative agent, and preferences regarding different aspects of sedation (i.e. production of arousable sedation, pain management, quality of patient’s feedback and overall preference).

Results

Of 65 pain specialists, 45 (69%) completed the survey. Most commonly used sedative was propofol (91%) and most common used analgesic was remifentanil (78%). Of the 45 respondents, 21 (47%) considered the use of dexmedetomidine, whereas 13 (29%) had experience with dexmedetomidine during neurostimulation. The most frequently mentioned positive property of dexmedetomidine was the easy production of arousable sedation. Most respondents who used dexmedetomidine preferred dexmedetomidine sedation over propofol sedation regarding all aspects of sedation.

Conclusions

The most commonly used sedation-analgesia regimen is the combination of propofol-remifentanil during the implantation of a neurostimulator among Dutch pain specialists. Only a small percentage of respondents had experience with the use of dexmedetomidine, despite its reported advantages.

Implications

When implanting a spinal cord neurostimulator, dexmedetomidine could be considered as a sedative, given its allowance for and preservation of a state of easy arousable sedation.

Analysis of Dexmedetomidine on the Quality of Awakening During Neurosurgery

Dexmedetomidine has a dose-dependent sedative and analgesic effect. To further evaluate the wake-up quality of dexmedetomidine in patients undergoing neurosurgery, a meta-analysis of dexmedetomidine in a randomized controlled trial of general anesthesia was performed. Firstly, an experimental algorithm was proposed, and then the data fusion algorithm was used to conduct randomized controlled trials. The clinical efficacy and safety of dexmedetomidine in the acupuncture of neurosurgical patients were evaluated one by one for quality evaluation and data extraction. The effect of different input variables on the depth of anesthesia was studied by using a multi-data fusion approach. The results show that the data fusion algorithm proposed can effectively connect redundant information and complementary information in multiple data, and estimate the real parameters of the measured object. In addition, data fusion brings great convenience to the design of control algorithms and controllers, and provides an effective basis for system simplification. Experiments have shown that dexmedetomidine is effective and safe in the operation of neurosurgical motor function, and the management of the recovery period is safe and effective. Based on the research, it can provide some reference for the awakening of patients undergoing neurosurgery, and promote the progress and development of medicine.