Anesthetic considerations for awake craniotomy

Awake microsurgical management of brain aneurysms: a comprehensive systematic review and meta-analysis on rationale, safety and clinical outcomes

INTRODUCTION

Awake microsurgery for brain aneurysm treatment has emerged as a tool for real-time intraoperative monitoring, opportune detection of ischemic complications, and reduction of surgical morbidity. Herein, we aimed to explore the current state of the procedure's rationale, safety and clinical outcomes.

METHODS

In accordance with PRISMA guidelines, five databases were queried for articles reporting awake microsurgical management of brain aneurysms. Aggregate study results were combined using random-effects meta-analyses. Publication bias was evaluated through funnel plot analysis and Egger's regression test.

RESULTS

Out of 847 articles, 11 records satisfied the inclusion criteria. Seventy-five patients (68% female) with 75 brain aneurysms (68% unruptured) were analyzed. Clipping was the predominant technique (58%), followed by bypass (17%). Monitored anesthesia care was the principal anesthesia protocol (60%). The incidence of anesthesia-related complications was 1% [95%CI, 0.00-0.05, I2 = 19%], and the conversion rate from an awake-induced anesthesia protocol to general anesthesia was 1% [95%CI, 0.00-0.05, I2 = 0%]. No permanent anesthesia-related morbidity and mortality was reported. Complete aneurysm repair, occlusion and bypass patency rate was 100% [95%CI, 0.96-1.00, I2 = 0%]. The transient postoperative symptomatic event rate was 34% [95%CI, 0.06-0.81, I2 = 77%]. The overall morbidity rate was 4% [95%CI, 0.00-0.09, I2 = 0%], and the overall mortality rate was 0% [95%CI, 0.00-0.03, I2 = 0%].

CONCLUSION

Awake microsurgery of brain aneurysms is feasible, yet current evidence stems from observational studies. This procedure can reduce surgical morbidity by providing accurate and real-time neurological monitoring during aneurysm repair. While this technique appears to be tolerated, higher level evidence is needed to evaluate judiciously its safety and preference over existing practices for intraoperative neurological monitoring.

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.

Scalp Nerve Block Alleviates Headaches Associated With Sonication During Transcranial Magnetic Resonance-Guided Focused Ultrasound

BACKGROUND AND OBJECTIVES

In magnetic resonance-guided focused ultrasound (MRgFUS) procedures, headache is a frequent symptom and cause of treatment discontinuation. Herein, we assessed the efficacy of scalp nerve block (SNB) for alleviating headache during MRgFUS procedures.

METHODS

The effect of SNB on intraprocedural headache was examined by retrospectively comparing 2 patient cohorts at a single institution. During the study period from April 2020 to February 2022, an SNB protocol for all patients with a skull density ratio ≤0.55 was instituted on October 6, 2021. The number of patients with a skull density ratio ≤0.55 was 34 before the protocol and 36 afterward. Headache intensity was evaluated using a numerical rating scale (NRS) after each sonication. To evaluate the effect of SNB on headache intensity, multiple regression analysis was performed per patient and per sonication. In the per-patient analysis, the effect of SNB was evaluated using the maximum NRS, mean NRS, and NRS at the first ultrasound exposure that reached 52.5°C. In the per-sonication analysis, the effect of SNB was evaluated not only for the entire sonication but also for sonications classified into ≤9999 J, 10 000 to 29 999 J, and ≥30 000 J energy doses.

RESULTS

With SNB, headache alleviation was observed in the NRS after the first sonication that reached 52.5°C in each patient (β = -2.40, 95% CI -4.05 to -0.758, P = .00499), in the NRS when all sonications were evaluated (β = -0.647, 95% CI -1.19 to -0.106, P = .0201), and in the NRS when all sonications were classified into 10 000 to 29 999 J (β = -1.83, 95% CI -3.17 to -0.485, P = .00889).

CONCLUSION

SNB significantly reduced headache intensity during MRgFUS, especially that caused by sonication with a moderate-energy dose. These findings suggest that scalp nerves play a role in headache mechanisms during MRgFUS.

Asleep versus awake GPi DBS surgery for Parkinson's disease: A systematic review and meta-analysis

BACKGROUND

Patients with Parkinson's Disease (PD) who receive either asleep image-guided subthalamic nucleus deep brain stimulation (DBS) or the traditional awake technique have comparable motor outcomes. However, there are fewer studies regarding which technique should be chosen for globus pallidus internus (GPi) DBS. This systematic review and meta-analysis aims to compare the accuracy of lead placement and motor outcomes of asleep versus awake GPi DBS PD population.

METHODS

We systematically searched PubMed, Embase, and Cochrane for studies comparing asleep vs. awake GPi DBS lead placement in patients with PD. Outcomes were spatial accuracy of lead placement, measured by radial error between intended and actual location, motor improvement measured using (UPDRS III), and postoperative stimulation parameters. Statistical analysis was performed with Review Manager 5.1.7. and OpenMeta [Analyst].

RESULTS

Three studies met inclusion criteria with a total of 247 patients. Asleep DBS was used to treat 192 (77.7 %) patients. Follow-up ranged from 6 to 48 months. Radial error was not statistically different between groups (MD -0.49 mm; 95 % CI -1.0 to 0.02; I2 = 86 %; p = 0.06), with a tendency for higher target accuracy with the asleep technique. There was no significant difference between groups in change on motor function, as measured by UPDRS III, from pre- to postoperative (MD 8.30 %; 95 % CI -4.78 to 21.37; I2 = 67 %, p = 0.2). There was a significant difference in postoperative stimulation voltage, with the asleep group requiring less voltage than the awake group (MD -0.27 V; 95 % CI -0.46 to - 0.08; I2 = 0 %; p = 0.006).

CONCLUSION

Our meta-analysis indicates that asleep image-guided GPi DBS presents a statistical tendency suggesting superior target accuracy when compared with the awake standard technique. Differences in change in motor function were not statistically significant between groups.

Anaesthetic considerations and challenges during awake craniotomy

ABSTRACT

This article summarises the key anaesthetic considerations and challenges surrounding the perioperative management of a patient undergoing awake craniotomy. The main goals include patient comfort, facilitation of patient cooperation during the critical awake phase and maintenance of optimal operating conditions. These are achieved through appropriate patient selection and preparation, familiarity with the complexity of each surgical phase and potential complications that may arise, as well as maintenance of close communication among all team members. Challenges such as loss of patient cooperation, loss of airway, intraoperative nausea and vomiting, seizures, cerebral oedema, hypertension, blood loss and use of intraoperative magnetic resonance imaging are discussed. The importance of teamwork, competence, vigilance and clear management strategies for potential complications to maximise patient outcomes is also highlighted.

Awake Craniotomy in Conscious Sedation: The Role of A2 Agonists

BACKGROUND

In Awake Craniotomy (AC), α2-agonists and remifentanil (clonidine and dexmedetomidine) are used in the preoperative phase and throughout the procedure to combine monitored anesthesia care and local anesthesia. The study aims were to specify the key role of α2-agonists administered and to evaluate complication presence/absence in anesthesiologic management.

METHODS

42 patients undergoing AC in 3 different centers in the south of Italy (Foggia, San Giovanni Rotondo, and Bari) were recruited. Our protocol involves analgo-sedation by administering Dexmedetomidine and Remifentanil in continuous intravenous infusion, allowing the patient to be sedated and in comfort but contactable and spontaneously breathing. During pre-surgery, the patient is premedicated with intramuscular clonidine (2 µg/kg). In the operating setting, Dexmedetomidine in infusion and Remifentanil in Target Controlled Infusion for effect are started. At the end of the surgical procedure, the infusion of drugs was suspended.

RESULTS

There were no intraoperative side effects. The mean duration of interventions was 240 ± 62 min. The average quantity of Remifentanil and Dexmedetomidine infused during interventions were 4.2 ± 1.3 mg and 1.0 ± 0.3 mg, respectively. No significant side effects were described in the post-operative phase. A total of 86% of patients and 93% of surgeons were totally satisfied.

CONCLUSIONS

Synergy between opioid drugs and α2 agonists plays a fundamental role in ensuring procedure success.

Comparison of dexmedetomidine and propofol for sedation in awake craniotomy: A meta-analysis

BACKGROUND

Awake craniotomy (AC) is the preferred option for the resection of tumors adjacent to eloquent cortical areas and in cases of intractable epilepsy. It is mostly used to maintain the integrity of the brain during intracranial neurosurgical procedures. Awake craniotomy requires the use of ideal anesthetics, hypnotics, and analgesics to balance sedation, prompt the reversal of sedation, and prevent respiratory depression while maintaining communication between patient and medical team. Although a wide variety of anesthetics and hypnotics have been used for awake craniotomy over the past several decades, the optimal drug for the procedure has yet to be determined. The purpose of this meta-analysis was to compare dexmedetomidine and propofol in terms of intraoperative adverse events (i.e., hypertension, hypotension, nausea, vomiting, respiratory depression), patient and surgeon satisfaction, and procedure duration.

METHODS

We searched PubMed, Google Scholar, and the Cochrane Library for relevant articles published between the inception of these databases and April of 2022. The systematic search yielded 781 articles. After screening, we excluded 778 articles. The remaining three articles reporting 138 patients were selected for meta-analysis.

RESULTS

This meta-analysis showed no statistically significant difference between propofol and dexmedetomidine related to intraoperative adverse events, patient satisfaction, or procedure duration. The only statistically significant result was surgeon satisfaction, which appeared to be higher in the dexmedetomidine group.

CONCLUSIONS

Further high-quality randomized and controlled trials are needed to find a preferred agent for intraoperative sedation in awake craniotomy.

Awake brain surgery for autistic patients: Is it possible?

Background:

Awake neurosurgery is currently the mainstay for eloquent brain lesions. Opting for an awake operation is affected by a number of patient-related factors. We present a case of a patient with autistic spectrum disorder (ASD) that was successfully operated for a brain tumor through awake craniotomy. To the best of our knowledge, this is the first reported case in the literature.

Case Description:

A 42-year-old patient, with known ASD since his childhood, underwent awake craniotomy for a left supplementary motor area tumor. Detailed preoperative preparation of the patient was done to identify special requirements and establish a good patient-team relationship. Intraoperatively, continuous language and motor testing were performed. Conversation and music were the main distractors used. Throughout the operation, the patient remained calm and cooperative, even during a focal seizure. Mapping allowed for >80% resection of the tumor. Postoperatively, the patient recovered without any deficits.

Conclusion:

This case shows that with growing experience and meticulous preparation, the limits of awake craniotomy can be expanded to include more patients that were previously considered unfit.

Meta-Analysis of Anesthetic Efficacy and Safety of Propofol in Craniotomy Patients

The anesthetic effect and safety of propofol in craniotomy patients by meta-analysis is investigated. Relevant studies consistent with the anesthetic effect and safety of propofol in craniotomy patients are searched and screened from domestic and foreign literature databases such as Wanfang Medical Center, CNKI, VIP, and PubMed, and meta-analysis is performed by RevMan 5.2 software. Experimental results show that the recovery time, intracranial pressure, cerebral edema, partial cerebral oxygen pressure, glutamate, and MDA in the propofol group are better than those in the control group (P < 0.05), and the incidence of superoxide dismutase, TNF-α, and adr in the propofol group is better than that in the control group (P > 0.05). Intravenous anesthesia with propofol in patients with craniotomy has the advantage of rapid recovery, and this program can improve intracranial pressure, brain edema, and brain oxygen partial pressure and help to improve oxidative stress and inflammatory reaction.

The Efficacy of Remifentanil Combined with Propofol in Craniotomy for Tumor Was Evaluated by Wake Quality, Hemodynamics, and Adverse Reactions

In order to investigate the effect of remifentanil combined with propofol on awakening of craniotomy for tumor, a retrospective analysis is conducted. 86 patients who underwent craniotomy for brain tumor in our hospital from July 2020 to December 2021 are chosen to observe the quality of awakening, hemodynamic parameters, and the occurrence of adverse reactions. All patients are divided into group A (n = 43) and group B (n = 43) according to the use of anesthesia drugs. The intraoperative awakening quality and the hemodynamic parameters during different periods of the two groups are compared. The experimental results show that the incidence of postoperative adverse reactions in group B is significantly lower than that in group A (P < 0.05). It is clearly evident that remifentanil combined with protocol has good intraoperative wake-up effect in craniotomy for tumor and maintain the hemodynamic stability of patients. Also, it can obtain high wake-up quality and effectively reduce postoperative adverse reactions.

Enhanced Recovery After Surgery (ERAS) for Cranial Tumor Resection: A Review

Enhanced Recovery After Surgery (ERAS) protocols describe a standardized method of preoperative, perioperative, and postoperative care to enhance outcomes and minimize complication risks surrounding elective surgical intervention. A growing body of evidence is being generated as we learn to apply principles of ERAS standardization to neurosurgical patients. First applied in spinal surgery, ERAS protocols have been extended to cranial neuro-oncological procedures. This review synthesizes recent findings to generate evidence-based guidelines to manage neurosurgical oncology patients with standardized systems and assess ability of these systems to coordinate multidisciplinary, patient-centric care efforts. Furthermore, we highlight the potential utility of multimedia, app-based communication platforms to facilitate patient education, autonomy, and team communication within each of the three settings.

Awake craniotomy using a high-flow nasal cannula with oxygen reserve index monitoring - A report of two cases

BACKGROUND

Awake craniotomy is a well-tolerated procedure for the resection of brain tumors residing within or close to the eloquent cortical areas. Monitored anesthesia care (MAC) is a dominant anesthetic approach for awake craniotomy; however, it is associated with inherent challenges such as desaturation and hypercapnia, which may lead to various complications. The prevention of respiratory insufficiency is important for successful awake craniotomy. As measures to avoid respiratory depression, the use of high-flow nasal cannula (HFNC) can improve patient oxygenation and monitor the monitoring the oxygen reserve index (ORi) can detect hypoxia earlier.

CASE

We report two cases of awake craniotomy with MAC using HFNC and ORi. We adjusted the fraction of inspired oxygen of the HFNC according to the ORi level. The patient underwent successful awake craniotomy without a desaturation event or additional airway intervention.

CONCLUSIONS

Combined HFNC and ORi monitoring may provide adequate oxygen reserves in patients undergoing awake craniotomy.

Management and outcomes of low-grade gliomas in Africa: A scoping review

Introduction

Methods

Results

Conclusion

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Highlights for ‘Management and Outcomes of Low Grade Gliomas in Africa’.

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The burden of low-grade gliomas in Africa is underreported.

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There was no reported use of molecular pathology testing or intraoperative adjuncts.

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There were low rates of awake surgery for patients with supratentorial tumours.

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There was a lag in the uptake of techniques and technologies used in the management of low-grade gliomas.