Incidence and predicting factors of perioperative complications during monitored anesthesia care for awake craniotomy

The role of postoperative blood pressure management in early postoperative hemorrhage in awake craniotomy glioma patients

Postoperative hemorrhage can severely affect the patients' neurological outcome after awake craniotomy. Higher postoperative blood pressure can increase the risk of postoperative hemorrhage. The aim of this study was to investigate the role of postoperative blood pressure and other common radiological and epidemiological features with the incidence of postoperative hemorrhage. In this retrospective analysis, we included patients who underwent awake surgery at our institution. We assessed the blood pressure both intra- and postoperatively as well as the heart rate for the first 12 h. We compared a cohort with postoperative hemorrhage, who required further treatment (surgical revision or intravenous antihypertensive therapy), with a cohort with no postoperative hemorrhage. We included 48 patients with a median age of 39 years. 9 patients (19%) required further treatment due to postoperative hemorrhage, which was surgery in 2 cases and intensive blood pressure measurements in 7 cases. However, with early treatment, no significant difference in Performance scores at follow-up could be found. Patients with postoperative hemorrhage showed significantly higher postoperative systolic blood pressure during the hours 3-12 (p < 0.05) as well as intraoperatively throughout the procedure (p < 0.05). In ROC and Youden Test, a strong impact of systolic blood pressure over 140mmHg during the early postoperative course could be shown. Postoperative hemorrhage is a rare but possible complication in awake surgery glioma patients. To avoid postoperative hemorrhage, treating physicians should aim strictly on systolic blood pressure of under 140mmHg for the postoperative course.

A Comparison of Perioperative Complications and Outcomes in Patients Undergoing Cerebral Aneurysm Clipping Performed Ultra-Early (≤ 24 hours) versus Late (> 24 hours): A 7-Year Retrospective Study of 302 Patients

Objectives  The intracerebral aneurysm with subarachnoid hemorrhage (SAH) has a high morbidity and mortality rate. This study aimed to compare the incidences of perioperative complications in ultra-early surgery (within 24 hours) with those in late surgery (> 24 hours). Methods  Retrospective data were reviewed for 302 patients who underwent craniotomies with aneurysm clipping between January 2014 and December 2020. Perioperative data were obtained from the medical records and reviewed by the investigators. The complications were compared between ultra-early and late operations. We were interested in major complications such as delayed ischemic neurologic deficit (DIND), intraoperative aneurysm rupture (IAR), and anesthesia-related complications. The short-term (in hospital) and long-term (1 year) outcomes in patients with or without DIND and IAR were compared. The collected data was statistically analyzed. Results  Three hundred and two patients were analyzed, and 264 patients had completed follow-up. The ultra-early cases (150 patients) had a higher American Society of Anesthesiologists physical status, a lower Glasgow Coma Scale, and higher Hunt and Hess scales. The surgeons operated on more cases of the anterior cerebral artery as ultra-early operations. The incidence rates of DIND, IAR, severe hemodynamic instability, and cardiac arrest were 5.6, 8.3, 6.3, and 0.3%, respectively, which were not different between groups. However, the reintubation rate was higher in the ultra-early surgery cases (0 vs. 3.3%, p  = 0.023). The DIND and IAR patients had poorer short-term (in hospital) outcomes. Conclusions  There were no differences in major complications between ultra-early and late craniotomy with aneurysm clipping. However, the reintubation rate was strikingly higher in the ultra-early group. Patients with major complications had early, unfavorable outcomes.

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 Pediatric Patients: A Meta-analysis of Operative Outcomes

BACKGROUND

Awake craniotomy allows neurosurgeons to make critical decisions when operating in eloquent regions of the brain. The phenomenon of "waking up" during surgery is underexplored in pediatric patients, and the operative outcomes following awake craniotomy are not well understood. Correspondingly, the aim of this study was to quantitatively aggregate the contemporary metadata regarding the operative outcomes of awake craniotomy when used in the pediatric setting.

METHODS

Multiple electronic databases from inception to June 2023 were searched following PRISMA guidelines. Respective cohort-level outcomes were then abstracted and pooled by means of meta-analysis utilizing random-effects modeling, and trends evaluated by meta-regression analysis.

RESULTS

There were 4 observational studies that satisfied all selection criteria, describing a total cohort of 57 pediatric patients undergoing awake craniotomy. There were 34 (60%) male patients with a median age of 14 years old, with lesions on the left side in 80% of cases when reported. Meta-analysis demonstrated pooled incidences of intraoperative complication to be 17% (95% CI 4%-37%), the need to convert cases to general anesthesia to be 2% (95% CI 0%-9%), immediate postoperative complication to be 18% (95% CI 6%-33%), and long-term complications to be 6% (95% CI 0%-15%). The most common intraoperative complication reported was seizure. Certainty of these estimates were very low due to limited metadata. Meta-regression did not indicate any trend bias due to study and cohort parameters.

CONCLUSIONS

Multiple studies have demonstrated the feasibility of the awake craniotomy approach in pediatric patients. The risks for intraoperative and postoperative complications are non-zero, with their incidences trending towards incidences seen in the adult demographic. It is likely formal neuropsychologic preparation and follow-up will increase the candidacy and success of this approach in the future.

Early Postoperative Seizures Following Awake Craniotomy and Functional Brain Mapping for Lesionectomy

OBJECTIVE

Awake craniotomy with electrocorticography (ECoG) and direct electrical stimulation (DES) facilitates lesionectomy while avoiding adverse effects. Early postoperative seizures (EPS), occurring within 7 days following surgery, can lead to morbidity. However, risk factors for EPS after awake craniotomy including clinical and ECoG data are not well defined.

METHODS

We retrospectively studied the incidence and risk factors of EPS following awake craniotomy for lesionectomy, and report short-term outcomes between January 1, 2020, and December 31, 2022.

RESULTS

We included 138 patients (56 female) who underwent 142 awake craniotomies, average age was 50.78 ± 15.97 years. Eighty-eight (63.7%) patients had a preoperative history of tumor-related epilepsy treated with antiseizure medication (ASM), 12 (13.6%) with drug-resistance. All others (36.3%) received ASM prophylaxis with levetiracetam perioperatively and continued for 14 days. An equal number of cases (71) each utilized a novel circle grid or strip electrodes for ECoG. There were 31 (21.8%) cases of intraoperative seizures, 16 with EPS (11.3%). Acute abnormality on early postoperative neuroimaging (P = 0.01), subarachnoid hemorrhage (P = 0.01), young age (P = 0.01), and persistent postoperative neurologic deficits (P = 0.013) were associated with EPS. Acute abnormality on neuroimaging remained significant in multivariate analysis. Outcomes during hospitalization and early outpatient follow up were worse with EPS.

CONCLUSIONS

We report novel findings using ECoG and clinical features to predict EPS, including acute perioperative brain injury, persistent postoperative deficits and young age. Given worse outcomes with EPS, clinical indicators for EPS should alert clinicians of potential need for early postoperative EEG monitoring and perioperative ASM adjustment.

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.

Risk factors and predictors of intraoperative seizures during awake craniotomy: A systematic review and meta-analysis

Background

Awake craniotomy (AC) aims to minimize postoperative neurological complications while allowing maximum safe resection. Intraoperative seizures (IOSs) have been a reported complication during AC; however, literature delving into the predictors of IOS remains limited. Therefore, we planned a systematic review and meta-analysis of existing literature to explore predictors of IOS during AC.

Methods

From the inception until June 1, 2022, systematic searches of PubMed, Scopus, the Cochrane Library, CINAHL, and Cochrane's Central Register of Controlled Trials were conducted to look for published studies reporting IOS predictors during AC.

Results

We found 83 different studies in total; included were six studies with a total of 1815 patients, and 8.4% of them experienced IOSs. The mean age of included patients was 45.3 years, and 38% of the sample was female. Glioma was the most common diagnosis among the patients. A pooled random effect odds ratio (OR) of frontal lobe lesions was 2.42 (95% confidence intervals [CI]: 1.10-5.33, P = 0.03). Those with a pre-existing history of seizures had an OR of 1.80 (95% CI: 1.13-2.87, P = 0.01), and patients on antiepileptic drugs (AEDs) had a pooled OR of 2.47 (95% CI: 1.59-3.85, P < 0.001).

Conclusion

Patients with lesions of the frontal lobe, a prior history of seizures, and patients on AEDs are at higher risk of IOSs. These factors should be taken into consideration during the patient's preparation for an AC to avoid an intractable seizure and consequently a failed AC.

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.

Variability of Intraoperative Electrostimulation Parameters in Conscious Individuals: Language Fasciculi

OBJECTIVE

The authors analyzed the current-intensity thresholds for electrostimulation of language fasciculi and the possible consequences of threshold variability on brain mapping.

METHODS

A prospective protocol of subcortical electrostimulation was used in 50 patients undergoing brain mapping, directly stimulating presumed language fasciculi identified by diffusion tensor imaging.

RESULTS

The stimulation-intensity thresholds for identification of language fasciculi varied among patients (mean minimum current intensity of 4.4 mA, range = 1.5-10 mA, standard deviation = 1.1 mA), and 23% of fascicular interferences were detected only above 5 mA. Repeated stimulation of the same site with the same intensity led to different types of interferences in 20% of patients, and a higher current intensity led to changes in the type of response in 27%. The mean minimum stimulation intensities did not differ significantly between different fasciculi, between the different types of interference obtained, or with age, sex, or type of tumor. Positive results on cortical mapping were significantly associated with positive results on subcortical mapping (P < 0.001). Subcortical intensity thresholds were slightly lower than cortical ones (mean = 4.43 vs. 5.25 mA, P = 0.034). In 23 of 50 subcortical mappings, fascicular stimulation produced no language interference.

CONCLUSIONS

Individual variability of minimum stimulation-intensity thresholds for identification of language fasciculi is frequent. Nevertheless, even when a high current intensity was used, many stimulations on language fasciculi remained negative for various hypothetic reasons. Finding the optimal current intensity for identifying language fasciculi is of paramount importance to refine the clinical results and scientific data derived from brain mapping.