Awake Craniotomy for Microsurgical Obliteration of Mycotic Aneurysms: Technical Report of Three Cases

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.

Experiences in Awake Craniotomy from Borneo: A Case Series from Sarawak General Hospital

Background

The indications for awake craniotomy now spans from resection of tumours at eloquent areas of the brain, deep brain stimulation and treatment of aneurysms to name a few. In the region of East Malaysia where patients have various ethnic backgrounds and native languages, planning and execution of these procedures can be somewhat challenging.

Methods

This is a retrospective analysis of 11 awake surgeries conducted by the Department of Neurosurgery in Sarawak. The indications for awake craniotomy surgery in our sample population were intra-axial lesions in eloquent regions involving important cortical areas and subcortical tracts which were at risk of damage during tumour excision. Patients were assessed for intra-operative and post-operative neurological deficits.

Results

Eleven patients aged 20 years old-70 years old were included in this series. All patients were diagnosed with lesions in eloquent areas of the brain requiring surgical excision. Patients were of various ethnic backgrounds. The spoken language of these patients also varied based on their ethnicity. The histopathological diagnosis of nine patients were consistent with gliomas with three being of high grade. Three patients (27%) developed intra-operative deficits that were not present pre-operatively.

Conclusion

This case series serve to demonstrate the feasibility of awake craniotomies even in centres without vast experiences in awake surgeries and ideal adjuncts which in comparison may be readily available in different centres. Although careful patient selection has been emphasised, it is a difficult feat in a region consisting of at least 30 different ethnic groups with distinct languages and cultures.

Awake craniotomy without sedation in treatment of patients with lesional epilepsy

BACKGROUND

The use of awake craniotomy for surgical treatment of epilepsy was applied in surgery of convexital tumors, arteriovenous malformations, some superficial aneurysms, and stereotactic neurosurgery. The aim of this study was to show the advantages of awake craniotomy without sedation, accompanied by intraoperative neurophysiological monitoring in patients with symptomatic epilepsy.

METHODS

This article describes the results of surgical treatment in 41 patients with various pathologies; 31 among them suffered from epilepsy.

RESULTS

Most frequently, the pathological foci were located in frontal and parietal lobes nearby eloquent brain areas. Irrespective of damage location, simple partial and complex partial seizures were seen almost with the same frequency. Intraoperative mapping of eloquent cortical areas and subcortical tracts without sedation resulted in total resection of pathological area in 75% of cases with low rate of permanent neurological deficit (two patients). Minor perioperative complications, including the decrease in blood pressure in six patients and intraoperative convulsions in two patients, were handled and did not led to operation termination or anesthesia conversion. Excellent seizures control (Engel 1) was achieved in 80% of patients with available catamnesis.

CONCLUSION

Thus, the proposed method allows eliminating the complications associated with sedation and provides radical resection of pathological epileptogenic foci with low complication rate.

Awake surgery for hemispheric low-grade gliomas: oncological, functional and methodological differences between pediatric and adult populations

INTRODUCTION

Brain mapping through a direct cortical and subcortical electrical stimulation during an awake craniotomy has gained an increasing popularity as a powerful tool to prevent neurological deficit while increasing extent of resection of hemispheric diffuse low-grade gliomas in adults. However, few case reports or very limited series of awake surgery in children are currently available in the literature.

METHODS

In this paper, we review the oncological and functional differences between pediatric and adult populations, and the methodological specificities that may limit the use of awake mapping in pediatric low-grade glioma surgery.

RESULTS

This could be explained by the fact that pediatric low-grade gliomas have a different epidemiology and biologic behavior in comparison to adults, with pilocytic astrocytomas (WHO grade I glioma) as the most frequent histotype, and with WHO grade II gliomas less prone to anaplastic transformation than their adult counterparts. In addition, aside from the issue of poor collaboration of younger children under 10 years of age, some anatomical and functional peculiarities of children developing brain (cortical and subcortical myelination, maturation of neural networks and of specialized cortical areas) can influence direct electrical stimulation methodology and sensitivity, limiting its use in children.

CONCLUSIONS

Therefore, even though awake procedure with cortical and axonal stimulation mapping can be adapted in a specific subgroup of children with a diffuse glioma from the age of 10 years, only few pediatric patients are nonetheless candidates for awake brain surgery.

Awake craniotomy: A qualitative review and future challenges

Neurosurgery in awake patients incorporates newer technologies that require the anesthesiologists to update their skills and evolve their methodologies. They need effective communication skills and knowledge of selecting the right anesthetic drugs to ensure adequate analgesia, akinesia, along with patient satisfaction with the anesthetic conduct throughout the procedure. The challenge of providing adequate anesthetic care to an awake patient for intracranial surgery requires more than routine vigilance about anesthetic management.

Awake craniotomy for trapping a giant fusiform aneurysm of the middle cerebral artery

BACKGROUND

Giant fusiform aneurysms of the distal middle cerebral artery (MCA) are rare lesions that, because of the absence of an aneurysm neck and the presence of calcified walls and partial thrombosis, can be difficult to clip without sacrificing the parent vessel. Moreover, when the aneurysm is located in the dominant hemisphere, it is not possible to test language and cognitive functions during surgical intervention, making the closure of the parent vessel extremely dangerous.

CASE DESCRIPTION

A 46-year-old woman presented with a one-year history of frontal headache without neurological deficit. A magnetic resonance imaging and an angiography showed a giant fusiform aneurysm of the left M2 tract. Because of the location and the absence of a neck, the aneurysm was considered difficult to coil and not amenable to preoperative balloon occlusion; thus, the patient was a candidate for surgical treatment. After a preoperative psychological evaluation, patient underwent awake craniotomy with the asleep-awake-asleep technique. A standard left pterional approach was performed to expose the internal carotid artery, the MCA and the aneurysm originating from the frontal branch of the MCA. Neurological examination responses remained unchanged during temporary parent artery occlusion, and trapping was successfully performed.

CONCLUSIONS

Awake craniotomy is a useful option in intracranial aneurysm surgery because it permits neurological testing before vessels are permanently clipped or sacrificed. With the asleep-awake-asleep technique, it is possible to perform a standard pterional craniotomy, which allows good exposure of the vascular structures without cerebral retraction.

Intracranial infectious aneurysms: a comprehensive review

Intracranial infectious aneurysms, or mycotic aneurysms, are rare infectious cerebrovascular lesions which arise through microbial infection of the cerebral arterial wall. Due to the rarity of these lesions, the variability in their clinical presentations, and the lack of population-based epidemiological data, there is no widely accepted management methodology. We undertook a comprehensive literature search using the OVID gateway of the MEDLINE database (1950-2009) using the following keywords (singly and in combination): "infectious," "mycotic," "cerebral aneurysm," and "intracranial aneurysm." We identified 27 published clinical series describing a total of 287 patients in the English literature that presented demographic and clinical data regarding presentation, treatment, and outcome of patients with mycotic aneurysms. We then synthesized the available data into a combined cohort to more closely estimate the true demographic and clinical characteristics of this disease. We follow by presenting a comprehensive review of mycotic aneurysms, highlighting current treatment paradigms. The literature supports the administration of antibiotics in conjunction with surgical or endovascular intervention depending on the character and location of the aneurysm, as well as the clinical status of the patient. Mycotic aneurysms comprise an important subtype of potentially life-threatening cerebrovascular lesions, and further prospective studies are warranted to define outcome following both conservative and surgical or endovascular treatment.