Interest of awake surgery for ruptured cerebral arteriovenous malformations close to speech areas - Surgical note

Awake Craniotomy for Eloquent Brain Arteriovenous Malformations: A Systematic Review and Individual Patient Data Meta-Analysis

BACKGROUND

Arteriovenous malformations (AVMs) pose a risk of neurologic deterioration, particularly when located in eloquent areas. While awake surgery is well-established for treating low-grade gliomas near eloquent areas, its efficacy for AVMs is less conclusively reported.

METHODS

This study conducted a systematic review and individual patient data meta-analysis following Cochrane Collaboration and Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Literature searches were performed in PubMed, Embase, and Web of Science. Eligible studies included case reports, case series, retrospective or prospective cohorts, and randomized trials evaluating awake craniotomy (AC) for AVMs. Single proportion analysis with 95% confidence intervals (CIs) was utilized to pool the data. Case series and case reports were put together as a unique cohort.

RESULTS

An analysis of 20 studies encompassing 287 patients was performed. The individual patient data cohort had 53 patients. The primary outcome pooled analysis indicated an 88% (95% CI: 81%-95%; I2=63%) rate of total resection. Moreover, a rate of nearly 12% (95% CI: 5%-19%; I2=63%) of subtotal resection was observed. Furthermore, the analysis unveiled a 20% (95% CI: 13%-28%; I2=58%) rate of postoperative neurological deficits, alongside a 6% (95% CI: 3%-9%; I2=29%) rate of follow-up neurological deficits. The mean hospital stay was 4.13 (95% CI: 3.61-4.66; I2=73%) days.

CONCLUSIONS

AC for eloquent AVMs showed promising results. A significant rate of postoperative neurological deficits was found, which was reduced at follow-up. A small mean length of hospitalization was also found. These results suggest that AC for AVMs should be considered in eloquent lesion cases.

Feasibility of awake craniotomy for brain arteriovenous malformations: A scoping review

Background

Brain Arteriovenous Malformations (AVMs) located in proximity to eloquent brain regions are associated with poor surgical outcomes, which may be due to higher rates of postoperative neurological deterioration. Current treatment protocols include stereotactic radiosurgery, transarterial embolization, and surgical resection under general anesthesia. Awake Craniotomy (AC) allows intraoperative mapping of eloquent areas to improve post-operative neurologic outcomes.

Objectives

We reviewed the current literature reporting surgical outcomes and assessed the feasibility of AC for AVM resection.

Methods

The PRISMA guidelines were utilized as a template for the review. Three databases including PubMed, Scopus, and Cochrane Library were searched using a predefined search strategy. After removing duplicates and screening, full texts were analyzed. Outcomes including the extent of resection, intra-operative and post-operative complications, and long-term neurologic outcomes were assessed.

Results

12 studies were included with a total of 122 AVM cases. Spetzler-Martin grading was used for the classification of the AVMs. The asleep-awake-asleep protocol was most commonly used for AC. Complete resection was achieved in all cases except 5. Intraoperative complications included seizures (n = 2) and bleeding (n = 4). Short-term post-operative complications included hemorrhage (n = 3), neurologic dysfunctions including paresis (n = 3), hemiplegia (n = 10), dysphasia/aphasia (n = 6), cranial nerve dysfunction (n = 3), and pulmonary embolism (n = 1). Almost all neurological deficits after surgery gradually improved on subsequent follow-ups.

Conclusion

AVMs may shift the anatomical location of eloquent brain areas which may be mapped during AC. All studies recommended AC for the resection of AVMs in close proximity to eloquent areas as mapping during AC identifies the eloquent cortex thus promoting careful tissue handling which may preserve neurologic function and/or predict the postoperative functional status of the patients We, therefore, conclude that AC is a viable modality for AVMs resection near eloquent language and motor areas.

Surgical Outcomes of Awake Craniotomy for Treatment of Arteriovenous Malformations in Eloquent Cortex: A Systematic Review

OBJECTIVE

Arteriovenous malformations (AVMs) located in eloquent brain regions are historically associated with a poor prognosis. Awake craniotomy (AC) with the adjunct of brain mapping has the potential of identifying non-eloquent gyri to maximize resection, thereby theoretically decreasing the risk of neurologic deficits. With limited evidence regarding the efficacy of AC in treatment of eloquent AVMs, this review aims to investigate its surgical outcomes.

METHODS

A systematic search in the PubMed database was performed to identify all relevant studies up to February 2022.

RESULTS

A total of 13 studies were extracted for quantitative analysis, yielding a total of 46 patients. The mean age was 34.1 years, and most patients were female (54.8%). Seizures were the most frequently reported presenting symptom (41%, 19 of 46 cases). Spetzler-Martin Grade III was the most prevalent (45.9%, 17 cases) with a mean nidus size of 32.6 mm. Seventy-four percent of AVMs were located on the left side, with the frontal lobe being the most common location (30%, 14 of 46 cases). The most common eloquent regions were language (47.8%, 22 of 46 cases), motor (17.4%, 8 of 46 cases), and language + motor cortices (13.1%, 6 of 46 cases). Complete resection of AVM was achieved in 41 patients (89%). Intraoperative complications occurred in 14 of 46 cases (30.4%) with transient postoperative neurologic deficits in 14 patients (30.4%).

CONCLUSIONS

AC may enable precise microsurgical excision of eloquent AVMs with preservation of critical brain functions. Risk factors for poor outcomes include eloquent AVMs located in the language + motor regions and the occurrence of intraoperative complications such as seizures/hemorrhage.