Diagnostic Accuracy of Non-Contrast-Enhanced Time-Resolved MR Angiography to Assess Angioarchitectural Classification Features of Brain Arteriovenous Malformations.

This study aims to assess the diagnostic accuracy of non-contrast-enhanced 4D MR angiography (NCE-4D-MRA) compared to contrast-enhanced 4D MR angiography (CE-4D-MRA) for the detection and angioarchitectural characterisation of brain arteriovenous malformations (bAVMs). Utilising a retrospective design, we examined 54 MRA pairs from 43 patients with bAVMs, using digital subtraction angiography (DSA) as the reference standard. Both NCE-4D-MRA and CE-4D-MRA were performed using a 3-T MR imaging system. The primary objectives were to evaluate the diagnostic performance of NCE-4D-MRA against CE-4D-MRA and DSA and to assess concordance between imaging modalities in grading bAVMs according to four main scales: Spetzler-Martin, Buffalo, AVM embocure score (AVMES), and R2eDAVM. Our results demonstrated that NCE-4D-MRA had a higher accuracy and specificity compared to CE-4D-MRA (0.85 vs. 0.83 and 95% vs. 85%, respectively) and similar agreement, with DSA detecting shunts in bAVMs or residuals. Concordance in grading bAVMs was substantial between NCE-4D-MRA and DSA, particularly for the Spetzler-Martin and Buffalo scales, with CE-4D-MRA showing slightly higher kappa values for interobserver agreement. The study highlights the potential of NCE-4D-MRA as a diagnostic tool for bAVMs, offering comparable accuracy to CE-4D-MRA while avoiding the risks associated with gadolinium-based contrast agents. The safety profile of imaging techniques is a significant concern in the long-term follow up of bAVMs, and further prospective research should focus on NCE-4D-MRA protocol improvement for clinical use.

Microsurgery of Cerebral Arteriovenous Malformations in a Resource-Limited Setting: The First Case-Series from Iraq.

BACKGROUND: Cerebral arteriovenous malformations (AVMs) can lead to significant morbidity and are particularly challenging to manage in resource-limited settings where endovascular treatment modalities are unaffordable for most patients. OBJECTIVE: To describe the first case series of AVM from Iraq with an analysis of the related clinicoradiologic characteristics, operative features, and outcomes. METHODS: A single-center database from October 2018 to December 2022 was reviewed to analyze the characteristics of cerebral AVMs who underwent surgical treatment in Baghdad, Iraq. We collected patient demographics, clinical, radiologic, operative, and the follow-up combined outcome results (modified Rankin Scale score and the presence of AVM remnants). RESULTS: Of the 54 AVM patients treated with microsurgery, the majority of lesions have Spetzler-Martin grade of 3 (31.5%), followed by grade 1 (29.6%). The parietal lobe was the most common location of AVM in 25.9% of the cases, and the temporal location had better outcomes. The mean duration of surgery was 8.5 hours, ranging from 3 to 14 hours, with 20.3% of cases having undergone preoperative stereotactic radiosurgery, and just one patient received preoperative embolization. Good combined outcome (modified Rankin Scale 0-2 and no AVM remnant) was associated with lower SM grades (P=0.003); location in the nondominant hemisphere (P=0.036), and noneloquent regions (P=0.006); absence of deep venous drainage (P=0.042) and no intraoperative brain swelling (P=0.004). The mortality rate in our series was 5.5%. CONCLUSIONS: Good clinicoradiologic outcomes can be achieved through microsurgery in a setting where endovascular treatment is inaccessible to patients due to limited resources.

Unruptured Brain Arteriovenous Malformations: A Systematic Review and Meta-Analysis of Mortality and Morbidity in Aruba-Eligible Studies.

BACKGROUND: Treating unruptured brain arteriovenous malformations (bAVMs) represent significant challenges, with numerous uncertainties still in debate. The ARUBA trial induced further investigation into optimal management strategies for these lesions. Here, we present a systematic-review and meta-analysis focusing on ARUBA-eligible studies, aiming to correlate patient data with outcomes and discuss key aspects of these studies. METHODS: Following PRISMA guidelines, we conducted a systematic-review. Variables analyzed included bAVM Spetzler-Martin (SM) grade, treatment modalities, and outcomes such as mortality and neurological deficits. We compared studies with a minimum of 50% cases classified as SM 1-2 lesions and those with less than 50% in this category. Similarly, a comparison between studies with at least 50% microsurgery-cases and those with less than 50% was performed. We examined correlations between mortality incidence, SM distribution, and treatment modalities. RESULTS: Our analysis included 16 studies with 2.417 patients. The frequency of bAVMs SM-grade 1-2 ranged from 44% to 76%, SM-grade 3 from 19% to 48%, and SM 4-5 from 5 to 23%. Notably, studies with more than 50% cases presenting lesions SM-grade 1-2 presented significantly lower mortality rates than those with less than 50% cases of SM 1-2 lesions (P < 0.001). No significant difference in mortality rates or neurological deficits was identified between studies with more than 50% of microsurgery-cases and those with less than 50%. CONCLUSIONS: The analysis revealed that studies with a higher proportion of bAVMs presenting SM 1-2 lesions were associated with lower mortality rates. Mortality did not show a significant association with treatment modalities.

Mixed reality in neurosurgery: redefining the paradigm for arteriovenous malformation planning and navigation to improve patient outcomes.

OBJECTIVE: Brain arteriovenous malformations (AVMs) present significant challenges in neurosurgery, requiring detailed planning and execution. In this study, the authors aimed to evaluate the efficacy of mixed reality (MxR), a synergistic application of virtual reality (VR) and augmented reality (AR), in the surgical management of AVMs. METHODS: A retrospective review was conducted on 10 patients who underwent AVM resection between 2021 and 2023. Preoperative planning used patient-specific 360° VR models, while intraoperative guidance used AR markers for targeted disconnection of arterial feeders. Data were analyzed for surgical duration, blood loss, and postoperative outcomes, stratified by Spetzler-Martin (SM) and supplemented Spetzler-Martin (Supp-SM) grades. RESULTS: In 10 patients with cerebral AVMs, MxR significantly facilitated the identification of 21 arterial feeders, including challenging deep feeders. MxR-assisted surgeries demonstrated efficient identification and disconnection of arterial feeders, contributing to precise AVM resection. The mean surgical duration was approximately 5 hours 11 minutes, with a mean intraoperative blood loss of 507.5 ml. Statistically significant variations in surgical duration and blood loss were observed based on SM and supplemented Supp-SM grades. Two patients experienced worsened postoperative neurological deficits, underscoring the inherent risks of AVM surgeries. The marked difference in hospital stays between patients with ruptured and those with unruptured AVMs, particularly for SM grade III, highlights the significant impact of rupture status on postoperative recovery. CONCLUSIONS: In this study, the authors delineated a novel paradigm using MxR for the surgical intervention of AVMs. Using 3D VR for preoperative planning and AR for intraoperative guidance, they achieved unparalleled precision and efficiency in targeting deep arterial feeders. While the results are promising, larger studies are needed to further validate this approach.

Giant Brain Arteriovenous Malformation Managed by Staged Embolizations and Surgical Resection with Satisfactory Outcome.

Spetzler-Martin grade V (>6 cm) arteriovenous malformations (AVMs) are traditionally considered inoperable. A 35-year-old man presented with repeated seizures for 7 years, and computed tomography arteriography and magnetic resonance imaging revealed left deep hemispheric AVM. A combination of embolization and surgical resection successfully achieved a cure of the patient. Well-equipped neurosurgery facilities can best manage selective Spetzler-Martin grade V AVMs with no neurologic deficits contrary to their traditionally inoperable concept. Successful surgery offers the patient a better quality of life.

Ruptured bilateral brain arteriovenous malformations in a young woman with early pregnancy: a case report.

BACKGROUND: Brain arteriovenous malformations (AVMs) are rare congenital developmental vascular lesions, and often presents with symptoms upon rupture. The controversy exists as to whether pregnancy confers an increased risk of intracranial hemorrhage. The diagnosis of brain AVMs, in the absence of brain imaging, is challenging in resource-limited settings, particularly in sub-Saharan Africa. CASE PRESENTATION: A 22-year old black African woman, primigravida at 14 weeks of gestation, presented with a history of persistent throbbing headache which was treated at primary health care facilities with analgesics and anti-migraine medications without relief. She later developed severe headache 2 weeks prior to admission and one-day history of serial partial generalized tonic-clonic seizures which were followed by post-ictal confusion and persistent right upper limb weakness. Initial evaluation revealed her to be pregnant and she later underwent a brain magnetic resonance angiography (MRA) at a university teaching hospital which revealed bleeding bilateral parietal AMVs with intracerebral haematoma and associated perilesional vasogenic oedema. The patient was managed conservatively using antifibrinolytic drugs and prophylactic anti-seizure drugs. Seven months later, she underwent a control brain MRA which revealed resolution of intracranial haematoma and associated vasogenic oedema and had her seizures well controlled. The headache had subsided and the pregnancy was allowed to continue to term under close obstetric and neurological observation. On follow up visits she reported episodes of nasal bleeding which upon ENT examination revealed nasal AVMs, suggesting the diagnosis of hereditary hemorrhagic telangiectasia (HHT). CONCLUSION: AVMs are rare but should prompt suspicion in young patients with atypical Central Nervous System (CNS) manifestations without evident underlying causes.

Gamma Knife Radiosurgery for Spetzler-Martin Grade III Brain Arteriovenous Malformations.

BACKGROUND: Spetzler-Martin (SM) grade III arteriovenous malformations (AVMs) show angioarchitecture heterogeneity and lack a clearly defined treatment strategy. This study aims to evaluate outcomes after treatment of SM grade III AVMs with Gamma Knife radiosurgery (GKRS). METHODS: A single-institution retrospective analysis was conducted of 307 patients with SM grade III AVMs undergoing GKRS between October 2006 and December 2020 with follow-up times of at least 24 months. SM grade III AVMs were classified into 4 subtypes: IIIA (S1E1V1), IIIB (S2E0V1), subtype IIIC (S2E1V0), and IIID (S3E0V0). RESULTS: Over a median follow-up time of 50.3 months, complete AVM obliteration was achieved in 211 patients (68.7%). Complete obliteration rates in subtypes IIIA, IIIB, IIIC, and IIID were 80.8%, 55.4%, 53.4%, and 25.0%, respectively. Annual post-GKRS hemorrhage risk was 0.8%. Significant radiosurgery-induced imaging changes occurred in 7 patients (2.3%). Three variables were identified as predictors of obliteration in final forward stepwise regression models, including volume of AVM (B = -0.011; P < 0.001), age (B = -0.004; P = 0.024), and previous AVM hemorrhage (B = 0.187; P = 0.077). CONCLUSIONS: GKRS is a safe and effective treatment for SM grade III AVMs, particularly subtype IIIA (S1E1V1). AVM volume is the key predictor of post-GKRS obliteration.

Endovascular treatment as first-line therapy in Spetzler-Martin grade III brain arteriovenous malformations: a multicenter retrospective study.

OBJECTIVE: The management of Spetzler-Martin grade (SMG) III brain arteriovenous malformations (bAVMs) may be challenging, whatever the exclusion treatment modality chosen. The purpose of this study was to evaluate the safety and effectiveness of endovascular treatment (EVT) as a first-line treatment of SMG III bAVMs. METHODS: The authors performed a retrospective, two-center, observational cohort study. Cases recorded in institutional databases between January 1998 and June 2021 were reviewed. Patients who were ≥ 18 years of age, had ruptured or unruptured SMG III bAVMs, and received EVT as first-line therapy were included. Baseline characteristics of patients and bAVMs, procedure-related complications, clinical outcome according to the modified Rankin Scale, and angiographic follow-up were assessed. The independent risk factors of procedure-related complications and poor clinical outcome were assessed using binary logistic regression. RESULTS: One hundred sixteen patients with 116 SMG III bAVMs were included. The mean age of the patients was 41.9 ± 14.0 years. The most common presentation was hemorrhage (66.4%). Forty-nine (42.2%) bAVMs were found to be completely obliterated by EVT alone at follow-up. Complications occurred in 39 patients (33.6%), including 5 (4.3%) major procedure-related complications. There was no independent predictor of procedure-related complication. Age > 40 years and poor preoperative modified Rankin Scale score were the independent predictors of poor clinical outcome. CONCLUSIONS: EVT of SMG III bAVMs provides encouraging results but needs further improvement. When the embolization procedure performed with intent to cure appears difficult and/or risky, a combined technique (with microsurgery or radiosurgery) may be a safer and more effective strategy. In terms of safety and effectiveness, the benefit of EVT (alone or included in a multimodal management strategy) for SMG III bAVMs needs to be confirmed by randomized controlled trials.

Risk Factors of Brain Arteriovenous Malformation Embolization as Adjunctive Therapy: Single-Center 10-Year Experience.

OBJECTIVE: In the multimodality treatment of complex brain arteriovenous malformations (AVMs), the role of endovascular embolization is not fully elucidated. To assess the risk of embolization, we retrospectively evaluated the outcomes of endovascular treatment for AVM, focusing on the embolization-related complications. METHODS: The present study included patients with brain AVM who underwent embolization at our hospital between April 2011 and May 2021. Risk factors for peri- and postoperative complications were analyzed. RESULTS: During the study period, 36 AVMs were treated during 58 embolization sessions. The goal of the embolization was preoperative in 24 (67%), pre-radiosurgical in 9 (25%), and palliative in 3 (8%) cases. The overall complication rate was 43% (25 of 58) per session and 36% (13 of 36) per patient. Ischemic and hemorrhagic complications were observed in 14 (24%) and 14 (24%) cases, respectively. n-Butyl cyanoacrylate (n-BCA) embolization was detected as the significant risk for postoperative hemorrhage in the univariate (79% vs. 36%, P = 0.012; Fisher exact test) and the multivariable analysis (odds ratio 4.90, 95% confidence interval 1.08-22.2, P = 0.039). The number of embolized feeder in a single session also tended to be higher in a hemorrhagic complication group (median 3.5 vs. 2.0, P = 0.11; Mann-Whitney U-test). CONCLUSIONS: The risk of embolization in multimodality treatment for complex brain AVM was substantial. n-BCA embolization may carry a higher risk of postoperative hemorrhage. An accumulation of cases is awaited to investigate the effectiveness of minimal target embolization in the future.

Curative Embolization of Small Brain Arteriovenous Malformations by Ethyl Vinyl Alcohol Copolymer: A Systematic Review and Meta-Analysis.

The right choice in treating small (Spetzler-Ponce grade A) brain arteriovenous malformations (AVMs) is a matter of debate with varying views from neurology, neurosurgery, and interventional neuroradiology points of view. The Spetzler-Martin 1 and 2 brain AVMs, especially those in eloquent and deep areas that are difficult to access by micro-neurosurgery, are most suitable for a complete cure by endovascular embolization with ethyl vinyl alcohol (EVOH)-based agents. A literature search was done with keywords such as endovascular embolization of small brain AVM. Data from 13 articles are included in the study based on predetermined inclusion and exclusion criteria. Meta-analysis for the complete cure rate was done, publication bias was removed, and regression analysis showed a 76% cure rate with a 95% confidence interval (CI). Major complications were hemorrhage and neurological deficit, which ranged from 0-20% and 0-16% with a mean proportion of 0.11 and 0.09, respectively. Long-term (3-6 months) follow-up data showed 0-4% recurrence at three months, 0-8% recurrence at six months, and 2-10% permanent disability. The mortality rate ranged from 3% to 4%. Three illustrative cases with data from the author's institute are included in the article. To conclude, endovascular embolization for small brain AVMs is a satisfactory treatment modality, however, prospective registries and randomized controlled trials involving embolization versus neurosurgery and/or stereotactic radiosurgery (SRS) may validate the role of embolization in small brain AVMs as curative treatment.

IV and V grade arteriovenous Malformations: A multicenter surgical experience. Use of multiple grading system to predict surgical risk.

OBJECTIVE: The aim of our study is to report a multicenter experience in the treatment of IV and V grade arteriovenous malformations (AVMs) and to apply commonly used grading scales for surgical risk assessment for these vascular high-grade lesions. METHODS: Between January 2015 and December 2019, a retrospective study was conducted to identify patients undergoing microsurgical intervention for cAVMs at two Italian centers specialized in the treatment of vascular pathologies. Data on patients with Spetzler-Martin IV and V and with a score equal or more than 7 according to Lawton-Young classification were collected. Ruptured AVMs at admission were subsequently classified according to the new proposed AVICH classification. RESULTS: A total of 20 patients with high grade (IV and V) cAVMs were enrolled in the study and the average follow-up was 36.45 months. The outcome based on mRS was favorable in 65 % of cases. The pre-operative mRS was a factor influencing clinical outcome, as well as the number of bleedings preceding the treatment, age, and nidus characteristics. S-M IV, L-Y 3 and S-M supp 7 scores were associated with good outcome. Based on the AVICH classification, for ruptured cAVMs, having a score of 9 ore less was correlated to a postoperative mRS fewer or equal than 2. CONCLUSIONS: Surgical management for high-grade AVMs should be considered in highly selected patients with repeated bleeding or disabling symptoms. Classification systems provide an aid in selecting patients for surgery, also in grade IV and V. It is essential to establish common registers for the management of these complex vascular malformations.

Pediatric Cerebral Spetzler-Martin Grade 5 Arteriovenous Malformation.

Brain arteriovenous malformations (AVMs) are a type of intracranial high-flow vascular malformation composed of enlarged feeding arteries and draining veins. Without a capillary bed connection, there can be damage to the walls of the arteries and veins, which causes abnormally high blood flow. AVMs are rarely found in children and are thought to expand over time until they become symptomatic. We present an interesting case of a pediatric male who initially presented with seizure-like episodes and was found to have a large frontoparietal Spetzler-Martin (SM) grade 5 AVM after cerebral digital subtraction angiography. Unfortunately, given how much eloquent brain and deep cortical structures were intertwined in the SM5 AVM, risk-benefit analysis favored observation over surgical management. The patient's clinical presentation and imaging findings are described followed by a discussion of the epidemiology, grading system, and treatment of AVMs. After extensive literature review, this clinical entity has been previously reported but is relatively rare in children with prognosis and therapy correlating to the severity of the SM index.

Frailty Predicts Postoperative Functional Outcomes After Microsurgical Resection of Ruptured Brain Arteriovenous Malformations in Older Patients.

OBJECTIVE: To determine the effectiveness of the modified Frailty Index-5 (mFI-5) in predicting postoperative functional outcome after microsurgical resection of ruptured brain arteriovenous malformations (bAVMs). METHODS: A retrospective review was performed of patients undergoing microsurgical resection of acutely ruptured bAVMs. Demographics, bAVM characteristics, mFI-5, Ruptured Arteriovenous Malformation Grading Scale (RAGS) score, and Spetzler-Martin (S-M) grade were recorded. Predictive ability of mFI-5 for postoperative functional outcome measured by modified Rankin Scale (mRS) was assessed with univariate and multivariate logistic and linear regression. RAGS score and S-M grade alone were compared with adding mFI-5 to either RAGS score or S-M grade using area under the curve (AUC) analysis. RESULTS: In total, 109 patients were included. For every 1-point increase in mFI-5, there was a lower likelihood of good functional outcome (mRS score ≤2; odds ratio [OR], 0.33; confidence interval [CI], 0.15-0.60; P = 0.011). Healthy patients (mFI-5 = 0) were more likely to have good postoperative outcomes versus frail patients (mFI-5 ≥1) (OR, 3.32; CI, 1.24-8.97; P = 0.017). In multivariate analysis controlling for RAGS score, for every 1-point mFI-5 increase, there was a decreased likelihood of postoperative good functional outcome (OR, 0.32; CI, 0.14-0.63; P = 0.0026) and mFI-5 did not significantly predict secondary outcomes. S-M grade with mFI-5 showed better discrimination for postoperative good functional outcome (AUC 0.616), compared with S-M grade alone (AUC 0.544). RAGS score with mFI-5 showed the best discrimination for postoperative good functional outcome (AUC 0.798), compared with RAGS score alone (AUC 0.721). CONCLUSIONS: Measuring frailty with mFI-5 additive to established bAVM grading systems may improve assessment of individual patient likelihood of postoperative good functional outcome after hemorrhagic bAVM resection.

Ruptured brain arteriovenous malformation in a pregnant woman: a case report.

BACKGROUND: Brain arteriovenous malformations (bAVMs) are vascular lesions that commonly present with intracranial haemorrhage. Pregnancy has been associated with an increased risk of bAVM rupture. However, their natural history in pregnant women is uncertain. CASE DESCRIPTION: A 27-year-old female at 28 weeks of gestation presented with a compromised neurological status secondary to a ruptured left frontal Spetzler-Martin scale (SM) III + bAVM. An emergent caesarean section was performed due to the high risk of foetal distress. Endovascular treatment successfully controlled the bleeding site, and stereotactic radiosurgery was offered as a subsequent treatment option. CONCLUSION: bAVMs should be considered in pregnant women with intracranial haemorrhage. The management of these lesions during pregnancy is controversial. Surgical risk and foetal development should be considered when selecting a management strategy.

Microsurgical Treatment of Deep and Eloquent AVMs.

Over the past 30 years, the treatment of deep and eloquent arteriovenous malformations (AVMs) has moved away from microneurosurgical resection and towards medical management and the so-called minimally invasive techniques, such as endovascular embolization and radiosurgery. The Spetzler-Martin grading system (and subsequent modifications) has done much to aid in risk stratification for surgical intervention; however, the system does not predict the risk of hemorrhage nor risk from other interventions. In more recent years, the ARUBA trial has suggested that unruptured AVMs should be medically managed. In our experience, although these eloquent regions of the brain should be discussed with patients in assessing the risks and benefits of intervention, we believe each AVM should be assessed based on the characteristics of the patient and the angio-architecture of the AVM, in particular venous hypertension, which may guide us to treat even high-grade AVMs when we believe we can (and need to) to benefit the patient. Advances in imaging and intraoperative adjuncts have helped us in decision making, preoperative planning, and ensuring good outcomes for our patients. Here, we present several cases to illustrate our primary points that treating low-grade AVMs can be more difficult than treating high-grade ones, mismanagement of deep and eloquent AVMs at the behest of dogma can harm patients, and the treatment of any AVM should be tailored to the individual patient and that patient's lesion.

Curative Embolization for Pediatric Spetzler-Martin Grade III Cerebral Arteriovenous Malformations.

OBJECTIVE: Spetzler-Martin (SM) grade III arteriovenous malformations (AVMs) represent a gray zone due to their high variability in location, size, and angioarchitecture. In addition, there is a lack of information on curative embolization in the pediatric population, especially in this subgroup of lesions. Here we present our experience treating grade III AVMs by curative embolization in pediatric patients. METHODS: Clinical and angiographic data from pediatric patients with grade III SM AVMs were retrospectively collected between 2011 and 2020 in a referral institution. We grouped the AVMs into subtypes according to size (S), venous drainage (V), and eloquence (E) and obtained subtypes: IIIA (S1V1E1), IIIB (S2V1E0), IIIC (S2V0E1), and IIID (S3V0E0). RESULTS: A total of 61 embolization sessions were performed in 35 pediatric patients. There were 25 females (64%), and the mean age was 12.2 years (range 5-18). Complete angiographic occlusion was achieved in 16 patients (47%). In 13 patients (37%), the AVM was occluded with a single embolization session and most (12/13) had small lesions (IIIA subtype). Among the 19 patients with incomplete occlusion, most (58%) had large lesions (IIIB, IIIC, and IIID). Large AVMs (IIIB, IIIC, and IIID) underwent 36 sessions; however, only 3 patients (21%) achieved complete occlusion in 11 sessions. Eight intraoperative complications (13% procedures) occurred mainly in ruptured AVMs (7/8) and eloquent zones (7/8). CONCLUSIONS: Curative embolization for SM grade III AVMs in children carries a high complication rate, especially in small, ruptured, and eloquent lesions. In addition, acceptable immediate complete angiographic occlusion rates were achieved, especially in small AVMs.

Radiosurgery as a microsurgical adjunct: outcomes after microsurgical resection of intracranial arteriovenous malformations previously treated with stereotactic radiosurgery.

OBJECTIVE: Microsurgical resection of arteriovenous malformations (AVMs) can be aided by staged treatment consisting of stereotactic radiosurgery followed by resection in a delayed fashion. This approach is particularly useful for high Spetzler-Martin (SM) grade lesions because radiosurgery can reduce flow through the AVM, downgrade the SM rating, and induce histopathological changes that additively render the AVM more manageable for resection. The authors present their 28-year experience in managing AVMs with adjunctive radiosurgery followed by resection. METHODS: The authors retrospectively reviewed records of patients treated for cerebral AVMs at their institution between January 1990 and August 2019. All patients who underwent stereotactic radiosurgery (with or without embolization), followed by resection, were included in the study. Of 1245 patients, 95 met the eligibility criteria. Univariate and multivariate regression analyses were performed to assess relationships between key variables and clinical outcomes. RESULTS: The majority of lesions treated (53.9%) were high grade (SM grade IV-V), 31.5% were intermediate (SM grade III), and 16.6% were low grade (SM grade I-II). Hemorrhage was the initial presenting sign in half of all patients (49.5%). Complete resection was achieved among 84% of patients, whereas 16% had partial resection, the majority of whom received additional radiosurgery. Modified Rankin Scale (mRS) scores of 0-2 were achieved in 79.8% of patients, and 20.2% had poor (mRS scores 3-6) outcomes. Improved (44.8%) or stable (19%) mRS scores were observed among 63.8% of patients, whereas 36.2% had a decline in mRS scores. This includes 22 patients (23.4%) with AVM hemorrhage and 6 deaths (6.7%) outside the perioperative period but prior to AVM obliteration. CONCLUSIONS: Stereotactic radiosurgery is a useful adjunct in the presurgical management of cerebral AVMs. Multimodal therapy allowed for high rates of AVM obliteration and acceptable morbidity rates, despite the predominance of high-grade lesions in this series of patients.

Intermediate-grade brain arteriovenous malformations and the boundary of operability using the supplemented Spetzler-Martin grading system.

OBJECTIVE: Supplemented Spetzler-Martin grading (Supp-SM), which is the combination of Spetzler-Martin and Lawton-Young grades, was validated as being more accurate than stand-alone Spetzler-Martin grading, but an operability cutoff was not established. In this study, the authors surgically treated intermediate-grade AVMs to provide prognostic factors for neurological outcomes and to define AVMs at the boundary of operability. METHODS: Surgically treated Supp-SM intermediate-grade (5, 6, and 7) AVMs were analyzed from 2011 to 2018 at two medical centers. Worsened neurological outcomes were defined as increased modified Rankin Scale (mRS) scores on postoperative examinations. A second analysis of 2000-2011 data for Supp-SM grade 6 and 7 AVMs was performed to determine the subtypes with improved or unchanged outcomes. Patients were separated into three groups based on nidus size (S1: < 3 cm, S2: 3-6 cm, S3: > 6 cm) and age (A1: < 20 years, A2: 20-40 years, A3: > 40 years), followed by any combination of the combined supplemented grade: low risk (S1A1, S1A2, S2A1), intermediate risk (S2A2, S1A3, S3A1, or high risk (S3A3, S3A2, S2A3). RESULTS: Two hundred forty-six patients had intermediate Supp-SM grade AVMs. Of these patients, 102 had Supp-SM grade 5 (41.5%), 99 had Supp-SM grade 6 (40.2%), and 45 had Supp-SM grade 7 (18.3%). Significant differences in the proportions of patients with worse mRS scores at follow-up were found between the groups, with 24.5% (25/102) of patients in Supp-SM grade 5, 29.3% (29/99) in Supp-SM grade 6, and 57.8% (26/45) in Supp-SM grade 7 (p < 0.001). Patients with Supp-SM grade 7 AVMs had significantly increased odds of worse postoperative mRS scores (p < 0.001; OR 3.7, 95% CI 1.9-7.3). In the expanded cohort of 349 Supp-SM grade 6 AVM patients, a significantly higher proportion of older patients with larger Supp-SM grade 6 AVMs (grade 6+, 38.6%) had neurological deterioration than the others with Supp-SM grade 6 AVMs (22.9%, p = 0.02). Conversely, in an expanded cohort of 197 Supp-SM grade 7 AVM patients, a significantly lower proportion of younger patients with smaller Supp-SM grade 7 AVMs (grade 7-, 19%) had neurological deterioration than the others with Supp-SM grade 7 AVMs (44.9%, p = 0.01). CONCLUSIONS: Patients with Supp-SM grade 7 AVMs are at increased risk of worse postoperative neurological outcomes, making Supp-SM grade 6 an appropriate operability cutoff. However, young patients with small niduses in the low-risk Supp-SM grade 7 group (grade 7-) have favorable postoperative outcomes. Outcomes in Supp-SM grade 7 patients did not improve with surgeon experience, indicating that the operability boundary is a hard limit reflecting the complexity of high-grade AVMs.

Awake Craniotomy for Resection of Cerebral Arteriovenous Malformation: Initial Experience From a Low- and Middle-Income Country.

Global health has shown progress over the years; however, neurosurgical care has not followed the same trajectory due to it being presumably resource intensive. Awake craniotomy (AC) is a neurosurgical technique that can improve neurological outcomes, can potentially reduce costs and hospital stay, and can be easily employed in low- and middle-income countries (LMICs). It has proven to be beneficial in surgical resection of tumors located in the critical areas of the brain, but there is limited literature to support AC for resection of arteriovenous malformations (AVM). We present four cases of AVM that were successfully treated surgically under awake settings in a developing country. Two of the AVMs were Spetzler-Martin grade (SMG) 3, one was SMG 4, and one was SMG 1. All the patients underwent successful excision of AVMs, and the postoperative digital subtraction angiography (DSA) was negative for any residual. They had a total hospital stay of three to five days with a mean postoperative stay of two days. Only one patient showed transient conductive dysphasia, which resolved on subsequent follow-ups, and none of the patients developed any long-term neurological deficit. There are limited data from LMICs regarding the benefits of using AC for AVMs. However, our cases show that this technique can be applied for AVM resection, particularly in eloquent areas of the brain (parts of the cerebral cortex that control vision, language, sensory, and motor functions), to minimize potential neurological deficits. Even though it requires careful selection of cases, and needs a higher level of microsurgical and neuro-anesthesia expertise, it can lead to better postoperative outcomes, lesser morbidity, and a shorter hospital stay, contributing to low resource utilization, making it feasible in a resource-limited setting.

Three-Dimensional Printing Assisted Preoperative Surgical Planning for Cerebral Arteriovenous Malformation.

OBJECTIVE: The aim of this study to investigate the benefits of patient-based 3-dimensional (3D) cerebral arteriovenous malformation (AVM) models for preoperative surgical planning and education. METHODS: Fifteen patients were operated on for AVMs between 2015 and 2019 with patient-based 3D models. Ten patients' preoperative cranial angiogram screenings were evaluated preoperatively or perioperatively via patient-based 3D models. Two patients needed emergent surgical intervention; their models were solely designed based on their AVMs and used during the operation. However, the other patients who underwent elective surgery had the modeling starting from the skull base. These models were used both preoperatively and perioperatively. The benefits of patients arising from treatment with these models were evaluated via patient files and radiological data. RESULTS: Fifteen patients (10 males and five females) between 16 and 66 years underwent surgery. The mean age of the patients was 40.0±14.72. The most frequent symptom patients observed were headaches. Four patients had intracranial bleeding; the symptom of admission was a loss of consciousness. Two patients (13.3%) belonged to Spetzler-Martin (SM) grade I, four (26.7%) belonged to SM grade II, eight (53.3%) belonged to SM grade III, and one (6.7%) belonged to SM grade IV. The mean operation duration was 3.44±0.47 hours. Three patients (20%) developed transient neurologic deficits postoperatively, whereas three other patients died (20%). CONCLUSION: Several technological innovations have emerged in recent years to reduce undesired outcomes and support the surgical team. For example, 3D models have been employed in various surgical procedures in the last decade. The routine usage of patient-based 3D models will not only support better surgical planning and practice, but it will also be useful in educating assistants and explaining the situation to the patient as well.