Microsurgery for ARUBA Trial (A Randomized Trial of Unruptured Brain Arteriovenous Malformation)-Eligible Unruptured Brain Arteriovenous Malformations

Preoperative embolization of brain arteriovenous malformation and efficacy in intraoperative blood loss reduction: a quantitative study

BACKGROUND

Embolization of brain arteriovenous malformations (bAVMs) is often used as adjuvant therapy to microsurgical resection to reduce the high-risk features of bAVMs such as large size and high flow. However, the effect of preoperative embolization on surgical performance and patient outcome has shown mixed results. Heterogeneity in treatment goals, selection criteria, and unpredictable changes in bAVM hemodynamics after partial embolization may account for these uncertain findings. In this study we use an objective quantitative technique to assess the impact of preoperative embolization on intraoperative blood loss (IBL).

METHODS

Patients with bAVM treated with microsurgical resection only or in combination with preoperative embolization from 2012 to 2022 were retrospectively reviewed. Patients were included if quantitative magnetic resonance angiography was performed prior to any treatment. Correlation of baseline bAVM flow, volume, and IBL was evaluated between the two groups. Additionally, bAVM flow prior to and after embolization was compared.

RESULTS

Forty-three patients were included, 31 of whom required preoperative embolization (20 had more than one session). Mean bAVM initial flow (362.3 mL/min vs 89.6 mL/min, p=0.001) and volume (9.6 mL vs 2.8 mL, p=0.001) were significantly higher in the preoperative embolization group; flow decreased significantly after embolization (408.0 mL/min vs 139.5 mL/min, p<0.001). IBL was comparable between the two groups (258.6 mL vs 141.3 mL, p=0.17). Linear regression continued to show a significant difference in initial bAVM flow (p=0.03) but no significant difference in IBL (p=0.53).

CONCLUSION

Patients with larger bAVMs who underwent preoperative embolization had comparable IBL to those with smaller bAVMs undergoing only surgical treatment. Preoperative embolization of high-flow bAVMs facilitates surgical resection, reducing the risk of IBL.

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.

Impact of COVID-19 pandemic on treatment and outcomes of cerebral arteriovenous malformations

BACKGROUND

There has been a recent decrease in interventional management of cerebral arteriovenous malformations (AVMs). The objective of our study was to evaluate the changing patterns in management of AVMs in the first year of the COVID-19 pandemic.

METHODS

The National Inpatient Sample (NIS) database was used. From 2016 to 2020, patients with an International Classification of Diseases, 10th revision (ICD-10) diagnosis code for a cerebral AVM were included. An intervention was defined as ICD-10 code for surgical, endovascular, or stereotactic radiosurgery treatment. Odds ratios (ORs) were calculated using a logistic regression model with covariates deemed to be clinically relevant.

RESULTS

63 610 patients with AVMs were identified between 2016 and 2020, 14 340 of which were ruptured. In 2020, patients had an OR of 0.69 for intervention of an unruptured AVM (P<0.0001) compared with 2016-19. The rate of intervention for unruptured AVMs decreased to 13.5% in 2020 from 17.6% in 2016-19 (P<0.0001). The rate of AVM rupture in 2020 increased to 23.9% from 22.2% in 2016-19 (P<0.0001). In 2020, patients with ruptured AVMs had an OR for inpatient mortality of 1.72 compared with 2016-19. Linear regression analysis from 2016 to 2020 showed an inverse relationship between intervention rate and rupture rate (slope -0.499, R2=0.88, P=0.019).

CONCLUSION

In 2020, the rate of intervention for unruptured cerebral AVMs decreased compared with past years, with an associated increase in the rate of rupture. Patients with ruptured AVMs also had a higher odds of mortality.

Treatment outcomes for ARUBA-eligible brain arteriovenous malformations: a comparison of real-world data from the NVQI-QOD AVM registry with the ARUBA trial

BACKGROUND

Significant controversy exists about the management of unruptured cerebral arteriovenous malformations (AVMs). Results from A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) suggested that intervention increases the risk of stroke/death compared with medical management. However, numerous study limitations raised concerns about the trial's generalizability.

OBJECTIVE

To assess the rate of stroke/death and functional outcomes in ARUBA-eligible patients from a multicenter database, the Neurovascular Quality Initiative-Quality Outcomes Database (NVQI-QOD).

METHODS

We performed a retrospective analysis of prospectively collected data of ARUBA-eligible patients who underwent intervention at 18 participating centers. The primary endpoint was stroke/death from any cause. Secondary endpoints included neurologic, systemic, radiographic, and functional outcomes.

RESULTS

173 ARUBA-eligible patients underwent intervention with median follow-up of 269 (25-722.5) days. Seventy-five patients received microsurgery±embolization, 37 received radiosurgery, and 61 received embolization. Baseline demographics, risk factors, and general AVM characteristics were similar between groups. A total of 15 (8.7%) patients experienced stroke/death with no significant difference in primary outcome between treatment modalities. Microsurgery±embolization was more likely to achieve AVM obliteration (P<0.001). Kaplan-Meier survival curves demonstrated no difference in overall death/stroke outcomes between the different treatment modalities' 5-year period (P=0.087). Additionally, when compared with the ARUBA interventional arm, our patients were significantly less likely to experience death/stroke (8.7% vs 30.7%; P<0.001) and functional impairment (mRS score ≥2 25.4% vs 46.2%; P<0.01).

CONCLUSION

Our results suggest that intervention for unruptured brain AVMs at comprehensive stroke centers across the United States is safe.

Impact of tailored multimodal treatment for unruptured brain arteriovenous malformation: comparison with a randomized trial of unruptured brain arteriovenous malformations

PURPOSE

The first randomized controlled study on unruptured brain arteriovenous malformations (bAVM), the ARUBA trial, demonstrate the superiority of medical management; however, it failed to completely rule out the efficacy of therapeutic interventions due to several limitations. This study aimed to examine the outcomes of multimodal interventional treatment for bAVM in terms of safety and efficacy.

METHODS

We reviewed 226 consecutive patients with unruptured bAVM admitted to our institute between 2002 and 2022. Treatment methods were divided into medical management and therapeutic intervention, including microsurgery, stereotactic surgery, and endovascular intervention. First, the choice of therapeutic modalities was assessed in the pre-ARUBA (before February 2014) and post-ARUBA (after March 2014) eras. Second, the incidence of symptomatic stroke or death and functional prognosis with a modified Rankin scale (mRS) score of ≥2 at 5 years was compared between the medical management and therapeutic intervention.

RESULTS

In the pre- and post-ARUBA groups, 73% and 84% of patients underwent therapeutic interventions, respectively (p = 0.053). The rate of symptomatic stroke or death was lower in patients who underwent interventional therapies than in those who underwent medical management (9.7% vs. 22%, p = 0.022); however, the opposite was observed in the ARUBA trial (31% vs. 10%). The annual incidence of stroke or death was also lower in the interventional therapy group (4.3%/y vs. 1.8%/year, hazard ratio = 0.45, 95% confidence interval: 0.18-1.08, p = 0.032). The rate of mRS score of ≥2 after a 5-year follow-up was 18% and 6% in the medical treatment and intervention groups (p = 0.14).

CONCLUSIONS

The therapeutic intervention rate did not decrease, even after the publication of the ARUBA trial. The rate of stroke or death was lower in the intervention group, indicating that a tailored choice of multimodality is safe and effective for managing unruptured bAVM.

Recurrence of Cerebral Arteriovenous Malformation Following Complete Obliteration Through Endovascular Embolization

Arteriovenous malformation (AVM) recurrence after embolization was rarely reported. This study aimed to explore the potential risk factors of recurrence in angiographically obliterated AVMs treated with endovascular embolization. This study reviewed AVMs treated with embolization only in a prospective multicenter registry from August 2011 to December 2021, and ultimately included 92 AVMs who had achieved angiographic obliteration. Recurrence was assessed by follow-up digital subtraction angiography (DSA) or magnetic resonance imaging (MRI). Hazard ratios (HRs) with 95% confidence intervals were calculated using Cox proportional hazards regression models. Nineteen AVMs exhibited recurrence on follow-up imaging. The recurrence rates after complete obliteration at 6 months, 1 year, and 2 years were 4.35%, 9.78%, and 13.0%, respectively. Multivariate Cox regression analysis identified diffuse nidus (HR 3.208, 95% CI 1.030-9.997, p=0.044) as an independent risk factor for recurrence. Kaplan-Meier analysis confirmed a higher cumulative risk of recurrence with diffuse nidus (log-rank, p=0.016). Further, in the exploratory analysis of the effect of embolization timing after AVM rupture on recurrence after the complete obliteration, embolization within 7 days of the hemorrhage was found as an independent risk factor (HR 4.797, 95% CI 1.379-16.689, p=0.014). Kaplan-Meier analysis confirmed that embolization within 7 days of the hemorrhage was associated with a higher cumulative risk of recurrence in ruptured AVMs (log-rank, p<0.0001). This study highlights the significance of diffuse nidus as an independent risk factor for recurrence after complete embolization of AVMs. In addition, we identified a potential recurrent risk associated with early embolization in ruptured AVMs.

Multi-Stage Treatment for Spetzler-Martin Grades III, IV, and V Arteriovenous Malformations: Preoperative Embolization and Microsurgical Resection in a Consecutive Series of 250 Patients

PURPOSE

The treatment of high-grade brain AVMs is challenging and has no guidelines available to date. This study was aimed at reporting the experience of two centers in treating these AVMs through a multi-stage approach consisting of preoperative embolization and microsurgical resection.

METHODS

A retrospective review was performed for 250 consecutive patients with a diagnosis of high-grade brain AVM (Spetzler-Martin grades III, IV, and V) treated in two centers in Germany between January 1989 and February 2023. The analyzed data included demographic, clinical, morphological, and neurological data.

RESULTS

A total of 150 cases (60%) were classified as Spetzler-Martin grade III, 82 cases (32.8%) were classified as grade IV, and 18 cases (7.2%) were classified as grade V. Eighty-seven cases (34.8%) presented with hemorrhage. The devascularization percentages achieved were <50% in 24 (9.6%), 50-80% in 55 (22%), and >80% in 171 (68.4%) cases. The average number of sessions was 5.65 ± 5.50 and 1.11 ± 0.32 endovascular and surgical procedures, respectively, and did not significantly differ by rupture status. Death or dependency (mRS score ≥ 3) after the last follow-up was observed in 18.8% of patients and was significantly associated with age > 80 years and poor baseline neurological condition. The complete resection rate was 82.3% and was significantly associated with age > 80 years, large nidus, and deep venous drainage. Permanent disabling neurological deficit after at least 3 months of follow-up was diagnosed in 13.2% of patients and was significantly associated with age > 80 years and infratentorial locations.

CONCLUSION

A multi-stage treatment for high-grade AVMs is feasible for selected cases but comes at a functional cost. The devascularization percentage was not associated with the investigated outcomes. Age > 80 years was associated with poor safety and effectiveness outcomes; consequently, this treatment should be offered only in exceptional circumstances.

National reduction in cerebral arteriovenous malformation treatment correlated with increased rupture incidence

BACKGROUND

Recently, there has been a shift in management of unruptured cerebral arteriovenous malformations (AVMs) following studies suggesting that medical management alone was superior to interventional therapy.

OBJECTIVE

To evaluate the influence of contemporary AVM management on AVM rupture patterns in the United States.

METHODS

154 297 AVM admissions were identified between 2003 and 2017 in the National Inpatient Sample. Annual AVM intervention and rupture rates were computed and multivariable logistic regression assessed the likelihood of AVM intervention pre- and post-2014. Segmented regression identified significant change points and fitted segmented linear models for annual intervention and rupture rates. Correlation coefficients assessed the relationship between annual AVM intervention and rupture rates.

RESULTS

For unruptured AVMs, intervention likelihood and proportion decreased after 2014 (28.1% to 22.3%, p<0.0001; adjusted OR=0.857, 95% CI 0.751 to 0.977, p=0.02). Ruptured AVM admissions increased from 14.7% to 18.6% after 2014 (p<0.0001). Between 2003 and 2017, segmented linear regression identified one significant change point in intervention rate between 2014 and 2015. Average annual percent change for rupture incidence and intervention rate increased by 0.49% (p=0.0001) and decreased by 1.17% (p=0.0001), respectively. Annual AVM intervention rates were inversely correlated with annual AVM rupture incidence (Pearson coefficient=-0.82, p=0.0002). In 2017, the annual AVM rupture rate (20.6%) surpassed the annual AVM intervention rate (19.7%).

CONCLUSIONS

After 2014, the likelihood of intervention for unruptured AVMs decreased while the incidence of ruptured AVMs increased. These findings suggest that fewer unruptured AVM treatments may lead to increases in AVM rupture incidence.

Endovascular treatment of brain arteriovenous malformations: clinical outcomes of patients included in the registry of a pragmatic randomized trial

OBJECTIVE

The role of endovascular treatment in the management of patients with brain arteriovenous malformations (AVMs) remains uncertain. AVM embolization can be offered as stand-alone curative therapy or prior to surgery or stereotactic radiosurgery (SRS) (pre-embolization). The Treatment of Brain AVMs Study (TOBAS) is an all-inclusive pragmatic study that comprises two randomized trials and multiple registries.

METHODS

Results from the TOBAS curative and pre-embolization registries are reported. The primary outcome for this report is death or dependency (modified Rankin Scale [mRS] score > 2) at last follow-up. Secondary outcomes include angiographic results, perioperative serious adverse events (SAEs), and permanent treatment-related complications leading to an mRS score > 2.

RESULTS

From June 2014 to May 2021, 1010 patients were recruited in TOBAS. Embolization was chosen as the primary curative treatment for 116 patients and pre-embolization prior to surgery or SRS for 92 patients. Clinical and angiographic outcomes were available in 106 (91%) of 116 and 77 (84%) of 92 patients, respectively. In the curative embolization registry, 70% of AVMs were ruptured, and 62% were low-grade AVMs (Spetzler-Martin grade I or II), while the pre-embolization registry had 70% ruptured AVMs and 58% low-grade AVMs. The primary outcome of death or disability (mRS score > 2) occurred in 15 (14%, 95% CI 8%-22%) of the 106 patients in the curative embolization registry (4 [12%, 95% CI 5%-28%] of 32 unruptured AVMs and 11 [15%, 95% CI 8%-25%] of 74 ruptured AVMs) and 9 (12%, 95% CI 6%-21%) of the 77 patients in the pre-embolization registry (4 [17%, 95% CI 7%-37%] of 23 unruptured AVMs and 5 [9%, 95% CI 4%-20%] of 54 ruptured AVMs) at 2 years. Embolization alone was confirmed to occlude the AVM in 32 (30%, 95% CI 21%-40%) of the 106 curative attempts and in 9 (12%, 95% CI 6%-21%) of 77 patients in the pre-embolization registry. SAEs occurred in 28 of the 106 attempted curative patients (26%, 95% CI 18%-35%, including 21 new symptomatic hemorrhages [20%, 95% CI 13%-29%]). Five of the new hemorrhages were in previously unruptured AVMs (n = 32; 16%, 95% CI 5%-33%). Of the 77 pre-embolization patients, 18 had SAEs (23%, 95% CI 15%-34%), including 12 new symptomatic hemorrhages [16%, 95% CI 9%-26%]). Three of the hemorrhages were in previously unruptured AVMs (3/23; 13%, 95% CI 3%-34%).

CONCLUSIONS

Embolization as a curative treatment for brain AVMs was often incomplete. Hemorrhagic complications were frequent, even when the specified intent was pre-embolization before surgery or SRS. Because the role of endovascular treatment remains uncertain, it should preferably, when possible, be offered in the context of a randomized trial.

New approaches for brain arteriovenous malformations-related epilepsy

BACKGROUND

The purpose of this review is to present the current literature and to highlight the most recent findings in brain arteriovenous malformations (bAVM)-related epilepsy research.

METHODS

We searched Medline, PubMed, Biblioinserm, Cochrane Central to study the latest research reports about the different factors that could be responsible for the genesis of bAVM-related epilepsy. We analyzed if epileptogenesis has any characteristics traits and its relation with the vascular malformation. The results of different treatments on epilepsy were considered. Typical errors that may lead towards incorrect or worse management of the seizures for these patients were also examined.

RESULTS

The development of bAVM results from multifactorial etiologies and bAVM-related epileptogenesis is likely specific for this pathology. Different types of evidence demonstrate a bidirectional relationship between bAVM and epilepsy. Currently, there is not enough published data to determine what may be the right management for these patients.

CONCLUSIONS

A better understanding of epileptogenesis in conjunction with knowledge of the complex alterations of structures and functions following bAVM-related seizures is necessary. Identification of biomarkers that can identify subgroups most likely to benefit from a specific intervention are needed to help guide clinical management. A new concept for the treatment of epilepsy related to an unruptured bAVM that cannot be treated invasively is proposed as well as new therapeutic perspectives. The next necessary step will be to propose additional algorithms to improve the development of future trials.

A complex approach to the treatment of arteriovenous IV-V degree malformations according to Spetzler‒Martin scale. Clinical case

Four therapeutic approaches have been developed for the treatment of arteriovenous malformations (AVMs): microsurgery, radiosurgery, embolization, and conservative treatment. The lack of consensus regarding the choice of treatment method and the different specializations of the doctor who are onvolved to the patient with AVM often determine the wrong treatment strategy. We performed a prospective analysis of the results of AVM of the IV degree according to Spetzler‒Martin scale, 4–5 points on the Buffalo scale complex treatment, based on clinical and tomographic data after the use of partial endovascular embolization and radical microsurgical removal of the AVM node assisted by cell saving technology. According to cerebral angiography 4 months follow-up there is no visible AVM vessels, the malformation was completely resected.Treatment of large and giant AVMs (IV and V degrees according to the Spetzler‒Martin scale) requires tailored surgical treatment approache using endovascular, microsurgical and radiosurgical techniques, but in many cases without achieving a radical result. The use of cell saver technology is necessary to reduce the risks of intraoperative complications associated with blood loss during microsurgical intervention, and enables radical removal of the AVM and recovery of the patient. The role of cell saver technology is crucial in vascular microsurgical interventions, which are often accompanied by a significant volume of blood loss, ensuring rapid autologous hemotransfusion and restoration of circulating blood volume. Endovascular embolization is a necessary step to reduce the risks of intraoperative complications during microsurgical intervention, which, together with the use of cell saver technology, makes it possible to achieve radical AVM removal and patient recovery.

Microsurgery versus Microsurgery With Preoperative Embolization for Brain Arteriovenous Malformation Treatment: A Systematic Review and Meta-analysis

BACKGROUND

Preoperative embolization has traditionally been regarded as a safe and effective adjunct to microsurgical treatment of brain arteriovenous malformations (bAVM). However, there is currently no high-level evidence to ascertain this presumption.

OBJECTIVE

To compare the outcomes of microsurgery (MS) vs microsurgery with preoperative embolization (E + MS) in patients with bAVM through systematic review.

METHODS

We searched MEDLINE, PubMed, and Embase. The primary outcome was bAVM obliteration. Secondary outcomes were intraoperative bleeding (mL), complications, worsened modified Rankin Scale (mRS), and mortality. The pooled proportions of outcomes were calculated through the logit transformation method. The odds ratio (OR) of categorical data and mean difference of continuous data were estimated through the Mantel-Haenszel and the inverse variance methods, respectively.

RESULTS

Thirty-two studies met the eligibility criteria. One thousand eight hundred twenty-eight patients were treated by microsurgery alone, and 1088 were treated by microsurgery with preoperative embolization, respectively. The meta-analysis revealed no significant difference in AVM obliteration (94.1% vs 95.6%, OR = 1.15 [0.63-2.11], P = .65), mortality (1.7% vs 2%, OR = 0.88 [0.30-2.58], P = .82), procedural complications (18.2% vs 27.2%, OR = 0.47 [0.19-1.17], P = .10), worsened mRS (21.2% vs 18.5%, OR = 1.08 [0.33-3.54], P = .9), and intraoperative blood loss (mean difference = 182.89 [-87.76, 453.55], P = .19).

CONCLUSION

The meta-analysis showed no significant difference in AVM obliteration, mortality, complications, worse mRS, and intraoperative blood loss between MS and E + MS groups. For AVMs where MS alone has acceptable results, it is reasonable to bypass unnecessary preoperative embolization given higher postoperative complication risk.

Safety and Effectiveness of First-line Endovascular Management of Low-Grade Brain Arteriovenous Malformations : Single Center Experience in 145 Patients

PURPOSE

Spetzler-Martin grade (SMG) I-II (low-grade) brain arteriovenous malformations (BAVMs) are often considered safe for microsurgical resection; however, the role of endovascular treatment (EVT) remains to be clarified in this indication, especially for unruptured BAVMs. The purpose of our study was to assess the safety and effectiveness of endovascular treatment as the first-line treatment for low-grade BAVMs.

METHODS

From our local database, we retrospectively retrieved patients with low-grade BAVMs, either ruptured or unruptured, treated by embolization as first-line treatment in our department between January 2005 and January 2020. The primary endpoint was the total obliteration rate of BAVMs, and secondary endpoints were hemorrhagic complications and final clinical outcome, assessed through shift of the modified Rankin scale, and mortality rate secondary to BAVM embolization.

RESULTS

A total of 145 patients meeting inclusion criteria and treated by EVT as first-line therapy were included in the study (82 ruptured and 63 unruptured BAVMs). Overall, complete exclusion of BAVMs was achieved in 110 patients (75.9%); 58 patients (70.7%) with ruptured and 52 (82.5%) unruptured BAVMs, including 37.9% BAVMs excluded by EVT alone (35.5% among ruptured and 44.4% among unruptured BAVMs) and 38% by combined treatment (EVT and surgery or EVT and SRS). There was no BAVM volume cut-off predictive for total obliteration by embolization alone. Early minor hemorrhagic complications were reported in 14 patients (9.6%) and early major hemorrhagic complications were reported in 5 patients (3.4%). No late hemorrhagic complications (0%) occurred; mortality rate was 0.7% (1/145 patients). Improved/unchanged mRS was reported in 137 patients (94.5%).

CONCLUSION

Endovascular treatment alone or associated with others exclusion techniques, might be safe and effective for complete exclusion of low-grade brain arteriovenous malformations regardless of the volume.

Treatment of high-grade brain arteriovenous malformations using a hybrid operating room: A prospective single-arm study

BACKGROUND

Optimal treatment of patients with high Spetzler-Martin (S-M) grade brain arteriovenous malformations (BAVMs) remains controversial. Few studies have investigated outcomes in such patients treated in a hybrid operating room (hOR).

OBJECTIVE

To examine outcomes of one-stop hybrid BAVM treatment in patients with high-grade lesions.

METHODS

We prospectively enrolled patients with high-grade BAVMs (S-M grade ≥3) aged 18-65 years who underwent one-stop hybrid BAVM treatment at our hospital between October 2016 and March 2021. High-grade BAVM patients who underwent surgery from 2010 to 2016 served as historical controls.

RESULTS

Forty-one high-grade BAVM patients underwent one-stop hybrid treatment in a hOR. Sixty-one propensity score-matched patients comprised the historical control group. The groups did not significantly differ in patient and BAVM characteristics. Intraoperative angiography in four patients of the hOR group demonstrated residual nidus that required further immediate resection. Main procedural complications included hemorrhage, neurologic deficit, and seizure. In the historical control group, diffuse angioarchitecture and arteriovenous fistula were independent risk factors for incomplete resection.

CONCLUSIONS

One-stop hybrid BAVM treatment is safe and effective for removal of high-grade BAVMs, especially those with diffuse or complex angioarchitecture. Preoperative embolization can effectively reduce blood flow while preserving motor and language function. The combined application of functional magnetic resonance imaging, electrophysiological monitoring, and awake craniotomy can successfully avoid causing neurological injury.

Outcomes of Unruptured Low-Grade Brain Arteriovenous Malformations Using TOBAS (Treatment of Brain Arteriovenous Malformations Study) Criteria

BACKGROUND

Treatment of an unruptured brain arteriovenous malformation (bAVM) is a matter of debate, especially for low-grade bAVM (Spetzler-Martin grade I and II). The aim is to compare the outcomes of patients with low-grade unruptured bAVM after interventional or medical management in a pragmatic manner.

METHODS

Adults with unruptured low-grade bAVM diagnosed between 2006 and 2016 were included. The primary end points were death from all causes and disabling stroke that resulted in a modified Rankin Scale (mRS) score >2 at last follow-up.

RESULTS

Eighty-four patients presented with an unruptured Spetzler-Martin low-grade bAVM. Among these patients, 55 (65.5%) were treated and 29 (34.5%) were untreated, with no differences regarding clinical and radiologic characteristics. The modality of treatment was embolization in 25.5%, radiosurgery (alone, 30.9%; with embolization, 18.2%), and surgery (alone, 5.5%; with embolization, 20%). The rupture rate was 6.7% person-year in the untreated group; 12.7% (n = 7) of treated and 16.7% (n = 5) of untreated patients achieved the primary evaluation criteria (P = 0.744). Using a Kaplan-Meier curve, the probability of reaching this criterion at 5 years was not different between groups (P = 0.07). Complications resulting in an mRS score >2 at last follow-up occurred in 9.1%, in 80% of cases after embolization.

CONCLUSIONS

This study shows no differences between treated and untreated low-grade bAVM. Embolization seems to carry a high risk of complication and should be used with caution. The small number of cases must encourage cautious interpretations especially because of the spontaneous high-rupture rate. One major interest is to investigate center habits in pathology when treatment standards are limited.

Multimodality treatment for brain arteriovenous malformation in Mainland China: design, rationale, and baseline patient characteristics of a nationwide multicenter prospective registry

BACKGROUND

Brain arteriovenous malformation (AVM) is an important cause of hemorrhagic stroke in young adults, which can lead to severe neurological impairment. The registry of Multimodality treatment for brain ArTeriovenous malformation in mainland CHina (MATCH) is a national prospective registry to identify the natural history of AVMs in Asian population; to investigate traditional and emerging hemorrhagic predictors; and to explore the superiority of the multidisciplinary assessment in improving the long-term outcomes.  METHODS: Consecutive AVM patients will be enrolled from 52 participating hospitals in mainland China. Baseline demographic, clinical and imaging data will be collected prospectively. Conservation, microsurgery, embolization, stereotactic radiosurgery (SRS), and multimodal strategies are all included in this study. Patients will be divided into experimental and control group according to whether the treatment protocols are formulated by multidisciplinary team. Neurofunctional status, subsequent hemorrhage, seizure, and novel neurofunctional deficit will be queried at 3 months, annually (1 and 2 years), 3 years, and 10 years follow-up.

RESULTS

Between August 2011 and April 2021, 3241 AVMs were enrolled in 11 participating sites. Among them, 59.0% were male with an average age of 28.4 ± 14.6 years, 61.2% had rupture history and 2268 hemorrhagic events occurred before admission. The median Spetzler-Martin grade and Lawton-Young grade was 3 and 5, respectively. Microsurgery is the dominant strategy (35.7%), with a similar proportion of embolization, SRS, and a combination of both (12.7%; 14.8%; 11.8%; respectively). Among them, 15.43% underwent multidisciplinary assessment and received standardized treatment. At the most recent follow-up, 7.8% were lost and the median follow-up duration was 5.6 years.

CONCLUSIONS

The MATCH study is a large-sample nationwide prospective registry to investigate multimodality management strategy for AVMs. Data from this registry may also provide the opportunity for individualized risk assessment and the development of optimal individual management strategies.

TRIAL REGISTRATION

ClinicalTrials.gov Registry ( NCT04572568 ).

Stereotactic Radiosurgery for A Randomized Trial of Unruptured Brain Arteriovenous Malformations-Eligible Patients: A Meta-Analysis

BACKGROUND

The outcomes of A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) were controversial, and they suggested that intervention is inferior to medical management for unruptured brain arteriovenous malformations (AVMs). However, several studies have shown that stereotactic radiosurgery (SRS) is an acceptable therapy for unruptured AVMs.

OBJECTIVE

To test the hypothesis that ARUBA intervention arm's SRS results are meaningfully inferior to those from similar populations reported by other studies.

METHODS

We performed a literature review to identify SRS studies of patients who met the eligibility criteria for ARUBA. Patient, AVM, treatment, and outcome data were extracted for statistical analysis. Regression analyses were pooled to identify factors associated with post-SRS obliteration and hemorrhage.

RESULTS

The study cohort included 8 studies comprising 1620 ARUBA-eligible patients who underwent SRS. At the time of AVM diagnosis, 36% of patients were asymptomatic. The mean follow-up duration was 80 months. Rates of radiologic, symptomatic, and permanent radiation-induced changes were 45%, 11%, and 2%, respectively. The obliteration rate was 68% at last follow-up. The post-SRS hemorrhage and mortality rates were 8%, and 2%, respectively. Lower Spetzler-Martin grade (odds ratios [OR] = 0.84 [0.74-0.95], P = .005), lower radiosurgery-based AVM score (OR = 0.75 [0.64-0.95], P = .011), lower Virginia Radiosurgery AVM Scale (OR = 0.86 [0.78-0.95], P = .003), and higher margin dose (OR = 1.13 [1.02-1.25], P = .025) were associated with obliteration.

CONCLUSION

SRS carries a favorable risk to benefit profile for appropriately selected ARUBA-eligible patients, particularly those with smaller volume AVMs. Our findings suggest that the results of ARUBA do not reflect the real-world safety and efficacy of SRS for unruptured AVMs.

Hemodynamic changes during the obliteration process for cerebral arteriovenous malformations after radiosurgery

OBJECTIVE

The process of cerebral arteriovenous malformation (AVM) obliteration following radiosurgery is poorly understood. Authors of this retrospective study aimed to assess the changes in AVM hemodynamics after stereotactic radiosurgery (SRS) by using 3D flow magnetic resonance imaging (MRI) to elucidate the process of AVM obliteration.

METHODS

Twenty-four patients with AVMs treated with SRS between July 2015 and December 2017 were included in this study and classified into two groups depending on the duration of AVM obliteration: group A, obliteration within 3 years (n = 15); and group B, obliteration taking more than 3 years or no obliteration (n = 9). Blood flow (ml/min) in the largest feeding artery was measured before and after SRS by using time-averaged 3D flow MRI. The decreasing rate of blood flow in the feeding artery after SRS was calculated as the percent change from baseline blood flow. A Wilcoxon rank-sum test was used to compare the decreasing blood flow rate between the two groups at 4 and 12 months after SRS.

RESULTS

For the entire cohort, the mean decrease in blood flow in the feeding artery from baseline was 29% at 4 months and 71% at 12 months after SRS. In general, blood flow after SRS decreased faster in group A and slower in group B. The decreasing rates in blood flow at 4 and 12 months after SRS were significantly different between the two groups (p = 0.02 and < 0.001, respectively).

CONCLUSIONS

Tracking changes in AVM hemodynamics after SRS may be useful for assessing the progress of AVM obliteration and the therapeutic effects of SRS, possibly contributing to the prediction of subsequent obliteration outcome.

Interventional outcomes for patients eligible for entry into the ARUBA clinical trial: a systematic review and meta-analysis

OBJECTIVE

A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) suggested that medical management afforded outcomes superior to those following intervention for unruptured arteriovenous malformations (AVMs), but its findings have been controversial. Subsequent studies of AVMs that would have met the eligibility requirements of ARUBA have supported intervention for the management of some cases. The present meta-analysis was conducted with the object of summarizing interventional outcomes for ARUBA-eligible patients reported in the literature.

METHODS

A systematic literature search (PubMed, Web of Science, Google Scholar) for AVM intervention studies that used inclusion criteria identical to those of ARUBA (age ≥ 18 years, no history of AVM hemorrhage, no prior intervention) was performed. The primary outcome was death or symptomatic stroke. Secondary outcomes included AVM obliteration, hemorrhage, death, and poor outcome (modified Rankin Scale score ≥ 2 at final follow-up). Bias assessment was performed with the Newcastle-Ottawa Scale, and the results were synthesized as pooled proportions.

RESULTS

Of the 343 articles identified through database searches, 13 studies met the inclusion criteria, yielding an overall study cohort of 1909 patients. The primary outcome occurred in 11.2% of patients (pooled = 11%, 95% CI 8%-13%). The rates of AVM obliteration, hemorrhage, poor outcome, and death were 72.7% (pooled = 78%, 95% CI 70%-85%), 8.4% (pooled = 8%, 95% CI 6%-11%), 9.9% (pooled = 10%, 95% CI 7%-13%), and 3.5% (pooled = 2%, 95% CI 1%-4%), respectively. Annualized primary outcome and hemorrhage risks were 1.85 (pooled = 2.05, 95% CI 1.31-2.94) and 1.34 (pooled = 1.41, 95% CI 0.83-2.13) per 100 patient-years, respectively.

CONCLUSIONS

Intervention for unruptured AVMs affords acceptable outcomes for appropriately selected patients. The risk of hemorrhage following intervention compared favorably to the natural history of unruptured AVMs. The included studies were retrospective and varied in treatment and AVM characteristics, thereby limiting the generalizability of their data. Future studies from prospective registries may clarify patient, nidus, and intervention selection criteria that will refine the challenging management of patients with unruptured AVMs.

Fatal ruptured occult arteriovenous malformation in a young adult: An autopsy case report

Background:

Brain arteriovenous malformations (AVMs) are congenital developmental disorders with unclear causative factors and pathogenic mechanisms. Various epigenetic factors may influence the development and rupture of AVMs. Ruptured AVMs may lead to poor outcomes. Therefore, the risk factors of AVM rupture and treatment strategies for unruptured AVMs should be explored. Herein, we report a case of a fatal ruptured AVM diagnosed by radiological and autopsy findings and review the literature regarding AVM treatment.

Case Description:

A 46-year-old man was brought to the hospital with sudden loss of consciousness while sitting on the edge of the bathtub. On examination, he was unconscious with poor breathing efforts. He was intubated and a brain CT scan was performed, which showed an intracerebral hemorrhage (ICH) adjacent to the right trigone with massive intraventricular hemorrhage (IVH) and subarachnoid hemorrhage (SAH). Contrast-enhanced CT scan showed abnormal vessels adjacent to the hematoma. He was diagnosed with ICH associated with IVH and SAH caused by a ruptured abnormal vascular lesion. He underwent external ventricular drainage to control the intracranial pressure. He remained unconscious and died 16 h after hospital admission. Autopsy was performed to identify the cause of ICH. Pathological sections showed a mass of blood vessels, measuring 20 × 10 × 10 mm in size, within the hematoma with a single drainer connecting to the transverse sinus. These blood vessels had variable size, shape, and wall thickness on microscopy. Some vessels had abnormal thickened walls with discontinuous elastic fibers. Based on the radiological and autopsy findings, an ICH secondary to SpetzlerMartin Grade I AVM was confirmed.

Conclusion:

If the cause of ICH cannot be determined during a patient’s life, autopsy may be performed to determine the pathophysiology of occult vascular lesions, including AVMs. Patients with AVMs may have moderate or no symptoms before and after rupture. Because deep AVMs fed by posterior circulation have high risk of bleeding, surgical intervention should be considered for these patients to prevent a poor outcome. Low-grade and paraventricular AVMs in a young adult may be successfully treated with multimodal surgery.

Stereotactic Radio Surgery, Embolization and Conservative Management for Cerebral Arteriovenous Malformation: A New Zealand Experience of Long-Term Outcomes

OBJECTIVE

Cerebral arteriovenous malformations (AVMs) can be treated by microsurgery, stereotactic radiosurgery (SRS) as a stand-alone procedure, or combining embolization and conservative management. This single-center, retrospective review explored the outcomes of patients treated with SRS alone, embolization before SRS (ESRS), or conservative management for cerebral AVMs.

METHODS

Demographic details, Spetzler-Martin grade, SRS dose, obliteration, time to obliteration, imaging modality, rebleed, disease-specific mortality, and post-SRS complications were collected. Chi-square tests of independence and 1-way analysis of variance/Kruskal-Wallis tests were performed.

RESULTS

Two-hundred and thirty-nine patients were treated with SRS alone, 37 were treated with ESRS, and 83 were conservatively managed. Obliteration rates were 78% (SRS alone) and 70% (ESRS). Rebleed rates were comparable among SRS alone (4%), ESRS (0%), and conservative management (8%). Disease-specific mortality rates were significantly lower for SRS alone (1%) and ESRS (0%) compared with conservative management (6%, X² [2, n = 358] = 7.50, P = 0.024). Post-SRS complications occurred with SRS alone only and included radiation necrosis (n = 5), cavernous malformations (n = 2), and stroke (n = 1). Obliteration, rebleed, and disease-specific mortality rates were comparable among pediatric (<18 years), nonelderly (18-59 years), and elderly (≥60 years) age groups.

CONCLUSIONS

Findings suggest that SRS and ESRS are safe and effective treatments for cerebral AVM (when quantified by obliteration, rebleed, and disease-specific mortality rates). With multinational, prospective, randomized controlled trials with long follow-up periods, the effectiveness and safety of SRS and ESRS compared with conservative management for AVM will be further clarified.

Impact of Pre-operative Embolization With Onyx for Brain Arteriovenous Malformation Surgery

Objective

To clarify the safety and efficacy of pre-operative embolization using Onyx liquid embolic agent (Onyx; ev3) compared with N-butyl cyanoacrylate (NBCA; Cordis Neurovascular, Inc.) or coils in cerebral arteriovenous malformation (AVM) surgery.

Methods

This was a retrospective review of a prospectively collected clinical database of brain AVMs treated at our institute from January 2005 to March 2021. A total of 38 consecutive patients who underwent AVM resection after pre-operative embolization were included. Based on pre-operative embolization materials, the patients were divided into the pre-Onyx group (n = 16), in which NBCA or coils were used for embolization, and the Onyx group (n = 22). Patient characteristics and treatment results were compared between the two groups.

Results

Patient characteristics were comparable between the two groups in terms of age, sex, and rupture status. While the Spetzler-Martin grade was also similar between the two groups, the location of the AVM nidus in the eloquent area was slightly higher in patients in the Onyx group (72.7%) than in patients in the pre-Onyx group (43.8%) (P = 0.09). The embolization rate was higher in the pre-Onyx group (mean: 63.0%; range: 12.7-100%) than in the Onyx group (mean: 50.0%; range: 15.8-100%), but the difference was not statistically significant (P = 0.06). The time needed for surgical removal was shorter in the Onyx group (mean: 354.8 min; range: 144-884 min) than in the pre-Onyx group (mean: 457.9 min; range: 240-1,294 min); however, this difference was not statistically significant (P = 0.13). The amount of intraoperative bleeding was significantly lower in the Onyx group (mean: 129.8 ml; range: 20-540 mL) than in the pre-Onyx group (mean: 448.8 mL; range: 120-1,550 ml) (P = 0.0008). The surgical complication rates were comparable between the two groups (pre-Onyx group, 18.8%; Onyx group, 4.5%; P = 0.29).

Conclusions

Pre-operative embolization with Onyx can significantly reduce the amount of intraoperative bleeding in AVM resection and may contribute to safe AVM surgery.

Endovascular treatment in the multimodality management of brain arteriovenous malformations: report of the Society of NeuroInterventional Surgery Standards and Guidelines Committee

BACKGROUND

The purpose of this review is to summarize the data available for the role of angiography and embolization in the comprehensive multidisciplinary management of brain arteriovenous malformations (AVMs METHODS: We performed a structured literature review for studies examining the indications, efficacy, and outcomes for patients undergoing endovascular therapy in the context of brain AVM management. We graded the quality of the evidence. Recommendations were arrived at through a consensus conference of the authors, then with additional input from the full Society of NeuroInterventional Surgery (SNIS) Standards and Guidelines Committee and the SNIS Board of Directors.

RESULTS

The multidisciplinary evaluation and treatment of brain AVMs continues to evolve. Recommendations include: (1) Digital subtraction catheter cerebral angiography (DSA)-including 2D, 3D, and reformatted cross-sectional views when appropriate-is recommended in the pre-treatment assessment of cerebral AVMs. (I, B-NR) . (2) It is recommended that endovascular embolization of cerebral arteriovenous malformations be performed in the context of a complete multidisciplinary treatment plan aiming for obliteration of the AVM and cure. (I, B-NR) . (3) Embolization of brain AVMs before surgical resection can be useful to reduce intraoperative blood loss, morbidity, and surgical complexity. (IIa, B-NR) . (4) The role of primary curative embolization of cerebral arteriovenous malformations is uncertain, particularly as compared with microsurgery and radiosurgery with or without adjunctive embolization. Further research is needed, particularly with regard to risk for AVM recurrence. (III equivocal, C-LD) . (5) Targeted embolization of high-risk features of ruptured brain AVMs may be considered to reduce the risk for recurrent hemorrhage. (IIb, C-LD) . (6) Palliative embolization may be useful to treat symptomatic AVMs in which curative therapy is otherwise not possible. (IIb, B-NR) . (7) The role of AVM embolization as an adjunct to radiosurgery is not well-established. Further research is needed. (III equivocal, C-LD) . (8) Imaging follow-up after apparent cure of brain AVMs is recommended to assess for recurrence. Although non-invasive imaging may be used for longitudinal follow-up, DSA remains the gold standard for residual or recurrent AVM detection in patients with concerning imaging and/or clinical findings. (I, C-LD) . (9) Improved national and international reporting of patients of all ages with brain AVMs, their treatments, side effects from treatment, and their long-term outcomes would enhance the ability to perform clinical trials and improve the rigor of research into this rare condition. (I, C-EO) .

CONCLUSIONS

Although the quality of evidence is lower than for more common conditions subjected to multiple randomized controlled trials, endovascular therapy has an important role in the management of brain AVMs. Prospective studies are needed to strengthen the data supporting these recommendations.

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.

Utility of modified Rankin Scale for brain vascular malformations in hereditary hemorrhagic telangiectasia

Background

Approximately 10% of hereditary hemorrhagic telangiectasia (HHT) patients harbour brain vascular malformations (VMs). Intracranial hemorrhage (ICH) from brain VMs can lead to death or morbidity, while treatment options for brain VMs also have associated morbidity. The modified Rankin Scale (mRS) may provide an approach to identifying HHT-brain VM patients with poor outcomes, and their predictors. We aimed to measure the relationship between mRS score and brain VM, brain VM number, as well as other aspects of HHT, at enrollment and during prospective follow-up.

Methods

1637 HHT patients (342 with brain VMs) were recruited from 14 HHT centres of the Brain Vascular Malformation Consortium since 2010 and followed prospectively (mean = 3.4 years). We tested whether the presence of brain VM, other HHT organ involvement, and HHT mutation genotype were associated with worse mRS scores at baseline and during follow-up, using linear mixed models, adjusting for age, sex, and year of visit.

Results

Presence of brain VMs was not associated with worse mRS score at baseline and there was no significant worsening of mRS with prospective follow-up in these patients; 92% had baseline mRS of 0–2. HHT-related gastrointestinal (GI) bleeding was associated with worse mRS scores at baseline (0.37, 95% CI 0.26–0.47, p < 0.001), as were history of anemia (0.35, 95% CI 0.27–0.43, p < 0.001) and liver VMs (0.19, 95% CI 0.09–0.30, p < 0.001). Presence of pulmonary arteriovenous malformations (AVMs) was not associated with worse mRS scores at baseline. mRS score was not associated with either HHT genotype (Endoglin vs ACVRL1). Only GI bleeding was associated with a significantly worsening mRS during prospective follow-up (0.64, 95% CI 0.21–1.08, p = 0.004).

Conclusion

Most HHT-brain VM patients had good functional capacity (mRS scores 0–2) at baseline that did not change significantly over 3.4 mean years of follow-up, suggesting that mRS may not be useful for predicting or measuring outcomes in these patients. However, HHT patients with GI bleeding, anemia history or liver VMs had worse mRS scores, suggesting significant impact of these manifestations on functional capacity. Our study demonstrates the insensitivity of the mRS as an outcomes measure in HHT brain VM patients and reinforces the continued need to develop outcomes measures, and their predictors, in this group.

Current concepts and perspectives on brain arteriovenous malformations: A review of pathogenesis and multidisciplinary treatment

Brain arteriovenous malformations (bAVMs) are unusual vascular pathologies characterized by the abnormal aggregation of dilated arteries and veins in the brain parenchyma and for which the absence of a normal vascular structure and capillary bed leads to direct connections between arteries and veins. Although bAVMs have long been believed to be congenital anomalies that develop during the prenatal period, current studies show that inflammation is associated with AVM genesis, growth, and rupture. Interventional treatment options include microsurgery, stereotactic radiosurgery, and endovascular embolization, and management often comprises a multidisciplinary combination of these modalities. The appropriate selection of patients with brain arteriovenous malformations for interventional treatment requires balancing the risk of treatment complications against the risk of hemorrhaging during the natural course of the pathology; however, no definitive guidelines have been established for the management of brain arteriovenous malformations. In this paper, we comprehensively review the current basic and clinical studies on bAVMs and discuss the contemporary status of multidisciplinary management of bAVMs.

Treatments of unruptured brain arteriovenous malformations: A systematic review and meta-analysis

BACKGROUND

The best therapeutic option for unruptured brain arteriovenous malformations (bAVMs) patients is disputed.

OBJECTIVE

To assess the occurrence of obliteration and complications of patients with unruptured bAVMs after various treatments.

METHODS

A systematic literature search was performed in PubMed, EMBASE, Web of Science, and so on to identify studies fulfilling predefined inclusion criteria. Baseline, treatment, and outcomes data were extracted for statistical analysis.

RESULTS

We identified 28 eligible studies totaling 5852 patients. The obliteration rates were 98% in microsurgery group (95% confidence interval (CI): 96%-99%, I2 = 74.5%), 97% in surgery group (95%CI: 95%-99%, I2 = 18.3%), 87% in endovascular treatment group (95%CI: 80%-93%, I2 = 0.0%), and 68% in radiosurgery group (95%CI: 66%-69%, I2 = 92.0%). The stroke or death rates were 1% in microsurgery group (95%CI: 0%-2%, I2 = 0.0%), 0% in surgery group (95%CI: 0%-1%, I2 = 0.0%), 4% in endovascular treatment group (95%CI: 0%-8%, I2 = 85.8%), and 3% in radiosurgery group (95%CI: 3%-4%, I2 = 82.9%). In addition, the proportions of hemorrhage were 2% in microsurgery group (95%CI: 1%-4%, I2 = 0.0%), 23% in endovascular treatment group (95%CI: 7%-39%), and 12% in radiosurgery group (95%CI: 12%-13%, I2 = 99.2%). As to neurological deficit, the occurrence was 9% in microsurgery group (95%CI: 6%-11%, I2 = 94.1%), 20% in surgery group (95%CI: 13%-27%, I2 = 0.0%), 14% in endovascular treatment group (95%CI: 10%-18%, I2 = 64.0%), and 8% in radiosurgery group (95%CI: 7%-9%, I2 = 66.6%).

CONCLUSIONS

We found that microsurgery might provide lasting clinical benefits in some unruptured bAVMs patients for its high obliteration rates and low hemorrhage. These findings are helpful to provide a reference basis for neurosurgeons to choose the treatment of patients with unruptured bAVMs.

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.

Chinese Cerebrovascular Neurosurgery Society and Chinese Interventional & Hybrid Operation Society, of Chinese Stroke Association Clinical Practice Guidelines for Management of Brain Arteriovenous Malformations in Eloquent Areas

Aim: The aim of this guideline is to present current and comprehensive recommendations for the management of brain arteriovenous malformations (bAVMs) located in eloquent areas. Methods: An extended literature search on MEDLINE was performed between Jan 1970 and May 2020. Eloquence-related literature was further screened and interpreted in different subcategories of this guideline. The writing group discussed narrative text and recommendations through group meetings and online video conferences. Recommendations followed the Applying Classification of Recommendations and Level of Evidence proposed by the American Heart Association/American Stroke Association. Prerelease review of the draft guideline was performed by four expert peer reviewers and by the members of Chinese Stroke Association. Results: In total, 809 out of 2,493 publications were identified to be related to eloquent structure or neurological functions of bAVMs. Three-hundred and forty-one publications were comprehensively interpreted and cited by this guideline. Evidence-based guidelines were presented for the clinical evaluation and treatment of bAVMs with eloquence involved. Topics focused on neuroanatomy of activated eloquent structure, functional neuroimaging, neurological assessment, indication, and recommendations of different therapeutic managements. Fifty-nine recommendations were summarized, including 20 in Class I, 30 in Class IIa, 9 in Class IIb, and 2 in Class III. Conclusions: The management of eloquent bAVMs remains challenging. With the evolutionary understanding of eloquent areas, the guideline highlights the assessment of eloquent bAVMs, and a strategy for decision-making in the management of eloquent bAVMs.

Coexistence of arteriovenous malformation and meningioma in a single patient: Systematic review and illustrative case

BACKGROUND

The coexistence of intracranial arteriovenous malformation (AVM) and meningioma in a single patient is seldom reported, so the clinical profile, optimal management, and outcomes of these patients are mostly unknown.

METHODS

We performed a systematic review of the SCOPUS and PubMed databases for case reports and case series on patients with both intracranial AVMs and meningiomas. Data on demographics, clinical characteristics, surgical management, and outcomes were collected.

RESULTS

A total of 18 cases were reported in the literature, including the present case. The mean age at presentation was 54 years (range of 15-70 years), with no gender predilection. Most of the meningiomas and AVMs were frontal in location, and more than half of the lesions were contiguous. The most common presenting symptoms were seizures (67%), headache (44%), and weakness (33%). Majority of the patients underwent single stage meningioma and AVM excision (44%), followed by staged meningioma excision then AVM excision (17%) and meningioma excision only (17%). In all, 94% (17/18) of the meningiomas were excised compared to 72% (13/18) of the AVMs. Outcomes were reported in 15 patients; 80% were favorable, but there were 2 deaths and 1 tumor recurrence after 5 years.

CONCLUSION

The coexistence of an intracranial AVM with a meningioma is recognized but rarely reported in the literature. Individualized treatment should be employed in managing patients with concurrent lesions, and outcomes are generally favorable due to the benign nature of both these entities.

Intracranial Vascular Procedures

Anesthesia for intracranial vascular procedures is complex because it requires a balance of several competing interests and potentially can result in significant morbidity and mortality. Frequently, periods of ischemia, where perfusion must be maintained, are combined with situations that are high risk for hemorrhage. This review discusses the basic surgical approach to several common pathologies (intracranial aneurysms, arteriovenous malformations, and moyamoya disease) along with the goals for anesthetic management and specific high-yield recommendations.

Angiographic Evaluation and Endovascular Treatment Considerations of Brain Arteriovenous Malformations With a Transdural Blood Supply: A Single-Center Experience

Background: In rare circumstances, brain arteriovenous malformations (BAVMs) can recruit a transdural blood supply (TBS). The clinical and radiologic characteristics of BAVMs with a TBS are poorly understood.

Methods: A retrospective review of the medical records was conducted for adult patients who were admitted for BAVMs from Jan 2013 to Dec 2019. TBSs for BAVMs were divided into 3 types: (1) unilateral TBSs from the external carotid artery (ECA) and/or meningeal branch of the vertebral artery (VA); (2) bilateral TBSs from the ECA and/or meningeal branch of the VA; and (3) meningohypophyseal trunk TBSs of the internal carotid artery.

Results: Four hundred and twenty-eight patients were diagnosed with BAVMs during the study period, of whom 30 (7.0%, 30/428) were identified as having a TBS. Type 1, type 2, and type 3 TBSs were identified in 21 (70%, 21/30), 7 (23.3%, 7/30), and 2 (6.7%, 2/30) patients, respectively. Six (20%, 6/30) patients were conservatively managed. Twelve (40%, 12/30) patients underwent endovascular treatment (EVT) of the BAVM through non-TBS feeders. Eight (26.8%, 8/30) patients underwent EVT of the BAVM both through the TBS and non-TBS feeders. The modified Rankin Scale scores at the 3-month follow-up were 0, 1, 2, 4, and 5 in 24 (80%, 24/30), 2 (6.7%, 2/30), 2 (6.7%, 2/30), 1 (3.3%, 1/30), and 1 (3.3%, 1/30) patients, respectively. Good short-term recovery was achieved in 86.7% (26/30) of the patients. The size of the BAVMs with a TBS was larger than that of BAVMs without a TBS. Patients with higher Spetzler-Martin grades tended to have a TBS. No statistical difference was noted between the patients with and without a TBS with regard to age, sex, location, or concurrent aneurysms.

Conclusions: This study showed that a TBS was likely to develop in patients with larger BAVMs and that a TBS was likely to be located in the temporal lobe in patients BAVMs with higher SM grades. Weak structures were the primary targets of management. In addition, a BAVM could be embolized via the TBS.

Brain arteriovenous malformations

Brain arteriovenous malformations are an important cause of intracerebral hemorrhage in the young. Ruptured AVM's are often treated, as the risk of rebleeding is high. The treatment of incidentally discovered, unruptured AVMs is controversial as the morbidity and mortality of treatment may exceed that of the AVM's natural history. Management is multimodal and includes observation with follow up, as well as microsurgical resection, endovascular embolization, and stereotactic radiosurgery. Multidisciplinary teams are important in evaluating patients for treatment. The goal of treatment is complete AVM obliteration while preserving neurologic function.

Intermixed arteriovenous malformation and hemangioblastoma: case report and literature review

We report the third presentation of an intermixed arteriovenous malformation and hemangioblastoma. The rare occurrence of the diagnostic histologic features of both a neoplasm and vascular malformation in a single lesion is more common in gliomas, as angioglioma, and is termed an 'intermixed' lesion. We review the literature concerning the developmental biology of each lesion, and potential interplay in the formation of an intermixed vascular neoplasm and vascular malformation. The roles of cellular origin, genetic susceptibility, favourable microenvironment, altered local gene expression and key regulatory pathways are reviewed. Our review supports angiography and genetic profiling in intermixed lesions to inform management strategies. Consideration should be given to multimodality therapeutic interventions as required, including microsurgical resection, stereotactic radiosurgery and further research to exploit emerging molecular targets.

Multimodal cerebral arteriovenous malformation treatment: a 12-year experience and comparison of key outcomes to ARUBA

OBJECTIVE

Curative treatment of unruptured brain arteriovenous malformations (AVMs) remains controversial after the only randomized controlled trial, A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA), was halted prematurely because interim analysis revealed superiority of the medical management group. In contrast, meta-analyses of retrospective cohorts suggest that intervention is much safer than was found in ARUBA.

METHODS

The authors retrospectively analyzed 318 consecutive adult patients with brain AVMs treated at their institution with embolization, surgery, and/or proton beam radiosurgery. Analysis was performed in 142 ARUBA-eligible patients (baseline modified Rankin Scale [mRS] score 0-1, no history of hemorrhage), and results were compared to primary and secondary outcomes from ARUBA, as well as to natural history cohorts.

RESULTS

The annualized stroke rate (hemorrhagic or ischemic) in this cohort was 1.8%, 4.9% in the first 12 months and 0.8% after the first 12 months, which was lower than in natural history studies and the ARUBA medical management arm (p = 0.001). The primary ARUBA endpoint of symptomatic stroke was reached in 13 patients (9.2%), which compares favorably to the ARUBA intervention arm (39.6%, p = 0.0001) and is similar to the ARUBA medical management arm (9.2%, p = 1.0). The secondary ARUBA endpoint (mRS score ≥ 2 at 5 years of follow-up) was reached in 14.3% of patients, compared to 40.5% in the ARUBA intervention arm (p = 0.002) and 16.7% in the ARUBA medical management arm (p = 0.6).

CONCLUSIONS

This multimodal approach to the selection and treatment of patients with brain AVMs yields good clinical outcomes with key safety endpoints (stroke, death, and mRS score 0-1) better than the ARUBA intervention arm and similar to the ARUBA medical arm at 5 years of follow-up. Results compare favorably to natural history cohorts at longer follow-up times. This suggests that tertiary care centers with integrated programs, expertise in patient selection, and individualized treatment approaches may allow for better clinical outcomes than reported in ARUBA. It supports current registry studies and merits consideration of future randomized controlled trials in patients with brain AVMs.

Brain arteriovenous malformations: A review of natural history, pathobiology, and interventions

Brain arteriovenous malformations (AVMs) are anomalous direct shunts between cerebral arteries and veins that convalesce into a vascular nidus. The treatment strategies for AVMs are challenging and variable. Intracranial hemorrhage and seizures comprise the most common presentations of AVMs. However, incidental AVMs are being diagnosed with increasing frequency due to widespread use of noninvasive neuroimaging. The balance between the estimated cumulative lifetime hemorrhage risk vs the risk of intervention is often the major determinant for treatment. Current management options include surgical resection, embolization, stereotactic radiosurgery (SRS), and observation. Complete nidal obliteration is the goal of AVM intervention. The risks and benefits of interventions vary and can be used in a combinatorial fashion. Resection of the AVM nidus affords high rates of immediate obliteration, but it is invasive and carries a moderate risk of neurologic morbidity. AVM embolization is minimally invasive, but cure can only be achieved in a minority of lesions. SRS is also minimally invasive and has little immediate morbidity, but AVM obliteration occurs in a delayed fashion, so the patient remains at risk of hemorrhage during the latency period. Whether obliteration can be achieved in unruptured AVMs with a lower risk of stroke or death compared with the natural history of AVMs remains controversial. Over the past 5 years, multicenter prospective and retrospective studies describing AVM natural history and treatment outcomes have been published. This review provides a contemporary and comprehensive discussion of the natural history, pathobiology, and interventions for brain AVMs.

Microsurgery for Spetzler-Martin Grade I-III Arteriovenous Malformations: Analysis of Surgical Results and Correlation of Lawton-Young Supplementary Grade and Supplemented Spetzler-Martin Score with Functional Outcome

OBJECTIVE

To analyze the results of microsurgery for Spetzler-Martin (SM) grade I-III AVMs and evaluate the correlation of the Lawton-Young (LY) supplementary grade, supplemented Spetzler-Martin (SM-Supp/combined) score with the functional outcome.

METHODS

A total of 42 patients with SM grade I-III AVMs who had undergone surgery at our institute during a 3-year period (June 2013 to May 2016) were included in the present study.

RESULTS

All 42 patients had undergone primary surgery without previous embolization. Three patients (7.1%) had died due to surgical site hematoma in the postoperative period. One patient was lost to follow-up. The mean follow-up period for the remaining patients was 27 ± 14 months (range, 12-62 months). At the final follow-up examination of ≥12 months (FFU), 92.7% of the patients had a good outcome (modified Rankin scale [mRS] score ≤1), with an improved or unchanged mRS score in 87.8%. An AVM size >3 cm, diffuse AVM, SM grade III, and SM-Supp score >5 were associated with worsened mRS score at discharge and FFU. Higher LY grade (IV and V), eloquent AVM location, deep venous drainage, age >40 years, and unruptured presentation were not associated with worsened mRS score at both discharge and FFU. Of the 20 ARUBA-eligible patients, 19 (95%) had good outcomes. Postoperative angiograms for 39 patients revealed complete excision of the AVM in 37 (94.9%) and a residual AVM in 2 (5.1%).

CONCLUSIONS

High cure rates and excellent clinical outcomes can be expected with microsurgery for most patients with SM grade I-III AVMs. An AVM size >3 cm, diffuse AVM nidus, SM grade III, and SM-Supp score >5 are associated with postoperative worsening of functional scores in patients with SM grade I-III AVMs.

S-shaped distal access catheter supported microcatheter navigation into the lenticulostriate artery feeders of brain arteriovenous malformations

BACKGROUND

Although the embolization of lenticulostriate artery feeders is often warranted in the treatment of brain arteriovenous malformations, it is technically challenging due to steep and repeated angulations. Here, we describe our novel technique of navigating a flow-guided microcatheter into lenticulostriate artery feeders using the strong support provided by an S-shaped distal access catheter.

METHODS

We reviewed our retrospective cohort of brain arteriovenous malformations, in which lenticulostriate artery feeders were attempted to embolize.

RESULT

During the study period, endovascular embolization was performed in 25 arteriovenous malformations cases. Of these, eight lenticulostriate artery feeders were present in six cases (24%). In two cases, lenticulostriate artery feeder catheterization was avoided from the beginning due to the small diameters of the feeders. After all, microcatheter navigation for lenticulostriate artery feeders were attempted in four cases with six lenticulostriate artery feeders. In all the six feeders, the S-shaped distal access catheter was successful in supporting the microcatheter to advance distally to the lenticulostriate artery feeders, even if other approaches were unsuccessful. Of the six catheterized lenticulostriate artery feeders, four were embolized. Symptomatic infarction in the lenticulostriate artery territory and mild vasospasm occurred in two cases each, but they did not result in permanent neurological deficits.

CONCLUSION

Although some potential complications need to be considered, the S-shaped distal access catheter technique appears to be an effective alternative approach to gaining access to difficult feeders of arteriovenous malformations.

The effect of preoperative embolization and flow dynamics on resection of brain arteriovenous malformations

OBJECTIVE

Preoperative embolization of brain arteriovenous malformations (AVMs) is performed to facilitate resection, although its impact on surgical performance has not been clearly defined. The authors tested for associations between embolization and surgical performance metrics.

METHODS

The authors analyzed AVM cases resected by one neurosurgeon from 2006 to 2017. They tested whether cases with and without embolization differed from one another with respect to patient and AVM characteristics using t-tests for continuous variables and Fisher's exact tests for categorical variables. They used simple and multivariable regression models to test whether surgical outcomes (blood loss, resection time, surgical clip usage, and modified Rankin Scale [mRS] score) were associated with embolization. Additional regression analyses integrated the peak arterial afferent contrast normalized for the size of the region of interest (Cmax/ROI) into models as an additional predictor.

RESULTS

The authors included 319 patients, of whom 151 (47%) had preoperative embolization. Embolized AVMs tended to be larger (38% with diameter > 3 cm vs 19%, p = 0.001), less likely to have hemorrhaged (48% vs 63%, p = 0.013), or be diffuse (19% vs 29%, p = 0.045). Embolized AVMs were more likely to have both superficial and deep venous drainage and less likely to have exclusively deep drainage (32% vs 17% and 12% vs 23%, respectively; p = 0.002). In multivariable analysis, embolization was not a significant predictor of blood loss or mRS score changes, but did predict longer operating times (+29 minutes, 95% CI 2-56 minutes; p = 0.034) and increased clip usage (OR 2.61, 95% CI 1.45-4.71; p = 0.001). Cmax/ROI was not a significant predictor, although cases with large Cmax/ROI tended to have longer procedure times (+25 minutes per doubling of Cmax/ROI, 95% CI 0-50 minutes; p = 0.051).

CONCLUSIONS

In this series, preoperative embolization was associated with longer median resection times and had no association with intraoperative blood loss or mRS score changes.

Radiosurgery for Cerebral Arteriovenous Malformation (AVM) : Current Treatment Strategy and Radiosurgical Technique for Large Cerebral AVM

Arteriovenous malformations (AVMs) are congenital anomalies of the cerebrovascular system. AVM harbors 2.2% annual hemorrhage risk in unruptured cases and 4.5% annual hemorrhage risk of previously ruptured cases. Stereotactic radiosurgery (SRS) have been shown excellent treatment outcomes for patients with small- to moderated sized AVM which can be achieved in 80–90% complete obliteration rate with a 2–3 years latency period. The most important factors are associated with obliteration after SRS is the radiation dose to the AVM. In our institutional clinical practice, now 22 Gy (50% isodose line) dose of radiation has been used for treatment of cerebral AVM in single-session radiosurgery. However, dose-volume relationship can be unfavorable for large AVMs when treated in a single-session radiosurgery, resulting high complication rates for effective dose. Thus, various strategies should be considered to treat large AVM. The role of pre-SRS embolization is permanent volume reduction of the nidus and treat high-risk lesion such as AVM-related aneurysm and high-flow arteriovenous shunt. Various staging technique of radiosurgery including volume-staged radiosurgery, hypofractionated radiotherapy and dose-staged radiosurgery are possible option for large AVM. The incidence of post-radiosurgery complication is varied, the incidence rate of radiological post-radiosurgical complication has been reported 30–40% and symptomatic complication rate was reported from 8.1% to 11.8%. In the future, novel therapy which incorporate endovascular treatment using liquid embolic material and new radiosurgical technique such as gene or cytokine-targeted radio-sensitization should be needed.

Arteriovenous malformation presenting with epilepsy: a multimodal approach to diagnosis and treatment

Arteriovenous malformation (AVM) presenting with epilepsy significantly impacts patient quality of life, and it should be considered very much a seizure disorder. Although hemorrhage prevention is the primary treatment aim of AVM surgery, seizure control should also be at the forefront of therapeutic management. Several hemodynamic and morphological characteristics of AVM have been identified to be associated with seizure presentation. This includes increased AVM flow, presence of long pial draining vein, venous outflow obstruction, and frontotemporal location, among other aspects. With the advent of high-throughput image processing and quantification methods, new radiographic attributes of AVM-related epilepsy have been identified. With respect to therapy, several treatment approaches are available, including conservative management or interventional modalities; this includes microsurgery, radiosurgery, and embolization or a combination thereof. Many studies, especially in the domain of microsurgery and radiosurgery, evaluate both techniques with respect to seizure outcomes. The advantage of microsurgery lies in superior AVM obliteration rates and swift seizure response. In addition, by incorporating electrophysiological monitoring during AVM resection, adjacent or even remote epileptogenic foci can be identified, leading to extended lesionectomy and improved seizure control. Radiosurgery, despite resulting in reduced AVM obliteration and prolonged time to seizure freedom, avoids the risks of surgery altogether and may provide seizure control through various antiepileptic mechanisms. Embolization continues to be used as an adjuvant for both microsurgery and radiosurgery. In this study, the authors review the latest imaging techniques in characterizing AVM-related epilepsy, in addition to reviewing each treatment modality.

Treatment Outcomes of Endovascular Embolization Only in Patients with Unruptured Brain Arteriovenous Malformations: A Subgroup Analysis of ARUBA (A Randomized Trial of Unruptured Brain Arteriovenous Malformations)

BACKGROUND AND PURPOSE

Endovascular embolization only has been advocated for treatment of brain arteriovenous malformations in recent trials. Our aim was to evaluate the results of embolization only in a cohort of patients who were enrolled in the A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) study at 39 clinical sites in 9 countries.

MATERIALS AND METHODS

We analyzed the rates and severity of stroke and death in patients who underwent embolization only. Events were identified through in-person neurologic follow-up visits performed at 6-month intervals during the first 2 years and annually, with telephone contact every 6 months thereafter. All event-related data were reviewed by independent adjudicators.

RESULTS

Among 30 patients who had embolization planned, 26 underwent embolization only. A total of 13 stroke events were reported in the follow-up period among 26 subjects (ischemic, hemorrhagic, or both in 4, 7, and 2 subjects, respectively). The adverse event occurred after the first embolization in 11 of 13 patients. One patient had a major motor deficit, and 2 patients developed major visual field deficits. One event was fatal. The modified Rankin Scale score was 0-2 at last follow-up in 11 of the 12 stroke survivors. Estimated stroke-free survival was 46% at 12 months.

CONCLUSIONS

Although the rates of stroke and/or death were high in patients treated with embolization only in ARUBA, the rates of favorable outcomes following stroke were high during follow-up.

Microsurgery Versus Stereotactic Radiosurgery for Brain Arteriovenous Malformations: A Matched Cohort Study

BACKGROUND

Microsurgery (MS) and stereotactic radiosurgery (SRS) remain the preferred interventions for the curative treatment of brain arteriovenous malformations (AVM), but their relative efficacy remains incompletely defined.

OBJECTIVE

To compare the outcomes of MS to SRS for AVMs through a retrospective, matched cohort study.

METHODS

We evaluated institutional databases of AVM patients who underwent MS and SRS. MS-treated patients were matched, in a 1:1 ratio based on patient and AVM characteristics, to SRS-treated patients. Statistical analyses were performed to compare outcomes data between the 2 cohorts. The primary outcome was defined as AVM obliteration without a new permanent neurological deficit.

RESULTS

The matched MS and SRS cohorts were each comprised of 59 patients. Both radiological (85 vs 11 mo; P < .001) and clinical (92 vs 12 mo; P < .001) follow-up were significantly longer for the SRS cohort. The primary outcome was achieved in 69% of each cohort. The MS cohort had a significantly higher obliteration rate (98% vs 72%; P = .001), but also had a significantly higher rate of new permanent deficit (31% vs 10%; P = .011). The posttreatment hemorrhage rate was significantly higher for the SRS cohort (10% for SRS vs 0% for MS; P = .027). In subgroup analyses of ruptured and unruptured AVMs, no significant differences between the primary outcomes were observed.

CONCLUSION

For patients with comparable AVMs, MS and SRS afford similar rates of deficit-free obliteration. Nidal obliteration is more frequently achieved with MS, but this intervention also incurs a greater risk of new permanent neurological deficit.

Results of Surgery for Low-Grade Brain Arteriovenous Malformation Resection by Early Career Neurosurgeons: An Observational Study

BACKGROUND

For sustainability of arteriovenous malformation (AVM) surgery, results from early career cerebrovascular neurosurgeons (ECCNs) must be acceptably safe.

OBJECTIVE

To determine whether ECCNs performance of Spetzler-Ponce Class A AVM (SPC A) resection can be acceptably safe.

METHODS

ECCNs completing a cerebrovascular fellowship (2004-2015) with the last author were included. Inclusion of the ECCN cases occurred if they: had a prospective database of all AVM cases since commencing independent practice; were the primary surgeon on SPC A; and had made the significant management decisions. All SPC A surgical cases from the beginning of the ECCN's independent surgical practice to a maximum of 8 yr were included. An adverse outcome was considered a complication of surgery leading to a new permanent neurological deficit with a last modified Rankin Scale score >1. A cumulative summation (Cusum) plot examined the performance of each surgery. The highest acceptable level of adverse outcomes for the Cusum was 3.3%, derived from the upper 95% confidence interval of the last author's reported series.

RESULTS

Six ECCNs contributed 110 cases for analysis. The median number of SPC A cases operated by each ECCN was 16.5 (range 4-40). Preoperative embolization was performed in 5 (4.5%). The incidence of adverse outcomes was 1.8% (95% confidence interval: <0.01%-6.8%). At no point during the accumulated series did the combined cohort become unacceptable by the Cusum plot.

CONCLUSION

ECCNs with appropriate training appointed to large-volume cerebrovascular centers can achieve results for surgery for SPC A that are not appreciably worse than those published from high-volume neurosurgeons.

Expert Consensus on the Management of Brain Arteriovenous Malformations

Brain arteriovenous malformations (bAVMs) are complex, heterogeneous, and uncommon intracranial lesions. They can be treated by one or a combination of the following treatment modalities, namely embolization, radiosurgery, or microsurgical resection. In Spetzler-Martin Grade 4 and 5 arteriovenous malformations (AVMs), conservative management may be the best option. A group of experts in the management of AVMs of different disciplines gathered in January 2019 in Hanoi to compile the “Expert Consensus on the Management of Brain Arteriovenous Malformations”.