Long-term outcomes of brainstem arteriovenous malformations after different management modalities: a single-centre experience

Dosimetric predictors of toxicity for brainstem metastases and AVMs treated with stereotactic radiosurgery: An international, multi-institutional analysis

BACKGROUND

There are limited data on dosimetric predictors of radiation-induced changes (RICs) for brainstem metastases or arteriovenous malformations (AVMs) following single-fraction stereotactic radiosurgery (SRS).

METHODS

We examined a multi-institutional cohort of patients with brainstem metastases or AVMs treated with SRS. We evaluated predictors of RICs graded per CTCAE(Common Terminology Criteria for Adverse Events), including D5%, D95%, D0.03 cc, and D0.5 cc (brainstem minus lesion). Univariate logistic regressions were initially performed with independent variables trending towards significance included on multivariate logistic regression.

RESULTS

A total of 124 brainstem lesions treated with SRS were analyzed (21 AVMs and 103 metastases). The median prescription dose was 16 Gy(range: 13-23 Gy), and the median treatment volume was 0.48 cc(range: 0.002-11.19 cc). The incidence of RICs was 9.7 % (with 3/12 being Grade 3-4 and no Grade 5). All cases occurred in brainstem metastases, with no cases among those of the midbrain-pons transition. Treatment volumes ≥ 1cc were correlated with a higher symptomatic RIC incidence(6/57 vs. 6/65; p = 0.04). Notably, all RIC cases had a D0.5 cc ≥ 15 Gy(12/87 vs. 0/32). Both D5%≥6 Gy(9/55 vs. 3/69; p = 0.04) and D95%≥1 Gy(7/31 vs. 5/93; p = 0.01) were significantly correlated with higher incidence of RICs and D0.03 cc ≥ 22 Gy was correlated with a lower risk(2/61 vs. 9/63; p = 0.03). On MVA, D0.03 cc ≥ 22 Gy remained a significant predictor of a lower incidence of RICs(odds ratio = -1.72 (95 % CI: -3.32 to -0.12; p = 0.04).

CONCLUSIONS

Incidence of RICs was low following SRS for brainstem metastases and AVMs. We recommend optimizing radiosurgical plans for D0.5 cc < 15 Gy with consideration of D5% and D95%, with less emphasis on D0.03 cc to allow to meet the former metrics as feasible.

Long-Term Outcomes of Stereotactic Radiosurgery Focused Treatment of Brain Arteriovenous Malformations Based on Rupture Status: A Systematic Review and Meta-Analysis

Stereotactic radiosurgery (SRS) is a non-invasive treatment option for brain arteriovenous malformations (bAVMs). However, SRS cures are delayed, making it less favorable for higher risk ruptured bAVMs (rbAVMs) than unruptured (ubAVMs). This systematic review and meta-analysis explores the long-term outcomes of SRS-focused protocols for rbAVMs and ubAVMs. This study adhered to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. Literature search was conducted using PubMed, Ovid Medline, Scopus, and hand-search on January 30th, 2025. The inclusion criteria encompassed studies: distinguishing cohorts by rupture status, reporting post-SRS outcomes, and without overlapping series. Pooled analysis was performed from 24 articles using DerSimonian-Laird random effects models. Subgroup and meta-regression analyses were also conducted. All analyses were performed using R. For rbAVMs, the pooled rupture, obliteration, and mortality rates were 7.14% (95% CI: 5.76%-8.64%), 65.0% (95% CI: 57.2%-72.4%), and 0.87% (95% CI: 0.00%-5.14%), respectively, and for ubAVMs, 6.13% (95% CI: 4.71%-7.69%), 59.5% (95% CI: 51.3%-67.3%), and 0.89% (95% CI: 0.00%-3.82%), respectively. Subgroup meta-analyses of rupture rates and obliteration rates showed no significant differences based on prior treatments (Q = 2.47, p = 0.48; Q = 4.34, p = 0.23; respectively) or volume-staging protocols (Q = 4.90, p = 0.18; Q = 1.12, p = 0.77, respectively). Meta-regression analysis for rbAVMs demonstrated a positive correlation between intranidal aneurysms and rupture rate (p < 0.05, R2 = 100%), an inverse correlation between Spetzler-Martin (SM) grade I-II bAVMs and obliteration rate (p < 0.05, R2 = 68.6%), and a positive correlation between SM grade III-V bAVMs and obliteration rate (p < 0.05, R2 = 68.0%). Meta-regression analysis for ubAVMs demonstrated an inverse correlation between eloquent-region lesions and rupture rate (p < 0.05, R2 = 31.3%), and surprisingly a positive correlation between mean age and obliteration rate (p < 0.05, R2 = 23.8%). SRS-focused studies show similar long-term outcomes regardless of rupture status, but presence of underlying factors indicates the need for individualized risk-benefit analysis.

Regional Variations in the Management of Cerebral Arteriovenous Malformations: A Nationwide Inpatient Sample Analysis of Surgical Excision and Endovascular Embolization

INTRODUCTION

Cerebral arteriovenous malformations (AVMs) represent a complex neurosurgical challenge with management strategies that vary significantly across regions. The decision to treat unruptured AVMs, in particular, is controversial, with options ranging from conservative management to surgical excision or endovascular embolization. This study investigates regional variations in treating unruptured and ruptured AVMs in the United States.

METHODS

We analyzed data from the Nationwide Inpatient Sample (NIS) from 2016 to 2021, identifying 34,900 unruptured AVM cases and 11,580 ruptured AVM cases in adult patients. Multivariate logistic regression models were used to determine regional predictors of undergoing open surgery, with the New England region serving as the reference group.

RESULTS

For unruptured AVMs, 81.0 % of patients underwent no intervention, 14.3 % received embolization, and 3.9 % underwent surgical excision. The odds of undergoing surgery were significantly lower in the Middle Atlantic (OR 0.377, CI 0.223-0.638, p < 0.001), South Atlantic (OR 0.380, CI 0.224-0.643, p < 0.001), and Pacific (OR 0.535, CI 0.331-0.864, p = 0.0105) regions compared to New England. In contrast, for ruptured AVMs, 73.5 % of patients did not receive intervention, while 16.5 % received embolization, and 2.8 % underwent combined treatment. The odds of undergoing surgery were significantly higher in the Middle Atlantic (OR 9.062, CI 1.147-71.61, p = 0.0366), East North Central (OR 9.695, CI 1.249-75.28, p = 0.0298), and Mountain (OR 8.656, CI 1.013-74.01, p = 0.0487) regions compared to New England.

CONCLUSIONS

This study reveals significant regional disparities in the management of AVMs, with patients in certain regions being significantly less or more likely to undergo surgery. These findings highlight the need for standardized treatment guidelines to ensure equitable access to appropriate care across the United States.

Efficacy of radiosurgery with and without angioembolization: A subgroup analysis of effectiveness in ruptured versus unruptured arteriovenous malformations - An updated systematic review and meta-analysis

Background

Congenital arterial defects such as cerebral arteriovenous malformations (AVMs) increase brain bleeding risk. Conservative therapy, microsurgical removal, percutaneous embolization, stereotactic radiosurgery (SRS), or a combination may treat this serious disease. This study compares angioembolization with SRS to SRS alone in ruptured or unruptured brain ateriovenous malformations (BAVM) patients.

Methods

We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations for this study. Until September 2023, PubMed/Medline, Cochrane, and Clinicaltrials.gov were searched for literature. English-language studies comparing SRS alone to embolization with SRS on ruptured or non-ruptured AVMs that could not be operated on were considered. The Newcastle-Ottawa Scale assessed research study quality.

Results

Results included 46 studies with a total of 7077 participants. There was a greater obliteration rate in the SRS-only group (60.4%) than in the embolization plus SRS group (49.73%). Particularly in the SRS-only group, ruptured AVMs showed a noticeably greater obliteration rate than unruptured AVMs (P = 0.002). However, no notable differences were found in hemorrhagic events or radiation-induced changes between the two groups; however, the SRS-only group had a slightly greater, yet not statistically significant, mortality rate.

Conclusion

Our data showed that ruptured brain AVMs had a much greater obliteration rate than unruptured ones, mostly due to SRS alone, without embolization. The aggregated data showed no significant changes, whereas SRS alone decreased radiation-induced alterations and hemorrhagic rates but with increased mortality. SRS alone may have a higher risk-to-reward ratio for nidus obliteration in ruptured brain AVM patients, so it should be used without embolization, although more research is needed to determine the effects of immediate and late complications.

Re-rupture in ruptured brain arteriovenous malformations: a retrospective cohort study based on a nationwide multicenter prospective registry

BACKGROUND

This study aimed to investigate the natural history of re-rupture in ruptured brain arteriovenous malformations (AVMs) and to provide comprehensive insights into its associated factors and prevention.

METHODS

This study included 1712 eligible ruptured AVMs from a nationwide multicenter prospective collaboration registry between August 2011 and September 2021. The natural rupture risk before intervention and the annual rupture risk after intervention were both assessed. Cox proportional hazard regression models and Kaplan-Meier survival curves were used to explore independent factors associated with AVM re-rupture. The correlation between these factors and AVM re-rupture was verified in multiple independent cohorts, and the prevention effect of intervention timing and intervention strategies on AVM re-rupture was further analyzed.

RESULTS

The annual re-rupture risk in ruptured AVMs was 7.6%, and the cumulative re-rupture risk in the first 1, 3, 5, and 10 years following the initial rupture were 10%, 25%, 37.5%, and 50%, respectively. Cox proportional hazard regression analysis confirmed adult patients, ventricular system involvement, and any deep venous drainage as independent factors associated with AVM re-rupture. The intervention was found to significantly reduce the risk of AVM re-rupture (annual rupture risk 11.34% vs 1.70%, p<0.001), especially in those who underwent surgical resection (annual rupture risk 0.13%).

CONCLUSIONS

The risk of re-rupture in ruptured AVMs is high. Adult patients, ventricular system involvement, and any deep venous drainage are independent risk factors for re-rupture. Applying the results universally to all ruptured AVM cases may be biased. Intervention could effectively reduce the risk of re-rupture.

Association of the combined stereotactic radiosurgery and embolization strategy and long-term outcomes in brain arteriovenous malformations with a volume ≤10 mL: a nationwide multicenter observational prospective cohort study

BACKGROUND

To compare the long-term outcomes of stereotactic radiosurgery (SRS) with or without prior embolization in brain arteriovenous malformations (AVMs) (volume ≤10 mL) for which SRS is indicated.

METHODS

Patients were recruited from a nationwide multicenter prospective collaboration registry (the MATCH study) between August 2011 and August 2021, and categorized into combined embolization and SRS (E+SRS) and SRS alone cohorts. We performed propensity score-matched survival analysis to compare the long-term risk of non-fatal hemorrhagic stroke and death (primary outcomes). The long-term obliteration rate, favorable neurological outcomes, seizure, worsened mRS score, radiation-induced changes, and embolization complications were also evaluated (secondary outcomes). Hazard ratios (HRs) were calculated using Cox proportional hazards models.

RESULTS

After study exclusions and propensity score matching, 486 patients (243 pairs) were included. The median (IQR) follow-up duration for the primary outcomes was 5.7 (3.1-8.2) years. Overall, E+SRS and SRS alone were similar in preventing long-term non-fatal hemorrhagic stroke and death (0.68 vs 0.45 per 100 patient-years; HR=1.46 (95% CI 0.56 to 3.84)), as well as in facilitating AVM obliteration (10.02 vs 9.48 per 100 patient-years; HR=1.10 (95% CI 0.87 to 1.38)). However, the E+SRS strategy was significantly inferior to the SRS alone strategy in terms of neurological deterioration (worsened mRS score: 16.0% vs 9.1%; HR=2.00 (95% CI 1.18 to 3.38)).

CONCLUSIONS

In this observational prospective cohort study, the combined strategy of E+SRS does not show substantial advantages over SRS alone. The findings do not support pre-SRS embolization for AVMs with a volume ≤10 mL.

Location-based clinical and angiographic profile of brain arteriovenous malformations - a single-center observational study

BACKGROUND

The location of brain arteriovenous malformations (bAVM) is one of the most relevant prognostic factors included in surgical, endovascular and radiosurgical scores. However, their characteristics according to location are seldom described. The goal of this study was to describe the clinical and angiographic characteristics of bAVM classified according to their location.

METHODS

This retrospective observational study included patients diagnosed with bAVM and attending a national referral hospital during the period 2010-2020. Data regarding clinical and angiographic variables were extracted, including characteristics on nidus, arterial afferents, venous drainage and associated aneurysms. BAVM were classified in 8 groups according to their location: frontal, temporal, parieto-occipital, periventricular, deep, cerebellar, brainstem and mixed. Data distribution for each group was determined and between-group differences were assessed.

RESULTS

A total of 269 bAVM (in 258 patients) were included. The most frequent location was parieto-occipital; and the least frequent, brainstem. Statistically significant differences were observed between groups for most studied variables, including: clinical presentation, functional status at admission; nidus size and density, classification according to the Spetzler-Martin, Buffalo and modified Pollock-Flickinger scales; number, diameter, origin and type of afferents; number, diameter, type and direction of venous drainage, retrograde venous flow; and presence and size of flow-related aneurysms.

CONCLUSION

The clinical and angiographic differences observed between brain AVM groups allow the formulation of profiles according to their location.

Radiosurgery With Prior Embolization Versus Radiosurgery Alone for Intracranial Arteriovenous Malformations: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

The addition of adjuvant embolization to radiosurgery has been proposed as a means of improving treatment outcomes of intracranial arteriovenous malformations (AVMs). However, the relative efficacy and safety of radiosurgery with adjuvant embolization vs radiosurgery alone remain uncertain. Moreover, previous systematic reviews and meta-analyses have included a limited number of studies and did not consider the effects of baseline characteristics, including AVM volume, on the outcomes. This systematic review aimed to evaluate the efficacy of preradiosurgery embolization for intracranial AVMs with consideration to matching status between participants in each treatment group.

METHODS

A systematic review and meta-analysis were conducted by searching electronic databases, including PubMed, Scopus, and Cochrane Library, up to January 2023. All studies evaluating the utilization of preradiosurgery embolization were included.

RESULTS

A total of 70 studies (9 matched and 71 unmatched) with a total of 12 088 patients were included. The mean age of the included patients was 32.41 years, and 48.91% of the patients were female. Preradiosurgery embolization was used for larger AVMs and patients with previous hemorrhage ( P < .01, P = .02, respectively). The obliteration rate for preradiosurgery embolization (49.44%) was lower compared with radiosurgery alone (61.42%, odds ratio = 0.56, P < .01), regardless of the matching status of the analyzed studies. Although prior embolization was associated higher rate of cyst formation ( P = .04), it lowered the odds of radiation-induced changes ( P = .04). The risks of minor and major neurological deficits, postradiosurgery hemorrhage, and mortality were comparable between groups.

CONCLUSION

This study provides evidence that although preradiosurgery embolization is a suitable option to reduce the AVM size for future radiosurgical interventions, it may not be useful for same-sized AVMs eligible for radiosurgery. Utilization of preradiosurgery embolization in suitable lesions for radiosurgery may result in the added cost and burden of an endovascular procedure.

Embolization of midbrain arteriovenous malformation fed by the artery of Percheron in a child, the first case report and literature review

BACKGROUND

Artery of Percheron (AOP) as main feeder artery of arteriovenous malformation (AVM) is extremely rare. Two cases of thalamic AVM fed by AOP have been reported to date and only one AVM been removed by microsurgery when attempt of intervention embolization failed. Midbrain AVM fed by AOP has not been reported yet.

CASE PRESENTATION

Here, we presented the first successful embolized case of midbrain AVM supplied by the AOP in a 10-year-old boy, who suffered dual oculomotor nerve palsy and secondary hemorrhage before embolization. During endovascular embolization, selective angiography by 1.2 Fr. Magic microcatheter showed an intranidal aneurysm located on the distal AOP. Two injections of a 1:4 ratio mixture of NBCA-MS completely occlude the nidus and intranidal aneurysm with no complications occurred. The child recovered well and the oculomotor deficits improved.

CONCLUSION

This case highlighted that AOP is a clinically significant branch associated with AVM in midbrain and thalamus. Moreover, intervention embolization of midbrain AVM fed by AOP is a considerable therapeutic strategy.

Association of nidus size and rupture in brain arteriovenous malformations: Insight from angioarchitecture and hemodynamics

This study aims to investigate the correlation between AVM size and rupture by examining natural history, angioarchitecture characteristics, and quantitative hemodynamics. A retrospective review of 90 consecutive AVMs from the MATCH registry was conducted. Patients were categorized into small nidus (< 3 cm) and large nidus (≥ 3 cm) groups based on the Spetzler-Martin grading system. Natural history analysis used prospective cohort survival data, while imaging analysis examined angioarchitecture characteristics and quantitative hemodynamic parameters measured with QDSA. The small-nidus group had a significantly higher annualized rupture risk (2.3% vs. 1.0%; p = 0.011). Cross-sectional imaging revealed independent hemorrhagic risk factors, including small nidus (OR, 4.801; 95%CI, 1.280-18.008; p = 0.020) and draining vein stenosis (OR, 6.773; 95%CI, 1.179-38.911; p = 0.032). Hemodynamic analysis identified higher stasis index in the feeding artery (OR, 2.442; 95%CI, 1.074-5.550; p = 0.033), higher stasis index in the draining vein (OR, 11.812; 95%CI, 1.907-73.170; p = 0.008), and lower outflow gradient in the draining vein (OR, 1.658; 95%CI, 1.068-2.574; p = 0.024) as independent predictors of AVM rupture. The small nidus group also showed a higher likelihood of being associated with hemorrhagic risk factors. Small AVM nidus has a higher risk of rupture based on natural history, angioarchitecture, and hemodynamics. Clinical Trial Registration-URL: http://www.clinicaltrials.gov . Unique identifier: NCT04572568.

Stereotactic radiosurgery outcome for deep-seated cerebral arteriovenous malformations in the brainstem and thalamus/basal ganglia: systematic review and meta-analysis

Deep-seated unruptured AVMs located in the thalamus, basal ganglia, or brainstem have a higher risk of hemorrhage compared to superficial AVMs and surgical resection is more challenging. Our systematic review and meta-analysis provide a comprehensive summary of the stereotactic radiosurgery (SRS) outcomes for deep-seated AVMs. This study follows the guidelines set forth by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Statement. We conducted a systematic search in December 2022 for all reports of deep-seated arteriovenous malformations treated with SRS. Thirty-four studies (2508 patients) were included. The mean obliteration rate in brainstem AVM was 67% (95% CI: 0.60-0.73), with significant inter-study heterogeneity (tau2 = 0.0113, I2 = 67%, chi2 = 55.33, df = 16, p-value < 0.01). The mean obliteration rate in basal ganglia/thalamus AVM was 65% (95% CI: 0.58-0.72) with significant inter-study heterogeneity (tau2 = 0.0150, I2 = 78%, chi2 = 81.79, df = 15, p-value < 0.01). The presence of deep draining veins (p-value: 0.02) and marginal radiation dose (p-value: 0.04) were positively correlated with obliteration rate in brainstem AVMs. The mean incidence of hemorrhage after treatment was 7% for the brainstem and 9% for basal ganglia/thalamus AVMs (95% CI: 0.05-0.09 and 95% CI: 0.05-0.12, respectively). The meta-regression analysis demonstrated a significant positive correlation (p-value < 0.001) between post-operative hemorrhagic events and several factors, including ruptured lesion, previous surgery, and Ponce C classification in basal ganglia/thalamus AVMs. The present study found that radiosurgery appears to be a safe and effective modality in treating brainstem, thalamus, and basal ganglia AVMs, as evidenced by satisfactory rates of lesion obliteration and post-surgical hemorrhage.

The impact of embolization on radiosurgery obliteration rates for brain arteriovenous malformations: a systematic review and meta-analysis

There exists no consensus in the literature regarding the impact of pre-stereotactic radiosurgery (SRS) embolization on obliteration rates and clinical outcome after radiosurgery treatment of intracranial arteriovenous malformations (AVM). We performed a systematic review of four databases and included studies with at least 10 patients evaluating obliteration rates of intracranial AVMs treated with SRS alone (SRS cohort) and combined pre-SRS embolization followed by SRS (E + SRS cohort). Meta-analytic results were pooled together via random-effects models. A total of 43 studies, with 7103 patients, were included in our analysis. Among our included patients, complete obliteration was achieved in 51.5% (964/1871) of patients in the E + SRS cohort as compared to 61.5% (3217/5231) of patients in the SRS cohort. Meta-analysis of the pooled data revealed that obliteration was significantly lower in the E + SRS cohort (pooled OR = 0.64, 95% CI = 0.54-0.75, p < 0.0001). The use of pre-SRS embolization was significantly associated with lower AVM obliteration rates when compared to treatment with SRS alone. Our analysis seeks to provide a macroscopic insight into the complex interaction between pre-SRS embolization and brain AVM obliteration rates and prognosis. Pre-SRS embolization may still be beneficial in select patients, and further studies are needed to identify patients who benefit from neoadjuvant AVM embolization.

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 ).

Pathological pericyte expansion and impaired endothelial cell-pericyte communication in endothelial Rbpj deficient brain arteriovenous malformation

Pericytes, like vascular smooth muscle cells, are perivascular cells closely associated with blood vessels throughout the body. Pericytes are necessary for vascular development and homeostasis, with particularly critical roles in the brain, where they are involved in regulating cerebral blood flow and establishing the blood-brain barrier. A role for pericytes during neurovascular disease pathogenesis is less clear—while some studies associate decreased pericyte coverage with select neurovascular diseases, others suggest increased pericyte infiltration in response to hypoxia or traumatic brain injury. Here, we used an endothelial loss-of-function Recombination signal binding protein for immunoglobulin kappa J region (Rbpj)/Notch mediated mouse model of brain arteriovenous malformation (AVM) to investigate effects on pericytes during neurovascular disease pathogenesis. We tested the hypothesis that pericyte expansion, via morphological changes, and Platelet-derived growth factor B/Platelet-derived growth factor receptor β (Pdgf-B/Pdgfrβ)-dependent endothelial cell-pericyte communication are affected, during the pathogenesis of Rbpj mediated brain AVM in mice. Our data show that pericyte coverage of vascular endothelium expanded pathologically, to maintain coverage of vascular abnormalities in brain and retina, following endothelial deletion of Rbpj. In Rbpj-mutant brain, pericyte expansion was likely attributed to cytoplasmic process extension and not to increased pericyte proliferation. Despite expanding overall area of vessel coverage, pericytes from Rbpj-mutant brains showed decreased expression of Pdgfrβ, Neural (N)-cadherin, and cluster of differentiation (CD)146, as compared to controls, which likely affected Pdgf-B/Pdgfrβ-dependent communication and appositional associations between endothelial cells and pericytes in Rbpj-mutant brain microvessels. By contrast, and perhaps by compensatory mechanism, endothelial cells showed increased expression of N-cadherin. Our data identify cellular and molecular effects on brain pericytes, following endothelial deletion of Rbpj, and suggest pericytes as potential therapeutic targets for Rbpj/Notch related brain AVM.

Long-Term Outcomes of Elderly Brain Arteriovenous Malformations After Different Management Modalities: A Multicenter Retrospective Study

Background: More and more elderly patients are being diagnosed with arteriovenous malformation (AVM) in this global aging society, while the treatment strategy remains controversial among these aging population. This study aimed to clarify the long-term outcomes of elderly AVMs after different management modalities.

Methods: The authors retrospectively reviewed 71 elderly AVMs (>60 years) in two tertiary neurosurgery centers between 2011 and 2019. Patients were divided into four groups: conservation, microsurgery, embolization, and stereotactic radiosurgery (SRS). The perioperative complications, short-term and long-term neurological outcomes, obliteration rates, annualized rupture risk, and mortality rates were compared among different management modalities in the ruptured and unruptured subgroups. Kaplan-Meier survival analysis was employed to compare the death-free survival rates among different management modalities. Logistic regression analyses were conducted to calculate the odds ratios (ORs) and 95% confidence intervals (CI) for predictors of long-term unfavorable outcomes (mRS > 2).

Results: A total of 71 elderly AVMs were followed up for an average of 4.2 ± 2.3 years. Fifty-four (76.1%) presented with hemorrhage, and the preoperative annualized rupture risk was 9.4%. Among these patients, 21 cases (29.6%) received conservative treatment, 30 (42.3%) underwent microsurgical resection, 13 (18.3%) received embolization, and 7 (9.9%) underwent SRS. In the prognostic comparison, the short-term and long-term neurological outcomes were similar between conservation and intervention both in the ruptured and unruptured subgroups (ruptured: p = 0.096, p = 0.904, respectively; unruptured: p = 0.568, p = 0.306, respectively). In the ruptured subgroup, the intervention cannot reduce long-term mortality (p = 0.654) despite the significant reduction of subsequent hemorrhage than conservation (p = 0.014), and the main cause of death in the intervention group was treatment-related complications (five of seven, 71.4%). In the logistic regression analysis, higher admission mRS score (OR 3.070, 95% CI 1.559–6.043, p = 0.001) was the independent predictor of long-term unfavorable outcomes (mRS>2) in the intervention group, while complete obliteration (OR 0.146, 95% CI 0.026–0.828, p = 0.030) was the protective factor.

Conclusions: The long-term outcomes of elderly AVMs after different management modalities were similar. Intervention for unruptured elderly AVMs was not recommended. For those ruptured, we should carefully weigh the risk of subsequent hemorrhage and treatment-related complications. Besides, complete obliteration should be pursued once the intervention was initiated.

Clinical Trial Registration:http://www.clinicaltrials.gov. Unique identifier: NCT04136860