Search

Background and Purpose: Rupture is the most life-threatening manifestation of cerebral AVMs. This study aimed to explore the hemodynamic mechanism of AVM rupture. We introduced a new quantitative DSA parameter that can reflect the degree of intranidal blood stasis, called the lesion-filling index., Materials and Methods: This study examined patients with AVMs who had undergone both DSA and MR imaging between 2013 and 2014. Clinical presentations, angioarchitecture, and hemodynamic parameters generated from quantitative DSA were analyzed using univariate and multivariable logistic regression. The lesion-filling index was defined as the arterial diagnostic window divided by the volume of the AVM. To assess the correlation between the lesion-filling index and rupture, we incorporated the lesion-filling index into 2 published prediction models widely recognized for predicting AVM rupture risk, R 2 eD and VALE. The DeLong test was used to examine whether the addition of the lesion-filling index improved predictive efficacy., Results: A total of 180 patients with AVMs were included. The mean lesion-filling index values in the ruptured group were higher compared with the unruptured group (390.27 [SD, 919.81] versus 49.40 [SD, 98.25]), P < .001). A higher lesion-filling index was significantly correlated with AVM rupture in 3 different multivariable logistic models, adjusting for angioarchitecture factors (OR = 1.004, P  = .02); hemodynamic factors (OR = 1.005, P  = .009); and combined factors (OR = 1.004, P  = .03). Both R 2 eD (area under the curve, 0.601 versus 0.624; P  = .15) and VALE (area under the curve, 0.603 versus 0.706; P  < .001) predictive models showed improved predictive performance after incorporating the lesion-filling index and conducting 10-fold cross-validation., Conclusions: The lesion-filling index showed a strong correlation with AVM rupture, suggesting that overperfusion is the hemodynamic mechanism leading to AVM rupture., (© 2024 by American Journal of Neuroradiology.)

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., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Due to the high mortality and disability rate of intracranial hemorrhage, headache is not the main focus of research on cerebral arteriovenous malformation (AVM), so research on headaches in AVM is still scarce, and the clinical understanding is shallow. This study aims to delineate the risk factors associated with headaches in AVM and to compare the effectiveness of various intervention treatments versus conservative treatment in alleviating headache symptoms., Methods: This study conducted a retrospective analysis of AVMs who were treated in our institution from August 2011 to December 2021. Multivariable logistic regression analysis was employed to assess the risk factors for headaches in AVMs with unruptured, non-epileptic. Additionally, the effectiveness of different intervention treatments compared to conservative management in alleviating headaches was evaluated through propensity score matching (PSM)., Results: A total of 946 patients were included in the analysis of risk factors for headaches. Multivariate logistic regression analysis identified that female (OR 1.532, 95% CI 1.173-2.001, p = 0.002), supply artery dilatation (OR 1.423, 95% CI 1.082-1.872, p = 0.012), and occipital lobe (OR 1.785, 95% CI 1.307-2.439, p < 0.001) as independent risk factors for the occurrence of headaches. There were 443 AVMs with headache symptoms. After propensity score matching, the microsurgery group (OR 7.27, 95% CI 2.82-18.7 p < 0.001), stereotactic radiosurgery group(OR 9.46, 95% CI 2.26-39.6, p = 0.002), and multimodality treatment group (OR 8.34 95% CI 2.87-24.3, p < 0.001) demonstrate significant headache relief compared to the conservative group. However, there was no significant difference between the embolization group (OR 2.24 95% CI 0.88-5.69, p = 0.091) and the conservative group., Conclusions: This study identified potential risk factors for headaches in AVMs and found that microsurgery, stereotactic radiosurgery, and multimodal therapy had significant benefits in headache relief compared to conservative treatment. These findings provide important guidance for clinicians when developing treatment options that can help improve overall treatment outcomes and quality of life for patients., (© 2024. The Author(s).)

Aims: To compare the efficacy and deficiency of conservative management (CM), microsurgery (MS) only, and microsurgery with preoperative embolization (E + MS) for unruptured arteriovenous malformations (AVMs)., Methods: We prospectively included unruptured AVMs undergoing CM, MS, and E + MS from our institution between August 2011 and August 2021. The primary outcomes were long-term neurofunctional outcomes and hemorrhagic stroke and death. In addition to the comparisons among CM, MS, and E + MS, E + MS was divided into single-staged hybrid and multi-staged E + MS for further analysis. Stabilized inverse probability of treatment weighting using propensity scores was applied to control for confounders by treatment indication across the three groups., Results: Of 3758 consecutive AVMs admitted, 718 patients were included finally (266 CM, 364 MS, and 88 E + MS). The median follow-up duration was 5.4 years. Compared with CM, interventions (MS and E + MS) were associated with neurological deterioration. MS could lower the risk of hemorrhagic stroke and death. Multi-staged E + MS was associated with neurological deterioration and higher hemorrhagic risks compared with MS, but the hybrid E + MS operation significantly reduced the hemorrhage risk., Conclusion: In this study, unruptured AVMs receiving CM would expect better neurofunctional outcomes but bear higher risks of hemorrhage than MS or E + MS. The single-staged hybrid E + MS might be promising in reducing inter-procedural and subsequent hemorrhage., (© 2023 The Authors. CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)

Objective: Reducing the incidence of delayed postoperative hemorrhage (DPH) is one of the challenges in the surgical treatment of patients with brain arteriovenous malformations (bAVMs). This study aimed to identify several risk factors for DPH after bAVM resection and evaluate the impact of these risk factors in patients with bAVMs., Methods: The authors retrospectively reviewed consecutive patients with bAVMs who underwent microsurgical resection between August 2011 and September 2021. Patients were divided into either the DPH group or non-DPH group based on whether they experienced a postoperative intracerebral hemorrhage into the bAVM bed within 14 days after bAVM resection. Factors associated with DPH were assessed using multivariate logistic regression analyses., Results: A total of 1284 consecutive patients with bAVMs were evaluated; DPH events occurred in 18 patients (1.4%). There were several differences in vascular architecture between the two cohorts. A giant nidus, a nidus involved in the eloquent area, a periventricular nidus, and a nidus accompanied by venous ectasia were more likely to be associated with DPH events. The multivariate analysis identified two independent factors associated with DPH: maximum diameter (OR 1.44 per 1-cm increase, 95% CI 1.13-1.83) and periventricular lesion (OR 4.10, 95% CI 1.33-12.59). The area under the receiver operating characteristic curve for the maximum lesion diameter and development of DPH was 0.71 (95% CI 0.58-0.84). The cutoff value for the maximum bAVM diameter was 4.15 cm. Furthermore, patients with a giant bAVM, of which the maximum diameter was ≥ 4.15 cm, had a higher DPH risk after surgery (HR 5.79, 95% CI 2.01-16.67; p < 0.01). The incidence rates of DPH for patients with periventricular lesions were higher than those for patients without periventricular lesions (HR 4.50, 95% CI 1.77-11.40; p < 0.01)., Conclusions: Patients with giant bAVMs or periventricular lesions are at higher risk for DPH after surgery. Strategies such as blood pressure control, preoperative embolization, intraoperative monitoring, and careful patient selection should be considered to reduce the risk of DPH in high-risk patients.

Background: This study aimed to compare the risk and benefit profile of microsurgery (MS) and stereotactic radiosurgery (SRS) as the first-line treatment for unruptured and ruptured arteriovenous malformations (AVMs)., Materials and Methods: The authors included AVMs underwent MS or SRS as the first-line treatment from a nationwide prospective multicenter registry in mainland China. The authors used propensity score-matched methods to balance baseline characteristics between the MS and SRS groups. The primary outcomes were long-term hemorrhagic stroke or death, and the secondary outcomes were long-term obliteration and neurological outcomes. Subgroup analyses and sensitivity analyses with different study designs were performed to confirm the stability of our findings., Results: Of the 4286 consecutive AVMs in the registry from August 2011 to December 2021; 1604 patients were eligible. After matching, 244 unruptured and 442 ruptured AVMs remained for the final analysis. The mean follow-up duration was 7.0 years in the unruptured group and 6.1 years in the ruptured group. In the comparison of primary outcomes, SRS was associated with a higher risk of hemorrhagic stroke or death both in the unruptured and ruptured AVMs (unruptured: hazard ratio 4.06, 95% CI: 1.15-14.41; ruptured: hazard ratio 4.19, 95% CI: 1.58-11.15). In terms of the secondary outcomes, SRS was also observed to have a significant disadvantage in long-term obliteration [unruptured: odds ratio (OR) 0.01, 95% CI: 0.00-0.04; ruptured: OR 0.09, 95% CI: 0.05-0.15]. However, it should be noted that SRS may have advantages in preventing neurofunctional decline (unruptured: OR 0.56, 95% CI: 0.27-1.14; ruptured: OR 0.41, 95% CI: 0.23-0.76). The results of subgroup analyses and sensitivity analyses were consistent in trend but with slightly varied powers., Conclusions: This clinical practice-based real-world study comprehensively compared MS and SRS for AVMs with long-term outcomes. MS is more effective in preventing future hemorrhage or death and achieving obliteration, while the risk of neurofunctional decline should not be ignored., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Objective: The optimal microsurgical timing in ruptured brain arteriovenous malformations (AVMs) is not well understood and is surrounded by controversy. This study aimed to elucidate the impacts of microsurgical resection timing on clinical outcomes., Methods: The authors retrieved and reviewed the records on all ruptured AVMs treated at their institution and registered in a nationwide multicenter prospective collaboration registry between August 2011 and August 2021. Patients were dichotomized into an early resection group (≤ 30 days from the last hemorrhagic stroke) and a delayed resection group (> 30 days after the last hemorrhagic stroke). Propensity score-matched analysis was used to compare long-term outcomes. The primary outcome was neurological status as assessed using the modified Rankin Scale (mRS). The secondary outcomes were complete obliteration rate, postoperative seizure, and postoperative hemorrhage., Results: Of the 3649 consecutive AVMs treated at the authors' institution, a total of 558 ruptured AVMs were microsurgically resected and had long-term follow-up. After propensity score matching, 390 ruptured AVMs (195 pairs) were included in the comparison of outcomes. The mean (± standard deviation) clinical follow-up duration was 4.93 ± 2.94 years in the early resection group and 5.61 ± 2.56 years in the delayed resection group. Finally, as regards the distribution of mRS scores, short-term neurological outcomes were better in the delayed resection group (risk difference [RD] 0.3%, 95% CI -0.1% to 0.6%, p = 0.010), whereas long-term neurological outcomes were similar between the two groups (RD 0.0%, 95% CI -0.2% to 0.2%, p = 0.906). Long-term favorable neurological outcomes (early vs delayed: 90.8% vs 90.3%, p > 0.999; RD 0.5%, 95% CI -5.8% to 6.9%; RR 1.01, 95% CI 0.94-1.07) and long-term disability (9.2% vs 9.7%, p > 0.999; RD -0.5%, 95% CI -6.9% to 5.8%; RR 0.95, 95% CI 0.51-1.75) were also similar between these groups. In terms of secondary outcomes, postoperative seizure (early vs delayed: 8.7% vs 5.6%, p = 0.239; RD 3.1%, 95% CI -2.6% to 8.8%; RR 1.55, 95% CI 0.74-3.22), postoperative hemorrhage (1.0% vs 1.0%, p > 0.999; RD 0.0%, 95% CI -3.1% to 3.1%; RR 1.00, 95% CI 0.14-7.04), and hospitalization time (16.4 ± 8.5 vs 19.1 ± 7.9 days, p = 0.793) were similar between the two groups, whereas early resection had a lower complete obliteration rate (91.3% vs 99.0%, p = 0.001; RD -7.7%, 95% CI -12.9% to 3.1%; RR 0.92, 95% CI 0.88-0.97)., Conclusions: Early and delayed resection of ruptured AVMs had similar long-term neurological outcomes. Delayed resection can lead to a higher complete obliteration rate, although the risk of rerupture during the resection waiting period should be vigilantly monitored.

Background: Brain arteriovenous malformations (AVMs) account for 25% of hemorrhagic strokes in young adults. Although embolization has been widely performed as a stand-alone procedure to cure brain AVM, it is undermined whether patients benefit from this treatment. This study aimed to compare the long-term outcome of hemorrhagic stroke or death in patients with either conservative management or stand-alone embolization for AVM., Methods: The study population was derived from a nationwide multicenter prospective collaboration registry (the MATCH registry) between August 2011 and August 2021. The propensity score-matched survival analysis was performed in the overall and stratified AVM cases (unruptured and ruptured), respectively, to compare the long-term outcome of hemorrhagic stroke or death, and neurological status. The efficacy of distinct embolization strategies was also evaluated. Hazard ratios (HRs) with 95% CI were calculated using Fine-Gray competing risk models., Results: Of the 3682 consecutive AVMs, 906 underwent either conservative management or embolization as the stand-alone management strategy. After propensity score matching, a total of 622 (311 pairs) patients constituted an overall cohort. The unruptured and ruptured subgroups were composed of 288 cases (144 pairs) and 252 cases (126 pairs), respectively. In the overall cohort, embolization did not prevent long-term hemorrhagic stroke or death compared with conservative management [2.07 vs. 1.57 per 100 patient-years; HR, 1.28 (95% CI, 0.81-2.04)]. Similar results were maintained in both unruptured AVMs [1.97 vs. 0.93 per 100 patient-years; HR, 2.09 (95% CI, 0.99-4.41)] and ruptured AVMs [2.36 vs. 2.57 per 100 patient-years; HR, 0.76 (95% CI, 0.39-1.48)]. Stratified analysis showed that the target embolization might be beneficial for unruptured AVMs [HR, 0.42 (95% CI, 0.08-2.29)], while the curative embolization improved the outcome of ruptured AVMs [HR, 0.29 (95% CI, 0.10-0.87)]. The long-term neurological status was similar between these two strategies., Conclusions: This prospective cohort study did not support a substantial superiority of embolization over conservative management for AVMs in preventing long-term hemorrhagic stroke or death., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Rupture and hemorrhage is the most serious complication of cerebral arteriovenous malformation(cAVMs), and have a significant impact on quality of life., Objectives: We investigated the hematoxylin and eosin staining and ultrastructural features of cAVMs and characterized the abnormal vascular structure of cAVMs., Methods: Light and electron microscopy were performed on a series of pathological specimens obtained from 12 patients with cAVMs who underwent surgical resection for the first time without radiosurgery or embolization therapy., Results: In tunica intima, we found that the vascular endothelial cells of cAVMs were damaged, and the lysis of the cell body occurred in multiple regions. In tunica media, the arrangement of the elastic layer was disordered, and the thickness was uneven. Part of the structure of the elastic lamina was missing. The part of tunica adventitia was fractured and discontinuous. In addition, we also observed the phenomenon that different blood vessels share the same vascular wall. Macrophage phagocytosis and lymphocyte infiltration in the adventitial region of ruptured cAVMs. Abnormal lipid deposition in vascular endothelial cells and smooth muscle cells., Conclusions: The structural incompleteness of cAVMs may be an important cause of hemorrhage., Competing Interests: Declaration of competing interest The author(s) declared no potential conflicts of interest concerning this article's research, authorship, and/or publication., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: To explore the hemodynamic changes after embolization of arteriovenous malformations (AVMs) using quantitative digital subtraction angiography (QDSA)., Methods: We reviewed 74 supratentorial AVMs that underwent endovascular embolization and performed a quantitative hemodynamic analysis comparing parameters in pre- and post-operative DSA in correlation with rupture. The AVMs were further divided into two subgroups based on the embolization degree: Group I: 0%-50%, Group II: 51%-100%. In the intergroup analysis, we examined the correlations between embolization degree and hemodynamic parameter changes., Results: A longer time to peak (TTP) of the main feeding artery (OR 11.836; 95% CI 1.388 to 100.948; P=0.024) and shorter mean transit time (MTT) of the nidus (OR 0.174; 95% CI 0.039 to 0.766; P=0.021) were associated with AVM rupture. After embolization, all MTTs were significantly prolonged (P<0.05). The full width at half maximum (FWHM) duration of the main feeding artery was significantly shortened (P<0.001), and several hemodynamic parameters of the main draining vein changed significantly (TTP: prolonged, P=0.005; FWHM: prolonged, P=0.014; inflow gradient: decreased, P=0.004; outflow gradient: decreased, P=0.042). In the subgroup analysis, several MTT parameters were significantly prolonged in both groups (P<0.05), and the MTT increase rate in Group II was greater than in Group I (P<0.05)., Conclusions: Embolization can significantly change the hemodynamics of AVMs, especially when an embolization degree >50% is obtained. Partial embolization may reduce the AVM rupture risk in hemodynamics perspective., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: The hemodynamics of a brain arteriovenous malformation (AVM) nidus may be closely related to clinical presentation. The authors of this study aimed to explore the hemorrhagic quantitative hemodynamic indicators of the nidus through quantitative digital subtraction angiography (QDSA)., Methods: The quantitative hemodynamic parameters were generated from QDSA. Three data sets were used to explore independent quantitative hemodynamic indicators associated with AVM rupture. The training data set was exploited to discover independent quantitative hemodynamic indicators of AVM rupture by performing univariate and multivariate logistic regression analyses. The authors plotted receiver operating characteristic curves to validate the diagnostic performance of the hemorrhagic hemodynamic indicators using the training and two external validation data sets. Kaplan-Meier survival analysis was adopted to verify the predictive power of these risk indicators of future hemorrhage in the external prospective validation data set., Results: A total of 151 patients were included in this study, 91 in the training set and 30 in each of the two validation sets. A higher stasis index and slower transnidal relative velocity (TRV) of the nidus were significantly correlated with AVM rupture. The areas under the curve (AUCs) of the stasis index (nidus) were 0.765 and 0.815 and those of the TRV (nidus) were 0.735 and 0.796, respectively, in the training and retrospective external validation sets. Kaplan-Meier survival analysis confirmed the validity of the stasis index and TRV in predicting future rupture risk in the prospective validation data set (p = 0.008 and 0.041, respectively, log-rank test)., Conclusions: A higher stasis index (nidus) and slower TRV (nidus) in QDSA were associated with AVM rupture and were effective indicators of future hemorrhage, suggesting that the core mechanisms underlying AVM rupture could be intravascular blood stasis and occlusive hyperemia of the nidus.

Objective: This study aimed to explore whether intervention can benefit Spetzler-Martin (SM) grade IV-V arteriovenous malformations (AVMs)., Methods: Eighty-two patients with SM grade IV-V AVMs were retrospectively reviewed from 2015 to 2018. Patients were divided into two groups: those who received conservative management (22 cases [26.8%]) and intervention (60 cases [73.2%], including 21 cases of microsurgery, 19 embolization, and 20 hybrid surgery). Neurofunctional outcomes were assessed with the modified Rankin Scale (mRS). The primary outcome was long-term neurofunctional status, and the secondary outcomes were short-term neurofunctional status, long-term obliteration rate, seizure control, and risk of subsequent hemorrhage., Results: Regarding the primary outcome, after an average of 4.7 years of clinical follow-up, long-term neurofunctional outcomes were similar after conservative management or intervention (absolute difference -0.4 [95% CI -1.5 to 0.7], OR 0.709 [95% CI 0.461-1.090], p = 0.106), whereas intervention had an advantage over conservative management for avoidance of severe disability (defined as mRS score > 3) (1.7% vs 18.2%, absolute difference 16.5% [95% CI -23.6% to 56.6%], OR 0.076 [95% CI 0.008-0.727], p = 0.025). Regarding the secondary outcomes, intervention was conducive to better seizure control (Engel class I-II) (70.0% vs 0.0%, absolute difference 70.0% [95% CI 8.6%-131.4%], p = 0.010) and avoidance of subsequent hemorrhage (1.4% vs 6.0%, absolute difference 4.6% [95% CI -0.4% to 9.6%], p = 0.030). In the subgroup analysis based on different intervention modalities, microsurgery and hybrid surgery achieved higher complete obliteration rates than embolization (p < 0.001), and hybrid surgery resulted in significantly less intraoperative blood loss than microsurgery (p = 0.041)., Conclusions: Intervention is reasonable for properly indicated SM grade IV-V AVMs because it provides satisfactory seizure control with decreased risks of severe disability and subsequent hemorrhage than conservative management. Clinical trial registration no.: NCT04572568 (ClinicalTrials.gov).

Comparison in pediatric hemorrhagic arteriovenous malformations (AVMs) to clarify the long-term neurological outcomes and prognostic predictors after surgical intervention was relatively rare, especially in the selection of surgical timing. The objective of this study was to elucidate these points. The authors retrospectively reviewed the pediatric hemorrhagic AVMs resected in their neurosurgical department between March 2010 and June 2017. The natural history was represented by rupture risk. Neurological outcome was assessed with the modified Rankin Scale (mRS) for children. Multivariate logistic regression analyses were used to assess the risk factors for disability (mRS > 2). The hemorrhagic early phase was defined as less than 30 days after bleeding. The corresponding prognosis of different surgical timing (early intervention or delayed intervention) was compared after propensity-score matching (PSM). A total of 111 pediatric hemorrhagic AVM patients were evaluated. The average patient age was 11.1 ± 4.0 years, with a mean follow-up of 4.3 ± 2.1 years. The annualized rupture risk was 9.3% for the pediatric hemorrhagic AVMs, and the annualized re-rupture risk was 9.8%. 7.2% of the patients had disabilities (mRS > 2) and 82.0% achieved neurological deficit-free (mRS < 2) at the last follow-up. Pre-treatment mRS (P = 0.042) and flow-related aneurysms (P = 0.039) were independent factors for long-term disability. In terms of short-term outcomes, early intervention was better than delayed intervention (P = 0.033), but the long-term outcomes were similar between the two groups (P = 0.367). Surgical intervention for pediatric hemorrhagic AVMs is recommended, most of the patients can achieve good neurological outcomes. Moreover, early surgical intervention is preferred after the initial hemorrhage.

Objective: The aims of this study are to clarify the long-term outcomes of brainstem arteriovenous malformations (AVMs) after different management modalities., Methods: The authors retrospectively reviewed 61 brainstem AVMs in their institution between 2011 and 2017. The rupture risk was represented by annualised haemorrhagic rate. Patients were divided into five groups: conservation, microsurgery, embolisation, stereotactic radiosurgery (SRS) and embolisation+SRS. Neurofunctional outcomes were evaluated by the modified Rankin Scale (mRS). Subgroup analysis was conducted between different management modalities to compare the long-term outcomes in rupture or unruptured cohorts., Results: All of 61 brainstem AVMs (12 unruptured and 49 ruptured) were followed up for an average of 4.5 years. The natural annualised rupture risk was 7.3%, and the natural annualised reruptured risk in the ruptured cohort was 8.9%. 13 cases were conservative managed and 48 cases underwent intervention (including 6 microsurgery, 12 embolisation, 21 SRS and 9 embolisation+SRS). In the selection of interventional indication, diffuse nidus were often suggested conservative management (p=0.004) and nidus involving the midbrain were more likely to be recommended for intervention (p=0.034). The risk of subsequent haemorrhage was significantly increased in partial occlusion compared with complete occlusion and conservative management (p<0.001, p=0.036, respectively). In the subgroup analysis, the follow-up mRS scores of different management modalities were similar whether in the rupture cohort (p=0.064) or the unruptured cohort (p=0.391), as well as the haemorrhage-free survival (p=0.145). In the adjusted Bonferroni correction analysis of the ruptured cohort, microsurgery and SRS could significantly improve the obliteration rate compared with conservation (p<0.001, p=0.001, respectively) and SRS may have positive effect on avoiding new-onset neurofunctional deficit compared with microsurgery and embolisation (p=0.003, p=0.003, respectively)., Conclusions: Intervention has similar neurofunctional outcomes as conservation in these brainstem AVM cohorts. If intervention is adopted, partial obliteration should be avoided because of the high subsequent rupture risk., Trial Registration Number: NCT04136860., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

To develope a colored realistic AVM model using three-dimensional (3D) printing for surgical planning and research. Raw computed tomography angiography (CTA) and magnetic resonance venography (MRV) data were integrated and used for reconstruction. Each AVM model included the nidus, the feeding arteries, the draining veins, the sinuses, the adjacent principal arteries, and the skull. The models were employed to plan surgical and endovascular treatments. Surgical feedback was obtained using a survey. Five AVM cases were included. The AVMs and the models thereof did not differ significantly in terms of length, width, or height, as measured via magnetic resonance imaging (all p > 0.05). The 3D AVM models were thus accurate. The overall score on the questionnaire survey was >4 point; the model thus aided the planning of interventional surgery. All surgeons were confident that the 3D models reflected the true lesional boundaries. Our 3D-printed intracranial AVM models were accurate, and can be used for preoperative planning and training of residents. The models improved surgeons' understanding of AVM structure, reducing operative time., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background and Purpose: Silent microhemorrhage (hemosiderin) has been observed in resected brain arteriovenous malformations (bAVM) tissue and may represent a subgroup at increased risk for clinical hemorrhage. Previous studies suggest that ruptured bAVMs have faster flow and shorter mean transit time of contrast in blood vessels than unruptured bAVMs. We hypothesized that flow would be faster in unruptured AVMs with hemosiderin compared with those without hemosiderin., Methods: We selected unruptured, supratentorial bAVMs >3.5 cc with pathology specimens. Hemodynamic features were evaluated using color-coding angiography, including contrast mean transit time of AVM nidus, time to peak (TTP) of feeding artery (FA) and draining vein (DV), and the ratio (TTP DV/FA). Characteristics of 9 cases with hemosiderin and 16 without hemosiderin were compared using 2-sample t tests and Fisher exact tests., Results: No difference in FA TTP and DV TTP was observed between groups. However, cases with hemosiderin had significantly shorter mean transit time compared with those without hemosiderin (1.11±0.28 versus 1.64±0.55 seconds; P =0.013) and a lower ratio of DV TTP/FA TTP (1.48±0.32 versus 1.94±0.61; P =0.045). Presence of venous varix was significantly associated with hemosiderin ( P =0.003). No other clinical or angioarchitectural factors were associated with hemosiderin., Conclusions: Shorter mean transit time through the AVM nidus, lower DV TTP/FA TTP, and the high prevalence of venous varices suggests that high flow is an important feature of unruptured bAVMs with hemosiderin., (© 2017 American Heart Association, Inc.)

Background: Seizure is the second-most common presentation in patients with arteriovenous malformations (AVMs) and superimposes a significant burden on pediatric patients. Postoperative seizure risk in unruptured AVMs is underreported in the pediatric AVM literature. We aimed to characterize and identify predictive factors for postoperative seizures in this study., Methods: We performed a retrospective review of all surgically treated pediatric patients with unruptured AVM at our institution from 2001 to 2014. Patients younger than 18 years of age were included. Baseline variables was compared against our outcome of interest, which was defined as patients with or without follow-up seizures. Multivariable Cox regression was performed to identify potential predictive factors., Results: The average age of all patients was 13.1 years, and 68.2% were male. Nine patients were asymptomatic (13.6%), and seizure presentation occurred in 57.6% (n = 38). During an average follow-up of 4.2 years, 12 (18.2%) patients experienced postoperative seizures, with 5 (17.9%) of 28 patients with seizures being de novo. In patients with seizure presentation, 81.6% were completely seizure-free throughout follow-up. In multivariable analysis, larger AVM size (hazard ratio [HR] 1.63, P = 0.023) and temporal location (HR 8.35, P = 0.007) were found to increase the risk of follow-up seizures. On the contrary, seizure presentation (HR 1.91, P = 0.369) and postoperative infection (HR 2.37, P = 0.265) were not associated., Conclusions: Surgery may eliminate most seizures with low risk of inducing de novo seizures in pediatric patients with unruptured AVM. Predictive factors for postoperative seizures included large AVM size and temporal location. For selected unruptured AVMs with small size and nontemporal location, consideration of surgery as primary treatment for persistent seizures is a reasonable option., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: Detailed and exact mechanisms underlying brain arteriovenous malformations (bAVM) are still clinically confusing. Understanding the quantitative changes in proteins and signaling pathways would provide useful information for clinicians to understand the formation and development of bAVM, guiding individualized treatment strategies. This study was performed to establish a large human bAVM proteome database using tandem mass tag labeling and to detect changes of protein expression and pathways in human bAVM., Experimental Design: This study used quantitative 6-plex tandem mass tag labeling to profile protein changes in bAVM lesions. Integrated bioinformatics analysis was used to classify and identify the altered proteins and relating signaling pathways. Western blot analyzes were used to validate the proteomic data., Results: Our work established the first human bAVM proteome databases to date. A total of 1264 proteins were identified, and the expression of 316 proteins was significantly differentially expressed, with 249 upregulated proteins. Bioinformatics analysis demonstrated that the altered proteins had close functional correlations, including integrin cell surface interactions, extracellular matrix organization, and smooth muscle contraction. Three signaling pathways (focal adhesions, tight junctions, and gap junctions), which represent an important arena of cell-cell interactions, were found to be activated in bAVM. The proteomics data are available via ProteomeXchange with identifier PXD003289., Conclusion and Clinical Relevance: Cell-cell interactions, including focal adhesions, tight junctions, and gap junctions, were significantly influenced in human bAVM. Understanding the molecular mechanisms that underlie bAVM would provide useful information for the development of future therapeutic approaches, guiding possible precise and individual treatment strategies., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Objective: We describe our single-center experience treating unruptured brain arteriovenous malformations (uBAVMs) with microsurgical treatment., Methods: During a 7-year period, 282 patients with uBAVMs were surgically treated at our institution. Patient clinical features, postsurgical complications, arteriovenous malformation obliteration rate, seizure control, and functional outcome were collected and analyzed. Seizure control was evaluated with the Engel classification system. Patient functional outcome was assessed with modified Rankin Scale score., Results: Complete obliteration was achieved in 98.2% of cases. Surgical mortality rate was zero, and overall mortality rate was 1.1%. Good functional outcome (modified Rankin Scale score 0-1) was achieved in 86.9% of all patients, including 92.5% of patients with Spetzler-Martin (S-M) grade I and II uBAVMs, 80.6% of patients with S-M grade III uBAVMs, and 62.5% of patients with S-M grade IV and V uBAVMs. Poor outcome was significantly associated with arteriovenous malformation size ≥6 cm, deep venous drainage, eloquent location, and poor seizure control (all P < 0.05). For 177 patients with presurgical seizures, good seizure outcome (Engel class I) was achieved in 124 (70.1%) patients after microsurgical treatment. A short history of seizure occurrence, fewer presurgical seizures, and generalized tonic-clonic seizure type may be predictors of good seizure outcome (all P < 0.05)., Conclusions: Good functional outcome can be achieved by microsurgical resection in S-M grade I and II and selected grade III uBAVMs. Surgical resection for high-grade (grade IV and V) uBAVMs is challenging. A high seizure-free rate can be achieved in patients with initial seizure presentation., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Introduction: Although microsurgical resection is currently the first-line treatment modality for arteriovenous malformations (AVMs), microsurgery of these lesions is complicated due to the fact that they are very heterogeneous vascular anomalies. The Spetzler-Martin grading system and the supplementary grading system have demonstrated excellent performances in predicting the risk of AVM surgery. However, there are currently no predictive models based on multimodal MRI techniques. The purpose of this study is to propose a predictive model based on multimodal MRI techniques to assess the microsurgical risk of intracranial AVMs., Methods and Analysis: The study consists of 2 parts: the first part is to conduct a single-centre retrospective analysis of 201 eligible patients to create a predictive model of AVM surgery based on multimodal functional MRIs (fMRIs); the second part is to validate the efficacy of the predictive model in a prospective multicentre cohort study of 400 eligible patients. Patient characteristics, AVM features and multimodal fMRI data will be collected. The functional status at pretreatment and 6 months after surgery will be analysed using the modified Rankin Scale (mRS) score. The patients in each part of this study will be dichotomised into 2 groups: those with improved or unchanged functional status (a decreased or unchanged mRS 6 months after surgery) and those with worsened functional status (an increased mRS). The first part will determine the risk factors of worsened functional status after surgery and create a predictive model. The second part will validate the predictive model and then a new AVM grading system will be proposed., Ethics and Dissemination: The study protocol and informed consent form have been reviewed and approved by the Institutional Review Board of Beijing Tiantan Hospital Affiliated to Capital Medical University (KY2016-031-01). The results of this study will be disseminated through printed media., Trial Registration Number: NCT02868008., Competing Interests: Conflicts of Interest: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Aim: For cerebral arteriovenous malformations (AVMs) involving language areas, right-sided language lateralization on functional magnetic resonance imaging (fMRI) has been reported, which is regarded as language cortex reorganization. The authors attempted to study if this right-sided language lateralization affects postoperative language outcome., Material and Methods: Clinical and imaging data of 43 right-handed AVM patients who underwent preoperative fMRI were retrospectively reviewed. All lesions involved the language cortex, with the Broca area involved in 13 patients and the Wernicke area involved in 30 patients. Lateralization indices (LI) of BOLD signal activations were calculated to determine language lateralization. All patients underwent craniotomy and total resection. Western aphasia battery (WAB) was used to evaluate language functions preoperatively, 1-2 weeks after surgery and 6-30 months after surgery., Results: On preoperative fMRI, right-sided lateralization was observed in 18 patients (41.9%, R Group), including 3 with rightsided lateralization in the Broca area alone, 14 in the Wernicke area alone, and 1 in both areas. The other 25 patients were non-rightsided lateralized (NR Group). One week after surgery, 7 patients in the R Group (38.9%) and 11 patients in the NR Group (44.0%) had language function deterioration, and no significant difference was found (p=0.983). At long-term follow-up, 3 patients in the R Group (16.7%) and 4 patients in the NR Group (16.0%) still had aphasia, and no significant difference was observed (p=1.000)., Conclusion: Although right-sided lateralization on fMRI might suggest language cortex reorganization, it is not a factor predicting better postoperative language outcome for AVM patients.

Background: Children with untreated brain arteriovenous malformations (bAVM) are at risk of encountering life-threatening hemorrhage very early in their lives. The primary aim of invasive treatment is to reduce unfavorable outcome associated with a bAVM rupture. A better understanding of the morbidity of bAVM hemorrhage might be helpful for weighing the risks of untreated bAVM and invasive treatment. Our aim was to assess the clinical outcome after bAVM rupture and identify features to predict severe hemorrhage in children., Methods: We identified all consecutive children admitted to our institution for bAVMs between July 2009 and December 2014. Clinical outcome after hemorrhagic presentation and subsequent hemorrhage was evaluated using the modified Rankin Scale (mRS) for children. The association of demographic characteristics and bAVM morphology with severe hemorrhage (mRS >3 or requiring emergency hematoma evacuation) was studied using univariate and multivariable regression analyses. A nomogram based on multivariable analysis was formulated to predict severe hemorrhage risk for individual patients., Results: A total of 134 patients were identified with a mean treatment-free follow-up period of 2.1 years. bAVM ruptured in 83 (62%) children: 82 had a hemorrhage at presentation and 6 of them experienced a recurrent hemorrhage during follow-up; 1 patient had other diagnostic symptoms but bled during follow-up. Among them, 49% (41/83) had a severe hemorrhage; emergency hematoma evacuation was required in 28% of them (23/83), and 24% (20/83) remained as disabled (mRS ≥3) at last follow-up. Forty-six percent (38/82) of children with hemorrhagic presentation were severely disabled (mRS >3). Forty-three percent (3/7) were severely disabled after subsequent hemorrhage. The annual rate of severe subsequent hemorrhage was 1% in the overall cohort and 3.3% in children with ruptured presentation. All the subsequent severe hemorrhage events occurred in children with severe hemorrhage history (7%, 3/41). Periventricular location, non-temporal lobe location, and long draining vein were predictors for severe hemorrhage in pediatric untreated bAVMs. A nomogram based on bAVM morphology was contracted to predict severe hemorrhage risk for individual patients, which was well calibrated and had a good discriminative ability (adjusted C-statistic, 0.72)., Conclusions: Evaluating bAVM morbidity and morphology might be helpful for weighing the risks of untreated bAVM in pediatric patients., (© 2017 S. Karger AG, Basel.)

Objective: We aimed to describe our single-center experience in treating cerebellar arteriovenous malformations (AVMs) with microsurgical resection., Methods: During a 16-year period, 181 patients with cerebellar AVMs were surgically treated at the Department of Neurosurgery in Beijing Tiantan Hospital. Patient functional status was evaluated using modified Rankin Scale (mRS) scores both before treatment and at the last follow-up. The mRS scores at the last follow-up were dichotomized as good outcome (mRS <3) and poor outcome (mRS ≥3). The treatment modalities, post-treatment complications, obliteration rate, and follow-up outcomes were analyzed., Results: Of the 181 patients, 172 (95%) patients presented with initial hemorrhage and 62 (34%) patients experienced rehemorrhage before microsurgical treatment. Complete obliteration of the AVMs was achieved in 177 (97.8%) patients. Good functional outcome was achieved in 144 (80%) of the patients. The surgical mortality rate was 4.4% (8/181), and overall mortality rate was 6.6% (12/181). Poor outcome was significantly associated with increasing age (P = 0.035; odds ratio [OR], 1.030; 95% CI 1.002-1.060), presurgical mRS ≥3 (P = 0.029; OR, 2.563; 95% CI 1.101-5.968), eloquent AVM location (P = 0.015; OR, 3.058; 95% CI 1.244-7.516), and presurgical rehemorrhage (P = 0.008; OR, 3.266; 95% CI 1.358-7.858)., Conclusion: Good outcome can be achieved by microsurgical resection in most patients with cerebellar AVMs. Increasing age at surgery, poor presurgical functional status, eloquent AVM location, and presurgical rehemorrhage are independent predictors of poor outcomes after AVM resection. We recommend early surgical resection for all surgically accessible cerebellar AVMs to prevent subsequent hemorrhage and resultant poor neurologic outcomes., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: The aim of this study was to identify the risk factors for subsequent hemorrhage in patients with untreated cerebellar arteriovenous malformations (AVMs)., Methods: We searched our AVM database at Beijing Tiantan Hospital and identified 149 patients with cerebellar AVMs who were at least 1 month treatment free after initial diagnosis between 2000 and 2015. The patients were followed up from initial diagnosis until subsequent hemorrhage, initiation of treatment, or the end of 2015. The natural history of cerebellar AVMs was analyzed., Results: The overall annual rupture rate was 8.6%, with a mean follow-up period of 4.2 years (range, 1 month to 15 years). The annual rupture rate for previously ruptured AVMs was 10.8% during the whole follow-up period, 12.4% in the first 5 years (18.8% in the first year and 9.0% in the subsequent 4 years) and 6.7% in more than 5 years after initial diagnosis. The overall annual rupture rate for previously unruptured AVMs was 4.0%. Childhood at diagnosis, AVM size ≥3 cm and exclusively deep venous drainage were independent risk factors for subsequent hemorrhage. Previous AVM rupture significantly increased the hemorrhagic risk during the first 5 years but did not significantly affect subsequent hemorrhage thereafter., Conclusions: Childhood at diagnosis, large AVM size, and AVMs with exclusively deep venous drainage are independent risk factors for subsequent hemorrhage in patients with cerebellar AVMs. Previous rupture may increase the hemorrhagic risk during the first 5 years after diagnosis but may not significantly increase the risk in the following years., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: To explore outcomes after microsurgery of brain arteriovenous malformations (AVMs) that failed to be obliterated by Gamma Knife radiosurgery (GKRS)., Methods: From January 2000 to January 2014, 42 consecutive patients underwent surgical resection of persistent AVMs after GKRS. These 42 patients with AVMs who underwent radiosurgery (radiosurgery group) were individually matched with 42 patients with AVMs who did not undergo radiosurgery (no radiosurgery group) based on patient and AVM characteristics. The modified Rankin Scale was used to assess neurologic status of patients. The effects of GKRS on AVM resection and surgical outcomes were analyzed., Results: After GKRS, the mean AVM volume was significantly reduced by 76.8% (P < 0.01), the size was reduced by 41% (P < 0.01), and the Spetzler-Martin grade was reduced in 61.9% of the patients (P < 0.01). During the time interval from radiosurgery to surgical resection, subsequent hemorrhages led to significant neurologic deterioration (P = 0.046). Compared with the control group, the frequency of preoperative embolization, operative time, and blood loss were significantly lower in the radiosurgery group (all P < 0.05). The no radiosurgery group had a significantly higher rate of worsening in mRS scores at 6 months after surgery (40.5% vs. 16.7%, P = 0.029). Good neurologic status (mRS score <3) was achieved in 81% of the radiosurgery group and 83% of the no radiosurgery group at the final follow-up evaluation., Conclusions: GKRS performed several years before microsurgical resection can facilitate resectability of AVMs and decrease the rate of postoperative neurologic deterioration. For patients with persistent AVMs several years after GKRS, microsurgical resection is recommended to achieve good clinical outcomes., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: To identify whether age, sex, and lesion location are associated with initial presentation in patients with brain arteriovenous malformations (AVMs)., Methods: Collected data of 3299 consecutive patients with AVM treated at Beijing Tiantan Hosptial from January 1980 to January 2015 were analyzed. The variables assessed were age at diagnosis, sex, AVM location, and mode of initial presentation., Results: Initial presentation was AVM hemorrhage in 57.9%, seizure in 20.9%, chronic headache in 14.9%, focal neurologic deficit in 5.2%, and incidental in 1.2%. Younger age and female sex were associated with initial hemorrhage (all P < 0.05). Hemorrhage was more likely to occur in patients with AVMs in the basal ganglia, the corpus callosum, the ventricles, the cerebellum, and the brainstem (all P < 0.05). Male sex was associated with initial seizure (P < 0.05). Initial seizure was more likely to occur in patients with AVMs in the frontal, temporal, parietal, frontotemporal, and frontoparietal lobe (all P < 0.05). Compared with frontal AVMs, temporal AVMs were more likely to present with hemorrhage (P < 0.05) and less likely to present with seizure (P < 0.05). AVMs involving the occipital lobe were more likely to present with chronic headaches (P < 0.05)., Conclusions: Initial AVM presentation varied with patient age, sex, and AVM locations. Younger age, female sex, and deep and infratentorial locations may be associated with initial hemorrhage. Male sex and frontal, temporal, and parietal AVM locations may be predictors of initial seizure. Chronic headache was more likely to occur in patients with AVMs involving the occipital lobe., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: We reviewed our prospective study of patients with occipital arteriovenous malformations (AVMs) to assess whether the display of optic radiation diffusion tensor imaging (DTI) during neuronavigation-guided surgery can reduce the severity of postoperative visual field deficits (VFDs) and to evaluate the factors associated with visual field preservation., Methods: Forty-six consecutive patients with occipital AVMs were randomized in our study. DTI of the optic radiation was displayed during neuronavigation surgery in 24 patients. The other 22 patients were treated surgically without neuronavigation. Modified Rankin Scale (mRS) scores and visual fields were evaluated preoperatively, immediately after surgery, and at the last follow-up., Results: The patients' baseline characteristics and AVM features were statistically similar between the 2 surgical groups. The postoperative obliteration rate was 100%. The postoperative mRS scores did not differ between the 2 groups (P > 0.05). Preexisting VFDs were more common (P = 0.00004) in patients who bled than in those with unruptured AVMs. The application of DTI-incorporated neuronavigation reduced the frequency and severity of postoperative VFDs (P = 0.013 and 0.001, respectively). Visual fields were more likely to be preserved in patients with an AVM >5 mm from the optic radiation (P = 0.025)., Conclusions: A history of hemorrhage is an independent risk factor for VFDs associated with occipital AVMs. Although not showing superiority in postoperative mRS, functional MRI navigation-guided surgery may help to radically resect occipital AVMs and preserve patient visual fields. A 5-mm distance from the optic radiation may be a suitable safety margin for visual field preservation., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: In this aging society, attention has not been fully given to brain arteriovenous malformations (AVMs) in elderly patients. This study sought to describe a single institution's experience treating arteriovenous malformations (AVMs) in elderly patients., Methods: We conducted a retrospective review of brain AVMs in elderly patients treated at our institution between 1990 and 2012 with a focus on the clinical features, risk of hemorrhage and treatment outcomes., Results: Of the 2790 patients in our AVM database, 98 patients were over the age of 60 at presentation. Forty-eight percent presented with hemorrhage. Risks of initial hemorrhage were history of hypertension, smaller AVM size (<3 cm) and exclusively deep venous drainage. Treatment modalities were microsurgical resection in 65 %, embolization alone in 10 %, stereotactic radiosurgery (SRS) in 11 % and observation in 14 %. Preoperative embolization was performed in 32 % in the surgical group. Complete obliteration was achieved in 95 % by microsurgery, 30 % by embolization alone and 45 % by SRS. Good functional outcome (modified Rankin Scale, mRS <2) was achieved in 69 % after a median follow-up of 5.8 years. Multivariate logistic analysis revealed that a pretreatment mRS score ≥2, eloquent location and higher S-M grade (IV or V) were associated with worsening functional status, whereas surgical resection was a negative factor. Posttreatment hemorrhage occurred in 8 %. AVM-related death occurred in three patients (2 by surgery and 1 by observation)., Conclusions: Brain AVMs in elderly patients still pose a high risk of hemorrhage. Initial hemorrhage may be associated with a history of hypertension, AVM size and exclusively deep venous drainage. Initial mRS score ≥2, eloquent location and higher S-M grade may be associated with worsening functional status. Microsurgical resection can be safe and effective for selected patients. Preoperative embolization is helpful in patients with S-M grade IV-V AVMs. For those with surgical contraindications, SRS and observation are treatment alternatives.

Objective: To explore the expression and role of Caveolin-1 in the angiogenesis of cerebral arteriovenous malformation (AVM)., Methods: A total of 55 fresh AVM samples at Affiliated Hospital, Inner Mongolia Medical University and Beijing Tiantan Hospital from August 2013 to May 2014 were collected to test the expressions of Caveolin-1, vascular endothelial growth factor (VEGF), vascular endothelial growth factor-receptor 2 (VEGF-R2) and endothelial nitric oxide synthase (eNOS) by immunohistochemistry and Western blot. And the relationship between the expressions of Caveolin-1 and VEGF, VEGF-R2 and eNOS was analysed., Results: The expression rates of Caveolin-1, VEGF, VEGF-R2 and eNOS in human AVM were 100%, 87.27%, 76.36% and 85.45%. And the values were significantly higher than those in normal superficial temporal artery. Western blot showed that the expressions of Caveolin-1, VEGF, VEGF-R2 and eNOS in hemorrahge AVM were higher than those in non-hemorrahge counterpart (P < 0.05). The expressions of Caveolin-1, VEGF, VEGF-R2 and eNOS were consistent., Conclusion: Caveolin-1 plays a positive regulatory role in the angiogenesis of AVM through the PI3K/Akt signaling pathway. In cerebral AVM, Caveolin-1 plays an important role in occurrence, progression, hemorrahge and degradation of brain AVM.

Introduction: Intracranial arteriovenous malformations (AVMs) are associated with high morbidity and mortality. Modern microsurgery has improved the results of surgical treatment of AVMs; however, the treatment of AVMs, particularly eloquently located AVMs, still carries a high risk. Functional MRI (fMRI) has been reported to be used for the preoperative evaluation of AVMs in small case series. The purpose is to identify the utility and efficacy of fMRI-guided microsurgery of AVMs in a large randomised controlled trial., Methods and Analysis: The study is a prospective, randomised controlled clinical trial. This study will enrol a total of 600 eligible patients. These eligible patients will be randomised to the standard microsurgery group and the fMRI-guided microsurgery group in a 1:1 ratio. Patient baseline characteristics and AVM architecture and characteristics will be described. In the fMRI-guided group, fMRI mapping of an eloquent cortex in all AVMs will be identified. Surgical complications and outcomes at pretreatment, post-treatment, at discharge and at 1-month, 3-month and 6-month follow-up intervals will be analysed using the modified Rankin Scale (mRS). This trial will determine whether fMRI-guided microsurgery could improve outcomes in patients with AVMs and also identify the safety and efficacy of fMRI-guided microsurgery., Ethics and Dissemination: The study protocol and written informed consent were reviewed and approved by the Institutional Review Board of Beijing Tiantan Hospital Affiliated to Capital Medical University (ky2012-016-02). Study findings will be disseminated in the printed media., Trial Registration Number: ClinicalTrials.gov NCT01758211., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Background: The treatment of giant arteriovenous malformations (AVMs) remains a challenge in the neurosurgical field. Microsurgery is one of the most effective ways for eliminating giant cerebral AVMs., Objective: To review surgical outcomes in treating the disease, and form conclusions regarding the indications for and outcomes of surgical treatment in giant intracranial AVMs., Methods: We studied 40 consecutive cases of giant AVMs treated in Beijing Tiantan Hospital between 2000 and 2008. The radiologic and clinical features were analyzed. The Spetzler-Martin grading system was used to classify the patients. All patients were surgically treated, and the final outcomes of the patients were gathered for analysis., Results: The major presenting symptoms were seizures, headaches, hemorrhage, and neurological deficits. The mean AVM diameter was 6.3 cm. According to the Spetzler-Martin grading system, 5 patients had grade III lesions, 21 had grade IV lesions, and 14 had grade V lesions. Out of the total 40 patients, 31 (77.5%) demonstrated excellent or good outcome. Complications included hemiparalysis, aphasia, hemianopia, cranial nerve dysfunction, and seizures. After follow-up, 27 of 30 (90%) surviving patients presented normal function or minimal symptoms., Conclusion: Presurgical evaluation of every candidate and treatment choice is the determining factor in therapy for giant AVMs. For giant cerebral AVMs located superficially or not involving critical components, a good outcome can be expected through surgical resection. The obliteration and recurrence rates were satisfying, and the complication rate was acceptable.

Background: Cerebral arteriovenous malformation (AVM) is a common vascular disease in neurosurgery, and the indication for alternative treatments remains controversial. In a review of a series of 2086 patients with AVMs, the clinical characteristics and surgical results were assessed., Methods: Collected data of 2086 consecutive patients with AVMs from January 1956 to October 2001 were analyzed. All patients were divided into 2 groups: traditional surgery group (from 1956 to 1991) and microsurgery group (from 1992 to 2001). The variables assessed for clinical characteristics in our study included age (at presentation), sex, Spetzler-Martin grade, and first presentations. Surgical complications were assessed between different surgery groups by chi(2) test., Results: Cerebral AVMs are more commonly diagnosed at age of 20 to 40 years, which comprises almost one half of the whole population. The size of the AVMs ranged from 1 to 9 cm. There were 77 cases of giant AVMs in this series that were treated by a combination of surgical resection and intraoperative embolization. Hemorrhage (43.4%), headache (24.9%), and seizure (17.3%) were the first 3 common presentations. Regarding Spetzler-Martin grading system, the percentage of grade 3 to 5 patients increased, whereas that of grade 1 patients decreased in the microsurgery group (P = .00). However, compared with the traditional surgery group, the incidence of main surgical complications (death, hemiparalysis, cranial nerve dysfunction, and gastrointestinal hemorrhage) decreased significantly in the microsurgery group (P = .00). Although the incidence of main surgical complications had no statistical difference between early (from 1992 to 1996) and late microsurgery subgroup (from 1997 to 2001) (P = .796), the incidence really decreased with increase of higher-grading patients (grade 3-5) in the late microsurgery group (P = .00)., Conclusions: Cerebral AVM is one of the important reasons for spontaneous intracranial hemorrhage in patients younger than 40. Spetzler-Martin grading system is helpful to predict the surgical risk. Microsurgical technique has made surgical treatment safer and become the best choice for patients with cerebral AVM.