Unruptured Arteriovenous Malformations Research Articles

Multimodality treatment of cerebral arteriovenous malformations

AbstractBackground: cerebral arteriovenous malformations (AVMs) , vascular lesions in the brain , can cause neurological complications like intracerebral hemorrhage. Treatment options include surgical excision , endovascular embolization , radiosurgery and multimodal therapy. Multimodality treatment uses two or more options to treat the same case , so maximizing the benefits of each option.Objectives: The aim is to evaluate outcome of patients with cerebral AVMs by surgery , embolization , radiosurgery and multimodality treatment in neurosurgery Department, Zagazig University Hospitals from May 2017 to May 2019.Patients and methods: 42 patients with AVM included 5 cases operated for excision, 23 cases for endovascular embolization, 14 cases for both endovascular embolization and gamma knife radiosurgery. in this study we used single modality approach (surgery or embolization) in 28 cases and multimodality approach (embolization followed by radiosurgery) in 14 cases.Results: multimodality treatment provides a better solution for large AVMs and those with residual nidus following embolization.Conclusion: management of AVMs depends on presenting symptoms , SMG , patient choice , center experience Key wordscerebral arteriovenous malformations, multimodality treatment, ruptured AVM , cerebral hemorrhage, unruptured AVM, stereotactic radiosurgery.

Bringing high-grade arteriovenous malformations under control: clinical outcomes following multimodality treatment in children.

Brain arteriovenous malformations (AVMs) consist of dysplastic blood vessels with direct arteriovenous shunts that can hemorrhage spontaneously. In children, a higher lifetime hemorrhage risk must be balanced with treatment-related morbidity. The authors describe a collaborative, multimodal strategy resulting in effective and safe treatment of pediatric AVMs. A retrospective analysis of a prospectively maintained database was performed in children with treated and nontreated pediatric AVMs at the University of California, San Francisco, from 1998 to 2017. Inclusion criteria were age ≤ 18 years at time of diagnosis and an AVM confirmed by a catheter angiogram. The authors evaluated 189 pediatric patients with AVMs over the study period, including 119 ruptured (63%) and 70 unruptured (37%) AVMs. The mean age at diagnosis was 11.6 ± 4.3 years. With respect to Spetzler-Martin (SM) grade, there were 38 (20.1%) grade I, 40 (21.2%) grade II, 62 (32.8%) grade III, 40 (21.2%) grade IV, and 9 (4.8%) grade V lesions. Six patients were managed conservatively, and 183 patients underwent treatment, including 120 resections, 82 stereotactic radiosurgery (SRS), and 37 endovascular embolizations. Forty-four of 49 (89.8%) high-grade AVMs (SM grade IV or V) were treated. Multiple treatment modalities were used in 29.5% of low-grade and 27.3% of high-grade AVMs. Complete angiographic obliteration was obtained in 73.4% of low-grade lesions (SM grade I-III) and in 45.2% of high-grade lesions. A periprocedural stroke occurred in a single patient (0.5%), and there was 1 treatment-related death. The mean clinical follow-up for the cohort was 4.1 ± 4.6 years, and 96.6% and 84.3% of patients neurologically improved or remained unchanged in the ruptured and unruptured AVM groups following treatment, respectively. There were 16 bleeding events following initiation of AVM treatment (annual rate: 0.02 events per person-year). Coordinated multidisciplinary evaluation and individualized planning can result in safe and effective treatment of children with AVMs. In particular, it is possible to treat the majority of high-grade AVMs with an acceptable safety profile. Judicious use of multimodality therapy should be limited to appropriately selected patients after thorough team-based discussions to avoid additive morbidity. Future multicenter studies are required to better design predictive models to aid with patient selection for multimodal pediatric care, especially with high-grade AVMs.

Management of Unruptured Cerebral Aneurysms and Arteriovenous Malformations.

Unruptured intracranial aneurysms and brain arteriovenous malformations (AVMs) may be detected as incidental findings on cranial imaging. This article provides a practical approach to the management of unruptured intracranial aneurysms and unruptured brain AVMs and reviews the risk of rupture, risk factors for rupture, preventive treatment options with their associated risks, and the approach of treatment versus observation for both types of vascular malformations. For unruptured intracranial aneurysms, scoring systems on the risk of rupture can help with choosing preventive treatment or observation with follow-up imaging. Although the literature provides detailed information on the complication risks of preventive treatment of unruptured intracranial aneurysms, individualized predictions of these procedural complication risks are not yet available. With observation with imaging, growth of unruptured intracranial aneurysms can be monitored, and prediction scores for growth can help determine the optimal timing of monitoring. The past years have revealed more about the risk of complications of the different treatment modalities for brain AVMs. A randomized clinical trial and prospective follow-up data have shown that preventive interventional therapy in patients with brain AVMs is associated with a higher rate of neurologic morbidity and mortality compared with observation. The risk of hemorrhage from both unruptured intracranial aneurysms and brain AVMs varies depending on the number of risk factors associated with hemorrhage. For both types of vascular malformations, different preventive treatment options are available, and all carry risks of complications. For unruptured intracranial aneurysms, the consideration of preventive treatment versus observation is complex, and several factors should be included in the decision making. Overall, it is recommended that patients with unruptured asymptomatic brain AVMs should be observed.

Predictive factors of epilepsy in arteriovenous malformation

ObjectiveStructural epilepsy related to cerebral arteriovenous malformation (AVM) suggests different epileptogenic mechanisms. The aim of our study was to determine factors associated with epilepsy into a retrospective cohort of AVM patients. Patients and methodsRuptured and unruptured AVM data retrieved from a prospective single center registry (2009–2016) were retrospectively assessed. Demographic, clinical and radiological features were identified in AVM patients with or without epilepsy according to the International League Against Epilepsy classification. ResultsEpilepsy concerned 22 out of 80 consecutive patients with AVM (27.5%). Univariate analysis comparing both groups revealed a significant association of different variables with the structural epilepsy: young age (P=0.02), large nidus size (P=0.02), venous dilation (P=0.02), posterior cerebral artery (PCA) feeder (P<0.001) and Spetzler-Martin grade (P=0.02). Based on multivariate analysis, only the PCA feeder was identified (OR=5.2 [95% CI 1.1–24,5], P=0.04). ConclusionPCA feeder for cerebral AVM was significantly associated with structural epilepsy. The hypothesis of a vascular steal phenomenon to the detriment of internal temporal lobe vascularization could be related to the development of epilepsy.

Single-session Curative Embolization of Unruptured Cerebellar Arteriovenous Malformation with Precipitating Hydrophobic Injectable Liquid

AbstractMicrosurgery is the treatment of choice for cerebellar arteriovenous malformations (AVMs). Nevertheless, endovascular therapy aims to be an effective treatment since the introduction of new embolic agents. Cerebellar AVMs represent a subgroup of vascular lesions with a high rate of hemorrhagic presentation compared with their cerebral counterpart. Moreover, they have a higher incidence of flow-related aneurysms when diagnosed. With this in mind, prompt treatment must be performed to avoid rebleeding with devastating consequences. Herein, we present the case of an unruptured cerebellar AVM treated with precipitating hydrophobic injectable liquid (PHIL) with complete obliteration.

Abstract 127: Radiosurgery for Unruptured Intervention-Naïve Pediatric Brain Arteriovenous Malformations

Background and Purpose: To evaluate, in a multicenter, retrospective cohort study, the outcomes after stereotactic radiosurgery (SRS) for unruptured, intervention-naïve pediatric brain arteriovenous malformations (AVM). Methods: We retrospectively analyzed the International Radiosurgery Research Foundation pediatric AVM database from 1987-2018. Pediatric patients with unruptured, previously untreated AVMs who underwent SRS were included. The primary endpoint was a composite of hemorrhagic stroke, death, or permanently symptomatic radiation-induced changes (RIC). Results: The study cohort comprised 101 patients (mean follow-up 80.8 months). The primary endpoint occurred in 14%, comprising hemorrhage stroke, death, and permanent RIC in 6%, 3%, and 8%, respectively. Estimated probabilities of the primary endpoint were 5.2%, 10.8%, and 23.0% at 2, 5, and 10 years, respectively (Figure 1). Estimated probabilities of AVM obliteration at 5 and 10 years were 64% and 82%, respectively (Figure 2). Single SRS treatment (p=0.007) and higher margin dose (p=0.005) were predictors of obliteration. Subgroup analysis of Spetzler-Martin grade I-III AVMs estimated primary endpoint probabilities of 3.7%, 8.4%, and 18.7% at 2, 5 and 10 years, respectively. Conclusion: Treatment of unruptured, intervention-naïve AVMs in the pediatric population with SRS carries an approximately 2% annual risk of morbidity and mortality, which appears to plateau after 10 years. The poorly described natural history of pediatric AVMs makes any comparison of SRS versus conservative management imperfect. However, due to the young age at diagnosis and excessive cumulative life hemorrhage risk of an untreated AVM in a child, SRS is likely to have a favorable long-term risk-benefit profile for appropriately selected unruptured pediatric AVMs.

Impact of AVM location on language cortex right-hemisphere reorganization: A voxel-based lesion-symptom mapping study

ObjectivesCerebral arteriovenous malformations (AVMs) are congenital malformations, and right-sided dominance of the language cortex is not a rare phenomenon for patients with AVM involving language area. We tried to use voxel-based lesion-symptom mapping (VLSM) method to depict the location of AVM nidus and to demonstrate the relationship between AVM location and the pattern of language cortex reorganization. Patients and methodsThe authors retrospectively reviewed clinical and imaging data of 70 adult patients with unruptured cerebral AVMs who underwent blood oxygen level–dependent (BOLD) functional magnetic resonance imaging (fMRI) of language task. All patients were right handed, and all lesions were located in the left cerebral hemisphere. Lateralization indexes (LI) of the BOLD signals were calculated for Broca and Wernicke areas separately and were used to reflect the degree of right-sided dominance of the two language areas. VLSM method was applied to study the relationship between AVM location and LI of language task activations. ResultsStatistical analysis revealed that the change of LI of Broca area was significantly associated with lesions located in the inferior frontal gyrus, pre- and post-central gyrus, supramarginal gyrus and middle frontal gyrus. The change of LI of Wernicke area was significantly associated with lesions located in the left superior, middle, inferior and transverse temporal gyrus. ConclusionThese findings provide new evidence that the language cortex reorganization patterns in AVM patients have anatomic specificity.

Gamma Knife Radiosurgery For Brain Vascular Malformations: Current Evidence And Future Tasks.

Gamma Knife radiosurgery (GKRS) has long been used for treating brain vascular malformations, including arteriovenous malformations (AVMs), dural arteriovenous fistulas (DAVFs), and cavernous malformations (CMs). Herein, current evidence and controversies regarding the role of stereotactic radiosurgery for vascular malformations are described. 1) It has already been established that GKRS achieves 70–85% obliteration rates after a 3–5-year latency period for small to medium-sized AVMs. However, late radiation-induced adverse events (RAEs) including cyst formation, encapsulated hematoma, and tumorigenesis have recently been recognized, and the associated risks, clinical courses, and outcomes are under investigation. SRS-based therapeutic strategies for relatively large AVMs, including staged GKRS and a combination of GKRS and embolization, continue to be developed, though their advantages and disadvantages warrant further investigation. The role of GKRS in managing unruptured AVMs remains controversial since a prospective trial showed no benefit of treatment, necessitating further consideration of this issue. 2) Regarding DAVFs, GKRS achieves 41–90% obliteration rates at the second post-GKRS year with a hemorrhage rate below 5%. Debate continues as to whether GKRS might serve as a first-line solo therapeutic modality given its latency period. Although the post-GKRS outcomes are thought to differ among lesion locations, further outcome analyses regarding DAVF locations are required. 3) GKRS is generally accepted as an alternative for small or medium-sized CMs in which surgery is considered to be too risky. The reported hemorrhage rates ranged from 0.5–5% after GKRS. Higher dose treatments (>15 Gy) were performed during the learning curve, while, with the current standard treatment, a dose range of 12–15 Gy is generally selected, and has resulted in acceptable complication rates (< 5%). Nevertheless, further elucidation of long-term outcomes is essential.

Interventions for treating brain arteriovenous malformations in adults.

Brain arteriovenous malformations (AVMs) are the single most common cause of intracerebral haemorrhage in young adults. Brain AVMs also cause seizure(s) and focal neurological deficits (in the absence of haemorrhage, migraine or an epileptic seizure); approximately one-fifth are incidental discoveries. Various interventions are used in an attempt to eradicate brain AVMs: neurosurgical excision, stereotactic radiosurgery, endovascular embolization, and staged combinations of these interventions. This is an update of a Cochrane Review first published in 2006, and last updated in 2009. To determine the effectiveness and safety of the different interventions, alone or in combination, for treating brain AVMs in adults compared against either each other, or conservative management, in randomized controlled trials (RCTs). The Cochrane Stroke Group Information Specialist searched the Cochrane Stroke Group Trials Register (last searched 7 January 2019), the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 1) in the Cochrane Library, MEDLINE Ovid (1980 to 14 January 2019), and Embase OVID (1980 to 14 January 2019). We searched international registers of clinical trials, the contents pages of relevant journals, and bibliographies of relevant articles (November 2009). We also contacted manufacturers of interventional treatments for brain AVMs (March 2005). We sought RCTs of any intervention for brain AVMs (used alone or in combination), compared against each other or against conservative management, with relevant clinical outcome measures. One author screened the results of the updated searches for potentially eligible RCTs for this updated review. Both authors independently read the potentially eligible RCTs in full and confirmed their inclusion according to the inclusion criteria. We resolved disagreement by discussion. We assessed the risk of bias in included studies and applied GRADE. We included one trial with 226 participants: A Randomized trial of Unruptured Brain Arteriovenous Malformations (ARUBA), comparing intervention versus conservative management for unruptured brain AVMs (that had never bled). The quality of evidence was moderate because we found just one trial that was at low risk of bias other than a high risk of performance bias due to participants and treating physicians not being blinded to allocated treatment. Data on functional outcome and death at a follow-up of 12 months were provided for 218 (96%) of the participants in ARUBA. In this randomized controlled trial (RCT), intervention compared to conservative management increased death or dependency (modified Rankin Scale score ≥ 2, risk ratio (RR) 2.53, 95% confidence interval (CI) 1.28 to 4.98; 1 trial, 226 participants; moderate-quality evidence) and the proportion of participants with symptomatic intracranial haemorrhage (RR 6.75, 95% CI 2.07 to 21.96; 1 trial, 226 participants; moderate-quality evidence), but there was no difference in the frequency of epileptic seizures (RR 1.14, 95% CI 0.63 to 2.06; 1 trial, 226 participants; moderate-quality evidence). Three RCTs are ongoing. We found moderate-quality evidence from one RCT including adults with unruptured brain AVMs that conservative management was superior to intervention with respect to functional outcome and symptomatic intracranial haemorrhage over one year after randomization. More RCTs will help to confirm or refute these findings.

Intracranial Arteriovenous Malformation RUpture riSk Study (ICARUSS): A Multicentric Case-Control Study

Introduction: Intracranial arteriovenous malformations (AVMs) cause intracranial hemorrhage, and the factors that have been associated with a high rupture risk are prior hemorrhage, a small nidus, a deep location of the nidus, a single draining vein, deep venous drainage, aneurysms associated with AVMs, or draining vein stenosis. The role of draining vein diameters in rupture risk is unknown. The aim of the present study was to investigate the predictors for intracranial AVM rupture and to examine the role of draining vein diameters as a surrogate measure of flow-shear stress in the nidus in predicting the risk of AVM rupture. Materials and Methods: Two hundred three patients were included in this multicenter case-control study, of which 117 (57%) had unruptured AVMs, and 86 (43%) had ruptured AVMs. Clinical and angiographic data were registered by 5 independent investigators who were blinded regarding the endpoints of the study. Results: In the univariate analysis, the variables associated with AVM rupture were age, a deep nidus, the nidus diameter, a deep draining vein, a single draining vein, deep and single draining veins, the draining vein diameter, and a draining vein diameter > 5 mm. The variables significantly associated with AVM hemorrhage risk after adjusted (multivariate) analysis were age (OR 0.97, 95% CI 0.95-0.99, p=0.015), a deep nidus (OR 3.21, 95% CI 1.11-9.22, p=0.030), nidus diameter (OR 0.94, 95% CI 0.91-0.96, p 5 mm (OR 5.80, 95% CI 2.70-12.47, p 5 mm was positively associated with the risk of AVM rupture. A prospective study is necessary to confirm these findings. Funding Statement: This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors. Declaration of Interests: The authors state: There are no competing interests to declare. Ethics Approval Statement: This was a multicentric, observational, case-control study. The study protocol was approved by the institutional review board, which waived the need for written informed consent from participants. The article was prepared accordingly, with recommendations from the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines.

Seizure Presentation in Patients With Brain Arteriovenous Malformations Treated With Stereotactic Radiosurgery: A Multicenter Study

Abstract INTRODUCTION Seizures are the second most common clinical presentation in patients with brain arteriovenous malformations (AVMs), and they are the most common presentation of unruptured AVMs. The aim of this multicenter, retrospective cohort study was to identify predictors of seizure presentation in AVM patients treated with stereotactic radiosurgery (SRS). METHODS We performed a retrospective review of AVM patients treated with SRS at 8 participating International Radiosurgery Research Foundation sites. Patient and AVM characteristics were compared between those with versus without a seizure presentation in univariable and multivariable models. Subgroup analysis of patients with cortical AVMs was performed. RESULTS The study cohort comprised 2333 AVM patients, including 419 (18%) with and 1914 (82%) without a seizure presentation. Prior AVM resection (OR = 7.65, P = .001), lack of prior AVM hemorrhage (OR = 0.004, P &lt; .001), cortical AVM location (OR = 1559.42, P &lt; .001), lower Spetzler-Martin (SM) grade (OR = 0.51, P = .007), and higher Virginia Radiosurgery AVM Score (VRAS; OR = 1.46, P = .008) were independent predictors of seizure presentation. The rate of seizure presentation in patients with cortical AVMs was 27%. Prior AVM resection (OR = 8.36, P &lt; .001), lack of prior AVM hemorrhage (OR = 0.004, P &lt; .001), and temporal AVM location (OR = 4.15, P &lt; .001) were independent predictors of seizure presentation for cortical AVMs. CONCLUSION We identified multiple factors associated with seizure presentation in AVM patients selected to undergo SRS. Prior AVM resection, cortical AVM location, and lack of prior AVM hemorrhage were the strongest predictors of pre-SRS seizures. SM grade and VRAS may have a role in seizure risk stratification. Among cortical AVMs, temporal lobe localization was predictive of seizure presentation.

Stereotactic Radiosurgery for Unruptured Versus Ruptured Pediatric Brain Arteriovenous Malformations.

Background and Purpose- The effects of prior hemorrhage on stereotactic radiosurgery (SRS) outcomes for pediatric arteriovenous malformations (AVMs) are not well defined. The aim of this multicenter, retrospective cohort study is to compare the SRS outcomes for unruptured versus ruptured pediatric AVMs. Methods- The International Radiosurgery Research Foundation pediatric AVM database from 1987 to 2018 was reviewed retrospectively. Favorable outcome was defined as AVM obliteration, no post-SRS hemorrhage, and no permanently symptomatic radiation-induced changes. Associations between prior hemorrhage and outcomes were adjusted for baseline differences, inverse probability weights, and competing risks. Results- The study cohort comprised 153 unruptured and 386 ruptured AVMs. Favorable outcome was achieved in 48.4% and 60.4% of unruptured and ruptured AVMs, respectively (adjusted odds ratio, 1.353; P=0.190). Cumulative AVM obliteration probabilities were 51.2%, 59.4%, 64.2%, and 70.0% for unruptured and 61.0%, 69.3%, 74.0%, and 79.3% for ruptured AVMs at 4, 6, 8, and 10 years, respectively (subhazard ratio, 1.311; P=0.020). Cumulative post-SRS hemorrhage probabilities were 4.5%, 5.6%, 5.6%, and 9.8% for unruptured and 4.7%, 6.1%, 6.1%, and 10.6% for ruptured AVMs at 4, 6, 8, and 10 years, respectively (subhazard ratio, 1.086; P=0.825). Probabilities of AVM obliteration (adjusted subhazard ratio, 0.968; P=0.850) and post-SRS hemorrhage (adjusted subhazard ratio, 1.663; P=0.251) were comparable between the 2 cohorts after inverse probability weight adjustments. Symptomatic (15.8% versus 8.1%; adjusted odds ratio, 0.400; P=0.008) and permanent (9.2% versus 5.0%; adjusted odds ratio, 0.441; P=0.045) radiation-induced change were more common in unruptured AVMs. Conclusions- The overall outcomes after SRS for unruptured versus ruptured pediatric AVMs are comparable. However, symptomatic and permanent radiation-induced change occur more frequently in pediatric patients with unruptured AVMs.

MR characteristics of unruptured intracranial arteriovenous malformations associated with seizure as initial clinical presentation

BackgroundPatients with intracranial arteriovenous malformations (AVMs) are at increased risk of seizures.ObjectiveTo identify MRI characteristics of unruptured intracranial AVMs associated with seizures at presentation.Materials and methodsA retrospective review was completed...

Curative treatment for low-grade arteriovenous malformations

BackgroundSpetzler-Martin (SM) grade I-II (low-grade) arteriovenous malformations (AVMs) are often considered safe for microsurgery or radiosurgery. The adjunctive use of preoperative embolization to reduce surgical risk in these AVMs remains...

The NASSAU (New ASSessment of cerebral Arteriovenous Malformations yet Unruptured) Analysis: Are the Results From The ARUBA Trial Also Applicable to Unruptured Arteriovenous Malformations Deemed Suitable for Gamma Knife Surgery?

The optimal management of unruptured brain arteriovenous malformations (AVMs) is controversial after the ARUBA trial. To confirm or repudiate the ARUBA conclusion that "medical management only is superior to medical management with interventional therapy for unruptured brain arteriovenous malformations." Data were collected from 1351 patients treated with Gamma Knife Surgery (GKS; Elekta AB, Stockholm, Sweden) for unruptured and untreated AVMs The follow-up was 8817 yr (median 5.0 and mean 6.5). The results of the analyses were compared to that found in patients randomized to medical management only in the ARUBA trial and extrapolated to a 10-yr time period. Our data were also compared to the natural course in a virtual AVM population for a 25-yr time period. The incidence of stroke was similar among ARUBA and our patients for the first 5 yr. Thereafter, the longer the follow-up, the relatively better outcome following treatment. Both the mortality rate and the incidence of permanent deficits in patients with small AVMs were the same as in untreated patients for the first 2 to 3 yr after GKS, after which GKS patients did better. Patients with large AVMs had a higher incidence of neurological deficits in the first 3 yr following GKS. The difference decreased thereafter, but the time until break even depended on the analysis method used and the assumed risk for hemorrhage in patent AVMs. The ARUBA trial conclusion that medical management is superior to medical management with interventional therapy for all unruptured AVMs could be repudiated.

Rôle de la neuroradiologie interventionnelle dans la prévention des accidents vasculaires hémorragiques

The risk of bleeding of unruptured aneurysms is increasing with aneurysm size. Small unruptured aneurysms can be treated conservatively with a regular MRI/MRA follow-up to detect a potential increase in size. If coiling is still the main endovascular technique for the treatment of unruptured aneurysms, several other techniques are now available including stent-assisted coiling, flow diversion, and flow disruption. After ARUBA study, there is no recommendation to treat unruptured brain AVMs. According to their hemorrhagic risk, dural arteriovenous fistulas with cortical venous drainage have to be treated, generally by endovascular approach through an arterial route.

“ARUBA” Aftermath: Subsequent Studies and Current Management of Unruptured Arteriovenous Malformations

“ARUBA” Aftermath: Subsequent Studies and Current Management of Unruptured Arteriovenous Malformations

Trends in the Incidence and Treatment of Cerebrovascular Diseases in Korea : Part I. Intracranial Aneurysm, Intracerebral Hemorrhage, and Arteriovenous Malformation.

ObjectiveTo analyze the incidence and treatment trends of hemorrhagic stroke (HS), according to HS subtypes, using nationwide data in Korea from January 2008 to December 2016. MethodsWe used data from the national health-claim database provided by the National Health Insurance Service for 2008–2016 using the International Classification of Diseases. The crude incidence and age-standardized incidence of each disease associated with HS, which included intracranial aneurysm (IA), hypertensive intracerebral hemorrhage (ICH), and arteriovenous malformation (AVM), were calculated and additional analysis was conducted according to age and sex. Changes in trends in treatment methods and number of treatments were analyzed for each cerebrovascular disease using the Korean Classification of Diseases procedure codes. ResultsIn 2016, the total number of newly diagnosed adult patients with HS was 24169, showing a decrease by 7.0% since 2008; the age-standardized incidence of HS was 46.2 per 100000 person-years. The age-standardized incidence of unruptured IA (UIA) in adults was 71.4 per 100000 person-years—increased by 2.6-fold since 2008—while that of ruptured IA (RIA) was 12.6 per 100000 person-years, which had decreased at a rate of 20.3% since 2008. The number of coil embolization (CE) for UIA increased by 3.4-fold over 9 years and exceeded that of clipping since 2008. With respect to RIA, CE increased by 2.0-fold over 9 years and exceeded that of clipping from 2014. As for spontaneous ICH in adults, the age-standardized incidence was 31.3 per 100000 person-years in 2016—decreased by 34.7% since 2008—and 14.6% of patients diagnosed with ICH were treated in 2016, which was not significantly different from the proportion of patients treated since 2008. The age-standardized incidence of unruptured AVM (UAVM) was 2.0 per 100000 person-year in 2016, while that of ruptured AVM (RAVM) was 2.4 per 100000 person-years in 2016, showing a decreasing rate of 17.2% from 2008. The total number of treated patients with AVM declined since 2014. ConclusionIn Korea, age-related cerebral vascular diseases, such as RIA, ICH, and RAVM, demonstrated a declining trend in agestandardized incidence; meanwhile, UIA and UAVM demonstrated an increased trend in both crude incidence and age-standardized incidence for 9 years. The increase in the elderly population, management of hypertension, and development of diagnostic and endovascular techniques appear to have influenced this trend.

Risk of Brain Arteriovenous Malformation Hemorrhage Before and After Stereotactic Radiosurgery.

Background and Purpose- Understanding the hemorrhage risks associated with brain arteriovenous malformations (AVMs) before and after stereotactic radiosurgery (SRS) is important. The aims of this multicenter, retrospective cohort study are to evaluate and compare the rates of pre- and post-SRS AVM hemorrhage and identify risk factors. Methods- We pooled AVM SRS data from 8 institutions participating in the International Radiosurgery Research Foundation. Predictors of post-SRS hemorrhage were determined using a multivariate logistic regression model. Pre- and post-SRS hemorrhage rates were compared using Fisher exact test. Ruptured and unruptured AVMs were matched in a 1:1 ratio using propensity scores, and their outcomes were compared. Results- The study cohort comprised 2320 AVM patients who underwent SRS. Deep AVM location (odds ratio, 1.86; 95% CI, 1.19-2.92; P=0.007), the presence of an AVM-associated arterial aneurysm (odds ratio, 2.44; 95% CI, 1.63-3.66; P<0.001), and lower SRS margin dose (odds ratio, 0.93; 95% CI, 0.88-0.98; P=0.005) were independent predictors of post-SRS hemorrhage. The post-SRS hemorrhage rate was lower for obliterated versus patent AVMs (6.0 versus 22.3 hemorrhages/1000 person-years; P<0.001). The AVM hemorrhage rate decreased from 15.4 hemorrhages/1000 person-years before SRS to 11.9 after SRS ( P=0.001). The outcomes of the matched ruptured versus unruptured AVM cohorts were similar. Conclusions- SRS appears to reduce the risk of AVM hemorrhage, although this effect is predominantly driven by obliteration. Deep-seated AVMs are more likely to rupture during the latency period after SRS. AVM-associated aneurysms should be considered for selective occlusion before SRS of the nidus to ameliorate the post-SRS hemorrhage rate of these lesions.

Rates and Predictors of Stroke in Medically Managed Patients with Unruptured Arteriovenous Malformations in ARUBA (A Randomized Trial of Unruptured Brain Arteriovenous Malformations) (S2.004)

Rates and Predictors of Stroke in Medically Managed Patients with Unruptured Arteriovenous Malformations in ARUBA (A Randomized Trial of Unruptured Brain Arteriovenous Malformations) (S2.004)