Gamma Knife Radiosurgery for Incidental, Symptomatic Unruptured, and Ruptured Brain Arteriovenous Malformations

Background: This study was performed to investigate clinical characteristics and outcome after gamma knife radiosurgery (GKS) in patients with incidental, symptomatic unruptured, or ruptured arteriovenous malformations (AVMs). Methods: A total of 491 patients with brain AVMs treated with GKS from June 2002 to September 2017 were retrospectively reviewed. All patients were classified into the incidental (n = 105), symptomatic unruptured (n = 216), or ruptured AVM (n = 170) groups. Results: The mean age at diagnosis of incidental, symptomatic unruptured, and ruptured AVMs was 40.3, 36.7, and 27.6 years, respectively. The mean nidus volume was 3.9, 5.7, and 2.4 cm3, respectively. Deep venous drainage was identified in 34, 54, and 76% patients, respectively. There were no significant differences in obliteration rates after GKS between the 3 groups (64.8, 61.1, and 65.9%, respectively) after a mean follow-up period of 60.5 months; however, patients with incidental AVM had a significantly lower post-GKS hemorrhage rate than patients with symptomatic unruptured or ruptured AVMs (annual hemorrhage rate of 1.07, 2.87, and 2.69%; p = 0.028 and p = 0.049, respectively). Conclusions: There is a significant difference in clinical and anatomical characteristics between incidental, symptomatic unruptured, and ruptured AVMs. The obliteration rate after GKS is not significantly different between the 3 groups. Meanwhile, an older age at diagnosis and lower hemorrhage rate after GKS in incidental AVMs suggest that they have a more indolent natural course with a lower life-long risk of hemorrhage.

Case Report: Gyral Brain Arteriovenous Malformation with Presentation Isolated From Intraventricular Hemorrhage

Introduction: Brain Arteriovenous Malformation (BAVM) is a rare disease with an incidence rate of 1.3 out of 100,000 people. The most common clinical manifestations in BAVM patients are intracranial hemorrhage. There were 38.5% of BAVM patients who had intraventricular hemorrhage (IVH), and the rate of IVH without parenchymal bleeding in the ruptured AVM is 7.8%. We reported a case of BAVM with intraventricular hemorrhage presentation without intracerebral hemorrhage (isolated IVH). Case: Male, 15 years old, with a chief complaint of acute decreased consciousness on activity, followed by vomiting and general onset seizures. There was no history of hypertension or trauma before. From the neurological examination, the GCS is 225, and there were positive pathological reflexes on both sides. From a head CT scan without contrast, we found IVH in bilateral lateral ventricles, ventricle III and ventricle IV, communicating hydrocephalus, and brain edema. Head and Neck Computed Tomography Angiography (CTA) found a compact AVM in the left centrum semiovale-cortex parietal (Spetzler Martin AVM grading system grade 3). Patients underwent EVD surgery for hydrocephalus. The following steps are cerebral DSA as the gold standard for AVM diagnostic and targeted embolization to prevent further bleeding. Conclusion: One of the causes of Isolated Intraventricular Hemorrhage (IIVH) is AVM. In this case, although the topography of AVM is in the gyral, it can cause IIVH manifestation if there is contact between the AVM nidus and the ventricle.

Acute surgical management of children with ruptured brain arteriovenous malformation

OBJECTIVERupture of brain arteriovenous malformation (AVM) is the main etiology of intracerebral hemorrhage (ICH) in children. Ensuing intracranial hypertension is among the modifiable prognosis factors and sometimes requires emergency hemorrhage evacuation (HE). The authors aimed to analyze variables associated with HE in children with ruptured AVM.METHODSThis study was a single-center retrospective analysis of children treated for ruptured AVM. The authors evaluated the occurrence of HE, its association with other acute surgical procedures (e.g., nidal excision, decompressive hemicraniectomy), and clinical outcome. Variables associated with each intervention were analyzed using univariable and multivariable models. Clinical outcome was assessed at 18 months using the ordinal King’s Outcome Scale for Childhood Head Injury.RESULTSA total of 104 patients were treated for 112 episodes of ruptured AVM between 2002 and 2018. In the 51 children (45.5% of cases) who underwent HE, 37 procedures were performed early (i.e., within 24 hours after initial cerebral imaging) and 14 late. Determinants of HE were a lower initial Glasgow Coma Scale score (adjusted odds ratio [aOR] 0.83, 95% CI 0.71–0.97 per point increase); higher ICH/brain volume ratio (aOR 18.6, 95% CI 13–26.5 per percent increase); superficial AVM location; and the presence of a brain herniation (aOR 3.7, 95% CI 1.3–10.4). Concurrent nidal surgery was acutely performed in 69% of Spetzler-Martin grade I–II ruptured AVMs and in 25% of Spetzler-Martin grade III lesions. Factors associated with nidal surgery were superficial AVMs, late HE, and absent alteration of consciousness at presentation. Only 8 cases required additional surgery due to intracranial hypertension. At 18 months, overall mortality was less than 4%, 58% of patients had a favorable outcome regardless of surgical intervention, and 87% were functioning independently.CONCLUSIONSHE is a lifesaving procedure performed in approximately half of the children who suffer AVM rupture. The good overall outcome justifies intensive initial management.

Morbidity and mortality associated with sequential flow reduction embolization technique of cerebral arteriovenous malformations using n-butyl cyanoacrylate

BackgroundEndovascular embolization of cerebral arteriovenous malformations (AVM) with liquid n-butyl cyanoacrylate (n-BCA) serves multiple purposes including AVM occlusion and flow reduction in preparation for other treatment modalities. The objective was to study the clinical, structural, and angiographic factors affecting complications associated with AVM treatment by sequential n-BCA embolizations for nidal occlusion versus quantitative flow reduction in preparation for surgical resection or radiosurgery.MethodsWe performed a retrospective review of all patients who underwent endovascular embolization of cerebral AVM at our institution between 1998 and 2019, during which time the technique of traditional embolization evolved to a strategy of targeted sequential flow reduction guided by serial flow imaging based on quantitative magnetic resonance angiography, in conjunction with a shift away from nidal penetration.ResultsAmong 251 patients, 47.8% of patients presented with ruptured AVM. On average, each patient underwent 2.4 embolizations, for a total of 613 sessions. Major morbidity related to embolization occurred in 18 (7.2%) patients, but this occurred disproportionately in the traditional embolization strategy (n=16, 8%) in contrast with the flow-targeting strategy (n=2, 3.8%). Four patients (1.6%) died in the overall group, and these all occurred with the traditional embolization strategy (2% of 199 patients); no deaths occurred in the flow-targeting strategy (n=52).ConclusionEmbolization with n-BCA targeted to sequential flow reduction and feeder occlusion with limited nidal penetration prior to definitive surgical or radiosurgical treatment can be safely performed with low overall morbidity and mortality.

The Ruptured Arteriovenous Malformation Grading Scale (RAGS): An Extension of the Hunt and Hess Scale to Predict Clinical Outcome for Patients With Ruptured Brain Arteriovenous Malformations

BACKGROUND Arteriovenous malformation (AVM) rupture is highly morbid. Outcomes after AVM rupture differ from other types of brain hemorrhage. There are no specific widely used grading systems designed to predict clinical outcome after AVM rupture. OBJECTIVE To develop an all-comers scoring system to grade patients with AVM rupture and predict clinical outcome more accurately than grading systems currently in use. METHODS We retrospectively reviewed patients who presented to our institution with a ruptured AVM. Using change in modified Rankin Score (mRS) as our response variable, we generated an ordinal logistic regression model to test for significant predictor variables. The full model was sequentially condensed until the simplest model with the highest area under the receiver operating curve (AUROC) was achieved. RESULTS A total of 115 patients who presented with ruptured AVMs were included in the study, with a mean follow-up time of 4 yr. The Ruptured AVM Grading Scale (RAGS) consists of the Hunt and Hess (HH) score (1-5), patient age (<35 = 0, 35-70 = 1, and >70 = 2), deep venous drainage (1), and eloquence (1). The RAGS score outperformed other neurosurgical grading scales in predicting change in mRS, with an AUROC greater than 0.80 across all follow-up periods. CONCLUSION The RAGS score is a simple extension of the HH scale that predicts clinical outcome after AVM rupture more accurately than other grading systems.

Isolated Intraventricular Hemorrhage Associated with Cerebral Vasospasm and Delayed Cerebral Ischemia following Arteriovenous Malformation Rupture

Background: Although it is well characterized in aneurysmal subarachnoid hemorrhage, vasospasm is exceedingly rare following cerebral arteriovenous malformation (AVM) rupture. Subsequently, this complication is poorly characterized with regard to delayed cerebral ischemia (DCI). We review cases of ruptured AVM to assess the frequency and severity of vasospasm on cerebral angiography, and DCI. Summary: We reviewed our institutional database of acute intracranial hemorrhages between 2005 and 2014. We identified patients with cerebral AVM rupture and evidence of vasospasm, which was confirmed with digital subtraction angiography (DSA). Cerebral angiograms were evaluated by 2 blinded neurointerventionalists for vasospasm. Statistical analyses were conducted on the angiographic results and variables of interest to determine predictors and associations of vasospasm and DCI. Thirty-six patients with acute intracranial hemorrhage due to ruptured cerebral AVM subsequently underwent cerebral angiography. The interrater reliability for vasospasm was 0.81. The incidence of vasospasm was 13.9% and the incidence of subsequent DCI was 11.1%. A significant relationship existed between isolated intraventricular hemorrhage and vasospasm (p = 0.001) and subsequent DCI (p = 0.006). Radiographic vasospasm was associated with DCI in 80% of the patients (p < 0.0001). No statistical significance existed between subarachnoid hemorrhage and the development of vasospasm or DCI (p = 1.000 and p = 0.626, respectively). All differences were significant at a 99% level of significance. Key Message: In cases of ruptured AVM, isolated intraventricular hemorrhage appears to be an independent risk factor for vasospasm and DCI. Vasospasm must be considered during late neurological deterioration following AVM hemorrhage, especially in the setting of isolated intraventricular hemorrhage.

120 Rates of Re-hemorrhage, Risk Factors, and Outcomes of Previously Ruptured Arteriovenous Malformations (AVMs)

INTRODUCTION The annual hemorrhage rate of unruptured AVMs is well established. However, hemorrhage risk of a previously ruptured AVM is not well defined. In this study, we describe the rate of AVM re-hemorrhage as well as the risk factors and outcomes associated with AVM re-hemorrhage from an institutional cohort. METHODS We retrospectively reviewed AVM patients from our institution seen from 1990–2015. Patients with hemorrhagic presentation were stratified into 1) patients with subsequent re-hemorrhage prior to treatment and 2) patients without re-hemorrhage. Patient demographic, clinical and angiographic data was compared across study groups. Cumulative and annual re-rupture rates were determined using Kaplan-Meier survival analysis. RESULTS >Of the 247 patients with hemorrhagic presentation, 29(11.7%) re-bled prior to treatment. There were no statistically significant differences between groups for age, gender, race, Spetzler-Martin grade, eloquence involvement, deep venous drainage, venous stenosis, AVM location, feeding artery aneurysms and intranidal aneurysms. AVM size was larger in the re-hemorrhage group (3.5cm+/−2.1 vs. 2.5cm+/−1.4, P = 0.032). Multivariate analysis identified age(HR1.03[CI1.00-1.05], P = 0.043), Hispanic race(HR5.94[CI1.34-26.45], P = 0.019), AVM size (HR1.31[1.02-1.68], P = 0.035) and venous stenosis (HR3.9[1.03-14.73], P = 0.045) as risk factors for re-hemorrhage. Presence of a venous varix (HR0.04[CI0.00-0.37], P = 0.005 and significant venous dilatation (HR0.27[0.09-0.80], P = 0.018) decreased the risk of re-hemorrhage. The cumulative risk of rupture at 2, 4, 12, 26 and 52 weeks was 0.9%, 1.3%, 2%, 3.2% and 5.5% respectively. The annual rate of re-rupture decreased from 7.09%(year 1) to 2.89%(year 10). Outcomes (dichotomized as good((modified Rankin score (mRS) 0–2) or poor (mRS 3–6)) were significantly improved in the patients without re-hemorrhage(79.8%) compared to re-hemorrhage patients(58.6%)(P = 0.010). CONCLUSION The rate of re-rupture is low immediately following initial hemorrhage of an AVM, with increasing cumulative risk over time. Outcomes in patients are significantly improved if there is no re-hemorrhage. This study helps identify the rates and risk factors associated with AVM re-hemorrhage, such that timing of treatment of a ruptured AVM may be optimized.

Outcomes after intracerebral hemorrhage from arteriovenous malformations

Objective:To compare outcomes after intracerebral hemorrhage (ICH) from cerebral arteriovenous malformation (AVM) rupture and other causes of ICH.Methods:We performed a retrospective population-based study using data from the Nationwide Inpatient Sample. We used standard diagnosis codes to identify ICH cases from 2002 to 2011. Our predictor variable was cerebral AVM. Our primary outcomes were inpatient mortality and home discharge. We used logistic regression to compare outcomes between patients with ICH with and without AVM while adjusting for demographics, comorbidities, and hospital characteristics. In a confirmatory analysis using a prospective cohort of patients hospitalized with ICH at our institution, we additionally adjusted for hematoma characteristics and the Glasgow Coma Scale score.Results:Among 619,167 ICH hospitalizations, the 4,485 patients (0.7%, 95% confidence interval [CI] 0.6–0.8) with an AVM were younger and had fewer medical comorbidities than patients without AVM. After adjustment for confounders, patients with AVM had lower odds of death (odds ratio [OR] 0.5, 95% CI 0.4–0.7) and higher odds of home discharge (OR 2.0, 95% CI 1.4–3.0) than patients without AVM. In a confirmatory analysis of 342 patients with ICH at our institution, the 34 patients (9.9%, 95% CI 7.2–13.6) with a ruptured AVM had higher odds of ambulatory independence at discharge (OR 4.4, 95% CI 1.4–13.1) compared to patients without AVM.Conclusions:Patients with ICH due to ruptured AVM have more favorable outcomes than patients with ICH from other causes.

Reappearance of arteriovenous malformations after complete resection of ruptured arteriovenous malformations: true recurrence or false-negative early postoperative imaging result?

OBJECTIVE Ruptured arteriovenous malformations (AVMs) are often obliterated after emergency microsurgical treatment. However, some studies have reported AVM recurrence after the obliteration of ruptured AVMs. The authors report their experience with AVM recurrence after successful microsurgical treatment of ruptured AVMs. METHODS The authors reviewed the medical data of 139 consecutive patients who underwent microsurgery at the authors' institution for ruptured AVM between 2002 and 2012. Each patient underwent a conventional cerebral angiography examination immediately after the surgery. Subsequent follow-ups were performed with MR angiography after 6 months, and, if there was no indication of AVM recurrence, patients were followed up with conventional cerebral angiography between 1 and 2 years after the treatment; pediatric patients were followed up until age 18 years. Recurrence was defined as new radiological evidence of an AVM at the site of a ruptured AVM or a new hemorrhage in patients with angiographically documented AVM obliteration on postoperative angiograms. RESULTS The mean age of the patients at the time of ruptured AVM diagnosis was 30.8 years (SD ± 5, range 4–69 years), and 44 of the patients were younger than 18 years (the mean age at diagnosis in this pediatric subgroup was 11.4 years [range 4–17.9 years]). Complete AVM obliteration after the initial microsurgery was observed in 123 patients (89.5%). Reappearance of an AVM was noted in 7 patients between 12 and 42 months after the treatment, and all of these patients were younger than 18 years. The recurrent AVM was located in an eloquent zone in 4 patients, and deep venous drainage was noted in 3 patients. Radiosurgery was performed in 6 of these patients, and 1 patient underwent another microsurgical procedure. The authors noted only one rebleeding due to an AVM recurrence during the latency period after radiosurgery. CONCLUSIONS The recurrence of an AVM is fairly rare and affects mostly pediatric patients. Therefore, especially in children, long-term angiographic follow-up is required to detect AVM recurrence or an AVM remnant. The authors stress the need for discussion involving a multidisciplinary neurosurgical team to decide on treatment in cases of any AVM recurrence or remnant.