Obliteration Rate Research Articles

Onyx embolization for dural arteriovenous fistulas: a multi-institutional study

BackgroundAlthough the liquid embolic agent, Onyx, is often the preferred embolic treatment for cerebral dural arteriovenous fistulas (DAVFs), there have only been a limited number of single-center studies to evaluate...

Systematic Review and Meta-Analysis of the Dose-Response and Risk Factors for Obliteration of Arteriovenous Malformations Following Radiosurgery: An Update Based on the Last 20 Years of Published Clinical Evidence

ABSTRACT BACKGROUND Intracranial arteriovenous malformation (AVM) is a congenital lesion that can potentially lead to devastating consequences if not treated. Many institutional cohort studies have reported on the outcomes after radiosurgery and factors associated with successful obliteration in the last few decades. OBJECTIVE To quantitatively assess the dose-response relationship and risk factors associated with AVM obliteration using a systematic review and meta-analysis approach. METHODS Data were extracted from reports published within the last 20 yr. The dose-response fit for obliteration as a function of marginal dose was performed using inverse-variance weighting. Risk factors for AVM obliteration were assessed by combining odds ratios from individual studies using inverse-variance weighting. RESULTS The logistic model fit showed a clear association between higher marginal dose and higher rates of obliteration. There appeared to be a difference in the steepness in dose-response when comparing studies with patients treated using Gamma Knife radiosurgery (Elekta), compared to linear accelerators (LINACs), and when stratifying studies based on the size of treated AVMs. In the risk-factor analysis, AVM obliteration rate decreases with larger AVM volume or AVM diameter, higher AVM score or Spetzler-Martin (SM) grade, and prior embolization, and increases with compact AVM nidus. No statistically significant associations were found between obliteration rate and age, sex, prior hemorrhage, prior aneurysm, and location eloquence. CONCLUSION A marginal dose above 18 Gy was generally associated with AVM obliteration rates greater than 60%, although lesion size, AVM score, SM grade, prior embolization, and nidus compactness all have significant impact on AVM obliteration rate.

Early Outcomes and Complications of Endovascular Treatment of Cerebral Arteriovenous Malformations in Pediatric Patients

Introduction: Arteriovenous malformations (AVMs) are the commonest cause of hemorrhagic stroke in children. Endovascular embolization is a feasible treatment modality, but cure rates are heterogenous from one series to another. We aimed to describe the immediate obliteration rates and periprocedural complications of embolization of pediatric AVMs. Methods: Between 2011 and 2019, participants below 18 years of age with AVMs treated by the same neurosurgeon at a single center were included. The clinical features, immediate angiographic results, and periprocedural complications were retrospectively collected from the clinical records. Results: Thirty-four embolization sessions were performed on 20 children (12 females with a mean age of 13). Intracranial hemorrhage was the most common presentation (75%), and the majority were frontal (30%) and basal ganglia (30%) lesions. An immediate complete angiographic obliteration was achieved in 9 patients (45%) with low-grade lesions (Spetzler-Martin grade I and II). NBCA was the most common embolic agent used (52.9%). Complications were reported in 3 (8.8%) out of 34 sessions. Two of them were intraoperative perforations with clinical consequences. A slight cortical hemorrhage during the procedure was observed in 1 patient without clinical repercussions. Discussion: This single-surgeon single-center experience suggests that endovascular treatment is a safe and efficient treatment for pediatric AVMs. Pediatric prognostic scores for a suitable selection of candidates are needed. Further studies are required to validate these results.

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

Background: More and more elderly patients are being diagnosed with arteriovenous malformation (AVM) in this global aging society, while the treatment strategy remains controversial among these aging population. This study aimed to clarify the long-term outcomes of elderly AVMs after different management modalities.Methods: The authors retrospectively reviewed 71 elderly AVMs (>60 years) in two tertiary neurosurgery centers between 2011 and 2019. Patients were divided into four groups: conservation, microsurgery, embolization, and stereotactic radiosurgery (SRS). The perioperative complications, short-term and long-term neurological outcomes, obliteration rates, annualized rupture risk, and mortality rates were compared among different management modalities in the ruptured and unruptured subgroups. Kaplan-Meier survival analysis was employed to compare the death-free survival rates among different management modalities. Logistic regression analyses were conducted to calculate the odds ratios (ORs) and 95% confidence intervals (CI) for predictors of long-term unfavorable outcomes (mRS > 2).Results: A total of 71 elderly AVMs were followed up for an average of 4.2 ± 2.3 years. Fifty-four (76.1%) presented with hemorrhage, and the preoperative annualized rupture risk was 9.4%. Among these patients, 21 cases (29.6%) received conservative treatment, 30 (42.3%) underwent microsurgical resection, 13 (18.3%) received embolization, and 7 (9.9%) underwent SRS. In the prognostic comparison, the short-term and long-term neurological outcomes were similar between conservation and intervention both in the ruptured and unruptured subgroups (ruptured: p = 0.096, p = 0.904, respectively; unruptured: p = 0.568, p = 0.306, respectively). In the ruptured subgroup, the intervention cannot reduce long-term mortality (p = 0.654) despite the significant reduction of subsequent hemorrhage than conservation (p = 0.014), and the main cause of death in the intervention group was treatment-related complications (five of seven, 71.4%). In the logistic regression analysis, higher admission mRS score (OR 3.070, 95% CI 1.559–6.043, p = 0.001) was the independent predictor of long-term unfavorable outcomes (mRS>2) in the intervention group, while complete obliteration (OR 0.146, 95% CI 0.026–0.828, p = 0.030) was the protective factor.Conclusions: The long-term outcomes of elderly AVMs after different management modalities were similar. Intervention for unruptured elderly AVMs was not recommended. For those ruptured, we should carefully weigh the risk of subsequent hemorrhage and treatment-related complications. Besides, complete obliteration should be pursued once the intervention was initiated.Clinical Trial Registration: http://www.clinicaltrials.gov. Unique identifier: NCT04136860

Are Dynamic Arterial Spin-Labeling MRA and Time-Resolved Contrast-Enhanced MRA Suited for Confirmation of Obliteration following Gamma Knife Radiosurgery of Brain Arteriovenous Malformations?

Intra-arterial DSA has been traditionally used for confirmation of cure following gamma knife radiosurgery for AVMs. Our aim was to evaluate whether 4D arterial spin-labeling MRA and contrast-enhanced time-resolved MRA in combination can be an alternative to DSA for confirmation of AVM obliteration following gamma knife radiosurgery. In this prospective study, 30 patients undergoing DSA for confirmation of obliteration following gamma knife radiosurgery for AVMs (criterion standard) also underwent MRA, including arterial spin-labeling MRA and contrast-enhanced time-resolved MRA. One dataset was technically unsatisfactory, and the case was excluded. The DSA and MRA datasets of 29 patients were independently and blindly evaluated by 2 observers regarding the presence/absence of residual AVMs. The mean time between gamma knife radiosurgery and follow-up DSA/MRA was 53 months (95% CI, 42-64 months; range, 22-168 months). MRA total scanning time was 9 minutes and 17 seconds. Residual AVMs were detected on DSA in 9 subjects (obliteration rate = 69%). All residual AVMs were detected on at least 1 MRA sequence. Arterial spin-labeling MRA and contrast-enhanced time-resolved MRA showed excellent specificity and positive predictive values individually (100%). However, their sensitivity and negative predictive values were suboptimal due to 1 false-negative with arterial spin-labeling MRA and 2 with contrast-enhanced time-resolved MRA (sensitivity = 88% and 77%, negative predictive values = 95% and 90%, respectively). Both sensitivity and negative predictive values increased to 100% if a composite assessment of both MRA sequences was performed. Diagnostic accuracy (receiver operating characteristic) and agreement (κ) are maximized using arterial spin-labeling MRA and contrast-enhanced time-resolved MRA in combination (area under receiver operating characteristic curve = 1, P < .001; κ = 1, P < .001, respectively). Combining arterial spin-labeling MRA with contrast-enhanced time-resolved MRA holds promise as an alternative to DSA for confirmation of obliteration following gamma knife radiosurgery for brain AVMs, having provided 100% sensitivity and specificity in the study. Their combined use also enables reliable characterization of residual lesions.

Planning of gamma knife radiosurgery (GKR) for brain arteriovenous malformations using triple magnetic resonance angiography (triple-MRA)

Purpose Intra-arterial Digital Subtraction Angiography (DSA) is the gold standard technique for radiosurgery target delineation in brain Arterio-Venous Malformations (AVMs). This study aims to evaluate whether a combination of three Magnetic Resonance Angiography sequences (triple-MRA) could be used for delineation of brain AVMs for Gamma Knife Radiosurgery (GKR). Methods Fifteen patients undergoing DSA for GKR targeting of brain AVMs also underwent triple-MRA: 4D Arterial Spin Labelling based angiography (ASL-MRA), Contrast-Enhanced Time-Resolved MRA (CE-MRA) and High Definition post-contrast Time-Of-Flight angiography (HD-TOF). The arterial phase of the AVM nidus was delineated on triple-MRA by an interventional neuroradiologist and a consultant neurosurgeon (triple-MRA volume). Triple-MRA volumes were compared to AVM targets delineated by the clinical team for delivery of GKR using the current planning paradigm, i.e., stereotactic DSA and volumetric MRI (DSA volume). Difference in size, degree of inclusion (DI) and concordance index (CcI) between DSA and triple-MRA volumes are reported. Results AVM target volumes delineated on triple-MRA were on average 9.8% smaller than DSA volumes (95%CI:5.6–13.9%; SD:7.14%; p = .003). DI of DSA volume in triple-MRA volume was on average 73.5% (95%CI:71.2–76; range: 65–80%). The mean percentage of triple-MRA volume not included on DSA volume was 18% (95%CI:14.7–21.3; range: 7–30%). Conclusion The technical feasibility of using triple-MRA for visualisation and delineation of brain AVMs for GKR planning has been demonstrated. Tighter and more precise delineation of AVM target volumes could be achieved by using triple-MRA for radiosurgery targeting. However, further research is required to ascertain the impact this may have in obliteration rates and side effects.

Embolization of Brain Arteriovenous Malformations With Versus Without Onyx Before Stereotactic Radiosurgery.

Embolization of brain arteriovenous malformations (AVMs) using ethylene-vinyl alcohol copolymer (Onyx) embolization may influence the treatment effects of stereotactic radiosurgery (SRS) differently than other embolysates. To compare the outcomes of pre-SRS AVM embolization with vs without Onyx through a multicenter, retrospective matched cohort study. We retrospectively reviewed International Radiosurgery Research Foundation AVM databases from 1987 to 2018. Embolized AVMs treated with SRS were selected and categorized based on embolysate usage into Onyx embolization (OE+SRS) or non-Onyx embolization (NOE+SRS) cohorts. The 2 cohorts were matched in a 1:1 ratio using de novo AVM features for comparative analysis of outcomes. The matched cohorts each comprised 45 patients. Crude AVM obliteration rates were similar between the matched OE+SRS vs NOE+SRS cohorts (47%vs 51%; odds ratio [OR]=0.837, P=.673). Cumulative probabilities of obliteration were also similar between the OE+SRS vs NOE+SRS cohorts (subhazard ratio=0.992, P=.980). Rates of post-SRS hemorrhage, all-cause mortality, radiation-induced changes, cyst formation, and embolization-associated complications were similar between the matched cohorts. Sensitivity analysis for AVMs in the OE+SRS cohort embolized with Onyx alone revealed a higher rate of asymptomatic embolization-associated complications in this subgroup compared to the NOE+SRS cohort (36%vs 15%; OR=3.297, P=.034), but the symptomatic complication rates were similar. Nidal embolization using Onyx does not appear to differentially impact the outcomes of AVM SRS compared with non-Onyx embolysates. The embolic agent selected for pre-SRS AVM embolization should reflect both the experience of the neurointerventionalist and target of endovascular intervention.

Stereotactic Radiosurgery With Versus Without Embolization for Brain Arteriovenous Malformations.

Prior comparisons of brain arteriovenous malformations (AVMs) treated using stereotactic radiosurgery (SRS) with or without embolization were inherently flawed, due to differences in the pretreatment nidus volumes. To compare the outcomes of embolization and SRS, vs SRS alone for AVMs using pre-embolization malformation features. We retrospectively reviewed International Radiosurgery Research Foundation AVM databases from 1987 to 2018. Patients were categorized into the embolization and SRS (E+SRS) or SRS alone (SRS-only) cohorts. The 2 cohorts were matched in a 1:1 ratio using propensity scores. Primary outcome was defined as AVM obliteration. Secondary outcomes were post-SRS hemorrhage, all-cause mortality, radiologic and symptomatic radiation-induced changes (RIC), and cyst formation. The matched cohorts each comprised 101 patients. Crude AVM obliteration rates were similar between the matched E+SRS vs SRS-only cohorts (48.5%vs 54.5%; odds ratio=0.788, P=.399). Cumulative probabilities of obliteration at 3, 4, 5, and 6 yr were also similar between the E+SRS (33.0%, 46.4%, 56.2%, and 60.8%, respectively) and SRS-only (32.9%, 46.2%, 56.0%, and 60.6%, respectively) cohorts (subhazard ratio (SHR)=1.005, P=.981). Cumulative probabilities of radiologic RIC at 3, 4, 5, and 6 yr were lower in the E+SRS (25.0%, 25.7%, 26.7%, and 26.7%, respectively) vs SRS-only (45.3%, 46.2%, 47.8%, and 47.8%, respectively) cohort (SHR=0.478, P=.004). Symptomatic and asymptomatic embolization-related complication rates were 8.3% and 18.6%, respectively. Rates of post-SRS hemorrhage, all-cause mortality, symptomatic RIC, and cyst formation were similar between the matched cohorts. This study refutes the prevalent notion that AVM embolization negatively affects the likelihood of obliteration after SRS.

Arteriovenous malformation surgery in children: the Rady Children's Hospital experience (2002-2019).

Compared to adult AVMs, there is a paucity of data on the microsurgical treatment of pediatric AVMs. We report our institutional experience with pediatric AVMs treated by microsurgical resection with or without endovascular embolization and radiation therapy. We retrospectively reviewed all patients ≤ 18years of age with cerebral AVMs that underwent microsurgical resection at Rady Children's Hospital 2002-2019. Eighty-nine patients met inclusion criteria. The mean age was 10.3 ± 5.0years, and 56% of patients were male. In total, 72 (81%) patients presented with rupture. Patients with unruptured AVMs presented with headache (n = 5, 29.4%), seizure (n = 9, 52.9%), or incidental finding (n = 3, 17.7%). The mean presenting mRS was 2.8 ± 1.8. AVM location was lobar in 78%, cerebellar/brainstem in 15%, and deep supratentorial in 8%. Spetzler-Martin grade was I in 28%, II in 45%, III in 20%, IV in 6%, and V in 1%. Preoperative embolization was utilized in 38% of patients and more frequently in unruptured than ruptured AVMs (62% vs. 32%, p = 0.022). Radiographic obliteration was achieved in 76/89 (85.4%) patients. Complications occurred in 7 (8%) patients. Annualized rates of delayed rebleeding and recurrence were 1.2% and 0.9%, respectively. The mean follow-up was 2.8 ± 3.1years. A good neurological outcome (mRS score ≤ 2) was obtained in 80.9% of patients at last follow-up and was improved relative to presentation for 75% of patients. Our case series demonstrates high rates of radiographic obliteration and relatively low incidence of neurologic complications of treatment or AVM recurrence.

Improved Cerebral Arteriovenous Malformation Obliteration With 3-Dimensional Rotational Digital Subtraction Angiography for Radiosurgical Planning: A Retrospective Cohort Study.

Stereotactic radiosurgery (SRS) for cerebral arteriovenous malformations (AVMs) is well-established. Radiographic advantages exist for 3-dimensional rotational digital subtraction angiography (3DRA) over 2-dimensional digital subtraction angiography (2D DSA) in delineating AVM nidus structure for SRS treatment planning. However, currently there is limited to no data directly comparing 2D DSA versus 3DRA in terms of patient outcomes. To investigate whether the use of 3DRA over 2D DSA in radiosurgical treatment planning for AVMs associates with improved clinical outcomes. All AVM patients treated with SRS at our institution between the years 2000 and 2018 were identified. Primary outcomes were obliteration rates and time to obliteration (TTO); secondary outcomes included rates of post-SRS hemorrhage, salvage therapy, and symptomatic radionecrosis. A minimum of 12 mo of follow-up imaging/angiogram post-SRS was required, or alternatively evidence of obliteration on angiogram prior to 12 mo post-SRS. Single predictor and multivariable Cox regression and logistic regression models were constructed to test for association between radiographic, clinical, and treatment factors with outcomes. A total of 75 patients were included. Total 17 patients received 3DRA and 58 patients received 2D DSA, with a median follow-up of 3.29 yr. The 3DRA is significantly associated with improved TTO on single predictor (HR 2.87, 1.29-6.12; P=.0109) and multivariable analysis (HR 2.448, 1.076-5.750; P=.0330) and increased odds of achieving obliteration by 3 yr post-SRS on single predictor analysis (OR 6.044, 1.405-26.009; P=.0157). The 3DRA over 2D DSA in SRS treatment planning for AVMs may result in improved TTO and 3-yr obliteration rates. Further investigation and prospective study are warranted.

Morphometric Comparison of the Pterional Trans-Sylvian and the Pretemporal Trans-Clinoidal Approaches to the Posterior Communicating Artery.

Posterior communicating (Pcom) aneurysms in the modern era have tended toward increased complexity and technical difficulties. The pretemporal approach is a valuable extension to the pterional approach for basilar apex aneurysms, but its advantages for Pcom aneurysms have not been previously elucidated. To quantify characteristics of the pretemporal approach to the Pcom. We dissected 6 cadaveric heads (12 sides) with a pretemporal transclinoidal approach and measured the following variables: (1) exposed length of internal carotid artery (ICA) proximal to the Pcom artery; (2) exposed circumference of ICA at the origin of Pcom; (3) deep working area between the optic nerve and tentorium/oculomotor nerve; (4) superficial working area; (5) exposure depth; and (6) the frontotemporal (superior posterolateral) and (7) orbito-sphenoidal (inferior anterolateral) angles of exposure. Compared with pterional craniotomy, the pretemporal transclinoidal approach increased the exposed length of the proximal ICA from 3.3 to 11.7 mm (P=.0001) and its circumference from 5.1 to 7.8 mm (P=.0003), allowing a 210° view of the ICA (vs 137.9°). The deep and superficial working areas also significantly widened from 53.7 to 92.4 mm2 (P=.0048) and 252.8 to 418.2 mm2 (P=.0001), respectively; the depth of the exposure was equivalent. The frontotemporal and spheno-Sylvian angles increased by 17° (P=.0006) and 10° (P=.0037), respectively. The pretemporal approach can be useful for complex Pcom aneurysms by providing easier proximal control, wider working space, improved aneurysm visualization, and more versatile clipping angles. Enhanced exposure results in a potentially higher rate of complete aneurysm obliteration and complication avoidance.

MICROSURGICAL MANAGEMENT OF RECURRENT INTRACRANIAL ANEURYSMS FOLLOWING ENDOVASCULAR TREATMENT: A SINGLE INSTITUTION ILLUSTRATIVE CASE SERIES AND LITERATURE REVIEW.

SUMMARYMicrosurgical clipping and endovascular coiling are both effective management modalities for intracranial aneurysms, whereas recent procedures are mainly directed towards endovascular treatment because of its minimally invasive nature. However, such a treatment has been associated with a bigger risk of recurrent aneurysmal growth and re-bleeding urging a selection of optimal strategies to overcome these hazards. It seems that the most appropriate method of choice is microsurgical clipping, which is much more technically challenging due to recurrent aneurysm demanding configuration created by the initial coiling. Herein, we present an illustrative institutional case series of recurrent intracranial aneurysms following endovascular treatment, and discuss the controversies and benefits of their subsequent microsurgical management, based on our experience and on literature review. Considering the results reported in this paper, it seems that careful selective microsurgical neck clipping with/without aneurysmal sac resection and coil extraction remains the preferred management option for recurrent intracranial aneurysms, resulting in high obliteration rates, long-term occlusion stability, and low morbidity/mortality. In conclusion, to bring a satisfactory outcome, the multidisciplinary management of recurrent intracranial aneurysms after endovascular treatment should be adjusted to aneurysm morphology/size/location, and individualized according to patient needs.

The Preoperative Functional Downgrading of Brain AVMs.

The actual role of preoperative embolization of brain arteriovenous malformations (AVMs) is undervalued.The present study aims to describe the effectiveness, safety, technics, and results of the endovascular-based functional downgrading of brain AVMs.Data regarding 31 Spetzler-Martin (SM) grade III AVMs that consecutively underwent a combined endovascular-surgical treatment were reviewed. Clinical and radiological outcomes were evaluated according to modified Ranking Scale score (mRS) and postoperative angiography, respectively.Low-density Onyx was usedin all cases, and the timeframe between the embolizations was 10-15days. Procedures were 1.6 (±0.6) on average. Superselective nidal catheterization was essential to reach the deepest parts of the AVMs, which were the targets. Onyx made the nidus compact and easier to dissect. The Average obliteration rate was 29.6%, with negligible morbidity. Surgery was performed after 3.7days on average and the AVM exclusion was complete in 83.4% of cases. An mRS score between 0 and 2 was reported in 77.5% of patients, while the best outcome was achieved in small and medium-deep malformations.An effective and safe functional downgrading of brain AVMs must be based upon specific technical key aspects, which make surgery easier and, ultimately, allow for the achievement of the best outcome.

Microsurgical resection of an anterior medullary arteriovenous malformation.

Arteriovenous malformations (AVMs) in the brainstem, specifically medullary AVMs, are exceedingly rare and difficult to treat. These lesions are commonly more aggressive than supratentorial AVMs and pose their own unique treatment challenges. Current treatment options for these AVMs consist of endovascular embolization or open surgery. Radiosurgery is not favored because it is associated with potential risk to the brainstem and lower obliteration rates. Here the authors report the case of a 27-year-old man with a ruptured anterior medullary AVM. The patient underwent a successful far-lateral craniotomy for resection of the AVM.The video can be found here: https://youtu.be/lyOfOQ3sBdU

Does the Diffuseness of the Nidus Affect the Outcome of Stereotactic Radiosurgery in Patients with Unruptured Cerebral Arteriovenous Malformations?

Background: We proposed an algorithm to automate the components within the identification of components within the nidus of cerebral arteriovenous malformations (AVMs) which may be used to analyze the relationship between its diffuseness and treatment outcomes following stereotactic radiosurgery (SRS). Objectives: to determine the impact of the diffuseness of the AVM nidus on SRS outcomes. Methods: This study conducted regular follow-ups of 209 patients with unruptured AVMs who underwent SRS. The diffuseness of the AVM nidus was estimated by quantifying the proportions of vascular nidal component, brain parenchyma, and cerebrospinal fluid in T2-weighted MRIs. We used Cox regression analysis to characterize the association between nidal diffuseness and treatment outcomes in terms of obliteration rate and radiation-induced change (RICs) rate following SRS. Results: The median AVM volume was 20.7 cm³. The median duration of imaging follow-up was 51 months after SRS. The overall AVM obliteration rate was 68.4%. RICs were identified in 156 of the 209 patients (74.6%). The median proportions of the nidus of AVM and brain parenchyma components within the prescription isodose range were 30.2 and 52.2%, respectively. Cox regression multivariate analysis revealed that the only factor associated with AVM obliteration rate after SRS was AVM volume. However, a larger AVM volume (>20 mL) and a larger proportion of brain parenchyma (>50%) within the prescription isodose range were both correlated with a higher RIC rate following SRS. Conclusions: The diffuseness of the nidus indeed appears to affect the RIC rate following SRS in patients with unruptured AVMs.

Radiosurgery for unruptured brain arteriovenous malformations in the pre-ARUBA era: long-term obliteration rate, risk of hemorrhage and functional outcomes

The management of non-hemorrhagic arteriovenous malformations (AVMs) remains a subject of debate, even more since the ARUBA trial. Here, we report the obliteration rate, the risk of hemorrhage and the functional outcomes after Gamma Knife radiosurgery (GKRS) as first-line treatment for non-hemorrhagic AVMs treated before the ARUBA publication, in a reference university center with multimodal AVM treatments available. We retrospectively analyzed data from a continuous series of 172 patients harboring unruptured AVMs treated by GKRS as first-line treatment in our Lille University Hospital, France, between April 2004 and December 2013. The primary outcome was obliteration rate. Secondary outcomes were the hemorrhage rate, the modified Rankin Scale (mRS), morbidity and epilepsy control at last follow-up. The minimal follow-up period was of 3 years. Median age at presentation was 40 years (IQR 28; 51). Median follow-up was 8.8 years (IQR 6.8; 11.3). Median target volume was 1.9 cm3 (IQR 0.8–3.3 cm3), median Spetzler-Martin grade: 2 (IQR 1–2), median Pollock-Flickinger score: 1.07 (IQR 0.82–2.94), median Virginia score: 1 (IQR 1–2). Median treatment dose was 24 Gy at 50% isodose line. Twenty-three patients underwent a second GKRS after a median time of 58 months after first GKRS. The overall obliteration rate was of 76%, based primarily on cerebral angiography and/or rarely only upon MRI. Hemorrhage during the post-treatment follow-up was reported in 18 (10%) patients (annual risk of 1.1%). Transient post-GKRS morbidity was reported in 14 cases (8%) and persistent neurological deficit in 8 (4.6%) of patients. At last follow-up, 86% of patients had a mRS ≤ 1. Concerning patients with pretherapeutic epilepsy, 84.6% of them were seizure-free at last follow-up. GKRS as first-line therapeutic option for unruptured cerebral AVMs achieves high obliteration rates (76%) while maintaining a high-level patient’s autonomy. All hemorrhagic events occurred during the first 4 years after the initial GKRS. In cases with epilepsy, there was 84.6% seizure free at last follow-up. Permanent morbidity was reported in only 4.6%.

Stent-Assisted Coiling of Unruptured Intracranial Aneurysms with Wide Neck.

Objective:Morbidity and mortality in patients experiencing the rupture of intracranial aneurysm ruptures are high. We conducted a systematic review and meta-analysis to investigate the role of stent-assisted coiling (SAC) for unruptured intracranial aneurysms (UIAs) with wide neck.Materials and Methods:The current meta-analysis was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled proportions with 95% confidence intervals (CIs) of ten outcomes of interest were calculated.Results:We finally reviewed 13 studies, including 976 patients. The technical success of the method was 98.43% (95% CI: 95.62–99.95). Early outcomes included total periprocedural obliteration with a rate of 50.20% (95% CI: 36.09–64.30) and periprocedural rupture with zero rate. During the follow-up period, ranging from 6 months to 2 years, the total postprocedural obliteration rate was 63.83% (95% CI: 45.80–80.18) and the overall late rupture rate was 0.41% (95% CI: 0.00–2.38). The pooled in-stent stenosis rate was calculated at 1.24% (95% CI: 0.02–3.63). We also estimated a pooled rate of 0.02% (95% CI: 0.00–0.51) and 4.33% (95% CI: 2.03–7.23) for total mortality and overall neurological complications, respectively. A pooled rate of 3.94% (95% CI: 1.48–7.33) was found for stroke. Finally, the recanalization rate was recorded at 7.07% (95% CI: 4.35–10.26).Conclusions:SAC of UIAs with wide neck seems to be a safe and acceptable alternative to surgical clipping. Although early results concerning total periprocedural obliteration may be modest, follow-up outcomes may be indicative of adequate occlusion of treated UIAs.

Long term treatment efficacy & complications of hypofractionated stereotactic radiosurgery in brain arteriovenous malformations

ObjectiveTo evaluate long term treatment efficacy and complications of hypofractionated stereotactic radiosurgery (hfSRS) and identify factors that predict outcomes. MethodsA retrospective review was conducted on 34 consecutive patients who received hfSRS from 2008 to 2017. Demographic, clinical, angio-architectural characteristics, and radiosurgery data were extracted from the Clinical Data Analysis and Reporting System and our unit’s iPlan (BrainLAB, Munich) system. Data was analysed using SPSS. Results5-year obliteration rate was 39.1%. Most patients (n = 29, 85.3%) recovered well with GOS of 4–5. 26.9% (n = 9) patients have at least one post-radiosurgery complication including hemorrhage, neurological deficits, radionecrosis. Neurological morbidity and mortality was 17.6% (n = 6). A higher modified radiosurgery arteriovenous malformation score (mRBAS) is associated with a lower 5-year obliteration rate (Rho = -0.486, p = 0.025). None of the bAVM were obliterated once mRBAS exceeds 5.35. As expected, a larger 20-Gy volume outside lesion is associated with more complications and poorer GOS. Interestingly, irradiated drainage vein volume indexed to AVM volume (iiDVV) correlates with increased risks of post-hfSRS haemorrhage (Rho = 0.472, p = 0.031) and reduced event-free survival (Rho = −0.472, p = 0.031). Once iiDVV exceeds 20%, a high rebleeding rate after hfSRS is anticipated (AUC under ROC 0.889). ConclusionHypofractionated stereotactic radiosurgery is an alternative radiosurgery treatment for bAVM unsuitable for single-fraction SRS. mRBAS predicts obliteration rate and morbidity in hfSRS. Index irradiated drainage vein volume (iiDVV) is associated with event-free survival and rebleeding and should be minimized if feasible.

Surgical management of pediatric rolandic arteriovenous malformations: a single-center case series.

Pediatric rolandic arteriovenous malformations (AVMs) present a treatment challenge given the lifetime risk of hemorrhage, rehemorrhage, and associated long-term morbidity. Microsurgical resection has been recommended as the optimal treatment for AVMs in general, but there is no dedicated literature on the outcomes of resection of pediatric rolandic AVMs. Here, the study objective was to review the outcomes of microsurgical resection of pediatric rolandic AVMs in the modern era, together with the utilization of surgical adjuncts including navigation, intraoperative angiography, and neurophysiological monitoring. The authors performed a retrospective review of patients 18 years of age and younger with cerebral AVMs microsurgically treated between January 2000 and May 2016 at The Hospital for Sick Children. Only those patients with an AVM whose nidus was located within the rolandic region were analyzed. A descriptive analysis was performed to identify patient demographics, preoperative AVM characteristics, and postoperative obliteration rates and neurological complications. A total of 279 AVMs were evaluated in the study period. Twenty-three of these AVMs were rolandic, and the median age in the 11 microsurgically treated cases was 11 years (range 1-17 years). AVM hemorrhage was the most common presentation, occurring in 8 patients (73%). Lesions were either Spetzler-Martin grade II (n = 8, 73%) or grade III (n = 3, 27%). The postoperative obliteration rate of AVMs was 100%. The mean imaging follow-up duration was 33 months (range 5-164 months). There was no documented recurrence of an AVM during follow-up. One patient developed a transient postoperative hemiparesis, while another patient developed right fingertip hyperesthesia. Microsurgical resection of rolandic pediatric AVMs yields excellent AVM obliteration with minimal neurological morbidity in selected patients. The incorporation of surgical adjuncts, including neurophysiological monitoring and neuronavigation, allows accurate demarcation of functional cortex and enables effective resection.

Long-Term Outcomes Of Hypofractionated Stereotactic Radiotherapy For Treatment Of Arteriovenous Malformation

To evaluate the long-term obliteration and toxicity outcomes of arteriovenous malformation (AVM) treated with hypofractionated stereotactic radiotherapy (HSRT). Retrospective analysis of 40 patients treated for AVMs from 2004-2007 was performed. All the patients were treated with LINAC-based HSRT in five consecutive daily fractions to a prescription dose of 35 Gy using a median isodose line of 80% to the periphery. Eleven patients were lost to follow up and the remaining 29 were included in this study. Patients underwent regular follow up with MRIs and subsequent cerebral angiography for confirmation of nidus obliteration. Acute and long-term toxicity data were collected including rates of symptomatic radiation necrosis (RN), cerebral cyst formation, intracranial hemorrhage (ICH), and death. The median follow-up was 13 years (range 0.9-15.3 years). 20 (69%) were male and 9 (31%) were female. The median age at treatment was 44 years (range 14-62). The most common presenting symptom was intracranial hemorrhage (ICH) (13 pts; 45%). Five patients underwent embolization prior to HSRT. Four lesions were in eloquent locations (13.8%), defined as basal ganglia, thalamus, or brainstem. The median greatest diameter and volume measured 3.9 cm (range 1.8-8.7) and 11.43 cc (range 1.33-108.55), respectively. Median modified Radiosurgery Based AVM Score (mRBAS) was 2.02 (range 0.51-12.45). 23 of the 29 lesions obliterated (79%) with median time to obliteration of 3 years. 25 of the patients (86%) experienced radiation-induced adverse effects. 18 patients (62%) had symptoms that persisted beyond three years post-treatment. Eight patients (28%) had cerebral cyst formation. Seven patients (28%) underwent resection of chronic RN with a median time to surgery of 8 years. Four patients suffered post-treatment ICH with one patient death from associated complications. The experience at this single institution illustrates the importance of long-term follow up in evaluating the treatment of AVM with LINAC-based HSRT. While the obliteration rate of 79% is above average for the treatment of large AVM, a toxicity rate of 86%, which included chronic RN and cyst formation requiring intervention may substantially complicate long-term management and negatively impact quality of life. Risk of long-term HSRT complications must be weighed carefully against risk of hemorrhage and other complications associated with conservative management and open surgery for these lesions.