Stereotactic Radiosurgery for A Randomized Trial of Unruptured Brain Arteriovenous Malformations- Eligible Patients: A Meta-Analysis

Neurosurgery 91:684–692, 2022

The outcomes of A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) were controversial, and they suggested that intervention is inferior to medical management for unruptured brain arteriovenous malformations (AVMs). However, several studies have shown that stereotactic radiosurgery (SRS) is an acceptable therapy for unruptured AVMs.

OBJECTIVE: To test the hypothesis that ARUBA intervention arm’s SRS results are meaningfully inferior to those from similar populations reported by other studies.

METHODS: We performed a literature review to identify SRS studies of patients who met the eligibility criteria for ARUBA. Patient, AVM, treatment, and outcome data were extracted for statistical analysis. Regression analyses were pooled to identify factors associated with post-SRS obliteration and hemorrhage.

RESULTS: The study cohort included 8 studies comprising 1620 ARUBA-eligible patients who underwent SRS. At the time of AVM diagnosis, 36% of patients were asymptomatic. The mean follow-up duration was 80 months. Rates of radiologic, symptomatic, and permanent radiation-induced changes were 45%, 11%, and 2%, respectively. The obliteration rate was 68% at last follow-up. The post-SRS hemorrhage and mortality rates were 8%, and 2%, respectively. Lower Spetzler-Martin grade (odds ratios [OR] = 0.84 [0.74-0.95], P = .005), lower radiosurgery-based AVM score (OR = 0.75 [0.64-0.95], P = .011), lower Virginia Radiosurgery AVM Scale (OR = 0.86 [0.78-0.95], P = .003), and higher margin dose (OR = 1.13 [1.02-1.25], P = .025) were associated with obliteration.

CONCLUSION: SRS carries a favorable risk to benefit profile for appropriately selected ARUBA-eligible patients, particularly those with smaller volume AVMs. Our findings suggest that the results of ARUBA do not reflect the real-world safety and efficacy of SRS for unruptured AVMs.

Stereotactic radiosurgery with versus without prior Onyx embolization for brain arteriovenous malformations

J Neurosurg 135:742–750, 2021

Investigations of the combined effects of neoadjuvant Onyx embolization and stereotactic radiosurgery (SRS) on brain arteriovenous malformations (AVMs) have not accounted for initial angioarchitectural features prior to neuroendovascular intervention. The aim of this retrospective, multicenter matched cohort study is to compare the outcomes of SRS with versus without upfront Onyx embolization for AVMs using de novo characteristics of the preembolized nidus.

METHODS The International Radiosurgery Research Foundation AVM databases from 1987 to 2018 were retrospectively reviewed. Patients were categorized based on AVM treatment approach into Onyx embolization (OE) and SRS (OE+SRS) or SRS alone (SRS-only) cohorts and then propensity score matched in a 1:1 ratio. The primary outcome was AVM obliteration. Secondary outcomes were post-SRS hemorrhage, all-cause mortality, radiological and symptomatic radiation-induced changes (RICs), and cyst formation. Comparisons were analyzed using crude rates and cumulative probabilities adjusted for competing risk of death.

RESULTS The matched OE+SRS and SRS-only cohorts each comprised 53 patients. Crude rates (37.7% vs 47.2% for the OE+SRS vs SRS-only cohorts, respectively; OR 0.679, p = 0.327) and cumulative probabilities at 3, 4, 5, and 6 years (33.7%, 44.1%, 57.5%, and 65.7% for the OE+SRS cohort vs 34.8%, 45.5%, 59.0%, and 67.1% for the SRS-only cohort, respectively; subhazard ratio 0.961, p = 0.896) of AVM obliteration were similar between the matched cohorts. The secondary outcomes of the matched cohorts were also similar. Asymptomatic and symptomatic embolization-related complication rates in the matched OE+SRS cohort were 18.9% and 9.4%, respectively.

CONCLUSIONS Pre-SRS AVM embolization with Onyx does not appear to negatively influence outcomes after SRS. These analyses, based on de novo nidal characteristics, thereby refute previous studies that found detrimental effects of Onyx embolization on SRS-induced AVM obliteration. However, given the risks incurred by nidal embolization using Onyx, this neoadjuvant intervention should be used judiciously in multimodal treatment strategies involving SRS for appropriately selected large-volume or angioarchitecturally high-risk AVMs.

Embolization of Brain Arteriovenous Malformations With VersusWithout Onyx Before Stereotactic Radiosurgery

Neurosurgery 88:366–374, 2021

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.

OBJECTIVE: To compare the outcomes of pre-SRS AVM embolization with vs without Onyx through a multicenter, retrospective matched cohort study.

METHODS: 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.

RESULTS: 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.

CONCLUSION: 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 neurointerven- tionalist and target of endovascular intervention.

Stereotactic Radiosurgery With Versus Without Embolization for Brain ArteriovenousMalformations

Neurosurgery 88(2) 2021: 313–321

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.

OBJECTIVE: To compare the outcomes of embolization and SRS, vs SRS alone for AVMs using pre-embolization malformation features.

METHODS: 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.

RESULTS: 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 SRSonly (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.

CONCLUSION: This study refutes the prevalent notion that AVM embolization negatively affects the likelihood of obliteration after SRS.

Early surgery for superficial supratentorial spontaneous intracerebral hemorrhage: a Finnish Intensive Care Consortium study

Acta Neurochirurgica (2020) 162:3153–3160

The benefits of early surgery in cases of superficial supratentorial spontaneous intracerebral hemorrhage (ICH) are unclear. This study aimed to assess the association between early ICH surgery and outcome, as well as the cost-effectiveness of early ICH surgery.

Methods We conducted a retrospective, register-based multicenter study that included all patients who had been treated for supratentorial spontaneous ICH in four tertiary intensive care units in Finland between 2003 and 2013. To be included, patients needed to have experienced supratentorial ICHs that were 10–100 cm3 and located within 10 mm of the cortex. We used a multivariable analysis, adjusting for the severity of the illness and the probability of surgical treatment, to assess the independent association between early ICH surgery (≤ 1 day), 12-month mortality rates, and the probability of survival without permanent disability. In addition, we assessed the cost-effectiveness of ICH surgery by examining the effective cost per 1-year survivor (ECPS) and per independent survivor (ECPIS).

Results Of 254 patients, 27%were in the early surgery group. Overall 12-monthmortality was 39%, while 29%survived without a permanent disability. According to our multivariable analysis, early ICH surgery was associated with lower 12-month mortality rates (odds ratio [OR] 0.22, 95% confidence intervals [CI] 0.10–0.51), but not with a higher probability of survival without permanent disability (OR 1.23, 95% CI 0.59–2.56). For the early surgical group, the ECPS and ECPIS were €111,409 and €334,227, respectively. For the non-surgical cohort, the ECPS and ECPIS were €76,074 and €141,471, respectively.

Conclusions Early surgery for superficial ICH is associated with a lower 12-month mortality risk but not with a higher probability of survival without a permanent disability. Further, costs were higher and cost-effectiveness was, thus, worse for the early surgical cohort.

Design and Physical Properties of 3-Dimensional Printed Models Used for Neurointervention

Neurosurgery DOI:10.1093/neuros/nyaa134

Three-dimensional (3D) printing has revolutionized training, education, and device testing. Understanding the design and physical properties of 3D-printed models is important.

OBJECTIVE: To systematically review the design, physical properties, accuracy, and experimental outcomes of 3D-printed vascular models used in neurointervention.

METHODS: We conducted a systematic review of the literature between January 1, 2000 and September 30, 2018. Public/Publisher MEDLINE (PubMed), Web of Science, Compendex, Cochrane, and Inspec databases were searched using Medical Subject Heading terms for design and physical attributes of 3D-printed models for neurointervention. Information on design and physical properties like compliance, lubricity, flow system, accuracy, and outcome measures were collected.

RESULTS: A total of 23 articles were included. Nine studies described 3D-printed models for stroke intervention. Tango Plus (Stratasys) was the most common material used to develop these models. Four studies described a population-representative geometry model. All other studies reported patient-specific vascular geometry. Eight studies reported complete reconstruction of the circle of Willis, anterior, and posterior circulation. Four studies reported a model with extracranial vasculature. One prototype study reported compliance and lubricity. Reported circulation systems included manual flushing, programmable pistons, peristaltic, and pulsatile pumps. Outcomes included thrombolysis in cerebral infarction, post-thrombectomy flow restoration, surgical performance, and qualitative feedback.

CONCLUSION: Variations exist in the material, design, and extent of reconstruction of vasculature of 3D-printed models. There is a need for objective characterization of 3D-printed vascular models. We propose the development of population representative 3D-printed models for skill improvement or device testing.

A grading scale for surgically treated patients with spontaneous supratentorial intracerebral hemorrhage: the Surgical Swedish ICH Score

J Neurosurg 133:800–807, 2020

The authors aimed to develop the first clinical grading scale for patients with surgically treated spontaneous supratentorial intracerebral hemorrhage (ICH).

METHODS A nationwide multicenter study including 401 ICH patients surgically treated by craniotomy and evacuation of a spontaneous supratentorial ICH was conducted between January 1, 2011, and December 31, 2015. All neurosurgical centers in Sweden were included. All medical records and neuroimaging studies were retrospectively reviewed. Independent predictors of 30-day mortality were identified by logistic regression. A risk stratification scale (the Surgical Swedish ICH [SwICH] Score) was developed using weighting of independent predictors based on strength of association.

RESULTS Factors independently associated with 30-day mortality were Glasgow Coma Scale (GCS) score (p =0.00015), ICH volume ≥ 50 mL (p = 0.031), patient age ≥ 75 years (p = 0.0056), prior myocardial infarction (MI) (p =0.00081), and type 2 diabetes (p = 0.0093). The Surgical SwICH Score was the sum of individual points assigned as follows: GCS score 15–13 (0 points), 12–5 (1 point), 4–3 (2 points); age ≥ 75 years (1 point); ICH volume ≥ 50 mL (1 point); type 2 diabetes (1 point); prior MI (1 point). Each increase in the Surgical SwICH Score was associated with a progressively increased 30-day mortality (p = 0.0002). No patient with a Surgical SwICH Score of 0 died, whereas the 30-day mortality rates for patients with Surgical SwICH Scores of 1, 2, 3, and 4 were 5%, 12%, 31%, and 58%, respectively.

CONCLUSIONS The Surgical SwICH Score is a predictor of 30-day mortality in patients treated surgically for spontaneous supratentorial ICH. External validation is needed to assess the predictive value as well as the generalizability of the Surgical SwICH Score.

The impact of statin therapy after surgical or endovascular treatment of cerebral aneurysms

J Neurosurg 133:182–189, 2020

Cerebral aneurysms represent the most common cause of spontaneous subarachnoid hemorrhage. Statins are lipid-lowering agents that may expert multiple pleiotropic vascular protective effects. The authors hypothesized that statin therapy after coil embolization or surgical clipping of cerebral aneurysms might improve clinical outcomes.

METHODS This was a retrospective cohort study using the National Health Insurance Service–National Sample Cohort Database in Korea. Patients who underwent coil embolization or surgical clipping for cerebral aneurysm between 2002 and 2013 were included. Based on prescription claims, the authors calculated the proportion of days covered (PDC) by statins during follow-up as a marker of statin therapy. The primary outcome was a composite of the development of stroke, myocardial infarction, and all-cause death. Multivariate time-dependent Cox regression analyses were performed.

RESULTS A total of 1381 patients who underwent coil embolization (n = 542) or surgical clipping (n = 839) of cerebral aneurysms were included in this study. During the mean (± SD) follow-up period of 3.83 ± 3.35 years, 335 (24.3%) patients experienced the primary outcome. Adjustments were performed for sex, age (as a continuous variable), treatment modality, aneurysm rupture status (ruptured or unruptured aneurysm), hypertension, diabetes mellitus, household income level, and prior history of ischemic stroke or intracerebral hemorrhage as time-independent variables and statin therapy during follow-up as a time-dependent variable. Consistent statin therapy (PDC > 80%) was significantly associated with a lower risk of the primary outcome (adjusted hazard ratio 0.34, 95% CI 0.14–0.85).

CONCLUSIONS Consistent statin therapy was significantly associated with better prognosis after coil embolization or surgical clipping of cerebral aneurysms.


Stereotactic radiosurgery for arteriovenous malformations of the basal ganglia and thalamus: an international multicenter study

J Neurosurg 132:122–131, 2020

Arteriovenous malformations (AVMs) of the basal ganglia (BG) and thalamus are associated with elevated risks of both hemorrhage if left untreated and neurological morbidity after resection. Therefore, stereotactic radiosurgery (SRS) has become a mainstay in the management of these lesions, although its safety and efficacy remain incompletely understood. The aim of this retrospective multicenter cohort study was to evaluate the outcomes of SRS for BG and thalamic AVMs and determine predictors of successful endpoints and adverse radiation effects.

METHODS The authors retrospectively reviewed data on patients with BG or thalamic AVMs who had undergone SRS at eight institutions participating in the International Gamma Knife Research Foundation (IGKRF) from 1987 to 2014. Favorable outcome was defined as AVM obliteration, no post-SRS hemorrhage, and no permanently symptomatic radiation- induced changes (RICs). Multivariable models were developed to identify independent predictors of outcome.

RESULTS The study cohort comprised 363 patients with BG or thalamic AVMs. The mean AVM volume and SRS margin dose were 3.8 cm3 and 20.7 Gy, respectively. The mean follow-up duration was 86.5 months. Favorable outcome was achieved in 58.5% of patients, including obliteration in 64.8%, with rates of post-SRS hemorrhage and permanent RIC in 11.3% and 5.6% of patients, respectively. Independent predictors of favorable outcome were no prior AVM embolization (p = 0.011), a higher margin dose (p = 0.008), and fewer isocenters (p = 0.044).

CONCLUSIONS SRS is the preferred intervention for the majority of BG and thalamic AVMs. Patients with morphologically compact AVMs that have not been previously embolized are more likely to have a favorable outcome, which may be related to the use of a higher margin dose.


Stroke Thrombectomies Using ADAPT With Increasing Aspiration Catheter Size

Neurosurgery 86:61–70, 2020

Endovascular thrombectomy is currently the standard of care for acute ischemic stroke (AIS). Although earlier trials on endovascular thrombectomy were performed using stent retrievers, recently completed the contact aspiration vs stent retriever for successful revascularization (ASTER) and a comparison of direct aspiration versus stent retriever as a first approach (COMPASS) trials have shown the noninferiority of direct aspiration.

OBJECTIVE: To report the largest experience withADAPT thrombectomy and compare the impact of advancement in reperfusion catheter technologies on outcomes.

METHODS:We reviewed a retrospective database of AIS patients who underwent ADAPT thrombectomy between January 2013 and November 2017 at the Medical University of South Carolina. Demographics and baseline characteristics, technical variables, and radiological and clinical outcomes were reviewed.

RESULTS: Among 510 patients (mean age: 67.7, 50.6% females), successful recanalization at first pass was achieved in 61.8%, and with aspiration only in 77.5%.Mean procedure time was 27.4 min, and the rate of good outcomes (mRS 0-2) at 90 d was 42.9%. The rate of recanalization with aspiration only was significantly higher, and procedure timewas significantly lower in patients treated with larger catheters (ACE 064 and ACE 068) compared to smaller catheters (5MAX and ACE, P<.05). Therewere no differences in complication rates or postoperative parenchymal hemorrhage across groups (P > .05); however, use of ACE 068 was an independent predictor of good outcomes at 90 d on multivariate regression analysis (odds ratio = 1.6, P< .05).

CONCLUSION: Refinement of ADAPT thrombectomy by incorporating reperfusion catheters with higher inner diameters and thus higher aspiration forces is associated with better outcomes, shorter procedure times, and lower likelihood of using additional devices without impacting complication rates.


Shunt-Dependent Hydrocephalus After Aneurysmal Subarachnoid Hemorrhage: Predictors and Long-Term Functional Outcomes

Neurosurgery 83:393–402, 2018

Although chronic hydrocephalus requiring shunt placement is a known sequela of aneurysmal subarachnoid hemorrhage (aSAH), its effect on long-term functional outcomes is incompletely understood.

OBJECTIVE: To identify predictors of shunt-dependent hydrocephalus and shunt complications after aSAH and determine the effect of shunt dependence on functional outcomes in aSAH patients.

METHODS: We evaluated a database of patients treated for aSAH at a single center from 2000 to 2015. Favorable and unfavorable outcomes were defined as modified Rankin Scale grades 0 to 2 and 3 to 6, respectively. We performed statistical analyses to identify variables associated with shunt-dependent hydrocephalus, unfavorable outcome, and shunt complication.

RESULTS: Of the 888 aSAH patients, 116 had shunt-dependent hydrocephalus (13%). Older age (P = .001), intraventricular hemorrhage (IVH) (P = .004), higher World Federation of Neurological Surgeons (WFNS) grade (P < .001), surgical aneurysm treatment (P = .002), and angiographic vasospasm (P=.005) were independent predictors of shunt-dependent hydrocephalus in multivariable analysis. Functional outcome was evaluable in 527 aSAH patients (mean follow-up 18.6 mo), with an unfavorable outcome rate of 17%. Shunt placement (P < .001), shunt infection (P = .041), older age (P < .001), and higher WFNS grade (P = .043) were independently associated with an unfavorable outcome in multivariable analysis. Of the shunt-dependent patients, 18% had a shunt-related complication. Higher WFNS grade (P= .011), posterior circulation aneurysm (P= .018), and angiographic vasospasm (P=.008)were independent predictors of shunt complications inmultivariable analysis.

CONCLUSION: aSAH patients with shunt-dependent hydrocephalus have significantly poorer long-term functional outcomes. Patients with risk factors for post-aSAH shunt dependence may benefit from increased surveillance, although the effect of such measures is not defined in this study.

Validation of the unruptured intracranial aneurysm treatment score.

J Neurosurg 129:100–106, 2018

The purpose of this study was to compare the unruptured intracranial aneurysm treatment score (UIATS) recommendations with the real-world experience in a quaternary academic medical center with a high volume of patients with unruptured intracranial aneurysms (UIAs).

METHODS All patients with UIAs evaluated during a 3-year period were included. All factors included in the UIATS were abstracted, and patients were scored using the UIATS. Patients were categorized in a contingency table assessing UIATS recommendation versus real-world treatment decision. The authors calculated the percentage of misclassification, sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve.

RESULTS A total of 221 consecutive patients with UIAs met the inclusion criteria: 69 (31%) patients underwent treatment and 152 (69%) did not. Fifty-nine (27%) patients had a UIATS between -2 and 2, which does not offer a treatment recommendation, leaving 162 (73%) patients with a UIATS treatment recommendation. The UIATS was significantly associated with treatment (p < 0.001); however, the sensitivity, specificity, and percentage of misclassification were 49%, 80%, and 28%, respectively. Notably, 51% of patients for whom treatment would be recommended by the UIATS did not undergo treatment in the real-world cohort and 20% of patients for whom conservative management would be recommended by UIATS had intervention. The area under the ROC curve was 0.646.

CONCLUSIONS Compared with the authors’ experience, the UIATS recommended overtreatment of UIAs. Although the UIATS could be used as a screening tool, individualized treatment recommendations based on consultation with a cerebrovascular specialist are necessary. Further validation with longitudinal data on rupture rates of UIAs is needed before widespread use.


Trans-Sulcal Endoport-Assisted Evacuation of Supratentorial Intracerebral Hemorrhage

Operative Neurosurgery 14:524–531, 2018

The surgical management of supratentorial intracerebral hemorrhages (ICH) remains controversial due to large trials failing to show clear benefits. Several minimally invasive techniques have emerged as an alternative to a conventional craniotomy with promising results.

OBJECTIVE: To report our experience with endoport-assisted surgery in the evacuation of supratentorial ICH and its effects on outcome compared to matched medical controls. METHODS: Retrospective data were gathered of patients who underwent endoportassisted evacuation between January 2014 and October 2016 by a single surgeon. Patients who were managed medically during the same period were matched to the surgical cohort. Previously published cohorts investigating the same technique were analyzed against the present cohort.

RESULTS: Sixteen patients were identified and matched to 16 patients treated medically. Location, hemorrhage volume, and initial Glasgow Coma Scale (GCS) score did not differ significantly between the 2 cohorts. Themean volume reduction in the surgical cohort was 92.05%±7.05%. The improvement in GCS in the surgical cohortwas statistically significant (7-13, P = .006). Compared to the medical cohort, endoport-assisted surgery resulted in a statistically significant difference in in-hospital mortality (6.25% vs 75.0%, P < .001) and 30-d mortality (6.25% vs 81.25%, P < .001). Compared to previously published cohorts, the present cohort had lower median preoperative GCS (7 vs 10, P = .02), but postoperative GCS did not differ significantly (13 vs 14, P = .28).

CONCLUSION : Endoport-assisted surgery is associated with high clot evacuation and decreases 30-d mortality compared to a similar medical group.


Stereotactic radiosurgery alone or combined with embolization for brain arteriovenous malformations

J Neurosurg 128:1338–1348, 2018

Embolization of brain arteriovenous malformations (AVMs) prior to stereotactic radiosurgery (SRS) has been reported to negatively affect obliteration rates. The goal of this systematic review and meta-analysis was to compare the outcomes of AVMs treated with embolization plus SRS (E+SRS group) and those of AVMs treated with SRS alone (SRS group).

METHODS A literature review was performed using PubMed to identify studies with 10 or more AVM patients and obliteration data for both E+SRS and SRS groups. A meta-analysis was performed to compare obliteration rates between the E+SRS and SRS groups.

RESULTS Twelve articles comprising 1716 patients were eligible for analysis. Among the patients with radiological follow-up data, complete obliteration was achieved in 48.4% of patients (330/681) in the E+SRS group compared with 62.7% of patients (613/978) in the SRS group. A meta-analysis of the pooled data revealed that the obliteration rate was significantly lower in the E+SRS group (OR 0.51, 95% CI 0.41–0.64, p < 0.00001). Symptomatic adverse radiation effects were observed in 6.6% (27/412 patients) and 11.1% (48/433 patients) of the E+SRS and SRS groups, respectively. The annual post-SRS hemorrhage rate was 2.0%–6.5% and 0%–2.0% for the E+SRS and SRS groups, respectively. The rates of permanent morbidity were 0%–6.7% and 0%–13.5% for the E+SRS and SRS groups, respectively.

CONCLUSIONS Arteriovenous malformation treatment with combined embolization and SRS is associated with lower obliteration rates than those with SRS treatment alone. However, this comparison does not fully account for differences in the initial AVM characteristics in the E+SRS group as compared with those in the SRS group. Further studies are warranted to address these limitations.

Radiosurgery for Unruptured Brain Arteriovenous Malformations: An International Multicenter Retrospective Cohort Study

Neurosurgery 80:888–898, 2017

The role of intervention in the management of unruptured brain arteriovenous malformations (AVM) is controversial.

OBJECTIVE: To analyze in a multicenter, retrospective cohort study, the outcomes following radiosurgery for unruptured AVMs and determine predictive factors.

METHODS: We evaluated and pooled AVM radiosurgery data from 8 institutions participating in the International Gamma Knife Research Foundation. Patients with unruptured AVMs and ≥12 mo of follow-up were included in the study cohort. Favorable outcome was defined as AVM obliteration, no postradiosurgical hemorrhage, and no permanently symptomatic radiation-induced changes.

RESULTS: The unruptured AVM cohort comprised 938 patients with a median age of 35 yr. The median nidus volume was 2.4 cm3, 71% of AVMs were located in eloquent brain areas, and the Spetzler-Martin grade was III or higher in 57%. The median radiosurgical margin dose was 21 Gy and follow-up was 71 mo. AVM obliteration was achieved in 65%. The annual postradiosurgery hemorrhage rate was 1.4%. Symptomatic and permanent radiation-induced changes occurred in 9% and 3%, respectively. Favorable outcome was achieved in 61%. In the multivariate logistic regression analysis, smaller AVM maximum diameter (P = .001), the absence of AVM-associated arterial aneurysms (P = .001), and higher margin dose (P = .002) were found to be independent predictors of a favorable outcome. A margin dose ≥ 20 Gy yielded a significantly higher rate of favorable outcome (70% vs 36%; P < .001)

CONCLUSION: Radiosurgery affords an acceptable risk to benefit profile for patients harboring unruptured AVMs. These findings justify further prospective studies comparing radiosurgical intervention to conservative management for unruptured AVMs.


The Safety and Feasibility of Image-Guided BrainPath-Mediated Transsulcul Hematoma Evacuation: A Multicenter Study

Neurosurgery 80:515–524, 2017

Subcortical injury resulting from conventional surgical management of intracranial hemorrhage may counteract the potential benefits of hematoma evacuation.

OBJECTIVE: To evaluate the safety and potential benefits of a novel, minimally invasive approach for clot evacuation in a multicenter study.

METHODS: The integrated approach incorporates 5 competencies: (1) image interpretation and trajectory planning, (2) dynamic navigation, (3) atraumatic access system (BrainPath, NICO Corp, Indianapolis, Indiana), (4) extracorporeal optics, and (5) automated atraumatic resection. Twelve neurosurgeons from 11 centers were trained to use this approach through a continuing medical education–accredited course. Demographical, clinical,andradiologicaldataofpatientstreatedover2yearswereanalyzedretrospectively.

RESULTS: Thirty-nine consecutive patients were identified. The median Glasgow Coma Scale (GCS) score at presentation was 10 (range, 5-15). The thalamus/basal ganglion regions were involved in 46% of the cases. The median hematoma volume and depth were 36 mL (interquartile range [IQR], 27-65 mL) and 1.4 cm (IQR, 0.3-2.9 cm), respectively. The median time from ictus to surgery was 24.5 hours (IQR, 16-66 hours). The degree of hematoma evacuation was ≥90%, 75% to 89%, and 50% to 74% in 72%, 23%, and 5.0% of the patients, respectively. The median GCS score at discharge was 14 (range, 8-15). The improvement in GCS score was statistically significant (P < .001). Modified Rankin Scale data were available for 35 patients. Fifty-two percent of those patients had a modified Rankin Scale score of ≤2. There were no mortalities.

CONCLUSION: The approach was safely performed in all patients with a relatively high rate of clot evacuation and functional independence.


Predictive factors for decompressive hemicraniectomy in malignant middle cerebral artery infarction

Predictive factors for decompressive hemicraniectomy in malignant middle cerebral artery infarction

Acta Neurochir (2016) 158:865–873

The mortality rate of patients with brain oedema after malignant middle cerebral artery (MCA) infarction approaches 80 % without surgical intervention. Surgical treatment with ipsilateral decompressive hemicraniectomy (DHC) has been shown to dramatically improve survival rates. DHC currently lacks established inclusion criteria and additional research is needed to assess the impact of prognostic factors on functional outcome. The aim of this study was to assess the impact of prognostic factors on functional outcome.

Method A retrospective cohort study was carried out including 46 patients who underwent DHC at the Karolinska University Hospital between 2004 and 2014. The maximum time to surgery was 5 days after symptom debut. The primary endpoint was a dichotomised score on the modified Rankin Scale (mRS) 3 months after surgery, with favourable outcome defined as mRS ≤ 4.

Results When the study population was dichotomised according to the primary endpoint, a significant difference between the groups was seen in preoperative Glasgow Coma Score (GCS), blood glucose levels and the infarction’s involvement of the basal ganglia (p <0.05). In a logistic regression model, preoperative GCS contributed significantly with a 59.6 % increase in the probability of favourable outcome for each point gained in preoperative GCS (p=0.035).

Conclusions The results indicate that preoperative GCS, blood glucose and the infarction’s involvement of the basal ganglia are strong predictors of clinical outcome. These factors should be considered when assessing the probable outcome of DHC, and additional research based on these factors may contribute to improved inclusion criteria for DHC.

Effect of Prior Embolization on Cerebral Arteriovenous Malformation Radiosurgery Outcomes


Neurosurgery 77:406–417, 2015

Embolization before stereotactic radiosurgery (SRS) for cerebral arteriovenous malformations (AVM) has been shown to negatively affect obliteration rates, but its impact on the risks of radiosurgery-induced complications and latency period hemorrhage is poorly defined.

OBJECTIVE: To determine, in a case-control study, the effect of prior embolization on AVM SRS outcomes.

METHODS: We evaluated a database of AVM patients who underwent SRS. Propensity score analysis was used to match the case (embolized nidi) and control (nonembolized nidi) cohorts. AVM angioarchitectural complexity was defined as the sum of the number of major feeding arteries and draining veins to the nidus. Multivariate Cox proportional hazards regression analyses were performed on the overall study population to determine independent predictors of obliteration and radiation-induced changes.

RESULTS: The matching process yielded 242 patients in each cohort. The actuarial obliteration rates were significantly lower in the embolized (31%, 49% at 5, 10 years, respectively) compared with the nonembolized (48%, 64% at 5, 10 years, respectively) cohort (P = .003). In the multivariate analysis for obliteration, lower angioarchitectural complexity (P , .001) and radiologically evident radiation-induced changes (P = .016) were independent predictors, but embolization was not significant (P = .744). In the multivariate analysis for radiologic radiation-induced changes, lack of prior embolization (P = .009) and fewer draining veins (P = .011) were independent predictors.

CONCLUSION: The effect of prior embolization on AVM obliteration after SRS may be significantly confounded by nidus angioarchitectural complexity. Additionally, embolization could reduce the risk of radiation-induced changes. Thus, combined embolization and SRS may be warranted for appropriately selected nidi.

Predictors of Outcome, Complications, and Recanalization of the Solitaire Device

Solitaire Device

Neurosurgery 77:355–361, 2015

The use of mechanical thrombectomy in the management of acute ischemic stroke is becoming increasingly popular.

OBJECTIVE: To identify notable factors that affect outcome, revascularization, and complications in patients with acute ischemic stroke treated with the Solitaire Flow Restoration Revascularization device.

METHODS: Eighty-nine patients treated with the Solitaire Flow Restoration Revascularization device (ev3/Covidien Vascular Therapies, Irvine, California) were retrospectively analyzed. Three endpoints were considered: revascularization (Thrombolysis In Cerebral Infarction), outcome (modified Rankin Scale score), and complications. Univariate analysis and multivariate logistic regression were conducted to determine significant predictors.

RESULTS: The mean time from onset of symptoms to the start of intervention was 6.7 hours. The average procedure length was 58 minutes. The mean NIH Stroke Scale (NIHSS) score was 16 on arrival and 8 at discharge. Of the patients, 6.7% had a symptomatic intracerebral hemorrhage, 16.8% had fatal outcomes within 3 months post-intervention, and 81.4% had a successful recanalization. Thrombus location in the M1 segment of the middle cerebral artery was associated with successful recanalization (thrombolysis in cerebral infarction 2b/3) (P = .003). Of the patients, 56.6% had a favorable outcome (modified Rankin Scale score at 3 months: 0-2). In patients younger than 80 years of age, 66.7% had favorable outcome. Increasing age (P = .01) and NIHSS score (P = .002) were significant predictors of a poor outcome. On multivariate analysis, NIHSS score on admission (P = .05) was a predictor of complications. On univariate analysis, increasing NIHSS score fromadmission to 24 hours after the procedure (P = .05) and then to discharge (P = .04) was a predictor of complications. Thrombus location in the posterior circulation (P = .04) and increasing NIHSS score (P = .04) predicted mortality.

CONCLUSION: The Solitaire device is safe and effective in achieving successful recanalization after acute ischemic stroke. Important factors to consider include age, NIHSS score, and location.

Effects of Hematoma Reduction by Stereotactic Aspiration for Patients With Spontaneous Intracerebral Hemorrhage

Effects of Hematoma Reduction by Stereotactic Aspiration for Patients With Spontaneous Intracerebral Hemorrhage

Neurosurg Q 2015;25:17–23

Spontaneous intracerebral hemorrhage (ICH) is a devastating medical condition associated with significant morbidity and mortality. Whether the hematoma should be surgically removed remains controversial. This study was a retrospective analysis of patients with spontaneous ICH who were treated with computed tomography (CT)-guided stereotactic aspiration. The aim of this study was to investigate whether hematoma volume reduction in deep-seated ICH utilizing this minimally invasive surgical procedure improves clinical outcome.

Methods: Ninety-nine patients who suffered spontaneous ICH provided informed consent and were included in the study. Patients were divided into an operated group that underwent CT-guided stereotactic aspiration, and a nonoperated group that received only medical treatment. CT-guided stereotactic aspiration was performed at least 8 hours after onset of ICH. Using the Leksell stereotactic frame for guidance, a 4-mm-diameter catheter was inserted into the body of the hematoma through a frontal burr hole. Glasgow Coma Scale, motor function, and length of hospital stay were used to assess differences in outcomes between the 2 groups. The correlation between clinical outcome and stereotactic aspiration was evaluated using multivariate regression analysis.

Results: Ninety-nine consecutive patients were entered into this study. Patients in the operated group (n=41) were treated with CT-guided stereotactic hematoma aspiration. The 3-month Glasgow Outcome Scale score in the nonoperated group (n=58) was significantly lower than that in the operated group (2.32±1.26 vs. 3.15±1.33, P<0.001). Patients in the operated group experienced greater motor function recovery than those in the nonoperated group. The average length of hospital stay of the operated group was significantly shorter than that of the nonoperated group (31.2±14.6 vs. 41.7±17.2 d, P=0.002).

Conclusions: Stereotactic aspiration may improve the functional outcome and shorten the hospital stay of patients who have suffered spontaneous ICH. This procedure is minimally invasive and shows promise as a safe and effective treatment method for these patients.

%d bloggers like this: