Middle meningeal artery embolization for chronic subdural hematoma in cancer patients with refractory thrombocytopenia

OBJECTIVE

Surgical evacuation of chronic subdural hematoma (SDH) in cancer patients is often contraindicated owing to refractory thrombocytopenia. Middle meningeal artery embolization (MMAE) recently emerged as a potential alternative to surgical evacuation for patients with chronic SDH. The goal of this study was to evaluate the safety and efficacy of MMAE for chronic SDH in cancer patients with refractory thrombocytopenia.

METHODS

A multiinstitutional registry was reviewed for clinical and radiographic outcomes of cancer patients with transfusion-refractory thrombocytopenia and baseline platelet count < 75 K/µl, who underwent MMAE for chronic SDH.

RESULTS

MMAE was performed on a total of 31 SDHs in 22 patients, with a mean ± SD (range) platelet count of 42.1 ± 18.3 (9-74) K/µl. At the longest follow-up, 24 SDHs (77%) had reduced in size, with 15 (48%) showing > 50% reduction. Two patients required surgical evacuation after MMAE. There was only 1 procedural complication; however, 16 patients (73%) ultimately died of cancer-related complications. Median survival was significantly longer in the 16 patients with improved SDH than the 6 patients with worsened SDH after MMAE (185 vs 24 days, p = 0.029). Length of procedure, technical success rate, SDH size reduction, and complication rate were not significantly differ between patients who underwent transfemoral and transradial approaches.

CONCLUSIONS

Transfemoral or transradial MMAE is a potential therapeutic option for thrombocytopenic cancer patients with SDH. However, treatment benefit may be marginal for patients with high disease burden and limited life expectancy. A prospective trial is warranted to address these questions.

Endovascular catheter manometry reliability: a benchtop validation study

OBJECTIVE

Catheter manometry is used frequently in neuroendovascular surgery for assessing cerebrovascular pathology. The accuracy of pressure data with different catheter setups requires further validation.

METHODS

In a silicone human vascular model with a pulsatile pump, pressure measurements were taken through multiple arrangements of 2 guide catheters and 6 microcatheters. The systolic pressure, diastolic pressure, mean pressure, pulse pressure, and area under the curve of the waveform were recorded through catheters with controls at arterial blood pressure ranges. Linear regression modeling was performed, correlating transduction area and relative pulse pressure. Thresholds for acceptable accuracy were ≥ 90%.

RESULTS

Mean pressure demonstrated < 4% variation between all 24 catheter setups and respective controls. A strong linear correlation (r2 = 0.843, p < 0.0005) between microcatheter transduction area and relative pulse pressure with a threshold of 0.50 mm2 was seen (i.e., 0.031-inch inner diameter [ID]). For guide catheters with indwelling microcatheters, there was also a strong linear correlation (r2 = 0.840, p < 0.0005) of transduction area to pulse pressure. The guide catheters with obstructing microcatheters required a transduction area over fourfold higher compared with unobstructed microcatheters (2.21 mm2 vs 0.50 mm2).

CONCLUSIONS

Mean pressure measurements are accurate through microcatheters as small as 0.013-inch ID. Pulse pressure and waveform morphology may require a microcatheter ≥ 0.031-inch ID to achieve 90% accuracy, although the 0.027-inch ID microcatheter reached 85% accuracy. A 0.070-inch guide catheter with a microcatheter ≤ 0.042-inch outer diameter (e.g., Marksman 0.027-inch ID or smaller) allows accurate transduction of pulse pressure. Further validation of these benchtop findings is necessary before application in a clinical setting.

Long-term stability of Onyx: is there any indication for repeated angiography after dural arteriovenous fistula embolization?

OBJECTIVE

The natural course of dural arteriovenous fistulas (DAVFs) is unfavorable. Transarterial embolization with Onyx is currently the therapeutic method of choice, although the long-term stability of Onyx has been questioned. The literature reports a significant difference in the recurrence rate after complete DAVF occlusion and lacks larger series with long-term follow-up. The authors present the largest series to date with a long-term follow-up to determine the stability of Onyx, prospectively comparing magnetic resonance angiography (MRA) and digital subtraction angiography (DSA) as follow-up diagnostic methods.

METHODS

Demographics, clinical symptomatology, length of follow-up, diagnostic methods, and angiographic findings of DAVFs were recorded and retrospectively evaluated in 112 patients. A prospective group of 15 patients with more than 5 years of follow-up after complete DAVF occlusion was established. All 15 patients in the prospective group underwent a clinical examination and MRA; 10 of these patients also underwent DSA. The recurrences and the correlation between the two diagnostic methods were evaluated.

RESULTS

Among the 112 patients, 71 were men and 41 were women, with an average age of 60 years. Intracranial hemorrhage (40%) was the most common clinical presentation of DAVF. At the last follow-up, 73% of the patients experienced clinical improvement, 21% remained unchanged, and 6% worsened. Overall, 87.5% of the DAVFs were occluded entirely with endovascular treatment, and 93% of the DAVFs were classified as cured at the last follow-up (i.e., completely embolized DAVFs and DAVFs that thrombosed spontaneously or after Gamma Knife surgery). Two recurrences of DAVFs were recorded in the entire series. Both were first diagnosed by MRA and confirmed with DSA. The mean follow-up was 27.7 months. In the prospective group, a small asymptomatic recurrence was diagnosed. The mean follow-up of the prospective group was 96 months.

CONCLUSIONS

Onyx is a stable embolic material, although recurrence of seemingly completely occluded DAVFs may develop because of postembolization hemodynamic changes that accentuate primarily graphically absent residual fistula. These residuals can be diagnosed with MRA at follow-up. The authors' data suggest that MRA could be sufficient as the follow-up diagnostic method after complete DAVF occlusion with Onyx. However, larger prospective studies on this topic are needed.

Cost-effectiveness of endovascular thrombectomy in patients with low Alberta Stroke Program Early CT Scores (< 6) at presentation

OBJECTIVE

The utility of endovascular thrombectomy (EVT) in patients with acute ischemic stroke, large vessel occlusion (LVO), and low Alberta Stroke Program Early CT Scores (ASPECTS) remains uncertain. The objective of this study was to determine the health outcomes and cost-effectiveness of EVT versus medical management in patients with ASPECTS < 6.

METHODS

A decision-analytical study was performed with Markov modeling to estimate the lifetime quality-adjusted life-years (QALYs) and associated costs of EVT-treated patients compared to medical management. The study was performed over a lifetime horizon with a societal perspective in the US setting.

RESULTS

The incremental cost-effectiveness ratios were $412,411/QALY and $1,022,985/QALY for 55- and 65-year-old groups in the short-term model. EVT was the long-term cost-effective strategy in 96.16% of the iterations and resulted in differences in health benefit of 2.21 QALYs and 0.79 QALYs in the 55- and 65-year-old age groups, respectively, equivalent to 807 days and 288 days in perfect health. EVT remained the more cost-effective strategy when the probability of good outcome with EVT was above 16.8% or as long as the good outcome associated with the procedure was at least 1.6% higher in absolute value than that of medical management. EVT remained cost-effective even when its cost exceeded $100,000 (threshold was $108,036). Although the cost-effectiveness decreased with age, EVT was cost-effective for 75-year-old patients as well.

CONCLUSIONS

This study suggests that EVT is the more cost-effective approach compared to medical management in patients with ASPECTS < 6 in the long term (lifetime horizon), considering the poor outcomes and significant disability associated with nonreperfusion.

Endovascular treatment for calcified cerebral emboli in patients with acute ischemic stroke

OBJECTIVE

Calcified cerebral emboli (CCE) are a rare cause of acute ischemic stroke. The authors aimed to assess the association of CCE with functional outcome, successful reperfusion, and mortality. Furthermore, they aimed to assess the effectiveness of intravenous alteplase treatment and endovascular treatment (EVT), as well as the best first-line EVT approach in patients with CCE.

METHODS

The Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN) Registry is a prospective, observational multicenter registry of patients treated with EVT for acute ischemic stroke in 16 intervention hospitals in the Netherlands. The association of CCE with functional outcome, reperfusion, and mortality was evaluated using logistic regression models. Univariable comparisons were made to determine the effectiveness of intravenous alteplase treatment and the best first-line EVT approach in CCE patients.

RESULTS

The study included 3077 patients from the MR CLEAN Registry. Fifty-five patients (1.8%) had CCE. CCE were not significantly associated with worse functional outcome (adjusted common OR 0.71, 95% CI 0.44-1.15), and 29% of CCE patients achieved functional independence. An extended Thrombolysis in Cerebral Infarction score ≥ 2B was significantly less often achieved in CCE patients compared to non-CCE patients (adjusted OR [aOR] 0.52, 95% CI 0.28-0.97). Symptomatic intracranial hemorrhage occurred in 8 CCE patients (15%) vs 171 of 3022 non-CCE patients (6%; p = 0.01). The median improvement on the National Institutes of Health Stroke Scale (NIHSS) was 2 in CCE patients versus 4 in non-CCE patients (p = 0.008). CCE were not significantly associated with mortality (aOR 1.16, 95% CI 0.64-2.12). Intravenous alteplase use in CCE patients was not associated with functional outcome or reperfusion. In CCE patients with successful reperfusion, stent retrievers were more often used as the primary treatment device (p = 0.04).

CONCLUSIONS

While patients with CCE had significantly lower reperfusion rates and less improvement on the NIHSS after EVT, CCE were not significantly associated with worse functional outcome or higher mortality rates. Therefore, EVT should still be considered in this specific group of patients.

Basal ganglia cavernous malformations: case series and systematic review of surgical management and long-term outcomes

OBJECTIVE

Reports on basal ganglia cavernous malformations (BGCMs) are rare. Here, the authors report on their experience in resecting these malformations to offer insight into this infrequent disease subtype.

METHODS

The authors retrospectively reviewed a prospectively managed departmental database of all deep-seated cerebral cavernous malformations (CCMs) treated at Stanford between 1987 and 2019 and included for further analysis those with a radiographic diagnosis of BGCM. Moreover, a systematic literature review was undertaken using the PubMed and Web of Science databases.

RESULTS

The departmental database search yielded 331 patients with deep-seated CCMs, 44 of whom had a BGCM (13.3%). Headache was the most common presenting sign (53.5%), followed by seizure (32.6%) and hemiparesis (27.9%). Lesion location involved the caudate nucleus in 21.4% of cases compared to 78.6% of cases within the lentiform nucleus. Caudate BGCMs were larger on presentation and were more likely to present to the ependymal surface (p < 0.001) with intraventricular hemorrhage and hydrocephalus (p = 0.005 and 0.007, respectively). Dizziness and diplopia were also more common with lesions involving the caudate. Because of their anatomical location, caudate BGCMs were preferentially treated via an interhemispheric approach and were less likely to be associated with worsening perioperative deficits than lentiform BGCMs (p = 0.006 and 0.045, respectively). Ten patients (25.6%) were clinically worse in the immediate postoperative period, 4 (10.2%) of whom continued to suffer permanent morbidity at the last follow-up. A long-term good outcome (modified Rankin Scale [mRS] score 0-1) was attained in 74.4% of cases compared to the 69.2% of patients who had presented with an mRS score 0-1. Relative to their presenting mRS score, 89.8% of patients had an improved or unchanged status at the last follow-up. The median postoperative follow-up was 11 months (range 1-252 months). Patient outcomes after resection did not differ among surgical approaches; however, patients presenting with hemiparesis and lesions involving the globus pallidus or posterior limb of the internal capsule were more likely to suffer neurological deficits during the immediate perioperative period. Patients who had undergone awake surgeries were more likely to suffer neurological decline at the early as well as the late follow-up. When adjusting for awake craniotomy as a potential confounder of lesion location, a BGCM involving the posterior limb was predictive of developing early postoperative deficits, but this finding did not persist at the long-term follow-up.

CONCLUSIONS

Surgery is a safe and effective treatment modality for managing BGCMs, with an estimated long-term permanent morbidity rate of around 10%.

Development of cerebral microbleeds in patients with cerebral hyperperfusion following carotid endarterectomy and its relation to postoperative cognitive decline

OBJECTIVE

A primary cause of cognitive decline after carotid endarterectomy (CEA) is cerebral injury due to cerebral hyperperfusion. However, the mechanisms of how cerebral hyperperfusion induces cerebral cortex and white matter injury are not known. The presence of cerebral microbleeds (CMBs) on susceptibility-weighted imaging (SWI) is independently associated with a decline in global cognitive function. The purpose of this prospective observational study was to determine whether cerebral hyperperfusion following CEA leads to the development of CMBs and if postoperative cognitive decline is related to these developed CMBs.

METHODS

During the 27-month study period, patients who underwent CEA for ipsilateral internal carotid artery stenosis (≥ 70%) also underwent SWI and neuropsychological testing before and 2 months after surgery, as well as quantitative brain perfusion SPECT prior to and immediately after surgery.

RESULTS

According to quantitative brain perfusion SPECT and SWI before and after surgery, 12 (16%) and 7 (9%) of 75 patients exhibited postoperative cerebral hyperperfusion and increased CMBs in the cerebral hemisphere ipsilateral to surgery, respectively. Cerebral hyperperfusion was associated with an increase in CMBs after surgery (logistic regression analysis, 95% CI 5.08-31.25, p < 0.0001). According to neuropsychological assessments before and after surgery, 10 patients (13%) showed postoperative cognitive decline. Increased CMBs were associated with cognitive decline after surgery (logistic regression analysis, 95% CI 6.80-66.67, p < 0.0001). Among the patients with cerebral hyperperfusion after surgery, the incidence of postoperative cognitive decline was higher in those with increased CMBs (100%) than in those without (20%; p = 0.0101).

CONCLUSIONS

Cerebral hyperperfusion following CEA leads to the development of CMBs, and postoperative cognitive decline is related to these developed CMBs.

Comparison of robotic-assisted carotid stenting and manual carotid stenting through the transradial approach

OBJECTIVE

The objective of this study was to demonstrate the feasibility and safety of CorPath GRX robotic-assisted (RA) transradial (TR) carotid artery stenting (CAS) compared with manual TR CAS.

METHODS

The authors conducted a retrospective analysis of a prospectively maintained database and identified 13 consecutive patients who underwent TR CAS from June 2019 through February 2020. Patients were divided into 2 groups: RA (6 patients) and manual (7 patients).

RESULTS

Among 6 patients in the RA group with a mean age of 70.0 ± 7.2 years, technical success was achieved in all 6 (100%) procedures; there were no technical or access-site complications and no catheter exchanges. Transfemoral conversion was required in 1 (16.7%) case due to a tortuous aortic arch. There were no perioperative complications, including myocardial infarction, stroke, and mortality. The mean procedure duration was significantly longer in the RA group (85.0 ± 14.3 minutes [95% CI 69.9-100.0] vs 61.2 ± 17.5 minutes [95% CI 45.0-77.4], p = 0.0231). There was no significant difference in baseline characteristics, fluoroscopy time, contrast dose, radiation exposure, catheter exchanges, technical success, transfemoral conversion, technical or access-site complications, myocardial infarction, stroke, other complications, or mortality.

CONCLUSIONS

The authors' results suggest that RA TR CAS is feasible, safe, and effective. Neurovascular-specific engineering and software modifications are needed prior to complete remote control. Remote control has important implications regarding patient access to lifesaving procedures for conditions such as stroke and aneurysm rupture as well as operative precision. Future clinical investigations among larger cohorts are needed to demonstrate reliable performance and patient benefit.

Outcomes after coverage of lenticulostriate vessels by flow diverters: a multicenter experience

OBJECTIVE

With the increasing use of flow diversion as treatment for intracranial aneurysms, there is a concomitant increased vigilance in monitoring complications. The low porosity of flow diverters is concerning when the origins of vessels are covered, whether large circle of Willis branches or critical perforators. In this study, the authors report their experience with flow diverter coverage of the lenticulostriate vessels and evaluate their safety and outcomes.

METHODS

The authors retrospectively reviewed 5 institutional databases of all flow diversion cases from August 2012 to June 2018. Information regarding patient presentation, aneurysm location, treatment, and outcomes were recorded. Patients who were treated with flow diverters placed in the proximal middle cerebral artery (MCA), proximal anterior cerebral artery, or distal internal carotid artery leading to coverage of the medial and lateral lenticulostriate vessels were included. Clinical outcomes according to the modified Rankin Scale were reviewed. Univariate and multivariate analyses were performed to establish risk factors for lenticulostriate infarct.

RESULTS

Fifty-two patients were included in the analysis. Postprocedure cross-sectional images were available in 30 patients. Two patients experienced transient occlusion of the MCA during the procedure; one was asymptomatic, and the other had a clinical and radiographic ipsilateral internal capsule stroke. Five patients had transient symptoms without radiographic infarct in the lenticulostriate territory. Two patients experienced in-stent thrombosis, leading to clinical MCA infarcts (one in the ipsilateral caudate) after discontinuing antiplatelet therapy. Discontinuation of dual antiplatelet therapy prior to 6 months was the only variable that was significantly correlated with stroke outcome (p < 0.01, OR 0.3, 95% CI 0-0.43), and this significance persisted when controlled for other risk factors, including age, smoking status, and aneurysm location.

CONCLUSIONS

The use and versatility of flow diversion is increasing, and safety data are continuing to accumulate. Here, the authors provide early data on the safety of covering lenticulostriate vessels with flow diverters. The authors concluded that the coverage of these perforators does not routinely lead to clinically significant ischemia when dual antiplatelet therapy is continued for 6 months. Further evaluation is needed in larger cohorts and with imaging follow-up as experience develops in using these devices in more distal circulation.

Construction of a comprehensive endovascular test bed for research and device development in mechanical thrombectomy in stroke

OBJECTIVE

The development of new endovascular technologies and techniques for mechanical thrombectomy in stroke has greatly relied on benchtop simulators. This paper presents an affordable, versatile, and realistic benchtop simulation model for stroke.

METHODS

A test bed for embolic occlusion of cerebrovascular arteries and mechanical thrombectomy was developed with 3D-printed and commercially available cerebrovascular phantoms, a customized hydraulic system to generate physiological flow rate and pressure, and 2 types of embolus analogs (elastic and fragment-prone) capable of causing embolic occlusions under physiological flow.

RESULTS

The test bed was highly versatile and allowed realistic, radiation-free mechanical thrombectomy for stroke due to large-vessel occlusion with rapid exchange of geometries and phantom types. Of the transparent cerebrovascular phantoms tested, the 3D-printed phantom was the easiest to manufacture, the glass model offered the best visibility of the interaction between embolus and thrombectomy device, and the flexible model most accurately mimicked the endovascular system during device navigation. None of the phantoms modeled branches smaller than 1 mm or perforating arteries, and none underwent realistic deformation or luminal collapse from device manipulation or vacuum. The hydraulic system created physiological flow rate and pressure leading to iatrogenic embolization during thrombectomy in all phantoms. Embolus analogs with known fabrication technique, structure, and tensile strength were introduced and consistently occluded the middle cerebral artery bifurcation under physiological flow, and their interaction with the device was accurately visualized.

CONCLUSIONS

The test bed presented in this study is a low-cost, comprehensive, realistic, and versatile platform that enabled high-quality analysis of embolus-device interaction in multiple cerebrovascular phantoms and embolus analogs.

Early experience with a novel net temporary bridging device (Cascade) to assist endovascular coil embolization of intracranial aneurysms

OBJECTIVE

The goal of this study was to evaluate the effectiveness and safety of a new noncompletely occlusive net-assisted remodeling technique in which the Cascade net device is used for temporary bridging of intracranial aneurysms.

METHODS

Between July 2018 and May 2019, patients underwent coil embolization with the Cascade net device within 4 centers in Europe. Analysis of angiographic (modified Raymond-Roy classification [MRRC]) and clinical outcomes data was conducted immediately following treatment and at the 6-month follow-up.

RESULTS

Fifteen patients were included in the study (mean age 58 ± 13 years, 11/15 [73.3%] female). Ten patients had unruptured aneurysms, and 5 presented with ruptured aneurysms with acute subarachnoid hemorrhage. The mean aneurysm dome length was 6.27 ± 2.33 mm and the mean neck width was 3.64 ± 1.19 mm. Immediately postprocedure, MRRC type I (complete obliteration) was achieved in 11 patients (73.3%), whereas a type II (residual neck) was achieved in 4 patients (26.7%). Follow-up examination was performed in 7/15 patients and showed stabilization of aneurysm closure with no thromboembolic complications and only 1 patient with an increased MRRC score (from I to II) due to coil compression.

CONCLUSIONS

Initial experience shows that the use of a new noncompletely occlusive net-assisted remodeling technique with the Cascade net device may be safe and effective for endovascular coil embolization of intracranial aneurysms.

Long-term outcomes of coil embolization of unruptured intracranial aneurysms

OBJECTIVELong-term follow-up results of the treatment of unruptured intracranial aneurysms (UIAs) by means of coil embolization remain unclear. The aim of this study was to analyze the frequency of rupture, retreatment, stroke, and death in patients with coiled UIAs who were followed for up to 20 years at multiple stroke centers.METHODSThe authors retrospectively analyzed data from cases in which patients underwent coil embolization between 1995 and 2004 at 4 stroke centers. In collecting the late (≥ 1 year) follow-up data, postal questionnaires were used to assess whether patients had experienced rupture or retreatment of a coiled aneurysm or any stroke or had died.RESULTSOverall, 184 patients with 188 UIAs were included. The median follow-up period was 12 years (interquartile range 11-13 years, maximum 20 years). A total of 152 UIAs (81%) were followed for more than 10 years. The incidence of rupture was 2 in 2122 aneurysm-years (annual rupture rate 0.09%). Nine of the 188 patients with coiled UIAs (4.8%) underwent additional treatment. In 5 of these 9 cases, the first retreatment was performed more than 5 years after the initial treatment. Large aneurysms were significantly more likely to require retreatment. Nine strokes occurred over the 2122 aneurysm-years. Seventeen patients died in this cohort.CONCLUSIONSThis study demonstrates a low risk of rupture of coiled UIAs with long-term follow-up periods of up to 20 years. This suggests that coiling of UIAs could prevent rupture for a long period of time. However, large aneurysms might need to be followed for a longer time.

Precipitating hydrophobic injectable liquid embolization of intracranial vascular shunts: initial experience and technical note

Precipitating hydrophobic injectable liquid is a new liquid embolic agent used mainly for intracranial neurointervention. The agent is ready to use (no shaking is required), since iodine, the radiopaque material, is covalently bonded into the compound. Additionally, due to the absence of tantalum, minimal artifacts are seen on postprocedure follow-up CT scans, and the agent penetrates into vessels smaller than 10 µm. The authors report their initial experience with the use of this agent in neurovascular intervention.

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

OBJECTIVE

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.

FRED Italian Registry: a multicenter experience with the flow re-direction endoluminal device for intracranial aneurysms

OBJECTIVE

The introduction of flow-diverter devices (FDDs) has revolutionized the endovascular treatment of intracranial aneurysms. Here the authors present their Italian multicenter experience using the flow re-direction endoluminal device (FRED) in the treatment of cerebral aneurysms, evaluating both short- and long-term safety and efficacy of this device.

METHODS

Between February 2013 and December 2014, 169 consecutive aneurysms treated using FRED in 166 patients were entered into this study across 30 Italian centers. Data collected included patient demographics, aneurysm location and characteristics, baseline angiography, adverse event and serious adverse event information, morbidity and mortality rates, and pre- and posttreatment modified Rankin Scale scores, as well as angiographic and cross-sectional CT/MRI follow-up at 3-6 months and/or 12-24 months per institutional standard of care. All images were reviewed and adjudicated by an independent core lab.

RESULTS

Of the 169 lesions initially entered into the study, 4 were later determined to be extracranial or nonaneurysmal by the core lab and were excluded, leaving 165 aneurysms in 162 patients treated in 163 procedures. Ninety-one (56.2%) patients were asymptomatic with aneurysms found incidentally. Of the 165 aneurysms, 150 (90.9%) were unruptured. One hundred thirty-four (81.2%) were saccular, 27 (16.4%) were fusiform/dissecting, and the remaining 4 (2.4%) were blister-like. One hundred thirty-seven (83.0%) arose from the anterior circulation.FRED deployment was impossible in 2/163 (1.2%) cases, and in an additional 4 cases (2.5%) the device was misdeployed. Overall mortality and morbidity rates were 4.3% and 7.3%, respectively, with rates of mortality and morbidity potentially related to FRED of up to 2.4% and 6.2%, respectively. Neuroimaging follow-up at 3-6 months showed complete or nearly complete occlusion of the aneurysm in 94% of cases, increasing to 96% at 12-24 months' follow-up. Aneurysmal sac shrinkage was observed in 78% of assessable aneurysms.

CONCLUSIONS

This preliminary experience using FRED for endovascular treatment of complex unruptured and ruptured aneurysms showed a high safety and efficacy profile that is comparable to those of other FDDs currently in use.

Predictive factors of incomplete aneurysm occlusion after endovascular treatment with the Pipeline embolization device

OBJECTIVE

The Pipeline embolization device (PED) is a routine choice for the endovascular treatment of select intracranial aneurysms. Its success is based on the high rates of aneurysm occlusion, followed by near-zero recanalization probability once occlusion has occurred. Therefore, identification of patient factors predictive of incomplete occlusion on the last angiographic follow-up is critical to its success.

METHODS

A multicenter retrospective cohort analysis was conducted on consecutive patients treated with a PED for unruptured aneurysms in 3 academic institutions in the US. Patients with angiographic follow-up were selected to identify the factors associated with incomplete occlusion.

RESULTS

Among all 3 participating institutions a total of 523 PED placement procedures were identified. There were 284 procedures for 316 aneurysms, which had radiographic follow-up and were included in this analysis (median age 58 years; female-to-male ratio 4.2:1). Complete occlusion (100% occlusion) was noted in 76.6% of aneurysms, whereas incomplete occlusion (≤ 99% occlusion) at last follow-up was identified in 23.4%. After accounting for factor collinearity and confounding, multivariable analysis identified older age (> 70 years; OR 4.46, 95% CI 2.30-8.65, p < 0.001); higher maximal diameter (≥ 15 mm; OR 3.29, 95% CI 1.43-7.55, p = 0.005); and fusiform morphology (OR 2.89, 95% CI 1.06-7.85, p = 0.038) to be independently associated with higher rates of incomplete occlusion at last follow-up. Thromboembolic complications were noted in 1.4% and hemorrhagic complications were found in 0.7% of procedures.

CONCLUSIONS

Incomplete aneurysm occlusion following placement of a PED was independently associated with age > 70 years, aneurysm diameter ≥ 15 mm, and fusiform morphology. Such predictive factors can be used to guide individualized treatment selection and counseling in patients undergoing cerebrovascular neurosurgery.

Change in the angle of the anterior genu is associated with occlusion rate after Pipeline flow diversion

OBJECTIVE

The Pipeline embolization device (PED) is a self-expanding mesh stent that diverts blood flow away from an aneurysm; it has been successfully used to treat aneurysms of the proximal internal carotid artery (ICA). PEDs have a remarkable ability to alter regional blood flow along the tortuous segments of the ICA and were incidentally found to alter the angle of the anterior genu after treatment. The authors quantified these changes and explored their implications as they relate to treatment effect.

METHODS

The authors retrospectively reviewed cases of aneurysms treated with a PED between the ophthalmic and posterior communicating arteries from 2012 through 2015. The angles of the anterior genu were measured on the lateral projections of cerebral angiograms obtained before and after treatment with a PED. The angles of the anterior genu of patients without aneurysms were used as normal controls.

RESULTS

Thirty-eight patients were identified who had been treated with a PED; 34 (89.5%) had complete obliteration and 4 (10.5%) had persistence of their aneurysm at last follow-up (mean 11.3 months). After treatment, 32 patients had an increase, 3 had a decrease, and 3 had no change in the angle of the anterior genu. The average measured angle of the anterior genu was 36.7° before treatment and 44.3° after treatment (p < 0.0001). The average angle of the anterior genu of control patients was 43.32° (vs 36.7° for the preoperative angle in the patients with aneurysms, p < 0.057). The average change in the angle of patients with postoperative Raymond scores of 1 was 9.10°, as compared with 1.25° in patients with postoperative Raymond scores > 1 (p < 0.001).

CONCLUSIONS

Treatment with a PED significantly changes the angle of the anterior genu. An average change of 9.1° was associated with complete obliteration of treated aneurysms. These findings have important implications for the treatment and management of cerebral aneurysm.

Effect of balloon guide catheter utilization on contact aspiration thrombectomy

OBJECTIVEThe role of the balloon guide catheter (BGC) has not been evaluated in contact aspiration thrombectomy (CAT) for acute stroke. Here, the authors aimed to test whether the BGC was associated with recanalization success and good functional outcome in CAT.METHODSAll patients who had undergone CAT as the first-line treatment for anterior circulation intracranial large vessel occlusion were retrospectively identified from prospectively maintained registries for six stroke centers. The patients were dichotomized into BGC utilization and nonutilization groups. Clinical findings, procedural details, and recanalization success rates were compared between the two groups. Whether the BGC was associated with recanalization success and functional outcome was assessed.RESULTSA total of 429 patients (mean age 68.4 ± 11.4 years; M/F ratio 215:214) fulfilled the inclusion criteria. A BGC was used in 45.2% of patients. The overall recanalization and good outcome rates were 80.2% and 52.0%, respectively. Compared to the non-BGC group, the BGC group had a significantly reduced number of CAT passes (2.6 ± 1.6 vs 3.4 ± 1.5), shorter puncture-to-recanalization time (56 ± 27 vs 64 ± 35 minutes), lower need for the additional use of thrombolytics (1.0% vs 8.1%), and less embolization to a distal or different site (0.5% vs 3.4%). The BGC group showed significantly higher final (89.2% vs 72.8%) and first-pass (24.2% vs 8.1%) recanalization success rates. After adjustment for potentially associated factors, BGC utilization remained independently associated with recanalization (OR 4.171, 95% CI 1.523-11.420) and good functional outcome (OR 2.103, 95% CI 1.225-3.612).CONCLUSIONSBGC utilization significantly increased the final and first-pass recanalization rates and remained independently associated with recanalization success and good functional outcome.

A retained guidewire fractured with subsequent pericardial tamponade two years after endovascular neurointervention

Entrapment of aneurysm embolization hardware is an extremely rare complication of endovascular neurointerventional procedures. We describe a case of a retained guidewire in a 42-year-old male during an aneurysm embolization. After unsuccessful attempts at removal via interventional methods, we decided to leave the guidewire within the vessel. A guidewire fracture resulted in several fragments in the carotid artery and aorta with subsequent cardiac tamponade, pseudoaneurysm and aortojejunal fistula two years later. The fragments in the aorta were removed via interventional and surgical methods. We advocate early surgical management of the retained guidewires after unsuccessful retractions via interventional methods. Meticulous and gentle maneuvering is necessary to prevent such serious complications.

Microhemorrhagic transformation of ischemic lesions on T2*-weighted magnetic resonance imaging after Pipeline embolization device treatment

OBJECTIVEThe authors sought to demonstrate that hemorrhagic transformation of ischemic lesions is the main cause of delayed intracerebral hemorrhage (ICH) after Pipeline embolization device (PED) treatment and to estimate the rate of hemorrhagic transformation of new postprocedure ischemic lesions.METHODSPatients who underwent PED placement (PED group) from November 2015 to March 2017 or stent-mediated embolization (EN group) from December 2010 to October 2015 were retrospectively analyzed. Pre- and postprocedural MR images and 6-month follow-up MR images for each patient were scored for the presence of postprocedural bland ischemic and hemorrhagic lesions using diffusion-weighted MRI (DWI) and T2*-weighted MRI (T2*WI), respectively.RESULTSThe PED group comprised 28 patients with 30 intracranial aneurysms, and the EN group comprised 24 patients with 27 intracranial aneurysms. The mean number of ischemic lesions on DWI 1 day postprocedure was higher in the PED group than in the EN group (5.2 vs 2.7, p = 0.0010). The mean number of microbleeds detected on T2*WI 6 months postprocedure was higher in the PED group than in the EN group (0.6 vs 0.15, p = 0.028). A total of 36.7% of PED-treated patients exhibited new microbleeds on T2*WI at 6 months postprocedure, with at least 77.8% of these lesions representing hemorrhagic transformations of the new ischemic lesions observed on day 1 postprocedure. The rate of adjunctive coil embolization (27.3% vs 0.0%, p = 0.016) and the mean number of ischemic lesions observed 1 day postprocedure (6.6 vs 4.3, p = 0.020) were predictors of subsequent microbleeds in the PED group.CONCLUSIONSNew microbleeds detected using T2*WI at 6 months postprocedure were more common after PED treatment than after stent-mediated embolization. Approximately three-quarters of these lesions were hemorrhagic transformations of new ischemic lesions observed on day 1 postprocedure. Prevention of intraprocedural or postprocedural infarcts is necessary to reduce the risk of hemorrhagic complications following PED placement.

Idiopathic intracranial hypertension: 120-day clinical, radiological, and manometric outcomes after stent insertion into the dural venous sinus

OBJECTIVE Idiopathic intracranial hypertension (IIH) is commonly associated with venous sinus stenosis. In recent years, transvenous dural venous sinus stent (DVSS) insertion has emerged as a potential therapy for resistant cases. However, there remains considerable uncertainty over the safety and efficacy of this procedure, in particular the incidence of intraprocedural and delayed complications and in the longevity of sinus patency, pressure gradient obliteration, and therapeutic clinical outcome. The aim of this study was to determine clinical, radiological, and manometric outcomes at 3-4 months after DVSS in this treated IIH cohort. METHODS Clinical, radiographic, and manometric data before and 3-4 months after DVSS were reviewed in this single-center case series. All venographic and manometric procedures were performed under local anesthesia with the patient supine. RESULTS Forty-one patients underwent DVSS venography/manometry within 120 days. Sinus pressure reduction of between 11 and 15 mm Hg was achieved 3-4 months after DVSS compared with pre-stent baseline, regardless of whether the procedure was primary or secondary (after shunt surgery). Radiographic obliteration of anatomical stenosis correlating with reduction in pressure gradients was observed. The complication rate after DVSS was 4.9% and stent survival was 87.8% at 120 days. At least 20% of patients developed restenosis following DVSS and only 63.3% demonstrated an improvement or resolution of papilledema. CONCLUSIONS Reduced venous sinus pressures were observed at 120 days after the procedure. DVSS showed lower complication rates than shunts, but the clinical outcome data were less convincing. To definitively compare the outcomes between DVSS and shunts in IIH, a randomized prospective study is needed.

Predictive factors of medullary infarction after endovascular internal trapping using coils for vertebral artery dissecting aneurysms

OBJECTIVE The first choice of treatment in cases of vertebral artery dissecting aneurysms (VADAs) is endovascular internal trapping (EIT) of the dissecting segment using coils. However, this procedure carries the risk of medullary infarction, and the risk factors for this complication are not well understood. This study investigated the risk factors causing medullary infarction. METHODS One hundred patients who underwent EIT for VADAs were included in this study. Ninety-three patients presented with subarachnoid hemorrhage. In cases involving the posterior inferior cerebellar artery (PICA), partial internal trapping targeting the ruptured site was performed to preserve the PICA. The VADAs were classified into the distal VA stump group, proximal VA stump group, and entire VA stump group, according to the location of VA segments without adequate flow-out vessels (such as the PICA [VA stump]) at risk of delayed thrombosis. The occurrence of medullary infarction was examined in each group using diffusion-weighted MRI and/or clinical symptoms. Various measurements were performed on digital subtraction angiography, and the risk factors for medullary infarction were analyzed. RESULTS Medullary infarction occurred in 30 patients, affecting the posterolateral medulla in 27 patients and the anteromedial medulla in 3 patients. Medullary infarction occurred in 3 of 47 patients (6%) in the distal VA stump group, 10 of 19 patients (53%) in the proximal VA stump group, and 17 of 34 patients (50%) in the entire VA stump group. The length of trapping was significantly longer in the infarction group than in the noninfarction group but did not differ among the 3 groups. Total length (length of trapping plus VA stump) was a risk factor for medullary infarction in the proximal VA stumps. CONCLUSIONS The primary risk factor for medullary infarction after EIT is not the length of trapping; rather, it is the anatomical location of the VADAs. The risk of medullary infarction is low in cases with distal VA stumps, but the symptoms are severe. Preservation of the origin of the anterior spinal artery can reduce the risk of medullary infarction. The risk of medullary infarction is high in cases with proximal VA stumps, but the symptoms are mild. A shorter length of trapping, although less likely to lead to complications, cannot prevent medullary infarction because the total length depends on the anatomical location of the PICA and not on the surgical technique. Reconstructive therapy should be indicated for patients with ruptured VADAs at high risk of severe ischemic complications (e.g., patients with hypoplasia of the contralateral VA or cases involving the PICA or anterior spinal artery, which are inappropriate for partial internal trapping) or for patients with unruptured VADAs.

Flow diverter devices in ruptured intracranial aneurysms: a single-center experience

OBJECTIVE In this single-center series, the authors retrospectively evaluated the effectiveness, safety, and midterm follow-up results of ruptured aneurysms treated by implantation of a flow diverter device (FDD). METHODS The records of 17 patients (12 females, 5 males, average World Federation of Neurosurgical Societies score = 2.9) who presented with subarachnoid hemorrhage (SAH) due to the rupture of an intracranial aneurysm treated with an FDD were retrospectively reviewed. Of 17 ruptured aneurysms, 8 were blood blister-like aneurysms and the remaining 9 were dissecting aneurysms. The mean delay between SAH and treatment was 4.2 days. Intraprocedural and periprocedural morbidity and mortality were recorded. Clinical and angiographic follow-up evaluations were conducted between 6 and 12 months after the procedure. RESULTS None of the ruptured aneurysms re-bled after endovascular treatment. The overall mortality rate was 12% (2/17), involving 2 patients who died after a few days because of complications of SAH. The overall morbidity rate was 12%: 1 patient experienced intraparenchymal bleeding during the repositioning of external ventricular drainage, and 1 patient with a posterior inferior cerebellar artery aneurysm developed paraplegia due to a spinal cord infarction after 2 weeks. The angiographic follow-up evaluations showed a complete occlusion of the aneurysm in 12 of 15 surviving patients; of the 3 remaining cases, 1 patient showed a remnant of the aneurysm, 1 patient was retreated due to an enlargement of the aneurysm, and 1 patient was lost at the angiographic follow-up. CONCLUSIONS FDDs can be used in patients with ruptured aneurysms, where conventional neurosurgical or endovascular treatments can be challenging.

Reliability assessment of the Biffl Scale for blunt traumatic cerebrovascular injury as detected on computer tomography angiography

OBJECTIVE Blunt traumatic cerebrovascular injury (TCVI) represents structural injury to a vessel due to high-energy trauma. The Biffl Scale is a widely accepted grading scheme for these injuries that was developed using digital subtraction angiography. In recent years, screening CT angiography (CTA) has been used to identify patients with TCVI. The reliability of this scale, with injuries assessed using CTA, has not yet been determined. METHODS Seven independent raters, including 2 neurosurgeons, 2 neuroradiologists, 2 neurosurgical residents, and 1 neurosurgical vascular fellow, independently reviewed each presenting CTA of the neck performed in 40 patients with confirmed TCVI and assigned a Biffl grade. Ten images were repeated to assess intrarater reliability, for a total of 50 CTAs. Fleiss' multirater kappa (κ) and interclass correlation were calculated as a measure of interrater reliability. Weighted Cohen's κ was used to assess intrarater reliability. RESULTS Fleiss' multirater κ was 0.65 (95% CI 0.61-0.69), indicating substantial agreement as to the Biffl grade assignment among the 7 raters. Interclass correlation was 0.82, demonstrating excellent agreement among the raters. Intrarater reliability was perfect (weighted Cohen's κ = 1) in 2 raters, and near perfect (weighted Cohen's κ > 0.8) in the remaining 5 raters. CONCLUSIONS Grading of TCVI with CTA using the Biffl Scale is reliable.

Aneurysms with persistent patency after treatment with the Pipeline Embolization Device

The Pipeline Embolization Device (PED) was approved for the treatment of intracranial aneurysms from the petrous to the superior hypophyseal segment of the internal carotid artery. However, since its approval, its use for treatment of intracranial aneurysms in other locations and non-sidewall aneurysms has grown tremendously. The authors report on a cohort of 15 patients with 16 cerebral aneurysms that incorporated an end vessel with no significant distal collaterals, which were treated with the PED. The cohort includes 7 posterior communicating artery aneurysms, 5 ophthalmic artery aneurysms, 1 superior cerebellar artery aneurysm, 1 anterior inferior cerebellar artery aneurysm, and 2 middle cerebral artery aneurysms. None of the aneurysms achieved significant occlusion at the last follow-up evaluation (mean 24 months). Based on these observations, the authors do not recommend the use of flow diverters for the treatment of this subset of cerebral aneurysms.

Evolution of treatment and a detailed analysis of occlusion, recurrence, and clinical outcomes in an endovascular library of 260 dural arteriovenous fistulas

OBJECTIVE Many small series and technical reports chronicle the evolution of endovascular techniques for cranial dural arteriovenous fistulas (dAVFs) over the past 3 decades, but reports of large patient series are lacking. The authors provide a thorough analysis of clinical and angiographic outcomes across a large patient cohort. METHODS The authors reviewed their endovascular database from January 1996 to September 2015 to identify patients harboring cranial dAVFs who were treated initially with endovascular approaches. They extracted demographic, presentation, angiographic, detailed treatment, and long-term follow-up data, and they evaluated natural history, initial angiographic occlusion, complications, recurrence, and symptomatic resolution rates. RESULTS Across a cohort of 251 patients with 260 distinct dAVFs, the overall initial angiographic occlusion rate was 70%; recurrence or occult residual lesions were seen on subsequent angiography in 3% of cases. The overall complication rate was 8%, with permanent neurological complications occurring in 3% of cases. Among 102 patients with dAVFs without cortical venous reflux, rates of resolution/improvement of pulsatile tinnitus and ocular symptoms were 79% and 78%, respectively. Following the introduction of Onyx during the latter half of the study period, the number of treated dAVFs doubled; the initial angiographic occlusion rate increased significantly from 60% before the use of Onyx to 76% after (p = 0.01). In addition, during the latter period compared with the pre-Onyx period, the rate of dAVFs obliterated via a transarterial-only approach was significantly greater (43% vs 23%, p = 0.002), as was the number of dAVFs obliterated via a single arterial pedicle (29% vs 11%, p = 0.002). CONCLUSIONS Overall, in the Onyx era, the rate of initial angiographic occlusion was approximately 80%, as was the rate of meaningful clinical improvement in tinnitus and/or ocular symptoms after initial endovascular treatment of cranial dAVFs.

Endoscope-assisted transsphenoidal puncture of the cavernous sinus for embolization of carotid-cavernous fistula in a neurosurgical hybrid operating suite

Endovascular embolization is the treatment of choice for carotid-cavernous fistulas (CCFs), but failure to catheterize the cavernous sinus may occur as a result of vessel tortuosity, hypoplasia, or stenosis. In addition to conventional transvenous or transarterial routes, alternative approaches should be considered. The authors present a case in which a straightforward route to the CCF was accessed via transsphenoidal puncture of the cavernous sinus in a neurosurgical hybrid operating suite. This 82-year-old man presented with severe chemosis and proptosis of the right eye. Digital subtraction angiography revealed a Type B CCF with a feeding artery arising from the meningohypophyseal trunk of the right cavernous segment of the internal carotid artery. The CCF drained through a thrombosed right superior ophthalmic vein that ended deep in the orbit; there were no patent sinuses or venous plexuses connecting to the CCF. An endoscope-assisted transsphenoidal puncture created direct access to the nidus for embolization. Embolic agents were deployed through the puncture needle to achieve complete obliteration. Endoscope-assisted transsphenoidal puncture of the cavernous sinus is a feasible alternative to treat difficult-to-access CCFs in a neurosurgical hybrid operating suite.

Role of terminal and anastomotic circulation in the patency of arteries jailed by flow-diverting stents: from hemodynamic changes to ostia surface modifications

OBJECTIVE The outcome for jailing arterial branches that emerge near intracranial aneurysms during flow-diverting stent (FDS) deployment remains controversial. In this animal study, the authors aimed to elucidate the role of collateral supply with regard to the hemodynamic changes and neointimal modifications that occur from jailing arteries with FDSs. To serve this purpose, the authors sought to quantify 1) the hemodynamic changes that occur at the jailed arterial branches immediately after stent placement and 2) the ostia surface values at 3 months after stenting; both parameters were investigated in the presence or absence of collateral arterial flow. METHODS After an a priori power analysis, 2 groups (Group A and Group B) were created according to an animal flow model for terminal and anastomotic arterial circulation; each group contained 7 Large White swine. Group A animals possessed an anastomotic-type arterial configuration to supply the territory of the right ascending pharyngeal artery (APhA), while Group B animals possessed a terminal-type arterial configuration to supply the right APhA territory. Subsequently, all animals underwent FDS placement, thereby jailing the right APhAs. Mean flow rates and velocities inside the jailed branches were quantified using time-resolved 3D phase-contrast MR angiography before and after stenting. Three months after stent placement, the jailed ostia surface values were quantified on scanning electron micrographs. The data were analyzed using descriptive statistics and group comparisons with parametric and nonparametric tests. RESULTS The endovascular procedures were feasible, and there were no findings of in situ thrombus formation on postprocedural optical coherence tomography or ischemia on postprocedural diffusion-weighted imaging. In Group A, the mean flow rate values at the jailed right APhAs were reduced immediately following stent placement as compared with values obtained before stent placement (p = 0.02, power: 0.8). In contrast, the mean poststenting flow rates for Group B remained similar to those obtained before stent placement. Three months after stent placement, the mean ostia surface values were significantly higher for Group B (527,911 ± 306,229 μm²) than for Group A (89,329 ± 59,762 μm²; p < 0.01, power: 1.00), even though the initial dimensions of the jailed ostia were similar between groups. A statistically significant correlation was found between groups (A or B), mean flow rates after stent placement, and ostia surface values at 3 months. CONCLUSIONS When an important collateral supply was present, the jailing of side arteries with flow diverters resulted in an immediate and significant reduction in the flow rate inside these arteries as compared with the prestenting values. In contrast, when competitive flow was absent, jailing did not result in significant flow rate reductions inside the jailed arteries. Ostium surface values at 3 months after stent placement were significantly higher in the terminal group of jailed arteries (Group B) than in the anastomotic group (Group A) and strongly correlated with poststenting reductions in the velocity value.

Embolization of the choroidal artery in the treatment of cerebral arteriovenous malformations

OBJECTIVE The anterior and posterior choroidal arteries are often recruited to supply arteriovenous malformations (AVMs) involving important paraventricular structures, such as the basal ganglia, internal capsule, optic radiation, lateral geniculate body, and medial temporal lobe. Endovascular embolization through these arteries is theoretically dangerous because they supply eloquent territories, are of small caliber, and lack collaterals. This study aimed to investigate the safety and efficacy of embolization through these arteries. METHODS This study retrospectively reviewed 13 patients with cerebral AVMs who underwent endovascular embolization through the choroidal arteries between 2006 and 2014. Embolization was performed as a palliative procedure before open surgery or Gamma Knife radiosurgery. Computed tomography and MRI were performed the day after embolization to assess any surgical complications. The incidence and type of complications and their association with clinical outcomes were analyzed. RESULTS Decreased blood flow was achieved in all patients after embolization. Postoperative CT detected no hemorrhagic complications. In contrast, postoperative MRI detected that 4 of the 13 patients (30.7%) developed infarctions: 3 patients after embolization through the anterior choroidal artery, and 1 patient after embolization through the lateral posterior choroidal artery. Two of the 4 patients in whom embolization was from the cisternal segment of the anterior choroidal artery (proximal to the plexal point) developed symptomatic infarction of the posterior limb of the internal capsule, 1 of whom developed morbidity (7.7%). The treatment-related mortality rate was 0%. Additional treatment was performed in 12 patients: open surgery in 9 and Gamma Knife radiosurgery in 3 patients. Complete obliteration was confirmed by angiography at the last follow-up in 10 patients. Recurrent bleeding from the AVMs did not occur in any of the cases during the follow-up period. CONCLUSIONS Ischemic complications are possible following the embolization of cerebral AVMs through the choroidal artery, even with modern neurointerventional devices and techniques. Although further study is needed, embolization through the choroidal artery may be an appropriate treatment option when the risk of surgery or radiosurgery is considered to outweigh the risk of embolization.

Comparison of non-stent retriever and stent retriever mechanical thrombectomy devices for the endovascular treatment of acute ischemic stroke

OBJECTIVE Mechanical thrombectomy is standard of care for the treatment of acute ischemic stroke. However, limited data are available from assessment of outcomes of FDA-approved devices. The objective of this study is to compare clinical outcomes, efficacy, and safety of non-stent retriever and stent retriever thrombectomy devices. METHODS Between January 2008 and June 2014, 166 patients treated at Jefferson Hospital for Neuroscience for acute ischemic stroke with mechanical thrombectomy using Merci, Penumbra, Solitaire, or Trevo devices were retrospectively reviewed. Primary outcomes included 90-day modified Rankin Scale (mRS) score, recanalization rate (thrombolysis in cerebral infarction [TICI score]), and incidence of symptomatic intracranial hemorrhages (ICHs). Univariate analysis and multivariate logistic regression determined predictors of mRS Score 3-6, mortality, and TICI Score 3. RESULTS A total of 99 patients were treated with non-stent retriever devices (Merci and Penumbra) and 67 with stent retrievers (Solitaire and Trevo). Stent retrievers yielded lower 90-day NIH Stroke Scale scores and higher rates of 90-day mRS scores ≤ 2 (22.54% [non-stent retriever] vs 61.67% [stent retriever]; p < 0.001), TICI Score 2b-3 recanalization rates (79.80% [non-stent retriever] vs 97.01% [stent retriever]; p < 0.001), percentage of parenchyma salvaged, and discharge rates to home/rehabilitation. The overall incidence of ICH was also significantly lower (40.40% [non-stent retriever] vs 13.43% [stent retriever]; p = 0.002), with a trend toward lower 90-day mortality. Use of non-stent retriever devices was an independent predictor of mRS Scores 3-6 (p = 0.002), while use of stent retrievers was an independent predictor of TICI Score 3 (p < 0.001). CONCLUSIONS Stent retriever mechanical thrombectomy devices achieve higher recanalization rates than non-stent retriever devices in acute ischemic stroke with improved clinical and radiographic outcomes and safety.

Endovascular therapy of low- and intermediate-grade intracranial lateral dural arteriovenous fistulas: a detailed analysis of primary success rates, complication rates, and long-term follow-up of different technical approaches

OBJECTIVE Sinus-preserving (SP) embolization techniques augment endovascular treatment options for intracranial lateral dural arteriovenous fistulas (DAVFs). The authors aimed to perform a retrospective comparison of their primary success rates, complication rates, and long-term follow-up with those of sinus-occluding (SO) treatment variants in the collective of low- and intermediate-grade lateral DAVFs (Cognard Types I-IIb). METHODS Clinical symptoms, complication rates, and Cognard grading prior to and after endovascular DAVF treatment using different technical approaches was retrospectively analyzed in 36 patients with lateral DAVF Cognard Types I-IIb. The long-term success rate was determined by a standardized questionnaire. RESULTS The SO approaches offered a higher rate of definitive fistula occlusion (93% SO vs 71% SP) but were accompanied by a significantly higher complication rate (33% or 20% SO vs 0% SP). The patients interviewed reported very high satisfaction with their health in long-term follow-up in both groups. CONCLUSIONS A higher rate of definitive fistula occlusion in the SO group was attained at the price of a significantly higher complication rate. The SP approaches offered a good primary success rate in combination with a very low complication rate. Despite some limitations of the data (e.g., a small sample size) the authors thus recommend an SP variant as the primary therapeutic option for the endovascular treatment of low- and intermediate-grade DAVFs. The SO approaches should be restricted to cases in which SP treatment does not achieve a downgrading to no worse than Cognard Type IIa.

Endovascular treatment of cerebral aneurysms using the Woven EndoBridge technique in a single center: preliminary results

OBJECTIVE The Woven EndoBridge (WEB) is an innovative new technique for securing cerebral aneurysms. It is designed particularly for wide-necked bifurcation aneurysms that otherwise would be difficult to treat. There is a paucity of follow-up data in the literature due to the novelty of this technique. The authors reviewed their data from cases involving patients treated at Leeds General Infirmary with the WEB device. They assessed the safety and complication risk associated with the device and clinical and radiological follow-up outcomes in their patients. This is, to their knowledge, the first publication to include the new single-layer sphere device (WEB SLS) in addition to the original dual-layer (WEB DL) and the (nonsphere) single-layer (WEB SL) devices. METHODS Data from 22 patients who underwent 25 WEB treatments were analyzed. Of the 25 WEB procedures, 3 were performed on an acute basis, 1 was performed on a semiacute basis, and the remaining 21 were elective. A novel 6-point scoring system called the Leeds WEB aneurysm occlusion scale was created to ensure accurate assessment based on the morphology of the WEB device. Outcome was assessed at follow-up by MR angiography with or without digital subtraction angiography and the modified Rankin Scale (mRS). RESULTS Deployment of the WEB device was successful in 22 (88%) of 25 procedures; 3 (12%) of the attempts at WEB treatment were abandoned. One of the patients in whom treatment was abandoned underwent a successful second attempt. Immediately after the 22 procedures with successful deployment, 4 (18%) of the patients had a complete occlusion of the aneurysm and WEB device; 10 (45%) had varying degrees of occlusion within the WEB device but no aneurysm neck or remnant; 3 (14%) had a neck remnant; and 5 (23%) had an aneurysm remnant. Of the patients with an aneurysm remnant, 1 had a complete aneurysm occlusion at ≥ 3-months follow-up. In total, 6 (27%) patients had a residual aneurysm at ≥ 3-months radiological follow-up. One of these patients was admitted with hydrocephalus secondary to a recurrent aneurysm and later received a second WEB treatment with additional coiling. Only 1 patient developed new neurological symptoms. This patient went from an mRS score of 0 to a score of 1 and had radiological evidence of a thromboembolic event. Two patients showed radiological evidence of a new thromboembolic event on follow-up MRI but were clinically asymptomatic. CONCLUSIONS The WEB has shown itself to be a promising new device with the potential to increase the scope of treatment for difficult wide-necked bifurcation aneurysms. The technique is safe, and short-term results show effective occlusion of complex aneurysms with minimal complications associated with the procedure. Long-term efficacy, however, still needs to be assessed.

Anterior spinal and bulbar artery supply to the posterior inferior cerebellar artery revealed by a ruptured aneurysm: case report

The posterior inferior cerebellar artery (PICA) is a vessel located between the intra- and extracranial circulation. The artery is characterized by a complex embryological development and numerous anatomical variants. The authors present a case of the PICA supplied by both a hypertrophic anterior spinal artery and a hypoplastic bulbar artery. This unusual arrangement somehow completes the list of previously published variants, and the spontaneous rupture of a related aneurysm confirmed the fragility of this network. The authors discuss anatomical and treatment considerations.

Incidence and predictors of dural venous sinus pressure gradient in idiopathic intracranial hypertension and non-idiopathic intracranial hypertension headache patients: results from 164 cerebral venograms

OBJECTIVE Cerebral venous pressure gradient (CVPG) from dural venous sinus stenosis is implicated in headache syndromes such as idiopathic intracranial hypertension (IIH). The incidence of CVPG in headache patients has not been reported. METHODS The authors reviewed all cerebral venograms with manometry performed for headache between January 2008 and May 2015. Patient demographics, headache etiology, intracranial pressure (ICP) measurements, and radiographic and manometric results were recorded. CVPG was defined as a difference ≥ 8 mm Hg by venographic manometry. RESULTS One hundred sixty-four venograms were performed in 155 patients. There were no procedural complications. Ninety-six procedures (58.5%) were for patients with IIH. The overall incidence of CVPG was 25.6% (42 of 164 procedures): 35.4% (34 of 96 procedures) in IIH patients and 11.8% (8 of 68 procedures) in non-IIH patients. Sixty procedures (36.6%) were performed in patients with preexisting shunts. Seventy-seven patients (49.7%) had procedures preceded by an ICP measurement within 4 weeks of venography, and in 66 (85.7%) of these patients, the ICP had been found to be elevated. CVPG was seen in 8.3% (n = 5) of the procedures in the 60 patients with a preexisting shunt and in 0% (n = 0) of the 11 procedures in the 77 patients with normal ICP (p < 0.001 for both). Noninvasive imaging (MR venography, CT venography) was assessed prior to venography in 112 (68.3%) of 164 cases, and dural venous sinus abnormalities were demonstrated in 73 (65.2%) of these cases; there was a trend toward CVPG (p = 0.07). Multivariate analysis demonstrated an increased likelihood of CVPG in patients with IIH (OR 4.97, 95% CI 1.71-14.47) and a decreased likelihood in patients with a preexisting shunt (OR 0.09, 95% CI 0.02-0.44). CONCLUSIONS CVPG is uncommon in IIH patients, rare in those with preexisting shunts, and absent in those with normal ICP.

The impact of hybrid neurosurgeons on the outcomes of endovascular coiling for unruptured cerebral aneurysms

OBJECTIVE The impact of combined practices on the outcomes of unruptured cerebral aneurysm coiling remains an issue of debate. The authors investigated the association of combined open and endovascular expertise with the outcomes of unruptured cerebral aneurysm coiling. METHODS The authors performed a cohort study of 100% of Medicare fee-for-service claims data for elderly patients who underwent endovascular coiling for unruptured cerebral aneurysms between 2007 and 2012. To control for confounding, the authors used propensity score conditioning, with mixed effects to account for clustering at the hospital referral region level. RESULTS During the study period, there were 11,716 patients who underwent endovascular coiling for unruptured cerebral aneurysms and met the inclusion criteria. Of these, 1186 (10.1%) underwent treatment performed by hybrid neurosurgeons, and 10,530 (89.9%) by proceduralists who performed only endovascular coiling. Multivariable regression analysis with propensity score adjustment demonstrated a lack of association of combined practice with 1-year postoperative mortality (OR 0.84; 95% CI 0.58-1.23), discharge to rehabilitation (OR 1.0; 95% CI 0.66-1.51), 30-day readmission rate (OR 1.07; 95% CI 0.83-1.38), and length of stay (adjusted difference, 0.41; 95% CI -0.26 to 1.09). Higher procedural volume was independently associated with improved outcomes. CONCLUSIONS In a cohort of Medicare patients, the authors did not demonstrate a difference in mortality, discharge to rehabilitation, readmission rate, and LOS between hybrid neurosurgeons and proceduralists performing only endovascular coiling.

An unusual complication of atrial fibrillation ablation: case report

The authors report a complication of catheter ablation that, to their knowledge, has never been previously reported. A 63-year-old man had undergone successful transvenous catheter thermoablation for atrial fibrillation. The patient remained well until 3 days prior to further admission when he noticed itching in the right frontal area of his scalp. On palpating his scalp, he discovered a metallic body projecting out of it and he proceeded to extract 20 cm of wire from his head. The following day a progressive left hemiplegia developed, and the patient experienced a deteriorating level of consciousness. A CT scan of the brain showed a right frontotemporal intraparenchymal hemorrhage and revealed a metallic structure in the middle of the hematoma. The hematoma was evacuated and a decompressive craniotomy was performed. The guidewire was identified, but it was only possible to extract part of it. It was covered by fibrous tissue, secondary to inflammatory reaction. To the authors' knowledge, this is the first report of guidewire-induced brain hemorrhage. The guidewire apparently had not been removed and had spontaneously migrated from the heart to the brain and beyond to the scalp where it then exited the patient's head. The patient had been well before he attempted to pull out the wire. Earlier identification of the iatrogenic complication of a retained guidewire might have prevented the fatal outcome in this case.

Balloon-assisted microcatheter navigation for AVM embolization: technical note

Recurrent feeders may preclude a successful arterial catheterization of arteriovenous malformations (AVMs). In this paper, the authors report their experience with the use of a compliant balloon to assist the microcatheter navigation in AVMs supplied by feeders with recurrent configuration. Eight patients with AVMs supplied by recurrent feeders had unsuccessful microcatheter navigation after multiple attempts to catheterize the pedicle. A compliant balloon was inflated in the parent artery immediately after the origin of the feeder. The microcatheter was then advanced over the wire while the balloon provided support for the navigation. Distal access close to the nidus was achieved in all cases. Anatomical cure was documented in 75% cases. There were no arterial perforations or thromboembolic events. The described technique is a straightforward method for providing support to microcatheter navigation in certain cases of cerebral AVMs supplied by recurrent arterial feeders. This simple yet effective maneuver may enhance outcomes of AVM embolization by eliminating the need for excessive attempts of catheterization.

Preparedness of neurosurgery graduates for neuroendovascular fellowship: a national survey of fellowship programs

OBJECT

Endovascular interventions have become an essential part of a neurosurgeon's practice. Whether endovascular procedures have been effectively integrated into residency curricula, however, remains uncertain. The purpose of this study was to assess the preparedness of US neurosurgery graduate trainees for neuroendovascular fellowship.

METHODS

A multidomain, global assessment survey was sent to all directors/faculty of neuroendovascular fellowship programs involved in training of US neurosurgery graduates. Surveyees were asked to assess trainees as they entered fellowship.

RESULTS

The response rate was 78% (25/32). Of respondent program directors, 38% reported that new fellows did not know the history and imaging of the patient and 50% were unable to formulate an appropriate treatment plan. As many as 79% of fellows were unfamiliar with endovascular devices and 75% were unfamiliar with angiographic equipment. Furthermore, 58% of fellows were unable to perform femoral access, 54% were unable to perform femoral closure, 79% were unable to catheterize a major vessel, 86% were unable to perform a 4-vessel angiogram, and 100% were unable to catheterize an aneurysm. Additionally, program directors reported that over 50% of fellows could not recognize neurovascular anatomy and 54% could not recognize/classify vascular abnormalities. There was an overall agreement that fellows demonstrated professionalism and interest in research and had good communication/clinical skills.

CONCLUSIONS

The results of this study suggest potential gaps in the training of neurosurgery residents with regard to endovascular neurosurgery. In an era of minimally invasive therapies, changes in residency curricula may be needed to keep pace with the ever-changing field of neurosurgery.

Long-term catheter angiography after aneurysm coil therapy: results of 209 patients and predictors of delayed recurrence and retreatment

OBJECT

Aneurysm recurrence after coil therapy remains a major shortcoming in the endovascular management of cerebral aneurysms. The need for long-term imaging follow-up was recently investigated. This study assessed the diagnostic yield of long-term digital subtraction angiography (DSA) follow-up and determined predictors of delayed aneurysm recurrence and retreatment.

METHODS

Inclusion criteria were as follows: 1) available short-term and long-term (> 36 months) follow-up DSA images, and 2) no or only minor aneurysm recurrence (not requiring further intervention, i.e., < 20%) documented on short-term follow-up DSA images.

RESULTS

Of 209 patients included in the study, 88 (42%) presented with subarachnoid hemorrhage. On shortterm follow-up DSA images, 158 (75%) aneurysms showed no recurrence, and 51 (25%) showed minor recurrence (< 20%, not retreated). On long-term follow-up DSA images, 124 (59%) aneurysms showed no recurrence, and 85 (41%) aneurysms showed recurrence, of which 55 (26%) required retreatment. In multivariate analysis, the predictors of recurrence on long-term follow-up DSA images were as follows: 1) larger aneurysm size (p = 0.001), 2) male sex (p = 0.006), 3) conventional coil therapy (p = 0.05), 4) aneurysm location (p = 0.01), and 5) a minor recurrence on short-term follow-up DSA images (p = 0.007). Ruptured aneurysm status was not a predictive factor. The sensitivity of short-term follow-up DSA studies was only 40.0% for detecting delayed aneurysm recurrence and 45.5% for detecting delayed recurrence requiring further treatment.

CONCLUSIONS

The results of this study highlight the importance of long-term angiographic follow-up after coil therapy for ruptured and unruptured intracranial aneurysms. Predictors of delayed recurrence and retreatment include large aneurysms, recurrence on short-term follow-up DSA images (even minor), male sex, and conventional coil therapy.

Carotid cutdown for surgical retrieval of a guidewire introducer: an unusual complication after mitral valve repair

With the use of endovascular techniques and indwelling catheters, potential complications can include embolization of fragments or components of various systems. The authors describe the surgical retrieval of a guidewire introducer from the right common carotid artery (CCA). A 64-year-old man was found to have a foreign body within the right CCA on CT angiography after he had presented with a transient ischemic attack. He had undergone a complex mitral valve repair several months before presenting to the authors' facility. That procedure involved a femoral artery cutdown and the insertion of an endovascular aortic balloon for cardiac bypass. As in most endovascular procedures, guidewire introducers were probably used to facilitate the introduction of the guidewire into the system during the procedure. Although rare, iatrogenic embolization of the introducer probably occurred during use of the guidewire. The guidewire introducer was successfully retrieved without complication by using a standard carotid cutdown approach. It is extraordinarily unusual for an extracorporeal part of an implantable system to embolize to the carotid circulation. To the authors' knowledge, this is the only reported case of an embolized guidewire introducer and the use of a carotid exposure to retrieve an intraluminal foreign body. This case demonstrates that a carotid cutdown approach can be used successfully for the retrieval of intraluminal extracranial carotid artery foreign bodies.

Vessel perforation during withdrawal of Trevo ProVue stent retriever during mechanical thrombectomy for acute ischemic stroke

The authors report a case of an intracranial extravasation during the withdrawal of a Trevo ProVue stent retriever device in a patient being treated for acute ischemic stroke. An 82-year-old woman developed sudden left hemiparesis and aphasia during an urgent cardiac catheterization procedure for a non-ST elevation myocardial infarction. She had a baseline National Institutes of Health Stroke Scale (NIHSS) score of at least 10 and no improvement with intravenous administration of tissue plasminogen activator (tPA). Cerebral angiography was performed with conscious sedation, confirming an occlusion of the superior division of the right middle cerebral artery (MCA). Using standard technique, a Trevo thrombectomy device was deployed across the clot. Post-thrombectomy control angiography demonstrated complete revascularization of the right MCA. The device was then gently withdrawn without difficulty. Immediately afterward the patient's blood pressure showed a sudden and significant elevation. Immediate posttreatment angiography demonstrated active extravasation from the posterior wall of the communicating segment of the right internal carotid artery. Rapid cessation of bleeding was achieved with intravenous administration of protamine and induced hypotension. Immediate neurological assessment was performed, which showed motor improvement. An immediate postintervention CT scan confirmed a moderate-sized subarachnoid hemorrhage and contrast in the prepontine cistern. The patient was discharged home on postoperative Day 3 with an NIHSS score of zero. At 6-month follow-up in the neurointerventional clinic, her NIHSS and modified Rankin Scale scores were both zero. Endovascular stent retriever devices are increasingly being used as first-line thrombectomy devices in acute embolic strokes. A unique and previously undescribed complication is vessel perforation during withdrawal of a stent retriever. Conservative treatment options and reversal of anticoagulation should be the first line of treatment for such complications. In the authors' case, performing the procedure without anesthesia was helpful in assessing the patient's neurological status.

A 6-Fr guiding catheter (Slim Guide(®)) for use with multiple microdevices

BACKGROUND

We developed a new 6-Fr guiding catheter (Slim Guide(®)) that features a large lumen (0.072 inch) for performing advanced techniques as are required in patients with wide-necked aneurysms whose treatment with a single microcatheter is difficult.

METHODS

The Slim Guide was used to address 30 saccular and 20 dissecting aneurysms. All 50 patients presented with subarachnoid hemorrhage. To perform the advanced techniques we used SL-10(®) or Excel 14(®) and Hyperform(®) balloon microcatheters.

RESULTS

Of the 30 patients with saccular aneurysms, 20 were treated with the double microcatheter- and the other 10 with the balloon assist technique. All 20 patients with dissecting aneurysms were treated with the double microcatheter technique. We encountered slight interference during the treatment of one saccular aneurysm with the balloon assist technique using the Slim Guide guiding catheter; another patient with a saccular aneurysm treated with the balloon assist technique suffered a minor transient ischemic complication.

CONCLUSIONS

With the Slim Guide, the risks inherent in the application of advanced techniques may be decreased. Its use facilitates the coil embolization of aneurysms that pose treatment challenges.