Use of Pipeline Embolization Devices for treatment of a direct carotid-cavernous fistula.

BACKGROUND: The use of minimally porous endoluminal devices (MPEDs) such as the Pipeline Embolization Device (PED) has been described for the treatment of brain aneurysms. The benefit of using MPEDs to assist embolization of a direct high-flow carotid cavernous fistula resulting from a ruptured cavernous carotid artery aneurysm is not well documented. METHODS: We describe our experience with deploying a tailored multidevice PED construct across the cavernous internal carotid artery (ICA) wall defect in combination with transarterial coil embolization using the "jailed microcatheter" technique. RESULTS: A 59-year-old woman presented with acute left-sided ophthalmoplegia. Diagnostic cerebral angiography demonstrated a ruptured giant cavernous carotid aneurysm with fistulous outflow via the ipsilateral left superior ophthalmic vein and into the pterygoid venous plexi bilaterally. Via the Marksman microcatheter, a total of three PEDs measuring 4.5 mm × 18 mm, 4.5 mm × 20 mm, and 4.75 mm × 16 mm were telescoped within the ICA across the aneurysm neck. Coiling of the aneurysm fundus and cavernous sinus via the "jailed" Rapidtransit microcatheter was subsequently achieved. A 2-year follow-up digital subtraction angiography (DSA) demonstrated stable obliteration of the aneurysm and the fistula, coincident with complete resolution of the patient's symptoms. CONCLUSIONS: Based on our long-term clinical and angiographic results, we advocate that the presented method be a valid treatment option for selected cases.

Carotid Stenting without Embolic Protection Increases Major Adverse Events: Analysis of the National Surgical Quality Improvement Program.

BACKGROUND AND PURPOSE: Published data regarding embolic protection device efficacy is mixed, and its use during carotid artery stent placement remains variable. We, therefore, examined the frequency of embolic protection device use and its association with outcomes after carotid artery stent placement using a national quality improvement data base. MATERIALS AND METHODS: Patients undergoing carotid artery stent placement with or without embolic protection devices were identified in the American College of Surgeons National Surgical Quality Improvement Program data base. The primary outcome was the incidence of major adverse cardiovascular events (defined as death, stroke, or myocardial infarction/arrhythmia) within 30 days. Propensity scoring was used to create 2 matching cohorts of patients using demographic and baseline variables. RESULTS: Between 2011 and 2018, among 1200 adult patients undergoing carotid artery stent placement, 23.8% did not have embolic protection devices. There was no trend toward increased embolic protection device use with time. Patients without embolic protection device use received preoperative antiplatelets less frequently (90.6% versus 94.6%, P = .02), underwent more emergent carotid artery stent placement (7.2% versus 3.6%, P = .01), and had a higher incidence of major adverse cardiovascular events (OR = 1.81; 95% CI, 1.11-2.94) and stroke (OR = 3.31; 95% CI, 1.71-6.39). After compensating for baseline imbalances using propensity-matched cohorts (n = 261 for both), carotid artery stent placement without an embolic protection device remained associated with increased major adverse cardiovascular events (9.2% versus 4.2%; OR = 2.30; 95% CI, 1.10-4.80) and stroke (6.5% versus 1.5%; OR = 4.48; 95% CI, 1.49-13.49). CONCLUSIONS: Lack of embolic protection device use during carotid artery stent placement is associated with a 4-fold increase in the likelihood of perioperative stroke. Nevertheless, nearly one-quarter of patients in the American College of Surgeons National Surgical Quality Improvement Program underwent unprotected carotid artery stent placement. Efforts targeting improved embolic protection device use during carotid artery stent placement are warranted.

Refractory Stroke Thrombectomy: Prevalence, Etiology, and Adjunctive Treatment in a North American Cohort.

BACKGROUND AND PURPOSE: Acute stroke intervention refractory to mechanical thrombectomy may be due to underlying vessel wall pathology including intracranial atherosclerotic disease and intracranial arterial dissection or recalcitrant emboli. We studied the prevalence and etiology of refractory thrombectomy, the safety and efficacy of adjunctive interventions in a North American-based cohort. MATERIALS AND METHODS: We performed a multicenter, retrospective study of refractory thrombectomy, defined as unsuccessful recanalization, vessel reocclusion in <72 hours, or required adjunctive antiplatelet glycoprotein IIb/IIIa inhibitors, intracranial angioplasty and/or stenting to achieve and maintain reperfusion. Clinical and imaging criteria differentiated etiologies for refractory thrombectomy. Baseline demographics, cerebrovascular risk factors, technical/clinical outcomes, and procedural safety/complications were compared between refractory and standard thrombectomy groups. Multivariable logistic regression analysis was performed to determine independent predictors of refractory thrombectomy. RESULTS: Refractory thrombectomy was identified in 25/302 cases (8.3%), correlated with diabetes (44% versus 22%, P = .02) as an independent predictor with OR = 2.72 (95% CI, 1.05-7.09; P = .04) and inversely correlated with atrial fibrillation (16% versus 45.7%, P = .005). Refractory etiologies were secondary to recalcitrant emboli (20%), intracranial atherosclerotic disease (60%), and/or intracranial arterial dissection (44%). Four (16%) patients were diagnosed with early vessel reocclusion, and 21 patients underwent adjunctive salvage interventions with glycoprotein IIb/IIIa inhibitor infusion alone (32%) or intracranial angioplasty and/or stenting (52%). There were no significant differences in TICI 2b/3 reperfusion efficacy (85.7% versus 90.9%, P = .48), symptomatic intracranial hemorrhage rates (0% versus 9%, P = .24), favorable clinical outcomes (39.1% versus 48.3%, P = .51), or mortality (13% versus 28.3%, P = .14) versus standard thrombectomy. CONCLUSIONS: Refractory stroke thrombectomy is encountered in <10% of cases, independently associated with diabetes, and related to underlying vessel wall pathology (intracranial atherosclerotic disease and/or intracranial arterial dissection) or, less commonly, recalcitrant emboli. Emergent salvage interventions with glycoprotein IIb/IIIa inhibitors or intracranial angioplasty and/or stenting are safe and effective adjunctive treatments.

Flow Diversion of Posterior Circulation Aneurysms: Systematic Review of Disaggregated Individual Patient Data.

BACKGROUND: Experience with endoluminal flow diversion for the treatment of posterior circulation aneurysms is limited. PURPOSE: We sought to investigate factors associated with the safety and efficacy of this treatment by collecting disaggregated patient-level data from the literature. DATA SOURCES: PubMed, EMBASE, and Ovid were searched up through 2019 for articles reporting flow diversion of posterior circulation aneurysms. STUDY SELECTION: Eighty-four studies reported disaggregated data for 301 separate posterior circulation aneurysms. DATA ANALYSIS: Patient, aneurysm, and treatment factors were collected for each patient. Outcomes included the occurrence of major complications, angiographic occlusion, and functional outcomes based on the mRS. DATA SYNTHESIS: Significant differences in aneurysm and treatment characteristics were seen among different locations. Major complications occurred in 22%, angiographic occlusion was reported in 65% (11.3 months of mean follow-up), and good functional outcomes (mRS 0-2) were achieved in 67% (13.3 months of mean follow-up). Multivariate analysis identified age, number of flow diverters used, size, and prior treatment to be associated with outcome measures. Meta-analysis combining the current study with prior large nondisaggregated series of posterior circulation aneurysms treated with flow diversion found a pooled incidence of 20% (n = 712 patients) major complications and 75% (n = 581 patients) angiographic occlusions. LIMITATIONS: This study design is susceptible to publication bias. Use of antiplatelet therapy was not uniformly reported. CONCLUSIONS: Endoluminal flow diversion is an important tool in the treatment of posterior circulation aneurysms. Patient age, aneurysm size, prior treatment, and the number of flow diverters used are important factors associated with complications and outcomes.

GUide sheath Advancement and aspiRation in the Distal petrocavernous internal carotid artery (GUARD) Technique during Thrombectomy Improves Reperfusion and Clinical Outcomes.

BACKGROUND AND PURPOSE: Adjunctive techniques to stent retriever thrombectomy include balloon-guide catheters and/or distal access catheters for aspiration. We describe a novel technique using a flexible, 6 French 088 distal guide sheath advanced past the skull base to augment mechanical thrombectomy. We studied the relative safety and efficacy of this technique in the setting of a combined stent retriever-distal access catheter aspiration thrombectomy protocol. MATERIALS AND METHODS: We performed a retrospective case-control study of intracranial internal carotid artery or M1-M2 middle cerebral artery occlusions requiring mechanical thrombectomy. Patients were divided into 2 groups based on thrombectomy techniques: conventional stent retriever with distal access catheter aspiration without (standard) and with adjunctive GUide sheath Advancement and aspiRation in the Distal petrocavernous internal carotid artery (GUARD). Using propensity score matching, we compared procedural safety, reperfusion efficacy using the modified Thrombolysis in Cerebral Infarction scale and clinical outcomes with the modified Rankin Scale. RESULTS: In comparing the GUARD (45 patients) versus standard (45 matched case controls) groups, there were no significant differences in demographics, NIHSS presentations, IV rtPA use, median onset-to-groin puncture times, procedural complications, symptomatic intracranial hemorrhage, or mortality. The GUARD group demonstrated significantly higher successful mTICI ≥2b reperfusion rates (98% versus 80%, P = .015) and improved functional mRS ≤2 outcomes (67% versus 43%, P = .04), with independent effects of the GUARD technique confirmed in a multivariable logistic regression model. CONCLUSIONS: The GUARD technique during mechanical thrombectomy with combined stent retrieval-distal access catheter aspiration is safe and effective in improving reperfusion and clinical outcomes.

Diagnostic Accuracy of High-Resolution Black-Blood MRI in the Evaluation of Intracranial Large-Vessel Arterial Occlusions.

BACKGROUND AND PURPOSE: 3D high-resolution black-blood MRI or MR vessel wall imaging allows evaluation of the intracranial arterial wall and extraluminal pathology. We investigated the diagnostic accuracy and reliability of black-blood MRI for the intraluminal detection of large-vessel arterial occlusions. MATERIALS AND METHODS: We retrospectively identified patients with intracranial arterial occlusions, confirmed by CTA or DSA, who also underwent 3D black-blood MRI with nonenhanced and contrast-enhanced T1 sampling perfection with application-optimized contrasts by using different flip angle evolution (T1 SPACE) sequences. Black-blood MRI findings were evaluated by 2 independent and blinded neuroradiologists. Large-vessel intracranial arterial segments were graded on a 3-point scale (grades 0-2) for intraluminal baseline T1 hyperintensity and contrast enhancement. Vessel segments were considered positive for arterial occlusion if focal weak (grade 1) or strong (grade 2) T1-hyperintense signal and/or enhancement replaced the normal intraluminal black-blood signal. RESULTS: Thirty-one patients with 38 intracranial arterial occlusions were studied. The median time interval between black-blood MRI and CTA/DSA reference standard studies was 2 days (range, 0-20 days). Interobserver agreement was good for T1 hyperintensity (κ = 0.63) and excellent for contrast enhancement (κ = 0.89). High sensitivity (100%) and specificity (99.8%) for intracranial arterial occlusion diagnosis was observed with either intraluminal T1 hyperintensity or contrast-enhancement imaging criteria on black-blood MRI. Strong grade 2 intraluminal enhancement was maintained in >80% of occlusions irrespective of location or chronicity. Relatively increased strong grade 2 intraluminal T1 hyperintensity was noted in chronic/incidental versus acute/subacute occlusions (45.5% versus 12.5%, P = .04). CONCLUSIONS: Black-blood MRI with or without contrast has high diagnostic accuracy and reliability in evaluating intracranial large-vessel arterial occlusions with near-equivalency to DSA and CTA.

Adjunctive Efficacy of Intra-Arterial Conebeam CT Angiography Relative to DSA in the Diagnosis and Surgical Planning of Micro-Arteriovenous Malformations.

BACKGROUND AND PURPOSE: Micro-arteriovenous malformations are an underrecognized etiology of intracranial hemorrhage. Our study aimed to assess the adjunctive efficacy of intra-arterial conebeam CTA relative to DSA in the diagnosis and surgical planning of intracranial micro-AVMs. MATERIALS AND METHODS: We performed a retrospective study of all micro-AVMs (≤1-cm nidus) at our institution. Blinded neuroradiologists qualitatively graded DSA and intra-arterial conebeam CTA images for the detection of specific micro-AVM anatomic parameters (arterial feeder, micronidus, and venous drainer) and defined an overall diagnostic value. Statistical and absolute differences in the overall diagnostic values defined the relative intra-arterial conebeam CTA diagnostic values, respectively. Blinded neurosurgeons reported their treatment approach after DSA and graded the adjunctive value of intra-arterial conebeam CTA to improve or modify treatment. Intra-arterial conebeam CTA efficacy was defined as interobserver agreement in the relative intra-arterial conebeam CTA diagnostic and/or treatment-planning value scores. RESULTS: Ten patients with micro-AVMs presented with neurologic deficits and/or intracranial hemorrhages. Both neuroradiologists assigned a higher overall intra-arterial conebeam CTA diagnostic value (P < .05), secondary to improved evaluation of both arterial feeders and the micronidus, with good interobserver agreement (τ = 0.66, P = .018) in the relative intra-arterial conebeam CTA diagnostic value. Both neurosurgeons reported that integrating the intra-arterial conebeam CTA data into their treatment plan would allow more confident localization for surgical/radiation treatment (8/10; altering the treatment plan in 1 patient), with good interobserver agreement in the relative intra-arterial conebeam CTA treatment planning value (τ = 0.73, P = .025). CONCLUSIONS: Adjunctive intra-arterial conebeam CTA techniques are more effective in the diagnostic identification and anatomic delineation of micro-AVMs, relative to DSA alone, with the potential to improve microsurgical or radiosurgery treatment planning.

Emergent Endovascular Management of Long-Segment and Flow-Limiting Carotid Artery Dissections in Acute Ischemic Stroke Intervention with Multiple Tandem Stents.

BACKGROUND AND PURPOSE: Although most cervical dissections are managed medically, emergent endovascular treatment may become necessary in the presence of intracranial large-vessel occlusions, flow-limiting and long-segment dissections with impending occlusion, and/or hypoperfusion-related ischemia at risk of infarction. We investigated the role of emergent endovascular stenting of long-segment carotid dissections in the acute ischemic stroke setting. MATERIALS AND METHODS: We retrospectively studied long-segment carotid dissections requiring stent reconstruction with multiple tandem stents (≥3 stents) and presenting with acute (<12 hours) ischemic stroke symptoms (NIHSS score, ≥4). We analyzed patient demographics, vascular risk factors, clinical presentations, imaging/angiographic findings, technical procedures/complications, and clinical outcomes. RESULTS: Fifteen patients (mean age, 51.5 years) with acute ischemic stroke (mean NIHSS score, 15) underwent endovascular stent reconstruction for vessel and/or ischemic tissue salvage. All carotid dissections presented with >70% flow limiting stenosis and involved the distal cervical ICA with a minimum length of 3.5 cm. Carotid stent reconstruction was successful in all patients with no residual stenosis or flow limitation. Nine patients (60%) harbored intracranial occlusions, and 6 patients (40%) required intra-arterial thrombolysis/thrombectomy, achieving 100% TICI 2b-3 reperfusion. Two procedural complications were limited to thromboembolic infarcts from in-stent thrombus and asymptomatic hemorrhagic infarct transformation (7% morbidity, 0% mortality). Angiographic and ultrasound follow-up confirmed normal carotid caliber and stent patency, with 2 cases of <20% in-stent stenosis. Early clinical improvement resulted in a mean discharge NIHSS score of 6, and 9/15 (60%) patients achieved a 90-day mRS of ≤2. CONCLUSIONS: Emergent stent reconstruction of long-segment and flow-limiting carotid dissections in acute ischemic stroke intervention is safe and effective, with favorable clinical outcomes, allowing successful thrombectomy, vessel salvage, restoration of cerebral perfusion, and/or prevention of recurrent thromboembolic stroke.

Endoluminal Reconstruction for Nonsaccular Aneurysms of the Proximal Posterior Cerebral Artery with the Pipeline Embolization Device.

BACKGROUND AND PURPOSE: Treatment options for nonsaccular posterior cerebral artery aneurysms include a range of surgical and endovascular reconstructive and deconstructive methods. However, no truly satisfactory treatment option is available to date for lesions arising from the P1 and P2 segments. The purpose of the present case series is to investigate both the efficacy and safety of the Pipeline Embolization Device in treating these challenging aneurysms. MATERIALS AND METHODS: We present a series of 6 consecutive patients who underwent endoluminal reconstruction with the Pipeline Embolization Device for nonsaccular P1 or P2 segment aneurysms between January 2009 and June 2013. RESULTS: Aneurysm location included the P1 segment in 2 patients and the P2 segment in 4 patients. Mean aneurysm diameter was 23 mm (range, 5-44 mm). Mean length of the arterial segment involved was 10 mm (range, 6-19 mm). Clinical presentation included mass effect in 4 patients and perforator stroke and subacute aneurysmal subarachnoid hemorrhage in 1 patient each. Endovascular reconstruction was performed by using 1 Pipeline Embolization Device in 5 patients and 2 overlapping Pipeline Embolization Devices in the remaining patient. Angiographic aneurysm occlusion was immediate in 1 patient, within 6 months in 4 patients, and within 1 year in the remaining patient. Index symptoms resolved in 4 patients and stabilized in the remaining 2. No new permanent neurologic sequelae and no aneurysm recurrence were recorded during the mean follow-up period of 613 days (range, 540-725 days). CONCLUSIONS: Endovascular reconstruction with the Pipeline Embolization Device for nonsaccular aneurysms arising from the P1 and P2 segments compares favorably with historical treatment options in terms of occlusion rate, margin of safety, and neurologic outcome.

Anterior choroidal artery patency and clinical follow-up after coverage with the pipeline embolization device.

BACKGROUND AND PURPOSE: Endoluminal reconstruction with the Pipeline Embolization Device is an effective treatment option for select intracranial aneurysms. However, concerns for the patency of eloquent branch arteries covered by the Pipeline Embolization Device have been raised. We aimed to examine the patency of the anterior choroidal artery and clinical sequelae after ICA aneurysm treatment. MATERIALS AND METHODS: We prospectively analyzed all patients among our first 157 patients with ICA aneurysms treated by the Pipeline Embolization Device who required placement of at least 1 device across the ostium of the anterior choroidal artery. The primary outcome measure was angiographic patency of the anterior choroidal artery at last follow-up. Age, sex, type of aneurysm, neurologic examination data, number of Pipeline Embolization Devices used, relationship of the anterior choroidal artery to the aneurysm, and completeness of aneurysm occlusion on follow-up angiograms were also analyzed. RESULTS: Twenty-nine aneurysms requiring placement of at least 1 Pipeline Embolization Device (median = 1, range = 1-3) across the anterior choroidal artery ostium were identified. At angiographic follow-up (mean = 15.1 months; range = 12-39 months), the anterior choroidal artery remained patent, with antegrade flow in 28/29 aneurysms (96.5%), while 24/29 (82.7%) of the target aneurysms were angiographically occluded by 1-year follow-up angiography. Anterior choroidal artery occlusion, with retrograde reconstitution of the vessel, was noted in a single case. A significant correlation between the origin of the anterior choroidal artery from the aneurysm dome and failure of the aneurysms to occlude following treatment was found. CONCLUSIONS: After placement of 36 Pipeline Embolization Devices across 29 anterior choroidal arteries (median = 1 device, range = 1-3 devices), 1 of 29 anterior choroidal arteries was found occluded on angiographic follow-up. The vessel occlusion did not result in persistent clinical sequelae. Coverage of the anterior choroidal artery origin with the Pipeline Embolization Device, hence, may be considered reasonably safe when deemed necessary for aneurysm treatment.

Foreign Body Emboli following Cerebrovascular Interventions: Clinical, Radiographic, and Histopathologic Features.

Foreign material emboli following cerebral, cardiac, and peripheral catheterizations have been reported since the mid-1990s. Catheter coatings have been frequently implicated. The most recent surge of interest in this phenomenon within the neurointerventional community is associated with procedures using flow-diversion devices for the treatment of cerebral aneurysms. Following coil-supported Pipeline embolization in 4 cases and stent-supported coiling in 1, 5 patients developed multiple subcentimeter enhancing lesions, usually with surrounding edema and variable magnetic susceptibility in the vascular territories of the treated aneurysms. Conventional angiography findings were unrevealing. Laboratory work-up showed mild CSF protein elevation with no leukocytosis. Brain biopsy in 2 cases revealed granulomatous angiitis encasing foreign material, identical in stain appearance to a polyvinylpyrrolidone catheter coating. Corticosteroid administration typically produced clinical improvement. A heterogeneous radiographic and clinical course was noted, with rise and fall in the number of enhancing lesions in 2 patients and persistence in others. The etiology may be related to widespread adoption of increasingly sophisticated catheterization techniques.