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Background: Aneurysm recurrence after coiling has been associated with aneurysm growth, (re)hemorrhage, and a greater need for follow-up. The second-generation HydroCoil Embolic System (HES; MicroVention, Inc) consists of a platinum core with integrated hydrogel and was developed to reduce recurrence through enhancing packing density and healing within the aneurysm., Objective: To compare recurrence between the second-generation HES and bare platinum coil (BPC) in the new-generation Hydrogel Endovascular Aneurysm Treatment Trial (HEAT)., Methods: HEAT is a randomized, controlled trial that enrolled subjects with ruptured or unruptured 3- to 14-mm intracranial aneurysms amenable to coiling. The primary endpoint was aneurysm recurrence using the Raymond-Roy scale. Secondary endpoints included minor and major recurrence, packing density, adverse events related to the procedure and/or device, mortality, initial complete occlusion, aneurysm retreatment, hemorrhage from target aneurysm during follow-up, aneurysm occlusion stability, and clinical outcome at final follow-up., Results: A total of 600 patients were randomized (HES, n = 297 and BPC, n = 303), including 28% with ruptured aneurysms. Recurrence occurred in 11 (4.4%) subjects in the HES arm and 44 (15.4%) subjects in the BPC arm (P = .002). While the initial occlusion rate was higher with BPC, the packing density and both major and minor recurrence rates were in favor of HES. Secondary endpoints including adverse events, retreatment, hemorrhage, mortality, and clinical outcome did not differ between arms., Conclusion: Coiling of small-to-medium aneurysms with second-generation HES resulted in less recurrence when compared to BPC, without increased harm. These data further support the use of the second-generation HES for the embolization of intracranial aneurysms., (© Congress of Neurological Surgeons 2020.)

Background: The safety of PipelineTM Embolization Device (PED; Medtronic Inc, Dublin, Ireland) in posterior circulation aneurysms is still controversial., Objective: To study complications associated with the treatment of posterior circulation aneurysms by conducting a subgroup analysis from the International Retrospective Study of PED registry., Methods: Data from 91 consecutive patients with 95 posterior circulation aneurysms at 17 centers between July 2008 to February 2013 were analyzed. The primary endpoint was defined as any complication leading to neurological morbidity or death. The outcome predictors were calculated using Kaplan-Meier and Cox regression methods., Results: The mean aneurysm size was 13.8 mm. Aneurysm types were saccular (36.8%), fusiform (29.5%), dissecting (28.4%), and others (5.3%). The median follow-up was 21.1 mo. Twelve (13.2%) patients encountered a primary endpoint event. In multivariate analysis for the primary endpoint, use of ≥3 PEDs and fusiform shape compared with other shapes had hazard ratios (HRs) of 7.77 (95% confidence interval [CI], 2.48-25.86; P = .0007) and 3.48 (95% CI, 1.06-13.39; P = .0488), respectively. The multivariate HR of aneurysm size for neurological morbidity after PED implantation was 1.11 (95% CI, 1.04-1.18; P = .0015), and HRs of ruptured aneurysm and age for neurological mortality were 8.1 (95% CI, 1.31-41.26; P = .0197) and 1.07 (95% CI, 1.02-1.15; P = .0262), respectively. Basilar artery aneurysm had an HR of 3.54 (95% CI, 1.12-14.18, P = .0529) in the univariate analysis for major outcomes., Conclusion: PED implantation may be considered for the treatment of posterior circulation aneurysms, especially of saccular or dissecting type. Our major complications appear to be comparable to those reported previously after clipping and coiling in the literature. Neurointerventionists should consider the shape, size, rupture, and location of complex posterior circulation aneurysms as well as age and PED number before the PED placement.

Background: No conventional surgical intervention has been shown to improve outcomes for patients with spontaneous intracerebral hemorrhage (ICH) compared with medical management., Objective: We report the initial multicenter experience with a novel technique for the minimally invasive evacuation of ICH using the Penumbra Apollo system (Penumbra Inc, Alameda, California)., Methods: Institutional databases were queried to perform a retrospective analysis of all patients who underwent ICH evacuation with the Apollo system from May 2014 to September 2014 at 4 centers (Medical University of South Carolina, Stony Brook University, University of California at San Diego, and Semmes-Murphy Clinic). Cases were performed either in the neurointerventional suite, operating room, or in a hybrid operating room/angiography suite., Results: Twenty-nine patients (15 female; mean age, 62 ± 12.6 years) underwent the minimally invasive evacuation of ICH. Six of these parenchymal hemorrhages had an additional intraventricular hemorrhage component. The mean volume of ICH was 45.4 ± 30.8 mL, which decreased to 21.8 ± 23.6 mL after evacuation (mean, 54.1 ± 39.1% reduction; P < .001). Two complications directly attributed to the evacuation attempt were encountered (6.9%). The mortality rate was 13.8% (n = 4)., Conclusion: Minimally invasive evacuation of ICH and intraventricular hemorrhage can be achieved with the Apollo system. Future work will be required to determine which subset of patients are most likely to benefit from this promising technology.

Background: Large or giant complex vertebrobasilar junction aneurysms have a dismal natural history and are often challenging to treat with standard endovascular or neurosurgical techniques., Objective: To report initial experience with endovascular treatment of these aneurysms using flow-diverting stents (FDS)., Methods: Ten patients with FDS treatment of complex vertebrobasilar junction aneurysms were collected from 4 large cerebrovascular centers. Clinical/angiographic presentation and outcome were retrospectively analyzed., Results: Of 10 aneurysms, 7 presented with brainstem compression, 2 with ischemia, and 1 with subarachnoid hemorrhage, and 3 were recurrent after stent-assisted treatments. Eight were giant. Morphology was fusiform in 5, fusiform dissecting in 1, and multilobulated saccular in 4. Six were partially thrombosed. In addition to FDS (mean number of devices, 3.9; range, 1-9), contralateral vertebral artery sacrifice and adjunctive coiling were performed in 9 and 5 of the 10 patients, respectively. At follow-up, 5 of 10 were completely occluded, 4 showed minimal residual filling, and 1 was retreated with an additional FDS. Postinterventionally, worsening mass effect and ischemic complications were seen in 2 and 4 of 10, respectively. Clinical outcome was good in 6 (modified Rankin Scale score, 0-2). Four fatalities were related to sequelae of subarachnoid hemorrhage, late FDS thrombosis, progressive mass effect, and delayed intracranial hemorrhage., Conclusion: FDS may be used to treat complex vertebrobasilar junction aneurysms with overall good angiographic outcome. A combined reconstructive/deconstructive approach appears useful to avoid endoleaks. FDS strategies, like other endovascular and neurosurgical approaches to these lesions, are associated with significant risk and therefore should be reserved for those cases in which alternative approaches either are deemed unsafe or are likely to be ineffective., Abbreviations: FDS, flow-diverting stentPED, Pipeline Embolization DeviceSAH, subarachnoid hemorrhageVA, vertebral arteryVBJ, vertebrobasilar junction.

Background: Enrollment in the stenting and aggressive medical management for the prevention of stroke in intracranial stenosis (SAMMPRIS) trial was halted owing to higher-than-expected 30-day stroke rates in the stenting arm. Improvement in periprocedural stroke rates from angioplasty and stenting for intracranial atherosclerotic disease (ICAD) requires an understanding of the mechanisms of these events., Objective: To identify the types and mechanisms of periprocedural stroke after angioplasty and stenting for ICAD., Methods: Patients who experienced a hemorrhagic or ischemic stroke or a cerebral infarct with temporary signs within 30 days of attempted angioplasty and stenting in SAMMPRIS were identified. Study records, including case report forms, procedure notes, and imaging were reviewed. Strokes were categorized as ischemic or hemorrhagic. Ischemic strokes were categorized as perforator territory, distal embolic, or delayed stent thrombosis. Hemorrhagic strokes were categorized as subarachnoid or intraparenchymal. Causes of hemorrhage (wire perforation, vessel rupture) were recorded., Results: Three patients had an ischemic stroke after diagnostic angiography. Two of these strokes were unrelated to the procedure. Twenty-one patients had an ischemic stroke (n = 19) or cerebral infarct with temporary signs (n = 2) within 30 days of angioplasty and stenting. Most (n = 15) were perforator territory and many of these occurred after angiographically successful angioplasty and stenting of the basilar artery (n = 8). Six patients experienced a subarachnoid hemorrhage (3 from wire perforation) and 7 had a delayed intraparenchymal hemorrhage., Conclusion: Efforts at reducing complications from angioplasty and stenting for ICAD must focus on reducing the risks of regional perforator infarction, delayed intraparenchymal hemorrhage, and wire perforation.

Background and Importance: Intracranial venous hypertension is known to be associated with venous outflow obstruction. We discuss the diagnosis and treatment of mechanical venous outflow obstruction causing pseudotumor cerebri., Clinical Presentation: We report 2 patients presenting with central venous outflow obstruction secondary to osseous compression of the internal jugular veins at the craniocervical junction. The point of jugular compression was between the lateral tubercle of C1 and a prominent, posteriorly located styloid process. In both cases, catheter venography showed high-grade jugular stenosis at the level of C1 with an associated pressure gradient. The dominant jugular vein was decompressed after the styloid process was resected. Postoperative imaging confirmed resolution of the jugular stenosis and normalization of preoperative pressure gradients. In both cases, the symptoms of intracranial hypertension resolved., Conclusion: Intracranial venous hypertension may result from extrinsic osseous compression of the jugular veins at the skull base. Although rare, this phenomenon is important to recognize because primary stenting not only is ineffective but also may actually exacerbate the outflow obstruction. The osseous impingement of the dominant jugular vein can be relieved via a decompressive styloidectomy, and the clinical results can be excellent.

Background: Double stenting in a Y configuration may be used to treat a subset of wide-necked aneurysms not amenable to reconstruction with a single stent., Objective: We studied the feasibility, safety, and mid-term angiographic outcome of patients treated using this technique., Methods: A retrospective review was undertaken of all coil embolizations of wide-necked aneurysms using double stents in a Y configuration., Results: Nineteen patients were identified from 2002 to 2010 (14 women, 5 men) with a mean age of 57.4 years. Stents were deployed in a Y configuration achieving complete occlusion (5/19), residual neck (5/19), and residual aneurysm filling (9/19). Angiographic follow-up was available for a mean of 16 months, and clinical follow up was available for a mean of 21.4 months. The incidence of complications at the initial treatment was 6 of 19 (31.6%), and delayed thromboembolic complications occurred in 2 of 19 (10.5%). An angiographic neck recurrence requiring retreatment developed in only 1 of the patients in whom complete occlusion was obtained with the initial treatment. Spontaneous thrombosis and complete occlusion on follow-up imaging were found in 6 patients in whom initial neck or aneurysm filling was observed. Ultimately, 12 of the aneurysms (63.2%) were completely occluded on follow-up angiography., Conclusion: Y-stent reconstruction enables the endovascular management of otherwise complex, wide-necked cerebral aneurysms and can be performed safely in experienced hands with satisfactory mid-term results, even in cases requiring retreatment.

Objective: We present 2 cases of carotid-cavernous fistulas that failed multiple attempts at transarterial and transvenous embolization. Direct transorbital puncture for embolization was successful in curing the fistulas. The relevant anatomy and technique are reviewed., Clinical Presentation: The first case is a 39-year-old man who presented with a 2-month history of worsening right-sided chemosis, proptosis, double vision, and progressive right eye vision loss. The second case is a 79-year-old woman with a 5-month history of right-sided chemosis and a 1-month history of complete left ophthalmoplegia. Cerebral angiography revealed an indirect carotid-cavernous fistula (CCF) in both patients, supplied by meningeal branches of the internal and/or external carotid arteries., Intervention: After multiple unsuccessful attempts at transarterial and transvenous embolization, the CCFs were accessed via direct percutaneous transorbital puncture of the inferior and superior ophthalmic veins, respectively. The fistulas were then successfully occluded with a combination of Onyx and detachable coils., Conclusion: In rare cases in which more conventional transvenous and transarterial routes to a CCF have been exhausted, direct percutaneous transorbital puncture represents a viable means of achieving catheterization of the fistulous connection. In most cases, where a prominent arterialized superior ophthalmic vein is present, direct puncture represents a reasonable alternative to ophthalmologic cut-down procedures. Transorbital puncture of the inferior ophthalmic vein provides a direct route to the cavernous sinus in cases where the superior ophthalmic vein is atretic and inaccessible by direct surgical cut-down procedures.

Background: The Pipeline embolization device (PED) is a new endoluminal construct designed to exclude aneurysms from the parent cerebrovasculature. We report the very late (>1 year) thrombosis of a PED construct placed for the treatment of a left vertebral aneurysm., Clinical Presentation: A patient with an occluded right vertebral artery and a large, fusiform intracranial left vertebral artery aneurysm was treated with PED and coil reconstruction. A durable, complete occlusion of the aneurysm was confirmed with control angiography at 1 year. The patient remained neurologically normal for 23 months until he experienced a transient visual disturbance followed weeks later by a minor brainstem stroke., Intervention: Imaging evaluation showed thrombosis of the PED construct with complete occlusion of the left vertebral artery. After this stroke, he was initially treated with dual antiplatelet therapy and was then converted to warfarin. The patient remained neurologically stable for 5 months until he experienced progressive basilar thrombosis that ultimately resulted in a fatal stroke., Conclusion: The PED represents a promising new endovascular technology for the treatment of cerebral aneurysms; however, as an investigational device, long-term follow-up data are sparse at this point. The etiology of the very late thrombosis of the PED construct in this case remains unknown; however, this report underscores the need for a continued, careful systematic evaluation and close long-term follow-up of treated patients.

Background: Vertebral origin angioplasty and stenting (VOAS) with bare metal stents is associated with a high rate of in-stent restenosis (ISR)., Objective: We evaluated the rate of ISR after VOAS with drug-eluting stents., Methods: Twenty patients (15 men, 5 women; age range, 36-88 years; mean, 63.7 years) were treated for VOAS with a paclitaxel-eluting stent (Taxus Express2, Boston Scientific, Natick, Massachusetts). Stenosis at follow-up was quantified as insignificant (0%-24%), mild (25%-49%), moderate (50%-74%), and severe (75%-100%). ISR was defined using a binary criteria of >50% stenosis at follow-up angiography., Results: All procedures were technically successful with no periprocedural complications. Follow-up angiography (range, 4-48 months; mean, 14.7 months) showed insignificant stenosis in 9 patients, mild in 6, moderate in 4, and severe in 1. In 1 patient with "moderate" stenosis, the stent migrated distally; therefore, the lesion restenosis was not within the stent. Thus, 4 of 19 patients (21%) exhibited binary moderate or severe ISR, and 5 of 20 showed restenosis at the lesion (25%). The patient with severe stenosis developed stent thrombosis>3 years after VOAS., Conclusion: VOAS with drug-eluting stents was associated with a low incidence of periprocedural complications. Although the rate of restenosis was half that seen with the use of bare metallic stents, 21% of patients still developed moderate or severe ISR. These patients may require>or=1 revascularization procedures. The risk of delayed stent thrombosis may necessitate lifelong dual antiplatelet medications.

Objectives: The Pipeline embolization device (PED) (Chestnut Medical Technologies, Inc., Menlo Park, CA) is a new microcatheter-delivered endovascular construct designed to achieve the curative reconstruction of the parent arteries giving rise to wide-necked and fusiform intracranial aneurysms. We present our initial periprocedural experience with the PED and midterm follow-up results for a series of 53 patients., Methods: Patients harboring large and giant wide-necked, nonsaccular, and recurrent intracranial aneurysms were selected for treatment. All patients were pretreated with dual antiplatelet medications for at least 72 hours before surgery and continued taking both agents for at least 6 months after treatment. A control digital subtraction angiogram was typically performed at 3, 6, and 12 months., Results: Fifty-three patients (age range, 11-77 years; average age, 55.2 years; 48 female) with 63 intracranial aneurysms were treated with the PED. Small (n = 33), large (n = 22), and giant (n = 8) wide-necked aneurysms were included. A total of 72 PEDs were used. Treatment was achieved with a single PED in 44 aneurysms, with 2 overlapping PEDs in 17 aneurysms, and with 3 overlapping PEDs in 2 aneurysms. The mean time between the treatment and last follow-up digital subtraction angiogram was 5.9 months (range, 1-22 months). Complete angiographic occlusion was achieved in 56%, 93%, and 95% of aneurysms at 3 (n = 42), 6 (n = 28), and 12 (n = 18) months, respectively. The only aneurysm that remained patent at the time of the 12-month follow-up examination had been treated previously with stent-supported coiling. The presence of a preexisting endoluminal stent may have limited the efficacy of the PED reconstruction in this aneurysm. No aneurysms demonstrated a deterioration of angiographic occlusion during the follow-up period (i.e., no recanalizations). No major complications (stroke or death) were encountered during the study period. Three patients (5%), all with giant aneurysms, experienced transient exacerbations of preexisting cranial neuropathies and headache after the PED treatment. All 3 were treated with corticosteroids, and these symptoms resolved within 1 month., Conclusion: Endovascular reconstruction with the PED represents a safe, durable, and curative treatment of selected wide-necked, large and giant cerebral aneurysms. The rate of complete occlusion at the time of the 12-month follow-up examination approached 100% in the present study. To date, no angiographic recurrences have been observed during serial angiographic follow-up.

Objective: To demonstrate the curative reconstruction of a giant circumferential basilar trunk aneurysm using the Pipeline embolization device (PED) (Chestnut Medical Technologies, Inc., Menlo Park, CA) alone, without embolization coils., Methods: A 13-year-old female patient was referred for the treatment of a 4-cm, partially thrombosed, circumferential midbasilar trunk aneurysm. Her presenting symptoms included headache, nystagmus, and left upper-extremity ataxia. Open surgical and conventional endovascular treatment options were thought to be of unacceptably high risk and unlikely to achieve a definitive treatment. The patient underwent PED treatment under a Food and Drug Administration compassionate use exemption., Results: An endovascular construct was built across the affected segment of the basilar trunk with 7 serially placed, telescoping PEDs, which bridged the 29-mm aneurysm neck. Completion angiography demonstrated considerably decreased flow into the aneurysm, with stasis persisting into the venous phase of angiography. No technical complications were encountered. No new neurological symptoms were evident, and the patient's original presenting symptoms resolved completely within 24 hours after the procedure. She was discharged on postoperative Day 3. Computed tomography performed on postoperative Day 5 demonstrated no change in the size of the collective aneurysm-thrombus mass. Conventional angiography performed on postoperative Day 7 showed anatomic reconstruction of the basilar artery and complete occlusion of the circumferential aneurysm. The patient remains neurologically normal., Conclusion: The PED provides a safe and definitive constructive treatment option for large, giant, and fusiform/circumferential aneurysms. The PED can achieve complete aneurysm occlusion without embolization coils. When applied judiciously, the PED may be used safely in vascular segments that give rise to eloquent perforators.

Objective: To describe delayed migration of a coil loop after adjunctive balloon remodeling of an anterior communicating artery aneurysm., Methods: A 56-year-old man with a subarachnoid hemorrhage from a small anterior communicating artery aneurysm underwent successful coil embolization with adjunctive balloon remodeling., Results: Eight days after the procedure, the patient returned with the acute onset of right lower extremity paralysis. Magnetic resonance imaging demonstrated an acute left anterior cerebral artery territory infarction. Angiography demonstrated that this infarct was secondary to the delayed migration of a coil loop out of the aneurysm and into the left A1 to A2 junction., Conclusion: Delayed migration of a coil loop after adjunctive balloon remodeling represents a rare but potentially severe complication of this technique.

Objective: In some patients, collateral circulation may preserve the viability of brain parenchyma distal to an intracranial arterial occlusion for hours or days after the presenting event. These patients may be good candidates for revascularization, even when they present outside of the accepted 6-hour time window for stroke intervention., Methods: Three patients were revascularized with the Wingspan stent system (Boston Scientific/Target, Fremont, CA) after presenting with subacute occlusions of intracranial arteries and progressive ischemic symptoms despite maximal medical therapy. All pre- and postprocedural imaging data and clinical records were reviewed., Results: Three patients (mean age, 64 years; 2 women, 1 man) presented with symptomatic intracranial occlusions of the internal carotid artery (n = 2) and vertebrobasilar system (n = 1). All 3 patients presented more than 6 hours after symptom onset, and no intravenous or intra-arterial thrombolysis had been instituted. In all cases, despite supportive medical therapy (anticoagulation and antiplatelet therapy and induced hypertension), the patients continued to demonstrate progressive ischemia, both clinically and on diffusion magnetic resonance imaging. All patients were successfully revascularized without periprocedural complications and improved clinically after revascularization., Conclusion: In selected patients, symptomatic subacute occlusions of intracranial arteries may be revascularized using the Wingspan stent system.

Objective: To describe a novel double-balloon trapping technique for endovascular embolization of a broad-based saccular aneurysm of the superior cerebellar artery., Clinical Presentation: A 62-year-old man with a history of diabetes, coronary artery disease, and smoking presented with a syncopal episode. Catheter angiography revealed a large (11.7 x 9.4 x 11.2 mm) right superior cerebellar artery (SCA) aneurysm with a 7-mm neck, incorporating the origin of the right SCA., Intervention: An endovascular double-balloon trapping technique was used. Using bilateral groin access and bilateral vertebral artery guide catheters, a 4 x 20 mm HyperGlide balloon (ev3 Neurovascular, Irvine, CA) was placed across the neck of the aneurysm, and a 4 x 7 mm HyperForm balloon (ev3 Endovascular Inc., Plymouth, MN) was placed within the aneurysm. The aneurysm was catheterized with an Echelon 14 microcatheter (ev3 Endovascular Inc.). The inflated HyperGlide balloon was used to protect the parent basilar artery and "trap" the smaller HyperForm balloon within the aneurysm. The HyperForm balloon was inflated within the aneurysm and gently retracted to protect the origin of the SCA at the aneurysm neck. The aneurysm was coiled with the balloons inflated. A 4.5 x 20 mm Neuroform stent (Boston Scientific, Natick, MA) was deployed across the aneurysm neck. Final procedural angiography showed near complete occlusion of the aneurysm and preservation of flow in the SCA. Follow-up angiography at 8 months showed progressive thrombosis with complete occlusion of the aneurysm, preserved patency of the SCA, and anatomic reconstruction of the native artery. The patient remained neurologically normal at the time of the follow-up evaluation., Conclusion: Double-balloon trapping is a novel endovascular technique that can be used to treat wide-necked aneurysms and maintain patency of side branches incorporated into the aneurysm neck.

Objective: Paraophthalmic aneurysms may exert mass effect on the optic apparatus. Although surgical clipping and endovascular coiling of these aneurysms can be complicated by immediate postoperative visual deterioration, endovascular coil embolization has the unique risk of visual complications later (>24 h) in the perioperative period., Methods: Six patients with a delayed onset of vision loss after technically successful coil embolization of paraophthalmic region aneurysms were identified. All available clinical, angiographic, and cross sectional imaging for these patients, in addition to histopathological data, were reviewed., Results: Six patients who underwent endovascular treatment of paraclinoid aneurysms at our institutions developed delayed postoperative visual decline. Four were treated with combination hydrogel-coated and bare platinum coils, one with hydrogel-coated coils, and one with bare platinum coils. Three patients presented with some degree of visual impairment caused by their aneurysms. Catheter angiography performed after the visual decline revealed no etiology in any of the cases. Magnetic resonance imaging was performed in all patients and was unremarkable in two. At follow-up, two had improved, three remained unchanged, and one patient died before any follow-up assessment of her vision., Conclusion: Both acute and delayed visual disturbances can present after the endovascular treatment of carotid artery paraophthalmic aneurysms. Delayed visual deterioration can be observed up to 35 days after embolization. Although the cause is still undefined, it is likely that the more delayed visual deterioration can be attributed to progression of mass effect and/or perianeurysmal inflammatory change. Our case series raises the possibility that this phenomenon may be more likely with HydroCoil (HydroCoil Embolic System; MicroVention, Aliso Viejo, CA). This possibility should be taken into account by neurointerventionists when selecting a coil type to treat large paraophthalmic aneurysms.

Objective: We describe our initial experience with the use of a novel, compliant guide catheter designed for placement within the cranial vasculature in a series of seven patients who were treated for various intracranial pathologies., Clinical Presentation: Seven patients were deemed to have either tortuous supra-aortic, intracranial, and/or extracranial vasculature or to require additional microcatheter support as the result of lesion location., Intervention: The patients were treated, in part, with the 6-French Neuron delivery catheter (Penumbra, Inc., San Leandro, CA) at the authors' two institutions. The guide catheter was positioned in various distal locations within the intracranial internal carotid artery or external carotid artery. Three patients were treated for unruptured intracranial aneurysms, 2 patients for intracranial atherosclerosis, 1 patient for an arteriovenous malformation, and 1 patient for a pseudoaneurysm., Conclusion: All lesions were successfully treated through a microcatheter advanced in a coaxial fashion through the guide catheter. There were no complications related to the positioning of the catheter. Distal intra- or extracranial placement of a specially designed, compliant guide catheter can be performed safely and may improve access and microcatheter stability in patients with tortuous vessels or difficult-to-reach lesions.

Objective: Microcatheters retained after Onyx (eV3 Neurovascular, Inc., Irvine, CA) embolization represent a potential source of thromboembolic complications. Catheter retention depends on the degree of Onyx reflux and vessel tortuosity. To overcome this problem, we have adapted a previously described monorail snare technique for stretched coils to remove an adherent microcatheter from the occipital artery during Onyx embolization of a dural arteriovenous fistula., Clinical Presentation: We used this technique successfully in a 62-year-old man with a posterior fossa dural arteriovenous fistula. An Echelon-10 microcatheter (eV3 Neurovascular, Inc.) system became adherent in the right occipital artery because of reflux and vessel tortuosity. Significant stretching of the microcatheter was observed during attempted removal., Intervention: A 2-mm Amplatz Goose Neck microsnare (Microvena Corp., White Bear Lake, MN) was placed through a Rapid Transit microcatheter (Cordis Corp., Miami, FL). The hub of the indwelling Echelon microcatheter was cut off and the snare advanced over the outside of the microcatheter. The snare and Rapid Transit microcatheter were then advanced into the guiding catheter (6-French) as a unit over the indwelling Echelon microcatheter. Using the adherent Echelon as a "monorail" guide, the snare and Rapid Transit microcatheter were advanced distally into the occipital artery and the snare was retracted to engage the microcatheter. The microcatheters and snare were then easily removed because of the second vector of force placed by the snare system on the adherent microcatheter very close to the point of adherence., Conclusion: The monorail snare technique represents a simple and safe way to remove an adherent microcatheter from an Onyx cast during the embolization of dural arteriovenous fistulas. Prospective knowledge of this technique will facilitate more aggressive embolization without the reservation that a retained microcatheter could require surgical removal or anticoagulation.

Objective: The Pipeline embolization device (PED; Chestnut Medical, Menlo Park, CA) is a new endovascular construct designed to exclude aneurysms from the parent cerebrovasculature. We report the results of the first two human implantations of this device in North America., Clinical Presentation: Two patients presenting with large, symptomatic, circumferential, fusiform intracranial vertebral artery aneurysms were treated with the PED. In both cases, more traditional open microneurosurgical and neuroendovascular treatment strategies had either failed or were associated with unacceptably high risk., Intervention: Three PEDs were placed across the aneurysms in each of the patients to achieve reconstruction of a new parent vessel through the center of a circumferential aneurysm. In the first patient, who had previously been treated with stent-supported coil embolization, the PED construct alone was sufficient to achieve parent vessel reconstruction and exclusion of the recurrent aneurysm. In the second patient, a microcatheter was jailed within the saccular portion of the aneurysm and the parent vessel was reconstructed with three telescoped PEDs. Although the PED construct dramatically reduced flow into the aneurysm, the lesion remained patent. Coiling of the saccular portion of the aneurysm was subsequently performed via the jailed microcatheter. Follow-up angiography performed 72 hours after the procedure demonstrated occlusion of the aneurysm with cylindrical reconstruction of the affected vascular segment. Neither patient has experienced any complication in the periprocedural period (30 d) or during subsequent long-term (>1 year) follow-up., Conclusion: The PED represents an important advance in the endovascular therapy of cerebral aneurysms, targeting primary parent vessel reconstruction rather than endosaccular occlusion as a means by which to achieve exclusion of the aneurysm and definitive anatomic reconstruction of the parent artery.

Objective: To describe a novel technique for single stent reconstruction of wide-necked aneurysms arising from the circle of Willis., Methods: Neuroform stents (Boston Scientific/Target, Fremont, CA) were placed across the basilar apex (right P1 to left P1) via the posterior communicating artery in two patients, across the left carotid terminus (left A1 to left M1) via the anterior communicating artery in two patients, and across the anterior communicating artery (left A1 to right A1) in one patient for stent-supported coil embolization., Results: Five women underwent successful deployment of the Neuroform stent across the circle of Willis to support subsequent coil embolization of a wide-necked cerebral aneurysm. In two patients with subarachnoid hemorrhage, initial dome coiling was performed for short-term protection, and stents were applied across the circle of Willis to support completion of coil embolization during a second session. None of the patients experienced any periprocedural or delayed neurological complications., Conclusion: Stenting across the circle of Willis represents a novel adjuvant technique to support the coiling of selected wide-necked intracranial aneurysms. This technique is particularly useful for wide-necked terminal aneurysms that incorporate both branches of a bifurcation in a configuration unfavorable for Y-stent reconstruction.

Objective: Balloon-mounted coronary stents (BMCS) have been adapted for use in the intracranial circulation for the treatment of symptomatic intracranial atheromatous disease (ICAD). We performed a retrospective analysis of our 7-year experience with these devices in an attempt to quantify the periprocedural risks and long-term outcomes in patients with symptomatic ICAD of the vertebrobasilar (VB) system treated with BMCS., Methods: A retrospective review of a prospectively maintained database was performed to determine the neurological and non-neurological periprocedural risks of BMCS treatment of ICAD. Patients were followed with serial transcranial Doppler (TCD) and, in some cases, angiographic imaging. The clinical status was determined based on clinic visits and by telephone interviews when possible., Results: Over the 6-year period from March 1999 to May 2005, 44 patients (35 men, 9 women; average age, 64.8 yr) with 47 symptomatic atheromatous lesions of the VB system were treated with BMCS. In two patients, the BMSC could not be delivered across the target lesion. Treatment of the remaining 45 lesions was technically successful (95.7%). The periprocedural neurological morbidity and mortality was 26.1% (10 clinically evident strokes, 2 deaths). One additional patient experienced a periprocedural transient ischemic attack (TIA). Two patients died of non-neurological causes within 6 months (4.3%, myocardial infarction and cholecystitis). The average stenosis measured 82.5%, declining to 10.0% stenosis after BMCS. TCD examinations showed a preprocedural velocity of 127.7 cm/second (n = 43; standard deviation, 63.7 cm/s), which declined to 54.0 cm/s immediately after the procedure (n = 42; standard deviation, 22.7 cm/s). In patients with serial TCD evaluations, velocities were typically constant over years of follow-up (six patients with >5 yr of follow-up; average velocity, 52.2 cm/s). Angiographic follow-up was available for 11 patients. Three patients had stent occlusion (all symptomatic with TIAs), one patient had greater than 50% in-stent restenosis (ISR) (symptomatic with TIA) and seven had no significant (<50%) stenosis. The overall ISR/occlusion rate was 12.5% (4 out of 32 lesions with angiographic and/or TCD follow-up > 6 mo). Of the 42 patients who successfully underwent BMCS, clinical follow-up was available for 33 (78.6%, average follow-up period, 43.5 mo), three patients died before any follow-up could be performed, and seven were lost to follow-up. Of the patients with follow-up, five had recurrent vertebrobasilar ischemic symptoms (15%; four TIA, one stroke). Four out of five patients with recurrent symptoms had ISR or occlusion verified on conventional angiography. At the time of the last follow-up examination, seven patients of 44 patients who underwent attempted treatment were dead (modified Rankin Scale [mRS] score, 6); four had an mRS score of 3 to 5, 16 had an mRS score of 1 or 2, and 10 had an mRS score of 0., Conclusion: Percutaneous transluminal angioplasty and stenting using BMCS for the treatment of symptomatic VB ICAD can be carried out with high rates of technical success and excellent immediate angiographic results. However, the procedure carries with it a very high rate of periprocedural morbidity and mortality. Greater than 50% ISR or stent occlusion occurred in 12.5% of the patients and was associated with recurrent TIAs. In the absence of ISR/occlusion, patients who tolerated the initial procedure did well neurologically and did not typically experience recurrent ischemic symptoms.

Objective: Patients with dural sinus thrombosis occasionally present with a malignant clinical course marked by parenchymal hemorrhage accompanied by either a severe neurological deficit or a persistent deterioration on therapeutic levels of antithrombotic medications. This scenario precludes traditional revascularization strategies with direct fibrinolytic infusion because of the risk of exacerbating the preexisting cerebral hemorrhage. In the current series, we describe our experience using the AngioJet (Possis Medical, Minneapolis, MN), a rheolytic mechanical thrombectomy device, in conjunction with systemic heparinization to achieve rapid sinus revascularization without fibrinolytic therapy., Methods: A retrospective review of a prospectively maintained database identified four patients ranging in age from 28 to 67 years (three women, one man) with cerebral venous thrombosis and rapidly deteriorating levels of consciousness who underwent transfemoral intravenous rheolytic thrombectomy using the AngioJet XMI and/or Xpeedior catheters (Possis Medical). The imaging features, treatment specifications, and disease outcome were reviewed., Results: All four patients underwent successful mechanical thrombectomy as indicated by restoration of blood flow through the affected sinuses. Three of the four patients demonstrated normalization of angiographic transit time after thrombectomy. In these three patients, rapid neurological improvement ensued. The fourth patient died during the periprocedural period. No procedural complications were encountered., Conclusion: Systemic heparinization with adjunctive rheolytic thrombectomy (without fibrinolytic therapy) is a safe and effective treatment strategy for selected patients with dural venous sinus thrombosis.

Neuroendovascular embolization represents a critical component of the multidisciplinary management of cerebral arteriovenous malformations. Safe and effective embolization may be performed only in the context of a well-designed, rational treatment plan that is fundamentally based on a clear understanding of the natural history of the lesion, as well as the cumulative risks of multimodality treatment. This article outlines the role of neuroendovascular embolization in arteriovenous malformation therapy with a specific emphasis on decision making in the context of formulating a treatment plan. The authors also provide a summary of the available embolic agents and their technical application, potential intraprocedural and periprocedural complications, and postprocedural management.

Objective: Intradural pseudoaneurysms have a malignant natural history and can be difficult to treat if parent vessel deconstruction is not feasible. These lesions often involve a long arterial segment and lack a defined saccular component that would safely accommodate the introduction of embolization coils. The current report describes the successful endovascular treatment of these lesions using a strategy of Neuroform stent reconstruction., Methods: A retrospective review of the prospectively maintained Neuroform databases from our two institutions identified all intracranial aneurysms treated with the Neuroform stent alone, without embolization coils. The clinical charts, procedural data, and angiographic results were reviewed., Results: Over a 38-month study period (10/02-2/06), 266 aneurysms were treated with the Neuroform stent. Of these, 10 were small "uncoilable" intradural pseudoaneurysms associated with subarachnoid hemorrhage. These lesions were treated using a strategy of endovascular stent reconstruction of the diseased vascular segment with one or more Neuroform stents (without concomitant coil embolization). Seven pseudoaneurysms were treated in the context of acute or subacute subarachnoid hemorrhage, and three were associated with a remote history of subarachnoid hemorrhage. Periprocedural complications occurred in two patients (clinically silent, intraprocedural thromboembolic event successfully treated with intra-arterial abciximab, symptomatic postprocedural stent thrombosis with successful thrombolysis, and excellent neurological recovery). Both complications occurred in patients with ruptured aneurysms and could be attributed to inadequate platelet inhibition at the time of the initial procedure. Follow-up conventional angiographic examinations were available for all 10 patients with pseudoaneurysms (1-18.5 mo; average, 9.0 mo). In nine cases, the aneurysms improved at follow-up, with either complete (n = 5) or near complete (n = 4) resolution. In one case, short-term follow-up (1 mo) demonstrated no significant change. No patient has rehemorrhaged after treatment., Conclusion: Endovascular Neuroform stent reconstruction represents an optimal strategy for the management of intradural pseudoaneurysms that require a constructive treatment strategy and are too small to accommodate the introduction of embolization coils. Nine out of 10 patients in the current series treated with this strategy demonstrated some degree of endovascular remodeling with either complete (n = 5) or partial (n = 4) angiographic resolution at follow-up. No rehemorrhages were encountered. Adequate antiplatelet therapy, even in the setting of acute subarachnoid hemorrhage, is prerequisite for the avoidance of thromboembolic complications.

Objective: Delayed in-stent stenosis is an important and well-characterized complication of angioplasty and stenting for the treatment of intra- and extracranial atheromatous disease. The current series describes the incidence and natural history of in-stent stenosis after the deployment of the Neuroform stent within the cerebrovasculature for the treatment of aneurysms., Methods: The collaborative Cleveland Clinic Foundation-Barrow Neurological Institute endovascular database was reviewed to identify cases of delayed moderate or severe in-stent stenosis observed during the follow-up of cerebral aneurysms treated with the Neuroform stent. The hospital charts, clinic records, and operative reports for these patients were reviewed., Results: Of a total of 156 patients with follow-up, nine (5.8%) cases of moderate or severe delayed (>2 mo) in-stent stenosis were identified, including two parent vessel occlusions. In two cases, patients presented 3 months after stent-supported aneurysm embolization with focal neurological symptoms. Both of these patients were treated with angioplasty. One eventually required surgical bypass. Of the seven asymptomatic patients, four demonstrated some degree of spontaneous resolution at follow-up, one progressed to complete occlusion, one is awaiting further follow-up, and one patient died of unrelated causes. Of the nine patients in the series, five were treated with "bioactive" coils (Matrix, Hydrocoil, Cerecyte), three were treated with bare platinum coils, and one was treated with stenting alone. The earliest time interval to diagnosis was 2.5 months and 3 months for asymptomatic and symptomatic patients, respectively. The earliest interval documented for spontaneous resolution was 9 months., Conclusion: Delayed Neuroform in-stent stenosis, occurring in 5.8% of cases, is not a rare phenomenon. The stenosis can be symptomatic and may require endovascular treatment or surgical bypass. In asymptomatic patients, a strategy of "watchful waiting" may be effective because many patients demonstrate partial or complete resolution at follow-up. The spontaneous resolution of delayed in-stent stenosis has not been previously described. This may be a phenomenon unique to the application of low radial force, self-expanding stents within the nonatheromatous cerebrovasculature.

Objective: Matrix detachable coils (MDC; Boston Scientific/Target, Fremont, CA) are platinum coils coated with a bioabsorbable polymeric material (polyglycolic-polylactic acid). In animal models, the introduction of polyglycolic-polylactic acid-coated coils into experimental aneurysms resulted in a cellular reaction which promoted stable intra-aneurysmal scar tissue formation. The current study was undertaken to assess the durability of aneurysm occlusion after embolization with MDC., Methods: All patients undergoing embolization were prospectively enrolled in an endovascular database at our institution. All coils used for embolization were recorded in the operative notes for the procedure. Only aneurysms embolized with 50% or greater length of MDC were included. All patients with Neuroform stents (Boston Scientific/Target, Fremont, CA) were excluded from the study. Patients were followed with conventional angiography and magnetic resonance angiography., Results: During a 20-month period, 131 aneurysms were embolized with MDC. Follow up data (average, 6.9 mo; range, 1.5-22 mo) were available for 82 aneurysms (61 with conventional angiography, 21 with magnetic resonance angiography only). Of the aneurysm patients with follow-up available, 65 had small aneurysms with small necks, three were small aneurysms with wide necks, 12 were large aneurysms, and two were giant aneurysms. Overall, there were 30 (36.6%) recanalizations, 19 (23.1%) of which required retreatment. In two additional patients, retreatment was either recommended (n = 1) or attempted unsuccessfully (n = 1). Fifty-two aneurysms were unchanged or demonstrated progressive thrombosis (63.4%). The recanalization rate for small aneurysms with small necks was 26.1% (17 out of 65) with a 13.8% retreatment rate (9/65). The recanalization rate for large aneurysms was 75% (9 out of 12) with seven requiring retreatment., Conclusion: In the absence of Neuroform stent support, aneurysms embolized with the MDC system demonstrated a significant rate of recanalization. Many of the recanalizations were of sufficient size to warrant retreatment. The rates of recanalization observed in the present series were comparable to, or worse than, those reported for bare platinum coils.

Introduction: Circumferential aneurysms, which incorporate >180 degrees of the circumference of the parent vessel, present a unique therapeutic challenge, particularly in circumstances in which a deconstructive treatment strategy is not feasible. We detail a novel technique for endovascular parent vessel reconstruction with aneurysm embolization., Methods: We performed a retrospective review of the prospectively maintained databases of our two institutions to identify cases in which a balloon-in-stent technique had been used to treat circumferential aneurysms. During the first stage of this technique, a stent (Neuroform [Boston Scientific, Natick, MA], Multilink Vision [Guidant, Indianapolis, IN], or Bx Velocity [Cordis, New Brunswick, NJ]) is placed across the neck of the aneurysm to achieve parent vessel reconstruction. During the second stage, aneurysm coil embolization is performed with a compliant temporary occlusion balloon (Sentry [Boston Scientific, Natick, MA] or Hyperglide [Microtherapeutics, Irvine, CA]) placed within the stent to unambiguously demarcate and protect the parent vessel. In some cases, during the course of the embolization, coils project over and obscure the parent vessel in both working views. Before each coil detachment, the protection balloon is deflated under blank fluoroscopic roadmap visualization. The absence of shifting of any portion of the coil mass during balloon deflation indicates that the introduced coil is external to the stent-reconstructed parent vessel (i.e., within the aneurysm) and can be detached. This process is repeated until satisfactory aneurysm embolization is achieved. After embolization, the balloon catheter may be exchanged for a stent delivery system to facilitate the placement of a second stent., Results: Seven patients underwent balloon-in-stent-assisted embolization over a 15-month period. Three were performed for internal carotid aneurysms, three for basilar trunk or basilar apex aneurysms, and one for a dissecting/fusiform V4 segment vertebral artery aneurysm. In three cases, the presence of the inflated balloon facilitated the manipulation of the image intensifier into a position which produced a "down-the-barrel" view of the parent vessel. In the four additional cases, for anatomic reasons, this view could not be achieved and coil mass projected over the reconstructed parent vessel in both views. Partial aneurysm occlusion (75-90%), was achieved in five cases, and near complete (>95%) occlusion was achieved in two cases. Complications included two significant retroperitoneal hematomas and two brainstem infarcts, both of which resulted in hemisensory symptoms., Conclusion: The balloon-in-stent technique provides a practical and safe treatment strategy for the management of circumferential aneurysms that are not amenable to deconstructive embolization.

Objective and Importance: Coil stretching represents a potentially hazardous technical complication not infrequently encountered during the embolization of cerebral aneurysms. Often, the stretched coil cannot be advanced into the aneurysm or withdrawn intact. The operator is then forced to attempt to retract the damaged coil, which may result in coil breakage, leaving behind a significant length of potentially thrombogenic stretched coil material within the parent vessel. To overcome this problem, we devised a technique to snare the distal, unstretched, intact portion of the platinum coil by use of the indwelling microcatheter and stretched portion of the coil as a monorail guide., Clinical Presentation: We have used this technique successfully in four patients to snare coils stretched during cerebral aneurysm embolization. Three of these patients were undergoing Neuroform (Boston Scientific/Target, Fremont, CA) stent-supported coil embolization of unruptured aneurysms. In all cases, the snare was advanced easily to the targeted site for coil engagement by use of the microcatheter as a monorail guide. Once the intact distal segment of the coil was ensnared, coil removal was uneventful, with no disturbance of the remainder of the indwelling coil pack or Neuroform stent., Technique: A 2-mm Amplatz Goose Neck microsnare (Microvena Corp., White Bear Lake, MN) was placed through a Prowler-14 microcatheter (Cordis Corp., Miami, FL). The hub of the indwelling SL-10 microcatheter (Boston Scientific, Natick, MA) was then cut away with a scalpel, leaving the coil pusher wire intact, and removed. The open 2-mm snare was then advanced over the outside of the coil pusher wire and microcatheter. The snare and Prowler-14 microcatheter were then advanced into the guiding catheter (6- or 7-French) as a unit over the indwelling SL-10 microcatheter. By use of the SL-10 microcatheter and coil as a "monorail" guide, the snare was advanced over and beyond the microcatheter and the stretched portion of the coil until the snare was in position to engage the distal unstretched coil. At this point, the snare was then closed around the intact portion of the coil, and the microcatheters, snare, and coil were removed as a unit., Conclusion: The monorail snare technique represents a fast, safe, and easy method by which a stretched coil can be removed.

Objective: The Neuroform microstent, a flexible, self-expanding, nitinol stent specifically designed for use in the cerebral vasculature, became available in North America for aneurysm treatment in November 2002. The present report details our experience with the Neuroform stent over the past 2 years, with an emphasis on evolving treatment strategies and treatment durability at initial (3-6 mo) follow-up., Methods: All patients included in this report were registered in a prospectively maintained database. We assessed the clinical history, indications for stent use, aneurysm dimensions, technical details of the procedures, degree of aneurysm occlusion, angiographic and clinical findings at follow-up, and complications., Results: Over a 20-month period, 64 patients with 74 aneurysms were treated with 86 Neuroform stents. Of 64 patients, 16 (25%) were treated in the context of subarachnoid hemorrhage (8 acute, 7 subacute, 1 remote). Indications for stent use included broad aneurysm neck (n = 51 stents; average neck, 5.1 mm; aneurysm size, 8.2 mm), fusiform/dissecting morphology (n = 17), salvage/bailout for coils prolapsed into the parent vessel (n = 7), and giant aneurysm (n = 11). Sixty-one aneurysms were stented and coiled with complete or near complete (>95%) occlusion in 28 patients (45.9%) and partial occlusion (<95%) in 33 patients (54%). Follow-up angiographic (n = 43) or magnetic resonance angiographic (n = 5) data (average follow-up, 4.6 mo; median, 4 mo; range, 1.5-13 mo) for 48 aneurysms (46 patients) after stent-supported coil embolization demonstrated progressive thrombosis in 25 patients (52%), recanalization in 11 patients (23%) (8 of whom were retreated), and no change in 12 patients (25%). Follow-up angiography in 5 additional patients with dissecting aneurysms treated with stents alone demonstrated interval vascular remodeling with decreased aneurysm size in all patients. Delayed, severe, in-stent stenosis was observed in 3 patients, 1 of whom was symptomatic and required angioplasty and subsequently superficial temporal artery-to-middle cerebral artery bypass surgery. Using the second-generation Neuroform2 delivery system (n = 53), very few technical problems with stent delivery and deployment have been encountered (n = 2)., Conclusion: The Neuroform stent facilitates adequate embolization of complex cerebral aneurysms, which would not otherwise be amenable to endovascular therapy. Initial follow-up data indicate favorable progressive thrombosis and recanalization rates for aneurysms after Neuroform stent-assisted embolization. These advantages of stenting were most evident for small aneurysms with wide necks.

Objective: Most complications related to endovascular neurointerventional procedures are thromboembolic. The objective of this study was to determine whether abciximab, a glycoprotein IIb/IIIa inhibitor, is a safe and effective agent for the treatment of thromboembolic complications encountered during interventional neuroradiological procedures., Methods: A search of a prospectively maintained database identified 13 patients who were treated for intraprocedural thromboembolic complications with abciximab, either alone or in combination with tissue plasminogen activator, during a 22-month period., Results: Of the 13 patients in our series (10 with aneurysms, 3 with arteriovenous malformations), 12 presented with unsecured vascular lesions, and in 9 cases the lesions were either acutely (<10 d) or subacutely (<6 mo) hemorrhagic. After the identification of a thromboembolic complication, each patient was treated with either intra-arterial (n = 5) or intravenous (n = 8) abciximab. Abciximab was administered intravenously as a 0.25-mg/kg bolus (n = 2), a 0.25-mg/kg bolus followed by a 12-hour 0.125-microg/kg/min infusion (n = 5), or a 12-hour 0.125-microg/kg/min infusion alone (n = 1). Intra-arterial abciximab (3.5-10 mg) was administered directly through a microcatheter positioned in the vicinity of the thrombus (n = 5). Five patients also were administered alteplase. Complete (n = 7) or partial (n = 6) resolution of thrombus was observed in all cases. Five patients had small infarcts in the distribution of the thromboembolic complication. In no case was new or increased hemorrhaging observed after thrombolysis., Conclusion: Abciximab (ReoPro), administered either intravenously or intra-arterially, is a viable option for the management of thromboembolic complications encountered during endovascular therapeutic procedures.

Introduction: The Neuroform microstent-a flexible, self-expandable, microcatheter-delivered, nitinol stent designed for the treatment of cerebral aneurysms-was recently approved for use in patients. We present the results of our initial experience in using the Neuroform stent to treat patients with cerebral aneurysms, with an emphasis on potential applications, technical aspects of deployment, and associated intra- and periprocedural complications., Methods: The records of all patients treated with the Neuroform stent were entered prospectively into a database. We assessed the clinical history, indications for stent use, aneurysm dimensions, and technical details of the procedures, including any difficulties with stent placement and/or deployment, degree of aneurysm occlusion, and complications., Results: During a 5-month period, 19 patients with 22 aneurysms were treated with the Neuroform stent. Twenty-five stents were deployed. Five patients had multiple stents placed. Five patients had ruptured aneurysms at the time of treatment. The indications for use were broad-necked aneurysms (n = 13; average neck length, 5.1 mm; average aneurysm size, 9 mm), fusiform or dissecting aneurysms (n = 3), salvage and/or bailout (n = 1), and giant aneurysms (n = 2). Technical problems included difficulty in deploying the stent (n = 6), inability to deploy the stent (n = 1), stent displacement (n = 2), inadvertent stent deployment (n = 1), and coil stretching (n = 1). Twenty-one of the 22 aneurysms were treated. Four aneurysms were stented without additional treatment, and 17 aneurysms were stented and coiled. Of the coiled aneurysms, complete or nearly complete (more than 95%) occlusion was achieved in 6 aneurysms, and partial occlusion was achieved in 11. Two clinically significant adverse events occurred, both of which were sequelae of periprocedural thromboembolic complications. One patient died after thrombolysis was attempted. The other patient made an excellent functional recovery after undergoing successful thrombolysis of a thrombosed basilar artery stent., Conclusion: The Neuroform stent is a useful device for the treatment of patients with aneurysms that may not otherwise be amenable to endovascular therapy. In the majority of cases, the stent can be deployed accurately, even within the most tortuous segments of the cerebral vasculature. Although delivery and deployment may be technically challenging, clinically significant complications are uncommon.

Objective: To assess the rate of restenosis after vertebral origin angioplasty and stenting (VOAS)., Methods: We reviewed the records of 33 patients (24 men, 9 women; age range, 49-81 yr; mean, 64.5 yr) who underwent VOAS during a period of 5 years and followed each for the development of adverse sequelae through a prospectively maintained database. A neuroradiologist not involved in the stenting procedures assessed original and follow-up angiograms for evidence of restenosis. Restenosis was quantified as insignificant (0-24%), mild (25-49%), moderate (50-74%), or severe (75-100%)., Results: Of the 33 patients, 30 presented with transient ischemic attacks or stroke. Most (31 of 33 patients) manifested other brachiocephalic stenoses, including 27 patients with occlusion, hypoplasia, or stenosis of the contralateral vertebral artery. Angiographic follow-up (mean, 16.2 mo) was obtained in 30 patients (2 patients died before follow-up, and 1 refused). Restenosis was mild in seven patients, moderate in eight, and severe in five. The combined rate of moderate-to-severe restenosis was 43.3%. No complications resulted in permanent morbidity. One patient died as a result of a stroke in a different vascular distribution 4 months after VOAS. Another patient died as a result of basilar thrombosis in which emergent stenting had been undertaken in an effort to perform thrombolysis., Conclusion: Despite a technical success rate of 97% and a low incidence of complications, VOAS is associated with a high rate of moderate-to-severe restenosis.