Curative cerebrovascular reconstruction with the Pipeline embolization device: the emergence of definitive endovascular therapy for intracranial aneurysms.

Endovascular, endosaccular, coil embolization has emerged as an established therapy for both ruptured and unruptured cerebral aneurysms. However, many aneurysms are not cured using conventional endovascular techniques. Coil embolization often results in incomplete aneurysm occlusion or recanalization in the ensuing months after treatment. The Pipeline embolization device (PED; Chestnut Medical) represents a new generation endoluminal implant which is designed to treat aneurysms by reconstructing the diseased parent artery. Immediately after implantation, the PED functions to divert flow from the aneurysm, creating an environment conducive to thrombosis. With time, the PED is incorporated into the vessel wall as neointimal-endothelial overgrowth occurs along the construct. Ultimately, this process results in the durable complete exclusion of the aneurysm from the cerebrovasculature and a definitive endoluminal reconstruction of the diseased parent artery.

Computational Modeling of Venous Sinus Stenosis in Idiopathic Intracranial Hypertension.

BACKGROUND AND PURPOSE: Idiopathic intracranial hypertension has been associated with dural venous sinus stenosis in some patients, but the hemodynamic environment of the dural venous sinuses has not been quantitatively described. Here, we present the first such computational fluid dynamics model by using patient-specific blood pressure measurements. MATERIALS AND METHODS: Six patients with idiopathic intracranial hypertension and at least 1 stenosis or atresia at the transverse/sigmoid sinus junction underwent MR venography followed by cerebral venography and manometry throughout the dural venous sinuses. Patient-specific computational fluid dynamics models were created by using MR venography anatomy, with venous pressure measurements as boundary conditions. Blood flow and wall shear stress were calculated for each patient. RESULTS: Computational models of the dural venous sinuses were successfully reconstructed in all 6 patients with patient-specific boundary conditions. Three patients demonstrated a pathologic pressure gradient (≥8 mm Hg) across 4 dural venous sinus stenoses. Small sample size precludes statistical comparisons, but average overall flow throughout the dural venous sinuses of patients with pathologic pressure gradients was higher than in those without them (1041.00 ± 506.52 mL/min versus 358.00 ± 190.95 mL/min). Wall shear stress was also higher across stenoses in patients with pathologic pressure gradients (37.66 ± 48.39 Pa versus 7.02 ± 13.60 Pa). CONCLUSIONS: The hemodynamic environment of the dural venous sinuses can be computationally modeled by using patient-specific anatomy and physiologic measurements in patients with idiopathic intracranial hypertension. There was substantially higher blood flow and wall shear stress in patients with pathologic pressure gradients.

Pipeline Embolization Device with or without Adjunctive Coil Embolization: Analysis of Complications from the IntrePED Registry.

Flow diversion to treat cerebral aneurysms has revolutionized neurointerventional surgery. Because the addition of coils potentially increases the time and complexity of endovascular procedures, we sought to determine whether adjunctive coil use is associated with an increase in complications. Patients in the International Retrospective Study of Pipeline Embolization Device registry were divided into those treated with the Pipeline Embolization Device alone (n = 689 patients; n = 797 aneurysms; mean aneurysm size, 10.3 ± 7.6 mm) versus those treated with the Pipeline Embolization Device and concurrent coil embolization (n = 104 patients; n = 109 aneurysms; mean aneurysm size, 13.6 ± 7.8 mm). Patient demographics and aneurysm characteristics were examined. Rates of neurologic morbidity and mortality were compared between groups. The Pipeline Embolization Device with versus without coiling required a significantly longer procedure time (135.8 ± 63.9 versus 96.7 ± 46.2 min; P < .0001) and resulted in higher neurological morbidity (12.5% versus 7.8%; P = .13). These data suggest that either strategy represents an acceptable risk profile in the treatment of complex cerebral aneurysms and warrants further investigation.

Posterior Inferior Cerebellar Artery Patency after Flow-Diverting Stent Treatment.

BACKGROUND AND PURPOSE: The rate of PICA occlusion after flow-diverting stent placement for vertebral and vertebrobasilar artery aneurysms is not known. The purpose of this study is to determine the medium-term rate of PICA patency and risk factors for occlusion after such aneurysm treatment. MATERIALS AND METHODS: Patients were identified who had vertebral or vertebrobasilar artery aneurysms and who were treated by placing a flow-diverting stent across the PICA ostium. Demographic and procedural factors associated with stent placement were recorded. Patency of the PICA was evaluated immediately after stent placement and on follow-up angiography. RESULTS: Thirteen patients with vertebral or vertebrobasilar artery aneurysms were treated in the study period, of whom 4 presented with subarachnoid hemorrhage. The average number of devices that spanned the PICA ostium was 1.77 (range, 1-3), with no immediate PICA occlusions. There were no postoperative strokes in the treated PICA territory, although there was 1 contralateral PICA-territory stroke of unclear etiology without clinical sequelae. In 11 patients with follow-up angiography at a mean of 10.6 months (range, 0.67-27.9 months), the PICA patency rate remained 100%. CONCLUSIONS: Flow-diverting stent placement across the PICA ostium in the treatment of vertebral and vertebrobasilar artery aneurysms may not result in immediate or midterm PICA occlusion.

Bioactive versus bare platinum coils in the treatment of intracranial aneurysms: the MAPS (Matrix and Platinum Science) trial.

BACKGROUND AND PURPOSE: The ability of polymer-modified coils to promote stable aneurysm occlusion after endovascular treatment is not well-documented. Angiographic aneurysm recurrence is widely used as a surrogate for treatment failure, but studies documenting the correlation of angiographic recurrence with clinical failure are limited. This trial compares the effectiveness of Matrix(2) polyglycolic/polylactic acid biopolymer-modified coils with bare metal coils and correlates the angiographic findings with clinical failure (ie, target aneurysm recurrence), a composite end point that includes any incident of posttreatment aneurysm rupture, retreatment, or unexplained death. MATERIALS AND METHODS: This was a multicenter randomized noninferiority trial with blinded end point adjudication. We enrolled 626 patients, divided between Matrix(2) and bare metal coil groups. The primary outcome was target aneurysm recurrence at 12 ± 3 months. RESULTS: At 455 days, at least 1 target aneurysm recurrence event had occurred in 14.6% of patients treated with bare metal coils and 13.3% of Matrix(2) (P = .76, log-rank test) patients; 92.8% of target aneurysm recurrence events were re-interventions for aneurysms that had not bled after treatment, and 5.8% of target aneurysm recurrence events resulted from hemorrhage or rehemorrhage, with or without retreatment. Symptomatic re-intervention occurred in only 4 (0.6%) patients. At 455 days, 95.8% of patients with unruptured aneurysms and 90.4% of those with ruptured aneurysms were independent (mRS ≤ 2). Target aneurysm recurrence was associated with incomplete initial angiographic aneurysm obliteration, presentation with rupture, and a larger aneurysmal dome and neck size. CONCLUSIONS: Tested Matrix(2) coils were not inferior to bare metal coils. Endovascular coiling of intracranial aneurysms was safe, and the rate of technical success was high. Target aneurysm recurrence is a promising clinical outcome measure that correlates well with established angiographic measurements.

Endovascular management of distal ACA aneurysms: single-institution clinical experience in 22 consecutive patients and literature review.

BACKGROUND AND PURPOSE: Distal ACA aneurysms remain difficult to treat with endovascular therapy, but improved technology and experience allows for the treatment of some of these aneurysms with excellent results. The purpose of this study was to assess the status of endovascular treatment of distal ACA aneurysms by comparing our results with recent endovascular and microsurgical series of distal ACA aneurysms. MATERIALS AND METHODS: Between 2000 and 2008, a total of 22 consecutive patients (14 women; mean age, 58.4 years) with distal ACA aneurysms underwent coil placement at Barrow Neurological Institute. Clinical presentations, radiographic findings, endovascular management, and outcomes were reviewed retrospectively. RESULTS: Of the 22 patients, 13 (59%) presented with subarachnoid hemorrhage. Six patients were HH grade I or II, 1 was grade III, 5 were grade IV, and 1 was grade V. Frontal lobe hematomas occurred in 5 patients with ruptured aneurysms. The mean aneurysm size was 7.5 mm (range, 2.8-25 mm); 55% were smaller than 7 mm. Twelve aneurysms (55%) arose from the origin of the callosomarginal artery (55%). Complete occlusion was achieved in 50% of the cases and near-complete occlusion in 45%. The few periprocedural complications included 1 retroperitoneal hematoma and 1 intraoperative rupture. Four patients had thromboembolic events adequately treated intraprocedurally with abciximab. No deaths occurred in the patients treated. CONCLUSIONS: The characteristics of the patients and aneurysms treated in our series were comparable to previous reports of endovascular treatment of ACA aneurysms with respect to rupture status. Periprocedural morbidity and mortality rates in our series fared well compared with previous reports, as did our combined rate of complete or near-complete occlusions. Recent advances in endovascular devices and techniques have improved outcomes of distal ACA aneurysms.

Performance and training standards for endovascular ischemic stroke treatment.

Stroke is the third leading cause of death in the USA, Canada, Europe, and Japan. According to the American Heart Association and the American Stroke Association, there are now 750,000 new strokes that occur each year, resulting in 200,000 deaths, or 1 of every 16 deaths, per year in the USA alone. Endovascular therapy for patients with acute ischemic stroke is an area of intense investigation. The American Stroke Association has given a qualified endorsement of intra-arterial thrombolysis in selected patients. Intra-arterial thrombolysis has been studied in two randomized trials and numerous case series. Although two devices have been granted FDA approval with an indication for mechanical stroke thrombectomy, none of these thrombectomy devices has demonstrated efficacy for the improvement of patient outcomes. The purpose of the present document is to define what constitutes adequate training to perform neuroendovascular procedures in patients with acute ischemic stroke and what performance standards should be adopted to assess outcomes. These guidelines have been written and approved by multiple neuroscience societies which historically have been directly involved in the medical, surgical and endovascular care of patients with acute stroke. The participating member organizations of the Neurovascular Coalition involved in the writing and endorsement of this document are the Society of NeuroInterventional Surgery, the American Academy of Neurology, the American Association of Neurological Surgeons/Congress of Neurological Surgeons Cerebrovascular Section, and the Society of Vascular & Interventional Neurology.

Endovascular treatment of unruptured intracranial aneurysms in the elderly: analysis of procedure related complications.

INTRODUCTION: The management of unruptured intracranial aneurysms in the elderly remains controversial. Treatment risks are thought to be higher in this group. Large series assessing endovascular treatment of unruptured intracranial aneurysms in the elderly are lacking. Our single center endovascular experience in treating unruptured intracranial aneurysms in the elderly is presented. METHODS: 77 patients, 70 years or older, were referred to the endovascular neurosurgery service for treatment of an unruptured intracranial aneurysm between February 2000 and May 2008. Hospital records, operative reports, angiograms and radiology reports were reviewed and analyzed retrospectively. RESULTS: 99 aneurysms were treated in 77 patients in 102 procedures. Mean patient age was 75±4 years, and the average aneurysm size was 11±7 mm. Adjuvant techniques were used in 66% of cases. Endovascular procedures included coiling alone (32%), balloon assisted coiling (19%), stent assisted coiling (37%), balloon assisted stent and coiling (8%), stent only (1%) and glue (2%). The permanent morbidity and mortality rates were 1% and 3%, respectively. Four adverse events were attributed to the patient's age. Posterior circulation aneurysms were associated with more adverse events (41%) than anterior circulation aneurysms (14%). Endovascular treatments using adjuvant techniques were associated with a higher complication rate than coiling alone. CONCLUSIONS: With only a 4% permanent rate of neurological morbidity and mortality, endovascular treatment of unruptured aneurysms can be performed safely in the elderly. Age should not be the limiting factor when considering endovascular therapy.

Neuroform stent assisted aneurysm treatment: evolving treatment strategies, complications and results of long term follow-up.

INTRODUCTION: This report details experience with the Neuroform stent, with an emphasis on evolving treatment strategies, complication rates and treatment durability. METHODS: All patients undergoing Neuroform stent assisted aneurysm treatment were registered in prospectively maintained endovascular databases at two institutions. RESULTS: 284 patients with 302 aneurysms underwent aneurysm treatment with Neuroform during a 42-month study period. Imaging follow-up was available for 166 of 286 saccular aneurysms which were treated with stents and coils (average interval 12.9 months). 80 demonstrated progressive thrombosis (48.2%), 40 were unchanged (24.1%) and 46 (27.7%) demonstrated re-canalization, 25 (15.1%) of which were major recanalizations requiring retreatment. The vast majority of recanalizations and retreatments were observed in large or giant aneurysms. A cumulative total of 25 ischemic strokes (8.8%) and eight neurovascular deaths (2.8%) were recorded in these patients. Ten of these strokes were associated with transient deficits which went on to complete resolution by the time of discharge or at the initial clinical follow-up, yielding a significant stroke rate of 5.3%. Delayed (>48 h) complications, including four deaths-related to stroke (n=2, 6 days and 8 weeks post-procedure) and spontaneous parenchymal hemorrhages (n=2)-represent events which are a direct consequence of stenting and likely would not have been encountered in the context of standard non-stent supported embolization techniques. CONCLUSION: Neuroform facilitates the endovascular treatment of complex and wide necked cerebral aneurysms. However, complete occlusion at angiographic follow-up remains uncommon and is observed in only one-third of patients. Delayed complications (>48 h) represent an important component of the overall complications associated with Neuroform assisted aneurysm embolization.

Reconstruction of the right anterior circulation with the Pipeline embolization device to achieve treatment of a progressively symptomatic, large carotid aneurysm.

INTRODUCTION: We present the use of the Pipeline embolization device (PED) to achieve reconstruction of the right anterior circulation in a patient with a dolichoectatic internal carotid artery (ICA) and middle cerebral artery (MCA) and an associated symptomatic, large, carotid-ophthalmic segment aneurysm. CLINICAL PRESENTATION: A 36-year-old man presented with progressive right eye vision loss followed by sudden severe headache. Subsequent neuroimaging revealed a large right carotid-ophthalmic segment aneurysm and diffuse ectasia of the supraclinoid ICA and proximal MCA. A coil embolization of the aneurysm was performed without stent support. Over the next year, the patient experienced increasing headache and progressive bitemporal vision loss. Serial MRI showed progressive coil compaction and recanalization of the aneurysm. TREATMENT: The right anterior circulation was reconstructed with a total of six PEDs that extended from the distal M1 segment of the MCA proximally into the distal cavernous segment of the ICA. Follow-up angiography at 1 and 4 months demonstrated progressive complete occlusion of the aneurysm and a reorganization of blood flow to the anterior cerebral and anterior choroidal arteries. MRI and radiographic imaging provided evidence of progressive contraction of the intra-aneurysmal thrombus. The patient's headaches resolved and serial visual field examinations have demonstrated gradual improvement after treatment. CONCLUSION: Extensive cerebrovascular reconstructions that are not possible using commercially available endovascular devices can be achieved with Pipeline. The safety, efficacy and long term implications of such reconstructions are currently being defined.

Performance and training standards for endovascular ischemic stroke treatment.

Stroke is the third leading cause of death in the USA, Canada, Europe, and Japan. According to the American Heart Association and the American Stroke Association, there are now 750,000 new strokes that occur each year, resulting in 200,000 deaths, or 1 of every 16 deaths, per year in the USA alone. Endovascular therapy for patients with acute ischemic stroke is an area of intense investigation. The American Stroke Association has given a qualified endorsement of intra-arterial thrombolysis in selected patients. Intra-arterial thrombolysis has been studied in two randomized trials and numerous case series. Although two devices have been granted FDA approval with an indication for mechanical stroke thrombectomy, none of these thrombectomy devices has demonstrated efficacy for the improvement of patient outcomes. The purpose of the present document is to define what constitutes adequate training to perform neuroendovascular procedures in patients with acute ischemic stroke and what performance standards should be adopted to assess outcomes. These guidelines have been written and approved by multiple neuroscience societies which historically have been directly involved in the medical, surgical and endovascular care of patients with acute stroke. The participating member organizations of the Neurovascular Coalition involved in the writing and endorsement of this document are the Society of NeuroInterventional Surgery, the American Academy of Neurology, the American Association of Neurological Surgeons/Congress of Neurological Surgeons Cerebrovascular Section, and the Society of Vascular & Interventional Neurology.

Curative cerebrovascular reconstruction with the Pipeline embolization device: the emergence of definitive endovascular therapy for intracranial aneurysms.

Endovascular, endosaccular, coil embolization has emerged as an established therapy for both ruptured and unruptured cerebral aneurysms. However, many aneurysms are not cured using conventional endovascular techniques. Coil embolization often results in incomplete aneurysm occlusion or recanalization in the ensuing months after treatment. The Pipeline embolization device (PED; Chestnut Medical) represents a new generation endoluminal implant which is designed to treat aneurysms by reconstructing the diseased parent artery. Immediately after implantation, the PED functions to divert flow from the aneurysm, creating an environment conducive to thrombosis. With time, the PED is incorporated into the vessel wall as neointimal-endothelial overgrowth occurs along the construct. Ultimately, this process results in the durable complete exclusion of the aneurysm from the cerebrovasculature and a definitive endoluminal reconstruction of the diseased parent artery.

Influence of patient age and stenosis location on wingspan in-stent restenosis.

BACKGROUND AND PURPOSE: Wingspan is a self-expanding, microcatheter-delivered microstent specifically designed for the treatment of symptomatic intracranial atherosclerotic disease. Our aim was to discuss the effect of patient age and lesion location on in-stent restenosis (ISR) rates after percutaneous transluminal angioplasty and stenting (PTAS) with the Wingspan system. MATERIALS AND METHODS: Clinical and angiographic follow-up results were recorded for all patients from 5 participating institutions. ISR was defined as >50% stenosis within or immediately adjacent (within 5 mm) to the implanted stent and >20% absolute luminal loss. For the present analysis, patients were stratified into younger (55 years) age groups. RESULTS: ISR occurred at a rate of 45.2% (14/31) in the younger group and 24.2% (15/62) in the older group (odds ratio, 2.6; 95% confidence interval, 1.03-6.5). In the younger group, ISR occurred after treatment of 13/26 (50%) anterior circulation lesions versus only 1/5 (20%) posterior circulation lesions. In the older group, ISR occurred in 9/29 (31.0%) anterior circulation lesions and 6/33 (18.2%) posterior circulation lesions. In young patients, internal carotid artery lesions (10/17 treated, 58.8%), especially those involving the supraclinoid segment (8/9, 88.9%), were very prone to ISR. When patients of all ages were considered, supraclinoid segment lesions had much higher rates of both ISR (66.6% versus 24.4%) and symptomatic ISR (40% versus 3.9%) in comparison with all other locations. CONCLUSION: Post-Wingspan ISR is more common in younger patients. This increased risk can be accounted for by a high prevalence of anterior circulation lesions in this population, specifically those affecting the supraclinoid segment, which are much more prone to ISR and symptomatic ISR than all other lesions.

Intraoperative spinal angiography.

OBJECT: The use of intraoperative angiography of the spine has become available to neurosurgeons as an adjunct in the management of complex spinal vascular malformations. These vascular malformations are rare, and the use of intraoperative angiography of the spine has not been well described. The authors report their recent experience with the use of this diagnostic modality. METHODS: Between 1995 and 1997, nine consecutive patients with type II or Type IV spinal arteriovenous malformations (AVMs) underwent intraoperative spinal angiography. The cervical spine was involved in three patients, the thoracic spine in five, and the thoracolumbar junction in one. In three patients, intraoperative spinal angiography revealed an unexpected finding (residual filling of the AVM). The results obtained using postoperative spinal angiography in all patients showed complete agreement with the intraoperative studies. No complications arose from obtaining the intraoperative spinal angiograms. CONCLUSIONS: Intraoperative spinal angiography is technically feasible, can be performed safely, and has adequate resolution. It detects unexpected residual AVM in one-third of cases.

Cerebral venous thrombosis: combined intrathrombus rtPA and intravenous heparin.

BACKGROUND AND PURPOSE: We chose to evaluate the safety and efficacy of combined intrathrombus rtPA and intravenous heparin in cerebral venous thrombosis (CVT). METHODS: We treated 12 patients with symptoms of 1 to 40 days' duration (eg, headache, somnolence, focal deficits, seizures, and nausea and vomiting). Pretreatment MRI disclosed subtle hemorrhagic venous infarction in 4 patients, obvious hemorrhagic infarction in 2, small parenchymal hemorrhage from recent pallidotomy in 1, and no focal lesion in 5. Magnetic resonance venography and contrast venography identified thrombi in the superior sagittal sinus (SSS) in 3 patients; transverse/sigmoid sinus (TS/SS) in 2; SSS and both TS/SS in 1; SSS and 1 TS/SS in 5; and SSS, 1 TS/SS, and straight sinus in 1 patient. A loading dose of rtPA was instilled throughout the clot at 1 mg/cm, followed by continuous intrathrombus infusion at 1 to 2 mg/h. Intravenous heparin was infused concomitantly. RESULTS: Flow was restored completely in 6 patients and partially in 3, with a mean rtPA dose of 46 mg (range, 23 to 128 mg) at a mean time of 29 hours (range, 13 to 77 hours). Symptoms improved in these 9 patients concomitantly with flow restoration. Flow could not be restored in 3 patients. In 1 of them, treatment was stopped when little progress had been made, and fibrinogen level dropped to 118 mg/dL. In the other 2 patients, hemorrhagic worsening occurred, and treatment was abbreviated after initial rtPA dosing. In 1 of these, the hematoma was evacuated. CONCLUSIONS: Our experience with intrathrombus rtPA in conjunction with intravenous heparin in patients with CVT is encouraging. This therapy should probably be regarded as unsafe in patients with obvious hemorrhage. Time to restore flow may be faster than with urokinase (an average of 71 hours has been reported for 29 documented patients). Further evaluation of rtPA with heparin in CVT is warranted.

Fatal basilar artery thrombosis after traumatic cervical facet dislocation. Case report.

The authors detail a rare case of basilar artery thrombosis in a patient with traumatic cervical spine facet dislocation. Although the patient's deficits could initially be explained by the spinal injury, deterioration to a "locked-in-state" could not. In addition to vertebral artery injuries, the basilar artery can also be indirectly involved in cases of cervical spine trauma. In the rare viable patient, immediate reduction of cervical spine dislocation may allow endovascular thrombolysis, if not otherwise contraindicated.