Felipe C. Albuquerque

Pipeline for Uncoilable or Failed Aneurysms: Results from a Multicenter Clinical Trial

PURPOSE To evaluate the safety and effectiveness of the Pipeline Embolization Device (PED; ev3/Covidien, Irvine, Calif) in the treatment of complex intracranial aneurysms. MATERIALS AND METHODS The Pipeline for Uncoilable or Failed Aneurysms is a multicenter, prospective, interventional, single-arm trial of PED for the treatment of uncoilable or failed aneurysms of the internal carotid artery. Institutional review board approval of the HIPAA-compliant study protocol was obtained from each center. After providing informed consent, 108 patients with recently unruptured large and giant wide-necked aneurysms were enrolled in the study. The primary effectiveness endpoint was angiographic evaluation that demonstrated complete aneurysm occlusion and absence of major stenosis at 180 days. The primary safety endpoint was occurrence of major ipsilateral stroke or neurologic death at 180 days. RESULTS PED placement was technically successful in 107 of 108 patients (99.1%). Mean aneurysm size was 18.2 mm; 22 aneurysms (20.4%) were giant (>25 mm). Of the 106 aneurysms, 78 met the studys primary effectiveness endpoint (73.6%; 95% posterior probability interval: 64.4%-81.0%). Six of the 107 patients in the safety cohort experienced a major ipsilateral stroke or neurologic death (5.6%; 95% posterior probability interval: 2.6%-11.7%). CONCLUSION PED offers a reasonably safe and effective treatment of large or giant intracranial internal carotid artery aneurysms, demonstrated by high rates of complete aneurysm occlusion and low rates of adverse neurologic events; even in aneurysms failing previous alternative treatments.

Preliminary experience using the Neuroform stent for the treatment of cerebral aneurysms.

INTRODUCTIONThe 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. METHODSThe 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. RESULTSDuring 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. CONCLUSIONThe 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.

The Barrow Ruptured Aneurysm Trial

OBJECT The purpose of this ongoing study is to compare the safety and efficacy of microsurgical clipping and endovascular coil embolization for the treatment of acutely ruptured cerebral aneurysms and to determine if one treatment is superior to the other by examining clinical and angiographic outcomes. The authors examined the null hypothesis that no difference exists between the 2 treatment modalities in the setting of subarachnoid hemorrhage (SAH). The current report is limited to the clinical results at 1 year after treatment. METHODS The authors screened 725 patients with SAH, resulting in 500 eligible patients who were enrolled prospectively in the study after giving their informed consent. Patients were assigned in an alternating fashion to surgical aneurysm clipping or endovascular coil therapy. Intake evaluations and outcome measurements were collected by nurse practitioners independent of the treating surgeons. Ultimately, 238 patients were assigned to aneurysm clipping and 233 to coil embolization. The 2 treatment groups were well matched. There were no anatomical exclusions. Crossing over was allowed, but primary outcome analysis was based on the initial treatment modality assignment. Posttreatment care was standardized for both groups. Patient outcomes at 1 year were independently assessed using the modified Rankin Scale (mRS). A poor outcome was defined as an mRS score > 2 at 1 year. The primary outcome was based on the assigned group; that is, by intent to treat. RESULTS One year after treatment, 403 patients were available for evaluation. Of these, 358 patients had actually undergone treatment. The remainder either died before treatment or had no identifiable source of SAH. A poor outcome (mRS score > 2) was observed in 33.7% of the patients assigned to aneurysm clipping and in 23.2% of the patients assigned to coil embolization (OR 1.68, 95% CI 1.08-2.61; p = 0.02). Of treated patients assigned to the coil group, 124 (62.3%) of the 199 who were eligible for any treatment actually received endovascular coil embolization. Patients who crossed over from coil to clip treatment fared worse than patients assigned to coil embolization, but no worse than patients assigned to clip occlusion. No patient treated by coil embolization suffered a recurrent hemorrhage. CONCLUSIONS One year after treatment, a policy of intent to treat favoring coil embolization resulted in fewer poor outcomes than clip occlusion. Although most aneurysms assigned to the coil treatment group were treated by coil embolization, a substantial number crossed over to surgical clipping. Although a policy of intent to treat favoring coil embolization resulted in fewer poor outcomes at 1 year, it remains important that high-quality surgical clipping be available as an alternative treatment modality.

Usefulness of the Neuroform stent for the treatment of cerebral aneurysms: results at initial (3-6-mo) follow-up.

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.

US Multicenter Experience With the Wingspan Stent System for the Treatment of Intracranial Atheromatous Disease: Periprocedural Results

Background and Purpose— The current report details our initial periprocedural experience with Wingspan (Boston Scientific/Target), the first self-expanding stent system designed for the treatment of intracranial atheromatous disease. Methods— All patients undergoing angioplasty and stenting with the Gateway balloon–Wingspan stent system were prospectively tracked. Results— During a 9-month period, treatment with the stent system was attempted in 78 patients (average age, 63.6 years; 33 women) with 82 intracranial atheromatous lesions, of which 54 were ≥70% stenotic. Eighty-one of 82 lesions were successfully stented (98.8%) during the first treatment session. In 1 case, the stent could not be delivered across the lesion; the patient was treated solely with angioplasty and stented at a later date. Lesions treated involved the internal carotid (n=32; 8 petrous, 10 cavernous, 11 supraclinoid segment, 3 terminus), vertebral (n=14; V4 segment), basilar (n=14), and middle cerebral (n=22) arteries. Mean±SD pretreatment stenosis was 74.6±13.9%, improving to 43.5±18.1% after balloon angioplasty and to 27.2±16.7% after stent placement. Of the 82 lesions treated, there were 5 (6.1%) major periprocedural neurological complications, 4 of which ultimately led to patient death within 30 days of the procedure. Conclusions— Angioplasty and stenting for symptomatic intracranial atheromatous disease can be performed with the Gateway balloon–Wingspan stent system with a high rate of technical success and acceptable periprocedural morbidity. Our initial experience indicates that this procedure represents a viable treatment option for this patient population.

Endovascular reconstruction with the Neuroform stent as monotherapy for the treatment of uncoilable intradural pseudoaneurysms.

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.

Wingspan in-stent restenosis and thrombosis: Incidence, clinical presentation, and management

OBJECTIVE: Wingspan (Boston Scientific, Fremont, CA) is a self-expanding stent designed specifically for the treatment of symptomatic intracranial atheromatous disease. The current series reports the observed incidence of in-stent restenosis (ISR) and thrombosis on angiographic follow-up. METHODS: A prospective, intent-to-treat registry of patients in whom the Wingspan stent system was used to treat symptomatic intracranial atheromatous disease was maintained at five participating institutions. Clinical and angiographic follow-up results were recorded. ISR was defined as stenosis greater than 50% within or immediately adjacent (within 5 mm) to the implanted stents and absolute luminal loss greater than 20%. RESULTS: To date, follow-up imaging (average duration, 5.9 mo; range, 1.5-15.5 mo) is available for 84 lesions treated with the Wingspan stent (78 patients). Follow-up examinations consisted of 65 conventional angiograms, 17 computed tomographic angiograms, and two magnetic resonance angiograms. Of these lesions with follow-up, ISR was documented in 25 and complete thrombosis in four. Two of the 4 patients with stent thrombosis had lengthy lesions requiring more than one stent to bridge the diseased segment. ISR was more frequent (odds ratio, 4.7; 95% confidence intervals, 1.4-15.5) within the anterior circulation (42%) than the posterior circulation (13%). Of the 29 patients with ISR or thrombosis, eight were symptomatic (four with stroke, four with transient ischemic attack) and 15 were retreated. Of the retreatments, four were complicated by clinically silent in-stent dissections, two of which required the placement of a second stent. One was complicated by a postprocedural reperfusion hemorrhage. CONCLUSION: The ISR rate with the Wingspan stent is higher in our series than previously reported, occurring in 29.7% of patients. ISR was more frequent within the anterior circulation than the posterior circulation. Although typically asymptomatic (76% of patients in our series), ISR can cause neurological symptoms and may require target vessel revascularization.OBJECTIVEWingspan (Boston Scientific, Fremont, CA) is a self-expanding stent designed specifically for the treatment of symptomatic intracranial atheromatous disease. The current series reports the observed incidence of in-stent restenosis (ISR) and thrombosis on angiographic follow-up. METHODSA prospective, intent-to-treat registry of patients in whom the Wingspan stent system was used to treat symptomatic intracranial atheromatous disease was maintained at five participating institutions. Clinical and angiographic follow-up results were recorded. ISR was defined as stenosis greater than 50% within or immediately adjacent (within 5 mm) to the implanted stents and absolute luminal loss greater than 20%. RESULTSTo date, follow-up imaging (average duration, 5.9 mo; range, 1.5–15.5 mo) is available for 84 lesions treated with the Wingspan stent (78 patients). Follow-up examinations consisted of 65 conventional angiograms, 17 computed tomographic angiograms, and two magnetic resonance angiograms. Of these lesions with follow-up, ISR was documented in 25 and complete thrombosis in four. Two of the 4 patients with stent thrombosis had lengthy lesions requiring more than one stent to bridge the diseased segment. ISR was more frequent (odds ratio, 4.7; 95% confidence intervals, 1.4–15.5) within the anterior circulation (42%) than the posterior circulation (13%). Of the 29 patients with ISR or thrombosis, eight were symptomatic (four with stroke, four with transient ischemic attack) and 15 were retreated. Of the retreatments, four were complicated by clinically silent in-stent dissections, two of which required the placement of a second stent. One was complicated by a postprocedural reperfusion hemorrhage. CONCLUSIONThe ISR rate with the Wingspan stent is higher in our series than previously reported, occurring in 29.7% of patients. ISR was more frequent within the anterior circulation than the posterior circulation. Although typically asymptomatic (76% of patients in our series), ISR can cause neurological symptoms and may require target vessel revascularization.

International Retrospective Study of the Pipeline Embolization Device: A Multicenter Aneurysm Treatment Study

BACKGROUND AND PURPOSE: Flow diverters are increasingly used in the endovascular treatment of intracranial aneurysms. Our aim was to determine neurologic complication rates following Pipeline Embolization Device placement for intracranial aneurysm treatment in a real-world setting. MATERIALS AND METHODS: We retrospectively evaluated all patients with intracranial aneurysms treated with the Pipeline Embolization Device between July 2008 and February 2013 in 17 centers worldwide. We defined 4 subgroups: internal carotid artery aneurysms of ≥10 mm, ICA aneurysms of <10 mm, other anterior circulation aneurysms, and posterior circulation aneurysms. Neurologic complications included spontaneous rupture, intracranial hemorrhage, ischemic stroke, permanent cranial neuropathy, and mortality. Comparisons were made with t tests or ANOVAs for continuous variables and the Pearson χ2 or Fisher exact test for categoric variables. RESULTS: In total, 793 patients with 906 aneurysms were included. The neurologic morbidity and mortality rate was 8.4% (67/793), highest in the posterior circulation group (16.4%, 9/55) and lowest in the ICA <10-mm group (4.8%, 14/294) (P = .01). The spontaneous rupture rate was 0.6% (5/793). The intracranial hemorrhage rate was 2.4% (19/793). Ischemic stroke rates were 4.7% (37/793), highest in patients with posterior circulation aneurysms (7.3%, 4/55) and lowest in the ICA <10-mm group (2.7%, 8/294) (P = .16). Neurologic mortality was 3.8% (30/793), highest in the posterior circulation group (10.9%, 6/55) and lowest in the anterior circulation ICA <10-mm group (1.4%, 4/294) (P < .01). CONCLUSIONS: Aneurysm treatment with the Pipeline Embolization Device is associated with the lowest complication rates when used to treat small ICA aneurysms. Procedure-related morbidity and mortality are higher in the treatment of posterior circulation and giant aneurysms.

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) and older (>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.

CURATIVE RECONSTRUCTION OF A GIANT MIDBASILAR TRUNK ANEURYSM WITH THE PIPELINE EMBOLIZATION DEVICE

OBJECTIVETo 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. METHODSA 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. RESULTSAn 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 patients 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. CONCLUSIONThe 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.