The pCONUS2 and pCONUS2 HPC Neck Bridging Devices : Results from an International Multicenter Retrospective Study.

INTRODUCTION: Bifurcation aneurysms represent an ongoing endovascular challenge with a variety of techniques and devices designed to address them. We present our multicenter series of the pCONUS2 and pCONUS2 HPC devices when treating bifurcation aneurysms. METHODS: We performed a retrospective review of our prospectively maintained databases at 3 tertiary neurointerventional centers to identify all patients who underwent coil embolization with the pCONUS2 or pCONUS2 HPC device between February 2015 and August 2021. We recorded baseline demographics, aneurysm data, complications, immediate and delayed angiographic results. RESULTS: We identified 55 patients with 56 aneurysms, median age 63 years (range 42-78 years), 67.3% female (n = 37). The commonest aneurysm location was the MCA bifurcation (n = 40, 71.4%). Average dome height was 8.9 ± 4.2 mm (range 3.2-21.5 mm), average neck width 6.4 ± 2.5 mm (range 2.6-14 mm), and average aspect ratio 1.3 ± 0.6 (range 0.5-3.3). The pCONUS2 was used in 64.3% and the pCONUS2 HPC in 35.7%. The procedural technical success rate was 98.2%. Intraoperative complications occurred in 5 cases (8.9%), 4 of which were related to the coils with partial thrombus formation on the pCONUS2 HPC seen in 1 case that was resolved with heparin. In relation to the procedure and treatment of the aneurysm the overall permanent morbidity was 1.8% (n = 1/55) and mortality 0%. Delayed angiographic follow-up (48 aneurysms) at median 12 months postprocedure (range 3-36 months) demonstrated adequate occlusion of 83.4% of aneurysms. CONCLUSION: The pCONUS2 and pCONUS2 HPC devices carry a high technical success rate, low complication and retreatment rate, and good rates of adequate occlusion. Larger prospective confirmatory studies are required.

The p48MW Flow Diverter-Initial Human Experience.

BACKGROUND AND PURPOSE: The use of flow diverters to treat aneurysms arising from small caliber parent vessels has been reported. This article reports the results of the first in experiences with the p48MW (p48 Movable Wire) in humans, a device specifically designed to target vessels 1.75-3 mm in diameter. METHODS: This monocentric study retrospectively reviewed the prospectively maintained database to identify all patients treated with the p48MW device between January 2017 and January 2019 at this institution. Patient demographics, aneurysm characteristics, angiographic and clinical follow-up were recorded as well as complications. RESULTS: A total of 25 patients (20 female) with an average age of 55 ± 12.9 years (range 34-84) with 25 aneurysms were identified. The majority of the aneurysms was located in the anterior circulation (19/25, 76%). The average aneurysm dome width was 3.98 ± 3.6 mm (range 1.2-13 mm). Complete occlusion was seen in 18/24 (75%) aneurysms with neck remnants in 1/24 (4.2%) and continued aneurysm filling seen in the remaining cases (5/24, 20.8%). Adequate occlusion was seen in 79.2% of aneurysms (Raymond Roy Classification [RRC] grade I or II) during the follow-up period. There was a single technical complication with inappropriate deployment of the first p48MW. There was a single clinical complication (4%); however, the patient made a complete recovery (modified Rankin Scale [mRS] 0) and one patient died secondary to uncontrollable status epilepticus following acute subarachnoid hemorrhage unrelated to the treatment. CONCLUSION: The p48MW is safe and effective for the treatment of aneurysms including those arising from distal vessels.

The Contour-Early Human Experience of a Novel Aneurysm Occlusion Device.

BACKGROUND AND PURPOSE: Endosaccular flow disruption is a recognized treatment options for treating both unruptured and ruptured aneurysms. The Contour device is designed to target the neck of an aneurysm and cause flow disruption within the aneurysm hence promoting thrombosis and neo-endothelialization at the neck. This article presents initial experiences with the Contour. METHODS: The prospectively maintained database was retrospectively reviewed to identify patients treated with the Contour device. Demographic data, aneurysm characteristics, clinical result, and clinical and radiological follow-up information were recorded. RESULTS: The review identified 3 patients (2 female), with 3 unruptured aneurysms, of average age 67 ± 8.7 years (range 62-77 years). The aneurysms were all located in the anterior circulation including one pericallosal, one at the A1-2 junction and one on the ICA bifurcation. The mean average dome height was 7.6 ± 0.62 mm (range 7.1-8.3 mm), dome width 5.7 ± 2 mm (range 3.5-7.5 mm), and neck width 3.6 ± 0.95 mm (range 2.5-4.2 mm). At follow-up angiography two of the aneurysms were completely occluded and one device had displaced into the aneurysm sac due to inappropriate positioning of the device. Of the patients one had minor stroke during the postoperative period but returned to baseline neurology. All patients were mRS 0 at last follow-up. CONCLUSION: The Contour is a promising new aneurysm occlusion device. Further studies with longer term follow-up are required to determine the efficacy of this novel device.

Long-Term Outcomes of the WEB Device for Treatment of Wide-Neck Bifurcation Aneurysms.

BACKGROUND AND PURPOSE: Treatment of wide-neck bifurcation aneurysms using endovascular therapy is still challenging even with the development of treatment devices. The purpose of this investigation was to assess the safety and efficacy of treatment with a Woven EndoBridge (WEB) device for wide-neck bifurcation aneurysms. MATERIALS AND METHODS: All patients treated with a WEB device at our institution between May 2009 and November 2016 were retrospectively evaluated. Clinical and imaging evaluation, aneurysm occlusion status, and modified Rankin scale score were analyzed 1 day after treatment and in the short- (<6 months), mid- (<24 months), and long-term (>24 months) follow-up periods. RESULTS: Forty-one cases of wide-neck aneurysms were analyzed in this study. Overall, 78.8% of the aneurysms had complete occlusion in the last follow-up, and 19.5% required retreatment with additional endovascular devices. A good clinical outcome (modified Rankin scale: 0-2) was obtained in 95.1% of the patients, and the overall treatment-related morbidity and mortality rates were 2.4% and 0.0%, respectively. The mean follow-up time was 15.3 ± 13.5 months. CONCLUSIONS: The results obtained in this study suggest that treatment of wide-neck bifurcation aneurysms with a WEB device is feasible with an acceptable safety and efficacy rate.

Analysis of Flow Dynamics and Outcomes of Cerebral Aneurysms Treated with Intrasaccular Flow-Diverting Devices.

BACKGROUND AND PURPOSE: Intrasaccular flow diversion offers a promising treatment option for complex bifurcation aneurysms. The purpose of this study was to compare the flow conditions between successfully occluded and incompletely occluded aneurysms treated with intrasaccular devices. MATERIALS AND METHODS: The hemodynamics in 18 completely occluded aneurysms after treatment with intrasaccular devices was compared against 18 that were incompletely occluded at follow-up. Hemodynamic and geometric parameters were obtained from computational fluid dynamics models constructed from 3D angiographies. Models of the intrasaccular devices were created and interactively deployed within the vascular models using posttreatment angiography images for guidance. Hemodynamic and geometric variables were compared using the Mann-Whitney test and univariate logistic regression analysis. RESULTS: Incomplete occlusion was associated with large posttreatment mean aneurysm inflows (P = .02) and small reductions in the mean inflow rate (P = .01) and inflow concentration index (P = .03). Incompletely occluded aneurysms were larger (P = .002) and had wider necks (P = .004) than completely occluded aneurysms and tended to have more complex flow patterns, though this trend was not significant after adjusting for multiple testing. CONCLUSIONS: The outcome of cerebral aneurysm treatment with intrasaccular flow diverters is associated with flow conditions created immediately after device implantation. Flow conditions unfavorable for immediate and complete occlusion seem to be created by improper positioning or orientation of the device. Complete occlusion is more difficult to achieve in larger aneurysms, aneurysms with wider necks, and aneurysms with stronger and more complex flows.

Treatment of Wide-Necked Bifurcation Aneurysms : Initial Results with the pCANvas Neck Bridging Device.

BACKGROUND: Recently, numerous devices dedicated to the treatment of wide-necked aneurysms have become available. We present our initial experience with the pCANvas device and present the technical success rate, clinical outcome and immediate angiographic occlusion rates. OBJECTIVE: We sought to determine the efficacy of flow with the pCANvas for the treatment of unruptured intracranial aneurysms. METHODS: We performed a retrospective review of our prospectively collected data to identify patients treated with the pCANvas device between February 2015 and February 2017. The patient demographics, aneurysm characteristics, immediate and delayed clinical and radiographic follow-up data were recorded. RESULTS: We identified 17 patients (13 female) treated only with the pCANvas device. The average age of the patients was 60.5 ± 13.3 years (range 25-75 years). The average dome width was 7.6 ± 3.2 mm (range 3-15.8 mm), dome height 7.1 ± 3.2 mm (range 3-12.9 mm) and neck width 5.4 ± 3.2 (range 3-16.3 mm). The average aspect ratio was 1.5 ± 0.8 (range 0.6-3.7). At the end of the procedure 15 aneurysms continued complete filling of the aneurysm (Raymond Roy Classification[RRC] 3) with 2 aneurysms showing only filling of the neck of the aneurysm (RRC 2). Early follow-up angiography was available for 16 patients and at this stage 11 aneurysms showed persistent and complete filling of the aneurysm (RRC 3), 5 aneurysms showed complete occlusion of the aneurysm (RRC 1) and 7 aneurysms underwent repeat treatment with coiling. CONCLUSION: The early results on the use of the pCANvas are promising; however, longer term follow-up and larger studies are required.

Treatment of Unruptured, Tandem Aneurysms of the ICA with a Single Flow Diverter.

BACKGROUND AND PURPOSE: Intracranial adjacent tandem lesions of the internal carotid artery (ICA) are rare and the optimal treatment strategy is unknown. This study was carried out to determine whether a single flow diverter stent (FDS) could be successfully used to treat these lesions. METHODS: The prospectively maintained database was retrospectively carried out to identify patients treated between February 2009 and February 2018 with multiple unruptured, tandem ICA aneurysms and treated with a single FDS. Demographic data, clinical presentation, aneurysm characteristics, treatment data, clinical result and clinical and radiological follow-up information were recorded. RESULTS: A total of 69 patients (62 female, 89.8%) with average age 55 ± 14.8 years were identified. In total there were 169 aneurysms and the majority of patients (n = 47, 68.1%) had only 2 tandem aneurysms. The largest aneurysms measured 7.69 ± 5.3 mm (range 1.5-26 mm) in height, 6.64 ± 4.71 mm (range 1.5-23 mm) in width and the smaller aneurysm measured 2.61 ± 1.32 mm (range 0.8-9.5 mm) in height and 2.32 ± 1.12 mm (range 0.7-8 mm) in width. In 36 patients the p64 was used, the PED in 28 patients and Surpass in 5 patients. Follow-up was available in 54 patients (130 aneurysms). At initial follow-up (7.2 ± 4.2 months) 45 (83.3%) of the larger aneurysms and 66 (86.8%) of the smaller aneurysms were satisfactorily occluded (Raymond-Roy classification RRC 1 or 2). At delayed follow-up (18 ± 14.6 months) 48 of the larger aneurysms (88.9%) and 71 of the smaller aneurysms (93.4%) were satisfactorily occluded. There were three complications including one death. CONCLUSION: A single FDS can be used to successfully treat multiple tandem aneurysms of the ICA with a high rate of aneurysm exclusion and an acceptable risk profile.

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.

Endovascular occlusion of pial arteriovenous macrofistulae, using pCANvas1 and adenosine-induced asystole to control nBCA injection.

Background In large-caliber pial macrofistulae (pMF), the combination of high blood flow velocity and large efferent artery diameter makes control over the endovascular vessel occlusion difficult and may result in the inadvertent venous passage of occlusive devices or embolic agents. Case descriptions Patient 1: A 27-year-old man presented with headache and ataxia. An infratentorial pMF supplied by both superior cerebellar arteries with venous ectasia was found. The first treatment attempt using balloons and coils failed since the position of either device could not be controlled because of a distal diameter of the feeding artery of 8 mm. In a second session a pCANvas1 (phenox) was deployed at the level of the arteriovenous connection and adenosine-induced asystole allowed the controlled injection of nBCA/Lipiodol with partial occlusion of the pMF. A remaining arteriovenous shunt was occluded under asystole in a third session. The procedures were well tolerated, the patient returned to normal and DSA confirmed the occlusion of the fistula. Patient 2: A 13-year-old boy with hereditary hemorrhagic teleangiectasia presented with an intracerebral hemorrhage from an aneurysm of the left MCA. Twelve weeks after the aneurysm treatment a feeding MCA branch (diameter 4.5 mm) of a right frontal pMF was catheterized. The macrofistula was occluded by deployment of a pCANvas1, followed by the injection of nBCAl/Lipiodol under adenosine-induced asystole. Conclusion pCANvas1 and adenosine-induced asystole allow a controlled injection of nBCA/Lipiodol for the endovascular occlusion of high-flow pMF without venous passage of the embolic agent.

Resonancia magnética de columna cervical con secuencia en flexión para el diagnóstico de la enfermedad de Hirayama / Magnetic resonance of the cervical spine with sequence in flexion for the diagnosis of Hirayama disease

La enfermedad de Hirayama o atrofia muscular espinal juvenil no progresiva de las extremidades superiores es una clase de mielopatía relacionada con la flexión del cuello. Afecta principalmente a hombres jóvenes (entre 15 y 25 años) y se caracteriza por una debilidad muscular asimétrica y unilateral de miembros superiores con atrofia. Suele presentarse de manera insidiosa, con curso progresivo y autolimitado a los 3-4 años del inicio del cuadro. Se cree que es producida por trastornos isquémicos en la microcirculación de las astas anteriores del segmento medular cervical entre C8 y T1 por la compresión en el segmento medular anterior debido al desplazamiento anterior de la duramadre al flexionar el cuello. Si bien existen varias teorías sobre la causa de este deslizamiento, la más aceptada se relaciona con la falta de crecimiento de la duramadre con respecto a la columna durante la pubertad. Esto provocaría un aumento de la tensión de la dura posteriory, como consecuencia, el desplazamiento anterior durante la flexión. Dado su excelente contraste tisular y la posibilidad de realizar adquisiciones en distintos planos, la resonancia magnética es el estudio de elección. Las imágenes deben ser obtenidas en posición neutra y en flexión cervical máxima para poner de manifiesto el desplazamiento de la dura, con el consiguiente aumento de la sensibilidad y especificidad de la prueba. Así, se logra mayor confianza en el diagnóstico y menor cantidad de falsos positivos, en comparación con la posición neutra como única adquisición.

Hirayama disease is a type of myelopathy related to neck flexion. It affects young male adults between 15 and 25 years, and is characterised by unilateral and asymmetric upper limb muscle weakness with atrophy. It usually presents insidiously, with a progressive course and self-limits in 3-4 years. It is believed that it could be produced by ischaemic disorders in the microcirculation of the anterior horns of the cervical spine segment C8 and T1 due to anterior displacement of the dura. There are several theories for the cause of this displacement, with the most accepted being the relationship between the lack of growth of the dura mater and the spine during puberty. This increases the tension of the posterior dura mater and consequently the anterior displacement during flexion. Due to its excellent tissue contrast and the possibility of acquisitions in different planes, magnetic resonance imaging is the study of choice. Images must be obtained in both neutral and cervical flexion to highlight the displacement of the dura mater. This increases the sensitivity and specificity of the test, giving greater confidence in the diagnosis, and reducing false positives compared to neutral as a single acquisition.

Lack of Association between Statin Use and Angiographic and Clinical Outcomes after Pipeline Embolization for Intracranial Aneurysms.

BACKGROUND AND PURPOSE: Use of statin medications has been demonstrated to improve clinical and angiographic outcomes in patients receiving endovascular stent placement for coronary, peripheral, carotid, and intracranial stenoses. We studied the impact of statin use on long-term angiographic and clinical outcomes after flow-diverter treatment of intracranial aneurysms. MATERIALS AND METHODS: We performed a post hoc analysis from pooled patient-level datasets from 3 Pipeline Embolization Device studies: the International Retrospective Study of the Pipeline Embolization Device, the Pipeline for Uncoilable or Failed Aneurysms Study, and the Aneurysm Study of Pipeline in an Observational Registry. We analyzed data comparing 2 subgroups: 1) patients on statin medication, and 2) patients not on statin medication at the time of the procedure and follow-up. Angiographic and clinical outcomes were compared by using the χ2 test, Fisher exact test, or Wilcoxon rank sum test. RESULTS: We studied 1092 patients with 1221 aneurysms. At baseline, 226 patients were on statin medications and 866 patients were not on statin medications. The mean length of clinical and angiographic follow-up was 22.1 ± 15.1 months and 28.3 ± 23.7 months, respectively. There were no differences observed in angiographic outcomes at any time point between groups. Rates of complete occlusion were 82.8% (24/29) versus 86.4% (70/81) at 1-year (P = .759) and 93.3% (14/15) versus 95.7% (45/47) at 5-year (P = 1.000) follow-up for statin-versus-nonstatin-use groups, respectively. There were no differences in any complication rates between groups, including major morbidity and neurologic mortality (7.5% versus 7.1%, P = .77). CONCLUSIONS: Our study found no association between statin use and angiographic or clinical outcomes among patients treated with the Pipeline Embolization Device.

Surpass Flow Diverter for Treatment of Posterior Circulation Aneurysms.

BACKGROUND AND PURPOSE: Flow diverters for the treatment of posterior circulation aneurysms remain controversial. We aimed to identify factors contributing to outcome measures in patients treated with the Surpass flow diverter for aneurysms in this location. MATERIALS AND METHODS: We conducted an observational study of 53 patients who underwent flow-diverter treatment for posterior circulation aneurysms at 15 centers. Key outcome measures were mortality, complete aneurysm occlusion, and modified Rankin Scale score at follow-up. RESULTS: At follow-up (median, 11.3 months; interquartile range, 5.9-12.7 months), 9 patients had died, resulting in an all-cause mortality rate of 17.3% (95% CI, 7%-27.6%); 7 deaths (14%) were directly related to the procedure and none occurred in patients with a baseline mRS score of zero. After adjusting for covariates, a baseline mRS of 3-5 was more significantly (P = .003) associated with a higher hazard ratio for death than a baseline mRS of 0-2 (hazard ratio, 17.11; 95% CI, 2.69-109.02). After adjusting for follow-up duration, a 1-point increase in the baseline mRS was significantly (P < .001) associated with higher values of mRS at follow-up (odds ratio, 2.93; 95% CI, 1.79-4.79). Follow-up angiography in 44 patients (median, 11.3 months; interquartile range, 5.9-12.7 months) showed complete aneurysm occlusion in 29 (66%; 95% CI, 50.1%-79.5%). CONCLUSIONS: Clinical results of flow-diverter treatment of posterior circulation aneurysms depend very much on patient selection. In this study, poorer outcomes were related to the treatment of aneurysms in patients with higher baseline mRS scores. Angiographic results showed a high occlusion rate for this subset of complex aneurysms.

Risk Factors for Ischemic Complications following Pipeline Embolization Device Treatment of Intracranial Aneurysms: Results from the IntrePED Study.

BACKGROUND AND PURPOSE: Risk factors for acute ischemic stroke following flow-diverter treatment of intracranial aneurysms are poorly understood. Using the International Retrospective Study of Pipeline Embolization Device (IntrePED) registry, we studied demographic, aneurysm, and procedural characteristics associated with postoperative acute ischemic stroke following Pipeline Embolization Device (PED) treatment. MATERIALS AND METHODS: We identified patients in the IntrePED registry with post-PED-treatment acute ischemic stroke. The rate of postoperative acute ischemic stroke was determined by demographics, comorbidities, aneurysm characteristics, and procedure characteristics (including anticoagulation use, platelet testing, number of devices used, sheaths, and so forth). Categoric variables were compared with χ(2) testing, and continuous variables were compared with the Student t test. Odds ratios and 95% confidence intervals were obtained by using univariate logistic regression. Multivariate logistic regression analysis was used to determine which factors were independently associated with postoperative stroke. RESULTS: Of 793 patients with 906 aneurysms, 36 (4.5%) patients had acute ischemic stroke. Twenty-six (72.2%) strokes occurred within 30 days of treatment (median, 3.5 days; range, 0-397 days). Ten patients died, and the remaining 26 had major neurologic morbidity. Variables associated with higher odds of acute ischemic stroke on univariate analysis included male sex, hypertension, treatment of MCA aneurysms, treatment of fusiform aneurysms, treatment of giant aneurysms, and use of multiple PEDs. However, on multivariate analysis, the only one of these variables independently associated with stroke was treatment of fusiform aneurysms (OR, 2.74; 95% CI, 1.11-6.75; P = .03). Fusiform aneurysms that were associated with stroke were significantly larger than those not associated with stroke (mean, 24.5 ± 12.5 mm versus 13.6 ± 6.8 mm; P < .001). CONCLUSIONS: Ischemic stroke following PED treatment is an uncommon-but-devastating complication. Fusiform aneurysms were the only variable independently associated with postoperative stroke.

Surpass flow diverter in the treatment of intracranial aneurysms: a prospective multicenter study.

BACKGROUND AND PURPOSE: Incomplete occlusion and recanalization of large and wide-neck brain aneurysms treated by endovascular therapy remains a challenge. We present preliminary clinical and angiographic results of an experimentally optimized Surpass flow diverter for treatment of intracranial aneurysms in a prospective, multicenter, nonrandomized, single-arm study. MATERIALS AND METHODS: At 24 centers, 165 patients with 190 intracranial aneurysms of the anterior and posterior circulations were enrolled. The primary efficacy end point was the percentage of intracranial aneurysms with 100% occlusion on 6-month DSA. The primary safety end point was neurologic death and any stroke through a minimum follow-up of 6 months. RESULTS: Successful flow-diverter delivery was achieved in 161 patients with 186 aneurysms (98%); the mean number of devices used per aneurysm was 1.05. Clinical follow-up (median, 6 months) of 150 patients (93.2%), showed that the primary safety end point occurred in 18 subjects. Permanent neurologic morbidity and mortality were 6% and 2.7%, respectively. Morbidity occurred in 4% and 7.4% of patients treated for aneurysms of the anterior and posterior circulation, respectively. Neurologic death during follow-up was observed in 1.6% and 7.4% of patients with treated intracranial aneurysms of the anterior and posterior circulation, respectively. Ischemic stroke at ≤30 days, SAH at ≤7 days, and intraparenchymal hemorrhage at ≤7 days were encountered in 3.7%, 2.5%, and 2.5% of subjects, respectively. No disabling ischemic strokes at >30 days or SAH at >7 days occurred. New or worsening cranial nerve deficit was observed in 2.7%. Follow-up angiography available in 158 (86.8%) intracranial aneurysms showed 100% occlusion in 75%. CONCLUSIONS: Clinical outcomes of the Surpass flow diverter in the treatment of intracranial aneurysms show a safety profile that is comparable with that of stent-assisted coil embolization. Angiographic results showed a high rate of intracranial aneurysm occlusion.

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 χ(2) 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.

The role of the pipeline embolization device for the treatment of dissecting intracranial aneurysms.

Intracranial dissecting aneurysms constitute rare lesions with complex management and elevated morbidity and mortality. Results of 23 patients harboring such lesions treated with the PED are reported. Standard dual antiplatelet therapy was instituted. Neurologic and angiographic assessments were obtained at 3, 6, and 12 months. Clinical presentation included SAH (52%), symptoms of mass effect (22%), ischemia (4%), and incidental finding (22%). The posterior circulation was affected in 91% of cases. Total occlusion was demonstrated in 69.5% of patients, with an increment to 87.5% considering only patients with at least 3 months of follow-up. Small aneurysms demonstrated higher rates of total occlusion (6/7) compared with large (5/7) and giant (5/9) ones. Good clinical outcome was achieved in 74% of patients. Reconstructive endovascular treatment of intracranial dissecting aneurysms with the PED provided good clinical and angiographic results with acceptable risks, representing an attractive therapeutic option for this complex disease, especially when parent vessel preservation is mandatory.

Clinical Application of Image-Based CFD for Cerebral Aneurysms.

During the last decade, the convergence of medical imaging and computational modeling technologies has enabled tremendous progress in the development and application of image-based computational fluid dynamics modeling of patient-specific blood flows. These techniques have been used for studying the basic mechanisms involved in the initiation and progression of vascular diseases, for studying possible ways to improve the diagnosis and evaluation of patients by incorporating hemodynamics information to the anatomical data typically available, and for the development of computational tools that can be used to improve surgical and endovascular treatment planning. However, before these technologies can have a significant impact on the routine clinical practice, it is still necessary to demonstrate the connection between the extra information provided by the models and the natural progression of vascular diseases and the outcome of interventions. This paper summarizes some of our contributions in this direction, focusing in particular on cerebral aneurysms.

The pipeline embolization device for the intracranial treatment of aneurysms trial.

BACKGROUND AND PURPOSE: Endoluminal reconstruction with flow diverting devices represents a novel constructive technique for the treatment of cerebral aneurysms. We present the results of the first prospective multicenter trial of a flow-diverting construct for the treatment of intracranial aneurysms. MATERIALS AND METHODS: Patients with unruptured aneurysms that were wide-necked (> 4 mm), had unfavorable dome/neck ratios (<1.5), or had failed previous therapy were enrolled in the PITA trial between January and May 2007 at 4 (3 European and 1 South American) centers. Aneurysms were treated with the PED with or without adjunctive coil embolization. All patients underwent clinical evaluation at 30 and 180 days and conventional angiography 180 days after treatment. Angiographic results were adjudicated by an experienced neuroradiologist at a nonparticipating site. RESULTS: Thirty-one patients with 31 intracranial aneurysms (6 men; 42-76 years of age; average age, 54.6 years) were treated during the study period. Twenty-eight aneurysms arose from the ICA (5 cavernous, 15 parophthalmic, 4 superior hypophyseal, and 4 posterior communicating segments), 1 from the MCA, 1 from the vertebral artery, and 1 from the vertebrobasilar junction. Mean aneurysm size was 11.5 mm, and mean neck size was 5.8 mm. Twelve (38.7%) aneurysms had failed (or recurred after) a previous endovascular treatment. PED placement was technically successful in 30 of 31 patients (96.8%). Most aneurysms were treated with either 1 (n = 18) or 2 (n = 11) PEDs. Fifteen aneurysms (48.4%) were treated with a PED alone, while 16 were treated with both PED and embolization coils. Two patients experienced major periprocedural stroke. Follow-up angiography demonstrated complete aneurysm occlusion in 28 (93.3%) of the 30 patients who underwent angiographic follow-up. No significant in-construct stenosis (≥ 50%) was identified at follow-up angiography. CONCLUSIONS: Intracranial aneurysm treatment with the PED is technically feasible and can be achieved with a safety profile analogous to that reported for stent-supported coil embolization. PED treatment elicited a very high rate (93%) of complete angiographic occlusion at 6 months in a population of the most challenging anatomic subtypes of cerebral aneurysms.

Aneurysm rupture following treatment with flow-diverting stents: computational hemodynamics analysis of treatment.

BACKGROUND AND PURPOSE: Flow-diverting approaches to intracranial aneurysm treatment had many promising early results, but recent apparently successful treatments have been complicated by later aneurysm hemorrhage. We analyzed 7 cases of aneurysms treated with flow diversion to explore the possible rupture mechanisms. MATERIALS AND METHODS: CFD analysis of pre- and posttreatment conditions was performed on 3 giant aneurysms that ruptured after treatment and 4 successfully treated aneurysms. Pre- and posttreatment hemodynamics were compared including WSS, relative blood flows, vascular resistances, and pressures, to identify the effects of flow-diverter placements. RESULTS: Expected reductions in aneurysm velocity and WSS were obtained, indicating effective flow diversion from the sac into the parent artery, consistent with periprocedural observations. In each case with postaneurysm rupture, the result of flow diversion led to an increase in pressure within the aneurysm. This pressure increase is related to larger effective resistance in the parent artery from placement of the devices and, in 2 cases, the reduction of a preaneurysm stenosis. CONCLUSIONS: Flow-diversion devices can cause intra-aneurysmal pressure increases, which can potentially lead to rupture, especially for giant aneurysms. This relates both to changes in the parent artery configuration, such as reduction of a proximal stenosis, and to the flow diversion into higher resistance parent artery pathways combined with cerebral autoregulation, leading to higher pressure gradients. These may be important effects that should be considered when planning interventions. Potentially dangerous cases could be identified with angiography and/or patient-specific CFD models.