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American Journal of Neuroradiology | 2013

Reduction of Coil Mass Artifacts in High-Resolution Flat Detector Conebeam CT of Cerebral Stent-Assisted Coiling

I van der Bom; S Hou; Ajit S. Puri; Gabriela Spilberg; Daniel Ruijters; P. van de Haar; B. Carelsen; Srinivasan Vedantham; Matthew J. Gounis; Ajay K. Wakhloo

BACKGROUND AND PURPOSE: Developments in flat panel angiographic C-arm systems have enabled visualization of both the neurovascular stents and host arteries in great detail, providing complementary spatial information in addition to conventional DSA. However, the visibility of these structures may be impeded by artifacts generated by adjacent radio-attenuating objects. We report on the use of a metal artifact reduction algorithm for high-resolution contrast-enhanced conebeam CT for follow-up imaging of stent-assisted coil embolization. MATERIALS AND METHODS: Contrast-enhanced conebeam CT data were acquired in 25 patients who underwent stent-assisted coiling. Reconstructions were generated with and without metal artifact reduction and were reviewed by 3 experienced neuroradiologists by use of a 3-point scale. RESULTS: With metal artifact reduction, the observers agreed that the visibility had improved by at least 1 point on the scoring scale in >40% of the cases (κ = 0.6) and that the streak artifact was not obscuring surrounding structures in 64% of all cases (κ = 0.6). Metal artifact reduction improved the image quality, which allowed for visibility sufficient for evaluation in 65% of the cases, and was preferred over no metal artifact reduction in 92% (κ = 0.9). Significantly higher scores were given with metal artifact reduction (P < .0001). CONCLUSIONS: Although metal artifact reduction is not capable of fully removing artifacts caused by implants with high x-ray absorption, we have shown that the image quality of contrast-enhanced conebeam CT data are improved drastically. The impact of the artifacts on the visibility varied between cases, and yet the overall visibility of the contrast-enhanced conebeam CT with metal artifact reduction improved in most the cases.


Journal of NeuroInterventional Surgery | 2015

Endovascular treatment of tandem vascular occlusions in acute ischemic stroke.

Ajit S. Puri; Anna Luisa Kühn; Hyon-Jo Kwon; Muhib Khan; S Hou; Eugene Lin; Ju-Yu Chueh; Imramsjah M. J. van der Bom; Guilherme Dabus; Italo Linfante; Matthew J. Gounis; Ajay K. Wakhloo

Background and purpose Tandem vascular occlusions are an important cause of acute ischemic stroke (AIS) and present unique treatment challenges. We report our experience of managing a subset of AIS patients with extracranial vascular stenting/angioplasty and intracranial revascularization. Methods Consecutive patients who presented at three centers with AIS from tandem vascular occlusions confirmed by brain and neck CT imaging were included in the study. We retrospectively analyzed the patient demographics, National Institute of Health Stroke Scale (NIHSS) score and modified Rankin Scale (mRS) score at the time of admission, treatment strategy, angiographic results using the Thrombolysis In Cerebral Infarction (TICI) score, and clinical and imaging follow-up. Results Twenty-eight patients were included. The mean NIHSS score at admission was 18. Extracranial carotid occlusions with a concomitant middle cerebral artery occlusion were seen in 89.3% of patients (n=25) and vertebral artery combined with basilar artery lesions in 10.7% (n=3). An antegrade approach (ie, treatment of the extracranial lesion first) was used in 24 patients (85.7%). Proximal occlusion recanalization was achieved usually with a stent (n=27; 96.4%). Pursuant to intracranial revascularization techniques, ≥TICI 2A recanalization was seen in 96.4% of patients. An mRS score of ≤2 at 90 days was achieved in 56.5% of patients. Conclusions Our study shows preliminary data from three centers on recanalization of tandem occlusions in patients presenting with AIS. There was a preference to revascularize the proximal occlusion using a stent followed by distal recanalization with mechanical thrombectomy, intra-arterial thrombolysis or a combination of these. This approach has low periprocedural complications and can achieve an excellent angiographic and clinical outcome.


Journal of NeuroInterventional Surgery | 2015

Flow diverter stents for unruptured saccular anterior circulation perforating artery aneurysms: safety, efficacy, and short-term follow-up

Anna Luisa Kühn; S Hou; M Perras; C Brooks; Matthew J. Gounis; Ajay K. Wakhloo; Ajit S. Puri

Background Anterior circulation perforating artery aneurysms including anterior choroidal artery and lenticulostriate artery aneurysms are rare. Injury to these vessels can lead to severe debilitating symptoms. Objective To present a new approach to treatment using flow diversion technology. Methods Patients treated with a Pipeline embolization device (PED) for perforator artery aneurysms at our institution between June 2012 and May 2013 were identified and included in our retrospective analysis. We evaluated patient vascular risk factors; family history of aneurysms; aneurysm characteristics; National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) on admission; and angiography follow-up and patient clinical outcome at discharge, 6 months, and 1 year. Results We included four patients with a mean age of 59.8 years. Two patients had a positive family history of aneurysms. Patient vascular risk factors included smoking, dyslipidemia, and hypertension. All patients presented with a NIHSS and mRS of 0 on admission. Aneurysms were located at the anterior choroidal (n=2) or lenticulostriate artery (n=2) and were treated with a single PED. No periprocedural or postprocedural complications occurred. The patients were discharged with no change in NHISS or mRS score. Six-month and 1-year follow-up angiography showed complete aneurysm occlusion. Mild intimal hyperplasia was seen in 2 cases at 6 months, but was resolved at the 1-year follow-up. No re-treatment was necessary. NIHSS and mRS remained 0 at follow-up time points. Conclusions Our preliminary results show that flow diversion technology is an effective and safe therapy for complex, hard-to-treat aneurysms in perforating arteries. Larger studies with long-term follow-up are needed to validate our promising results.


Journal of NeuroInterventional Surgery | 2016

Endovascular reconstruction of unruptured intradural vertebral artery dissecting aneurysms with the Pipeline embolization device

Anna Luisa Kühn; Peter Kan; Francesco Massari; J Lozano; S Hou; M Howk; Matthew J. Gounis; Ajay K. Wakhloo; Ajit S. Puri

Background Dissecting aneurysms of the vertebral artery (VA) are difficult to treat using current surgical and endovascular techniques. Objective To analyze retrospectively the efficacy and safety of flow diverters in the treatment of dissecting aneurysms of the vertebral artery. Methods We identified six patients with six unruptured VA dissecting aneurysms either arising from the V4 or V3–V4 junction that were treated with the Pipeline embolization device (PED) at our institution between July 2012 and February 2015. Among other parameters, technical feasibility of the procedure, procedure-related complications, angiographic results, and clinical outcome were evaluated. Results PED placement was achieved in all cases and immediate angiography follow-up demonstrated intra-aneurysmal contrast stasis with parent artery preservation. A temporary episode of dysarthria was noted in one patient. Major procedure-related complications were not observed. The 6-month follow-up (n=6) demonstrated complete/near-complete aneurysm obliteration in five patients and partial obliteration in one. At the 1-year follow-up (n=5) stable complete aneurysm occlusion was seen in two patients. Two cases showed progression from near complete occlusion and partial occlusion at 6 months to complete occlusion and near complete occlusion. One cases showed unchanged near complete occlusion. No aneurysmal bleeding, in-stent stenosis or thromboembolic complication was seen. National Institutes of Health Stroke Scale and modified Rankin scale scores remained unchanged from admission to discharge. Conclusions Our preliminary experience with the use of PED for the treatment of intradural VA dissecting aneurysms shows promising short-term results, making this technique a feasible and safe treatment option in patients suitable for this approach. However, long-term and larger cohort studies are needed to validate these results.


Case Reports | 2013

Double embolic protection during carotid artery stenting with persistent hypoglossal artery

Christine F. Silva; S Hou; Anna Luisa Kühn; Richard Whitten; Ajay K. Wakhloo

A woman presented with 75% stenosis of the right internal carotid artery (ICA) with extension to the origin of a persistent hypoglossal artery (PHA). The PHA is a rare fetal variant of carotid–basilar anastomosis that elevates the risk of ischemia and embolic infarction within the posterior cerebral circulation in patients with carotid disease proximal to the anastomosis. Our case is highly unique because of the extremely rare nature of the PHA with associated ICA stenosis that extended to the PHA. Additionally, a novel treatment approach was employed by stenting and angioplasty while protecting both the anterior and posterior cerebral circulations.


Journal of NeuroInterventional Surgery | 2016

Stent-assisted coil embolization of aneurysms with small parent vessels: safety and efficacy analysis

Anna Luisa Kühn; S Hou; Ajit S. Puri; Christine F. Silva; Matthew J. Gounis; Ajay K. Wakhloo

Background Stent-assisted coil embolization (SACE) is a viable therapeutic approach for wide-neck intracranial aneurysms. However, it can be technically challenging in small cerebral vessels (≤2 mm). Objective To present our experience with stents approved for SACE in aneurysms with small parent arteries. Methods All patients who underwent stent-assisted aneurysm treatment with either a Neuroform or an Enterprise stent device at our institution between June 2006 and October 2012 were identified. Additionally, we evaluated each patients vascular risk factors, aneurysm characteristics (ruptured vs non-ruptured, incidental finding, recanalized) and follow-up angiography data. Results A total of 41 patients with 44 aneurysms met our criteria, including 31 women and 10 men. Most of the aneurysms were located in the anterior circulation (75%). Stent placement in vessels 1.2–2 mm in diameter was successful in 93.2%. Thromboembolic complications occurred in 6 cases and vessel straightening was seen in 1 case only. Initial nearly complete to complete aneurysm obliteration was achieved in 88.6%. Six-month follow-up angiography showed coil compaction in three cases, one asymptomatic in-stent stenosis and stent occlusion. Twelve to 20-months’ follow-up showed stable coil compaction in two patients compared with previous follow-up, and aneurysm recanalization in two patients. Twenty-four to 36-months’ follow-up showed further coil compaction in one of these patients and aneurysm recanalization in a previous case of stable coil compaction on mid-term follow-up. Conclusions Our results suggest that SACE of aneurysms with small parent vessels is feasible in selected cases and shows good long-term patency rates of parent arteries.


Interventional Neuroradiology | 2014

Use of intermediate guide catheters as an adjunct in extracranial embolization to avoid onyx reflux into the anastomotic vasculature. A technical note.

Ajit S. Puri; Anna Luisa Kühn; S Hou; Ajay K. Wakhloo

Onyx is a non-adhesive polymer used for embolization of arteriovenous malformations and dural arteriovenous fistulas (DAVFs). The limiting factor for Onyx embolization is usually the amount of microcatheter reflux, which can be safely tolerated. The dual microcatheter technique, compliant balloon use proximally and the use of the dual lumen Scepter balloon have been described to prevent and limit proximal Onyx reflux. We describe the use the Navien 058 intermediate guide catheter to accept the Onyx reflux in its lumen and possibly also serve as a mechanical barrier to avoid reflux into the anastomotic channel connecting the occipital artery to the vertebral artery during DAVF embolization via the occipital artery. Complete embolization of the DAVF was achieved using the lumen of the Navien catheter to accept aggressive Onyx reflux. Complete cure of the DAVF was obtained with Onyx cast filling the entire venous pouch. Besides providing distal access support, intermediate guide catheters can also prevent embolic material reflux by accepting reflux into the lumen and providing a mechanical barrier.


Journal of NeuroInterventional Surgery | 2016

Onyx embolization in distal dissecting posterior inferior cerebellar artery aneurysms

Ajit S. Puri; Francesco Massari; S Hou; J Lozano; M Howk; M Perras; C Brooks; Matthew J. Gounis; Peter Kan; Ajay K. Wakhloo

Background Dissecting aneurysms located along the distal segments of the posterior inferior cerebellar artery (PICA) are extremely rare, accounting for only 0.5–0.7% of all intracranial aneurysms. Treatment of these aneurysms is challenging, both surgically and endovascularly. We present our preliminary experience and clinical data utilizing Onyx as an embolization agent in the treatment of these lesions with proximal parent artery preservation. Methods 7 consecutive ruptured peripheral PICA aneurysms, in 7 patients, were treated with superselective Onyx embolization at our institutions. According to the anatomical classification of Lister et al, these aneurysms were located in the lateral medullary segment (n=1), tonsillomedullary segment (n=1), and the telovelotonsillary segment (n=5) of the PICA. Technical feasibility, procedure related complications, angiographic results, follow-up diagnostic imaging, and clinical outcome were evaluated. Results In all cases, endovascular treatment was successful, with complete occlusion of the aneurysm with proximal parent artery preservation at the final postprocedural angiogram. Procedure related complications were not observed. One patient with a poor clinical condition at admission died during the initial hospital stay due to extensive subarachnoid and intraventricular hemorrhage. No rebleeding or recanalization was noted during follow-up. Two patients had a residual moderate to severe disability at follow-up. Favorable outcomes, with no or mild disability, were observed in four of the surviving patients. Conclusions Angiographic, diagnostic imaging, and clinical results of our small series indicate that Onyx embolization of dissecting distal PICA aneurysms with parent artery preservation is an effective option with acceptable morbidity and mortality rate, in those cases in which surgical clipping or endovascular coiling of the aneurysmal sac is not suitable.


Operative Neurosurgery | 2018

Pipeline Embolization Device for Pericallosal Artery Aneurysms: A Retrospective Single Center Safety and Efficacy Study

Katyucia de Macedo Rodrigues; Anna Luisa Kühn; Takamitsu Tamura; Guilherme Dabus; Peter Kan; M Marosfoi; J Diego Lozano; M Perras; C Brooks; M Howk; S Hou; David E Rex; Francesco Massari; Matthew J. Gounis; Ajay K. Wakhloo; Ajit S. Puri

BACKGROUND Pericallosal artery aneurysm treatment may be challenging using traditional endovascular techniques. OBJECTIVE To demonstrate the feasibility, efficacy, and safety of endovascular treatment of pericallosal artery aneurysm using flow diverters. METHODS We performed a retrospective review of our institutional database from July 2013 through July 2016 and identified 7 subjects with a pericallosal artery aneurysm treated with the Pipeline embolization device (ev3 Neurovascular, Medtronic, Dublin, Ireland) and at least 1 follow-up angiogram. Technical feasibility, procedural complication, angiographic results, and clinical outcome were evaluated. RESULTS Placement of the Pipeline embolization device was successful in all cases without evidence of procedural complication. Five out of 7 subjects showed a complete aneurysm occlusion at 6- to 12-mo follow-up angiogram. The 2 subjects with persistent aneurysm filling showed decreased aneurysm sac volume on follow-up angiograms (96% and 60%). There was no evidence of in-implant stenosis or intimal hyperplasia. No thromboembolic or hemorrhagic complications were seen during the follow-up period. Only 1 patient had a transient change in Modified Rankin scale score from baseline as a result of different unrelated procedure. CONCLUSION Our preliminary results demonstrate feasibility of the use of flow diverter stent for treatment of aneurysms of the pericallosal artery with rate of aneurysm occlusion comparable to literature and without evidence of increased procedural or short-term morbidity. A long-term and larger cohort study is needed to validate our findings.


Journal of NeuroInterventional Surgery | 2014

E-041 Use of Flow Diverters in the Endovascular Reconstruction of Fusiform Dissecting Vertebral Artery Aneurysms

Ajit S. Puri; Francesco Massari; S Hou; M Perras; C Brooks; Charles Stout; Matthew J. Gounis; Ajay K. Wakhloo

Introduction/purpose Fusiform aneurysms (FUANs) of vertebral artery are difficult to treat by using current surgical techniques. Endovascular techniques like parent vessel occlusion, trapping, coiling, stent assisted coiling or stent mono-therapy is currently used to treat these aneurysms. The purpose of this study is to assess the efficacy and safety of flow diverters (Pipeline Embolization Device) in the treatment of vertebral artery FUANs compared to currently used therapeutic modalities. Materials and methods From July 2012 to October 2013, a total of 5 vertebral artery fusiform dissecting aneurysms in 5 patients (2 men and 3 women; age range, 39–59 years; mean age, 50.8 years) were treated with pipeline embolization device (PED) at our institution. In 2 patients the aneurysms were an incidental finding whereas in the other 3 cases were associated to neurologic symptoms, such as visual changes, ataxia, facial numbness or vertigo. Location of the aneurysms was as follows: 4 aneurysms on the right and 1 on the left side. 4 aneurysms were centerd at the V4 segment of the vertebral artery (intradural); only one was located at the vertebral V3-V4 segments junction (intra/extradural). Only one patient had family history indicative for intracranial aneurysm. Aneurysms ranged from 5 to 13 mm in maximal diameter. The technical feasibility of the procedure, procedure-related complications, angiographic results, and clinical outcome were evaluated. Results In every case, endovascular treatment was achieved. Immediate angiography demonstrated intra-aneurysmal contrast stagnation, with parent artery preservation in all cases. Major procedure-related complications were not observed. A brief temporary episode of dysarthria was noted in one of the patient. None of the treated aneurysms experienced bleeding or thrombo-embolic complication during the follow-up time. At 6 month follow-up (4 patients) was noted a complete/near complete aneurysm obliteration in 3 patients and partial obliteration in 1 patient. At 1 year follow-up (2 patients) was noted a progression to complete aneurysm obliteration in 1 patient and stable partial embolization in 1 patient. No intimal hyperplasia was noted at 6–12 months follow-up in the cohort of patients analyzed. Conclusion In our preliminary experience vertebral artery fusiform dissecting aneurysms treatment with PED is a safe and efficacious option in treating dissecting or fusiform intracranial aneurysms. Long term studies and larger cohort is recommended for further evaluation of this treatment strategy. Disclosures A. Puri: None. F. Massari: None. S. Hou: None. M. Perras: None. C. Brooks: None. C. Stout: None. M. Gounis: None. A. Wakhloo: None.

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Ajay K. Wakhloo

University of Massachusetts Medical School

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Ajit S. Puri

University of Massachusetts Medical School

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Matthew J. Gounis

University of Massachusetts Medical School

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Anna Luisa Kühn

University of Massachusetts Medical School

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C Brooks

University of Massachusetts Medical School

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M Perras

University of Massachusetts Medical School

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M Howk

University of Massachusetts Medical School

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Peter Kan

Baylor College of Medicine

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