Nelson Hopkins - Academia.edu (original) (raw)
Papers by Nelson Hopkins
Neurosurgery, 2006
Medically refractory, symptomatic intracranial atherosclerotic disease has a poor prognosis. Base... more Medically refractory, symptomatic intracranial atherosclerotic disease has a poor prognosis. Based on the results of the Warfarin-Aspirin Symptomatic Intracranial Disease study, the risk of ipsilateral stroke at 1.8 years is between 13 and 14% in patients with symptomatic intracranial atherosclerosis. Synergistic advances in intracranial angioplasty and stenting, modern neuroimaging techniques, and periprocedural and postprocedural antithrombotic regimens are creating new models for the diagnosis and successful endovascular treatment of intracranial stenosis. In this article, the most recent clinical developments and concepts for the diagnosis and endovascular treatment of intracranial atherosclerotic disease are discussed.
Neurosurgery, Sep 1, 2002
Blood flow velocity (BFV) in the carotid artery is altered by stent placement. The significance o... more Blood flow velocity (BFV) in the carotid artery is altered by stent placement. The significance of these alterations is unknown. In our experience, both standard BFV criteria for stenosis and customized criteria recommended by other authors have led to high rates of false-positive studies. We reviewed our experience with Doppler ultrasonography immediately after extracranial carotid artery stent placement to define criteria for restenosis by BFV. Complete carotid angiograms and BFV results were available for 114 patients treated between January 1998 and December 1999. Angiographic images obtained immediately after stent placement and at follow-up were measured for residual or recurrent stenosis by a blinded reviewer according to the North American Symptomatic Carotid Endarterectomy Trial method. Results of BFV studies obtained within 1 week of stent placement were interpreted by using two standard criteria (A, peak in-stent systolic velocity greater than 125 cm/s; B, internal carotid artery-to-common carotid artery ratio greater than 3.0) and two customized criteria (C, peak in-stent velocity greater than 170 cm/s; D, internal carotid artery-to-common carotid artery ratio greater than 2.0). The results of follow-up angiography and the most recent Doppler study were compared for nine patients. On the basis of an examination of Doppler studies obtained immediately after stent placement, 36 patients met Criterion A for stenosis according to measured BFV (corresponding mean angiographic stenosis, 14.73 +/- 18.45%), 3 patients met Criterion B (mean stenosis, 1.67 +/- 2.89%), 8 patients met Criterion C (mean stenosis, 12.61 +/- 13.18%), and 14 met Criterion D (mean stenosis, 7.98 +/- 21.74%). No patient with Doppler criteria for significant stenosis had more than 50% residual stenosis. Three of nine patients who underwent follow-up angiography had stenosis of 50% or more; of these three patients, two underwent second angioplasty procedures. The peak in-stent systolic velocity or internal carotid artery-to-common carotid artery BFV ratio for each of the three patients with restenosis, but not for the six other patients, had increased by more than 80% since the immediate post-stenting Doppler study. Strict BFV criteria for restenosis after carotid artery stenting are less reliable than change in BFV over time. An immediate post-stenting Doppler study must be obtained to serve as a reference value for future follow-up evaluation.
Journal of Neuroimaging Official Journal of the American Society of Neuroimaging, Apr 1, 2001
American Journal of Neuroradiology, Apr 1, 2001
Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, Jan 15, 2014
The purpose of the prospective, multicenter, nonrandomized CABANA study was to evaluate periproce... more The purpose of the prospective, multicenter, nonrandomized CABANA study was to evaluate periprocedural clinical outcomes in high surgical risk patients with carotid artery stenosis treated with the Carotid WALLSTENT plus FilterWire EZ Embolic Protection System by a diverse group of clinicians. There is a need for additional evidence evaluating carotid artery stenting (CAS) performed by operators with various experience and training levels. The study enrolled symptomatic (≥50% carotid artery stenosis) and asymptomatic (≥80% carotid stenosis) patients at high risk for carotid endarterectomy. Study centers were grouped into three tiers based on previous CAS experience while individual operators were grouped by their CAS training. The primary endpoint was the 30-day composite of major adverse events [MAEs; including stroke, death, and myocardial infarction (MI)]. Individual event rates were evaluated across the overall study, and by center experience and physician training tier. Of 1,09...
Neurosurgery, 2009
Virtual histology-intravascular ultrasound (VH-IVUS) has been reported to be useful in detecting ... more Virtual histology-intravascular ultrasound (VH-IVUS) has been reported to be useful in detecting the components of coronary plaques in vivo. Recently, the application of VH-IVUS to peripheral interventions has been evaluated. The aim of this study was to examine the extent to which the necrotic core of carotid plaques could be assessed accurately by VH-IVUS compared with histopathology. A total of 37 carotid plaques underwent ex vivo VH-IVUS within 24 hours after endarterectomy. Ninety-five segments of virtual histological images were matched to histological sections. The area of the necrotic core on histological sections was compared with that on virtual histological images. Intraplaque hemorrhage (IPH) was histopathologically graded by its severity using immunohistochemical staining for glycophorin A as a marker. The relationship of the severity of the IPH to the necrotic core was histopathologically evaluated. The correlation between the necrotic core or IPH with symptomatology was also evaluated. The area of the necrotic core on virtual histological images (median, 8.0%; interquartile range, 5.0%-13%) was significantly smaller compared with that of the histological sections (median, 50%; interquartile range, 40%-63%) (P < 0.0001). The Bland-Altman analysis showed poor agreement in the necrotic core measurement between virtual histological images and histological sections (mean difference, 39.8%; 95% confidence interval, 35.8%-43.8%). Severe IPH was significantly associated with a larger necrotic core and symptomatology (P < 0.0001 and P = 0.0039, respectively). The area of necrotic core on the virtual histological analysis did not correlate with symptomatology (P = 0.70), but that on pathological analysis tended to correlate with symptomatology (P = 0.059). In the present virtual histological algorithm, the underestimation of the necrotic core was revealed. The lack of a hemorrhage component in the virtual histological algorithm is a leading cause of its underestimation.
Neurosurgery, 1998
To develop a rabbit aneurysm model that is more realistic in gross appearance and histological fe... more To develop a rabbit aneurysm model that is more realistic in gross appearance and histological features than previous models and to enable the development of a larger animal model. Ten rabbits received porcine pancreatic elastase, five at the right common carotid artery bifurcation and five others at the right superior thyroid artery origin. One control animal received collagenase and another received papaverine, each at the right superior thyroid artery origin. The agents were topically delivered to the arterial adventitia with a microsyringe after surgical exposure of the targeted arteries. The arteries were monitored for aneurysm growth with a video camera for up to 3 hours and were then removed and processed for histology. Saccular aneurysms developed in one of five animals after elastase application at the carotid bifurcation and in all five animals receiving elastase at the superior thyroid artery origin. Among the six aneurysms, recurrent minor hemorrhages occurred in four, thrombosis of the aneurysm sac in three, and rupture causing severe bleeding in one. Histological sections revealed thin-walled aneurysms composed only of collagen fibers and some cellular elements. No saccular dilation resulted from papaverine application. Collagenase application resulted in a hemorrhagic-thrombotic lesion in the arterial wall but no aneurysm formation. Arterial saccular aneurysms were induced in rabbits by topical application of elastase with an easy and efficient method. These aneurysms are histologically similar to natural aneurysms, and their arterial nature renders them more authentic than those of surgical models. This aneurysm model may serve as a foundation for further aneurysm research.
Neurosurgery, 2014
Endovascular technique represents an important, minimally invasive approach to treating cerebrova... more Endovascular technique represents an important, minimally invasive approach to treating cerebrovascular disease. In this article, we discuss the origins of endovascular neurosurgery as a discipline in the context of important technical milestones, evidence-based medicine, and future cerebrovascular neurosurgical training. Cerebrovascular neurosurgery has seen a steady, convergent evolution toward the surgeon capable of seamless incorporation of open and endovascular approaches to any complex vascular disease affecting the central nervous system. Neurosurgery must assume the leadership role in the multidisciplinary neurovascular team.
Neurocritical Care, 2005
Severe medically refractory intracranial stenosis portends a grave prognosis. Recent advances in ... more Severe medically refractory intracranial stenosis portends a grave prognosis. Recent advances in stent technology have enabled clinicians to treat these lesions. Evidence in the coronary literature suggests that stenting without predilation angioplasty is as safe and effective as stenting immediately preceded by predilation angioplasty for the treatment of severely stenotic lesions. Because of marked differences in vessel histology and differences in the sensitivity of the cerebral and coronary vascular beds to embolic insult, direct stenting of severe intracranial stenoses may be more prone to neurological complications than a conventional or staged stenting procedure. We reviewed our clinical experience with conventional, direct, and staged stenting for high-grade stenoses involving the posterior intracranial circulation. We also reviewed the literature and experimental data supporting the rationale for staged stenting. In our experience, no permanent neurological morbidity was identified in four patients treated with a staged approach. In contrast, one of three patients with conventional stenting of the basilar artery and two of four patients treated with direct basilar stenting had permanent neurological sequelae. For patients with high-grade posterior circulation intracranial stenoses involving the perforator-rich zones of the basilar artery, staged stenting may reduce procedure-related morbidity. A staged approach allows for plaque stabilization resulting from post-angioplasty fibrosis, which may protect patients from "snow-plowing," embolic shower of debris, or dissection. Further clinical, in vivo, and histological investigation is warranted.
Neurosurgery, 2011
This article describes delayed endovascular revascularization in a patient with clinical and radi... more This article describes delayed endovascular revascularization in a patient with clinical and radiographic evidence of posterior circulation hemodynamic failure in the setting of intracranial occlusive lesions.
Journal of Neurosurgery, 2003
The authors report a case of an iatrogenic carotid-cavernous fistula (CCF) associated with intrac... more The authors report a case of an iatrogenic carotid-cavernous fistula (CCF) associated with intracranial angioplasty. Angioplasty was performed using a 3 x 10-mm Open Sail coronary balloon in a patient with high-grade stenosis of the left cavernous internal carotid artery (ICA). After angioplasty, a perforation developed in the cavernous ICA, resulting in a CCF. A 3.5 x 9-mm S670 coronary stent was used to treat the fistula. To the authors' knowledge, this is the first reported case in which a CCF developed after angioplasty was performed using a coronary balloon. Long-term angiographic and clinical evaluation is needed to test the suitability and durability of intracranial angioplasty and stent placement in the treatment of symptomatic intracranial stenosis.
Journal of Neurosurgery, 2007
The authors report the successful staged stenting and coil embolization of a large vertebral arte... more The authors report the successful staged stenting and coil embolization of a large vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysm using the contralateral VA for access. A 67-year-old woman presented with a large ruptured VA-PICA aneurysm. Initial attempts to stent the wide-necked aneurysm from the ipsilateral side failed, so coil embolization of the dome was performed. During a second endovascular session, the aneurysm neck was successfully stented from the contralateral VA into the PICA. Six weeks later, coils were inserted into the aneurysm from the ipsilateral side. The coil result was stable at the 3-month follow-up examination.
Journal of Neuroimaging, 2005
Journal of Endovascular Therapy, 2005
To evaluate the feasibility of stenting and cerebral protection in patients with carotid bifurcat... more To evaluate the feasibility of stenting and cerebral protection in patients with carotid bifurcation disease. Carotid stenting with self-expanding nitinol stents was evaluated in 261 patients (157 men; mean age 70.9+/-9.7 years, range 41-90) treated at 33 clinical sites. Among these patients, 141 (54.3%) were symptomatic, and 71 (27.2%) had postendarterectomy restenotic lesions. An embolus protection device became available in the latter third of the study. The primary endpoint of the study was the 30-day composite occurrence of major adverse clinical events (all deaths, strokes, or myocardial infarctions [MI]). At 1 year, the endpoint included all deaths, strokes, or MIs at 30 days, plus all deaths or ipsilateral strokes between 31 days and 1 year. SMART stents were placed in 147 (56%) patients and Precise stents in 107 (41%); 7 (3%) patients were treated with non-study stents. Lesion success, defined as <30% postprocedural residual stenosis, was achieved in 249 (95%). An AngioGuard filter was used in 85 patients; of 90 filters employed, 78 (87%) were successfully deployed and retrieved. Visible material was noted in 42 (54%) retrieved filters. One (0.4%) stent thrombosis occurred at <30 days, and no restenotic lesions >80% were noted in up to 1 year of follow-up. At 30 days, stroke occurred in 16 (6.1%) patients, MI in 1 (0.4%), and 2 (0.8%) patients died. The 30-day rate of stroke, MI, or death was 6.9%. Major ipsilateral stroke occurred in 4 (1.5%) patients between 0 and 30 days; no new major ipsilateral strokes were noted up to 1 year. By Kaplan-Meier analysis, the 1-year risk of stroke, MI, or death was 10.9%+/-2.0%. The 1-year risk of major ipsilateral stroke was significantly lower in patients treated with embolus protection devices (0.0% versus 2.3%, p=0.05). The use of nitinol self-expanding stents in the carotid position appears to be a safe and efficacious alternative for the treatment of carotid bifurcation disease. The addition of embolus protection devices may diminish the risk of postprocedural major ipsilateral strokes.
International Congress Series, 2005
Catheterization and Cardiovascular Interventions, 2008
Journal of Clinical Neuroscience, 2011
The authors present a preliminary experience with ethyl-enevinylalcohol copolymer (Onyx) for hema... more The authors present a preliminary experience with ethyl-enevinylalcohol copolymer (Onyx) for hemangioblastoma vessel embolization before surgical resection. The patient presented with neck pain, dizziness, blurred vision, vomiting, and loss of balance. Diagnostic imaging revealed a posterior fossa cystic mass with a nodular component. Angiography demonstrated a significant vascular blush with arteriovenous shunting that was characteristic of a hemangioblastoma. Tumor vessels originating off the left posterior inferior cerebellar artery were embolized before surgery using Onyx 18 (ev3, Covidien Vascular Therapies, Mansfield, MA, USA). This resulted in complete obliteration of all tumor vessels, transforming a highly vascular tumor into an avascular mass. A safe and uneventful surgical resection was performed the next day. Onyx is a valuable embolic agent for preoperative hemangioblastoma vessel embolization. Because of its low viscosity, Onyx penetrates deeply into the tumor vasculature and allows complete obliteration of tumor vessels. Risks of the intervention have to be carefully weighed against the benefits. If preoperative embolization is indicated, the use of Onyx should be strongly considered.
Neurosurgery, 2006
Medically refractory, symptomatic intracranial atherosclerotic disease has a poor prognosis. Base... more Medically refractory, symptomatic intracranial atherosclerotic disease has a poor prognosis. Based on the results of the Warfarin-Aspirin Symptomatic Intracranial Disease study, the risk of ipsilateral stroke at 1.8 years is between 13 and 14% in patients with symptomatic intracranial atherosclerosis. Synergistic advances in intracranial angioplasty and stenting, modern neuroimaging techniques, and periprocedural and postprocedural antithrombotic regimens are creating new models for the diagnosis and successful endovascular treatment of intracranial stenosis. In this article, the most recent clinical developments and concepts for the diagnosis and endovascular treatment of intracranial atherosclerotic disease are discussed.
Neurosurgery, Sep 1, 2002
Blood flow velocity (BFV) in the carotid artery is altered by stent placement. The significance o... more Blood flow velocity (BFV) in the carotid artery is altered by stent placement. The significance of these alterations is unknown. In our experience, both standard BFV criteria for stenosis and customized criteria recommended by other authors have led to high rates of false-positive studies. We reviewed our experience with Doppler ultrasonography immediately after extracranial carotid artery stent placement to define criteria for restenosis by BFV. Complete carotid angiograms and BFV results were available for 114 patients treated between January 1998 and December 1999. Angiographic images obtained immediately after stent placement and at follow-up were measured for residual or recurrent stenosis by a blinded reviewer according to the North American Symptomatic Carotid Endarterectomy Trial method. Results of BFV studies obtained within 1 week of stent placement were interpreted by using two standard criteria (A, peak in-stent systolic velocity greater than 125 cm/s; B, internal carotid artery-to-common carotid artery ratio greater than 3.0) and two customized criteria (C, peak in-stent velocity greater than 170 cm/s; D, internal carotid artery-to-common carotid artery ratio greater than 2.0). The results of follow-up angiography and the most recent Doppler study were compared for nine patients. On the basis of an examination of Doppler studies obtained immediately after stent placement, 36 patients met Criterion A for stenosis according to measured BFV (corresponding mean angiographic stenosis, 14.73 +/- 18.45%), 3 patients met Criterion B (mean stenosis, 1.67 +/- 2.89%), 8 patients met Criterion C (mean stenosis, 12.61 +/- 13.18%), and 14 met Criterion D (mean stenosis, 7.98 +/- 21.74%). No patient with Doppler criteria for significant stenosis had more than 50% residual stenosis. Three of nine patients who underwent follow-up angiography had stenosis of 50% or more; of these three patients, two underwent second angioplasty procedures. The peak in-stent systolic velocity or internal carotid artery-to-common carotid artery BFV ratio for each of the three patients with restenosis, but not for the six other patients, had increased by more than 80% since the immediate post-stenting Doppler study. Strict BFV criteria for restenosis after carotid artery stenting are less reliable than change in BFV over time. An immediate post-stenting Doppler study must be obtained to serve as a reference value for future follow-up evaluation.
Journal of Neuroimaging Official Journal of the American Society of Neuroimaging, Apr 1, 2001
American Journal of Neuroradiology, Apr 1, 2001
Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, Jan 15, 2014
The purpose of the prospective, multicenter, nonrandomized CABANA study was to evaluate periproce... more The purpose of the prospective, multicenter, nonrandomized CABANA study was to evaluate periprocedural clinical outcomes in high surgical risk patients with carotid artery stenosis treated with the Carotid WALLSTENT plus FilterWire EZ Embolic Protection System by a diverse group of clinicians. There is a need for additional evidence evaluating carotid artery stenting (CAS) performed by operators with various experience and training levels. The study enrolled symptomatic (≥50% carotid artery stenosis) and asymptomatic (≥80% carotid stenosis) patients at high risk for carotid endarterectomy. Study centers were grouped into three tiers based on previous CAS experience while individual operators were grouped by their CAS training. The primary endpoint was the 30-day composite of major adverse events [MAEs; including stroke, death, and myocardial infarction (MI)]. Individual event rates were evaluated across the overall study, and by center experience and physician training tier. Of 1,09...
Neurosurgery, 2009
Virtual histology-intravascular ultrasound (VH-IVUS) has been reported to be useful in detecting ... more Virtual histology-intravascular ultrasound (VH-IVUS) has been reported to be useful in detecting the components of coronary plaques in vivo. Recently, the application of VH-IVUS to peripheral interventions has been evaluated. The aim of this study was to examine the extent to which the necrotic core of carotid plaques could be assessed accurately by VH-IVUS compared with histopathology. A total of 37 carotid plaques underwent ex vivo VH-IVUS within 24 hours after endarterectomy. Ninety-five segments of virtual histological images were matched to histological sections. The area of the necrotic core on histological sections was compared with that on virtual histological images. Intraplaque hemorrhage (IPH) was histopathologically graded by its severity using immunohistochemical staining for glycophorin A as a marker. The relationship of the severity of the IPH to the necrotic core was histopathologically evaluated. The correlation between the necrotic core or IPH with symptomatology was also evaluated. The area of the necrotic core on virtual histological images (median, 8.0%; interquartile range, 5.0%-13%) was significantly smaller compared with that of the histological sections (median, 50%; interquartile range, 40%-63%) (P < 0.0001). The Bland-Altman analysis showed poor agreement in the necrotic core measurement between virtual histological images and histological sections (mean difference, 39.8%; 95% confidence interval, 35.8%-43.8%). Severe IPH was significantly associated with a larger necrotic core and symptomatology (P < 0.0001 and P = 0.0039, respectively). The area of necrotic core on the virtual histological analysis did not correlate with symptomatology (P = 0.70), but that on pathological analysis tended to correlate with symptomatology (P = 0.059). In the present virtual histological algorithm, the underestimation of the necrotic core was revealed. The lack of a hemorrhage component in the virtual histological algorithm is a leading cause of its underestimation.
Neurosurgery, 1998
To develop a rabbit aneurysm model that is more realistic in gross appearance and histological fe... more To develop a rabbit aneurysm model that is more realistic in gross appearance and histological features than previous models and to enable the development of a larger animal model. Ten rabbits received porcine pancreatic elastase, five at the right common carotid artery bifurcation and five others at the right superior thyroid artery origin. One control animal received collagenase and another received papaverine, each at the right superior thyroid artery origin. The agents were topically delivered to the arterial adventitia with a microsyringe after surgical exposure of the targeted arteries. The arteries were monitored for aneurysm growth with a video camera for up to 3 hours and were then removed and processed for histology. Saccular aneurysms developed in one of five animals after elastase application at the carotid bifurcation and in all five animals receiving elastase at the superior thyroid artery origin. Among the six aneurysms, recurrent minor hemorrhages occurred in four, thrombosis of the aneurysm sac in three, and rupture causing severe bleeding in one. Histological sections revealed thin-walled aneurysms composed only of collagen fibers and some cellular elements. No saccular dilation resulted from papaverine application. Collagenase application resulted in a hemorrhagic-thrombotic lesion in the arterial wall but no aneurysm formation. Arterial saccular aneurysms were induced in rabbits by topical application of elastase with an easy and efficient method. These aneurysms are histologically similar to natural aneurysms, and their arterial nature renders them more authentic than those of surgical models. This aneurysm model may serve as a foundation for further aneurysm research.
Neurosurgery, 2014
Endovascular technique represents an important, minimally invasive approach to treating cerebrova... more Endovascular technique represents an important, minimally invasive approach to treating cerebrovascular disease. In this article, we discuss the origins of endovascular neurosurgery as a discipline in the context of important technical milestones, evidence-based medicine, and future cerebrovascular neurosurgical training. Cerebrovascular neurosurgery has seen a steady, convergent evolution toward the surgeon capable of seamless incorporation of open and endovascular approaches to any complex vascular disease affecting the central nervous system. Neurosurgery must assume the leadership role in the multidisciplinary neurovascular team.
Neurocritical Care, 2005
Severe medically refractory intracranial stenosis portends a grave prognosis. Recent advances in ... more Severe medically refractory intracranial stenosis portends a grave prognosis. Recent advances in stent technology have enabled clinicians to treat these lesions. Evidence in the coronary literature suggests that stenting without predilation angioplasty is as safe and effective as stenting immediately preceded by predilation angioplasty for the treatment of severely stenotic lesions. Because of marked differences in vessel histology and differences in the sensitivity of the cerebral and coronary vascular beds to embolic insult, direct stenting of severe intracranial stenoses may be more prone to neurological complications than a conventional or staged stenting procedure. We reviewed our clinical experience with conventional, direct, and staged stenting for high-grade stenoses involving the posterior intracranial circulation. We also reviewed the literature and experimental data supporting the rationale for staged stenting. In our experience, no permanent neurological morbidity was identified in four patients treated with a staged approach. In contrast, one of three patients with conventional stenting of the basilar artery and two of four patients treated with direct basilar stenting had permanent neurological sequelae. For patients with high-grade posterior circulation intracranial stenoses involving the perforator-rich zones of the basilar artery, staged stenting may reduce procedure-related morbidity. A staged approach allows for plaque stabilization resulting from post-angioplasty fibrosis, which may protect patients from "snow-plowing," embolic shower of debris, or dissection. Further clinical, in vivo, and histological investigation is warranted.
Neurosurgery, 2011
This article describes delayed endovascular revascularization in a patient with clinical and radi... more This article describes delayed endovascular revascularization in a patient with clinical and radiographic evidence of posterior circulation hemodynamic failure in the setting of intracranial occlusive lesions.
Journal of Neurosurgery, 2003
The authors report a case of an iatrogenic carotid-cavernous fistula (CCF) associated with intrac... more The authors report a case of an iatrogenic carotid-cavernous fistula (CCF) associated with intracranial angioplasty. Angioplasty was performed using a 3 x 10-mm Open Sail coronary balloon in a patient with high-grade stenosis of the left cavernous internal carotid artery (ICA). After angioplasty, a perforation developed in the cavernous ICA, resulting in a CCF. A 3.5 x 9-mm S670 coronary stent was used to treat the fistula. To the authors' knowledge, this is the first reported case in which a CCF developed after angioplasty was performed using a coronary balloon. Long-term angiographic and clinical evaluation is needed to test the suitability and durability of intracranial angioplasty and stent placement in the treatment of symptomatic intracranial stenosis.
Journal of Neurosurgery, 2007
The authors report the successful staged stenting and coil embolization of a large vertebral arte... more The authors report the successful staged stenting and coil embolization of a large vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysm using the contralateral VA for access. A 67-year-old woman presented with a large ruptured VA-PICA aneurysm. Initial attempts to stent the wide-necked aneurysm from the ipsilateral side failed, so coil embolization of the dome was performed. During a second endovascular session, the aneurysm neck was successfully stented from the contralateral VA into the PICA. Six weeks later, coils were inserted into the aneurysm from the ipsilateral side. The coil result was stable at the 3-month follow-up examination.
Journal of Neuroimaging, 2005
Journal of Endovascular Therapy, 2005
To evaluate the feasibility of stenting and cerebral protection in patients with carotid bifurcat... more To evaluate the feasibility of stenting and cerebral protection in patients with carotid bifurcation disease. Carotid stenting with self-expanding nitinol stents was evaluated in 261 patients (157 men; mean age 70.9+/-9.7 years, range 41-90) treated at 33 clinical sites. Among these patients, 141 (54.3%) were symptomatic, and 71 (27.2%) had postendarterectomy restenotic lesions. An embolus protection device became available in the latter third of the study. The primary endpoint of the study was the 30-day composite occurrence of major adverse clinical events (all deaths, strokes, or myocardial infarctions [MI]). At 1 year, the endpoint included all deaths, strokes, or MIs at 30 days, plus all deaths or ipsilateral strokes between 31 days and 1 year. SMART stents were placed in 147 (56%) patients and Precise stents in 107 (41%); 7 (3%) patients were treated with non-study stents. Lesion success, defined as <30% postprocedural residual stenosis, was achieved in 249 (95%). An AngioGuard filter was used in 85 patients; of 90 filters employed, 78 (87%) were successfully deployed and retrieved. Visible material was noted in 42 (54%) retrieved filters. One (0.4%) stent thrombosis occurred at <30 days, and no restenotic lesions >80% were noted in up to 1 year of follow-up. At 30 days, stroke occurred in 16 (6.1%) patients, MI in 1 (0.4%), and 2 (0.8%) patients died. The 30-day rate of stroke, MI, or death was 6.9%. Major ipsilateral stroke occurred in 4 (1.5%) patients between 0 and 30 days; no new major ipsilateral strokes were noted up to 1 year. By Kaplan-Meier analysis, the 1-year risk of stroke, MI, or death was 10.9%+/-2.0%. The 1-year risk of major ipsilateral stroke was significantly lower in patients treated with embolus protection devices (0.0% versus 2.3%, p=0.05). The use of nitinol self-expanding stents in the carotid position appears to be a safe and efficacious alternative for the treatment of carotid bifurcation disease. The addition of embolus protection devices may diminish the risk of postprocedural major ipsilateral strokes.
International Congress Series, 2005
Catheterization and Cardiovascular Interventions, 2008
Journal of Clinical Neuroscience, 2011
The authors present a preliminary experience with ethyl-enevinylalcohol copolymer (Onyx) for hema... more The authors present a preliminary experience with ethyl-enevinylalcohol copolymer (Onyx) for hemangioblastoma vessel embolization before surgical resection. The patient presented with neck pain, dizziness, blurred vision, vomiting, and loss of balance. Diagnostic imaging revealed a posterior fossa cystic mass with a nodular component. Angiography demonstrated a significant vascular blush with arteriovenous shunting that was characteristic of a hemangioblastoma. Tumor vessels originating off the left posterior inferior cerebellar artery were embolized before surgery using Onyx 18 (ev3, Covidien Vascular Therapies, Mansfield, MA, USA). This resulted in complete obliteration of all tumor vessels, transforming a highly vascular tumor into an avascular mass. A safe and uneventful surgical resection was performed the next day. Onyx is a valuable embolic agent for preoperative hemangioblastoma vessel embolization. Because of its low viscosity, Onyx penetrates deeply into the tumor vasculature and allows complete obliteration of tumor vessels. Risks of the intervention have to be carefully weighed against the benefits. If preoperative embolization is indicated, the use of Onyx should be strongly considered.