Grant C. Sorkin

The Pipeline embolization device for treatment of intracranial aneurysms

Flow diversion is a new endovascular technique developed for treatment of intracranial aneurysms. It is based on stent-induced modification of blood flow within and around an aneurysm inflow zone, leading to gradual intra-aneurysmal thrombosis and subsequent atrophy, while preserving flow into the parent vessel and perforating branches. Flow-diversion technique is well-suited for the treatment of large, giant, wide-necked, and fusiform intracranial aneurysms because it does not rely on endosaccular packing with coils but rather on the strategy of placing a stent across the aneurysm “neck” or across the diseased segment of a vessel in case of a fusiform aneurysm. Over time, neointimal endothelium covers the flow diverter such that it becomes incorporated into the parent vessel wall and occludes the aneurysm from the circulation, effectively repairing the diseased parent vessel segment. This report describes in detail the Pipeline embolization device (ev3-Covidien, Irvine, California, USA), its mechanism of action and deployment technique, and reviews the pertinent literature regarding safety, efficacy and potential risks and complications associated with the use of this flow diverter.

Submaximal angioplasty for symptomatic intracranial atherosclerosis: a prospective Phase I study.

OBJECTIVE Intracranial atherosclerotic disease (ICAD) accounts for approximately 10% of ischemic strokes. The recent Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) study demonstrated a high incidence of perioperative complications (15%) for treatment of ICAD with stenting. Although the incidence of stroke was lower in the medical arm, recurrent stroke was found in 12% of patients despite aggressive medical management, suggesting that intervention may remain a viable option for ICAD if perioperative risk is minimized. Angioplasty without stenting represents an alternative and understudied revascularization treatment for ICAD. Submaximal angioplasty limits the risks of thromboembolism, vessel perforation, and reperfusion hemorrhage that were frequently reported with stenting in the SAMMPRIS trial. The authors conducted a prospective Phase I trial designed to assess the safety of submaximal angioplasty in patients with symptomatic ICAD. METHODS This study was approved by the local institutional review board. Demographic and clinical data were prospectively collected. Angioplasty was performed with a balloon undersized to approximately 50%-70% of the nondiseased vessel diameter in patients with symptomatic ICAD who had angiographically significant stenosis of ≥ 70%. The primary outcome measure was the incidence of periprocedural complications (combined rate of death, stroke, and hemorrhage occurring within 30 days and at 1 year). RESULTS Among the 65 patients with symptomatic ICAD who were screened, 24 had significant angiographic stenosis that met the inclusion criteria of this study. The mean age was 64.08 years (median 65 years; SD ± 11.24 years), most were men (62.5%), and most were white (66.67%). Many patients had concomitants of vascular disease, including hypertension (95.8%), hyperlipidemia (70.83%), smoking history (54.1%), and diabetes mellitus (50.0%). Coronary artery disease (41.66%) and previous stroke or transient ischemic attack (45.83%) were frequently present. Most patients (75%) had anterior circulation stenosis. The mean preprocedure stenosis was 80.16% (median 80%, range 70%-95%). Submaximal angioplasty was performed in patients who met the inclusion criteria, with a mean postangioplasty stenosis rate of 54.62% (median 55.5%, range 31%-78%). Rates of ischemic stroke in the territory of the treated artery were 0% within 30 days and 5.55% (in the only patient who presented with recurrent stroke) at 1 year. The mortality and hemorrhage rates in this series were 0%. CONCLUSIONS This study demonstrates the safety of the submaximal angioplasty technique, with no permanent periprocedural complications in 24 treated patients.

Combined use of covered stent and flow diversion to seal iatrogenic carotid injury with vessel preservation during transsphenoidal endoscopic resection of clival tumor.

Background: Transsphenoidal tumor resection can lead to internal carotid artery (ICA) injury. Vascular disruption is often treated with emergent vessel deconstruction, incurring complications in a subset of patients with poor collateral circulation and resulting in minor and major ischemic strokes. Methods: We attempted a novel approach combining a covered stent graft (Jostent) and two flow diverter stents [Pipeline embolization devices (PEDs)] to treat active extravasation from a disrupted right ICA that was the result of a transsphenoidal surgery complication. This disruption occurred during clival tumor surgery and required immediate sphenoidal sinus packing. Emergent angiography revealed continued petrous carotid artery extravasation, warranting emergent vessel repair or deconstruction for treatment. To preserve the vessel, we utilized a covered Jostent. Due to tortuosity and lack of optimal wall apposition, there was reduced, yet persistent extravasation from an endoleak after Jostent deployment that failed to resolve despite multiple angioplasties. Therefore, we used PEDs to divert the flow. Results: Flow diversion relieved the extravasation. The patient remained neurologically intact post-procedure. Conclusions: This case demonstrates successful combined use of a covered stent and flow diverters to treat acute vascular injury resulting from transsphenoidal surgery. However, concerns remain, including the requirement of dual antiplatelet agents increasing postoperative bleeding risks, stent-related thromboembolic events, and delayed in-stent restenosis rates.

Carotid artery stenting outcomes: do they correlate with antiplatelet response assays?

Objective Limited data exist regarding the use of antiplatelet response assays during neuroendovascular intervention. We report outcomes after carotid artery stenting (CAS) based on aspirin and P2Y12 assays. Methods We retrospectively identified patients who had aspirin and P2Y12 assays at the time of stenting. Aspirin (325 mg) and clopidogrel (75 mg) were started 7–10 days pre-intervention. If not possible, aspirin (650 mg) and clopidogrel (600 mg) loading doses were given pre-intervention. Assays were checked on postoperative day 0/1. Outcomes included neurological ischemic sequela at 30 days, 1 and 2 years, as well as 30 day death/hemorrhage/myocardial infarction. Results 449 patients were included. Mean P2Y12 reaction unit (PRU) values were higher in patients with an ipsilateral ischemic event (stroke/transient ischemic attack (TIA)) or stroke (alone) at 1 and 2 years than in patients with no events: ischemic event versus no event at 1 year, 252 vs 202 (p=0.008); stroke versus no stroke at 1 year, 252 versus 203(p=0.029); ischemic event versus no event at 2 years, 244 vs 203 (p=0.047); stroke versus no stroke at 2 years, 243 versus 203 (p=0.082). Ischemic event free survival (stroke/TIA, p=0.0268) and overall survival (p=0.0291) post-CAS were longer in patients with PRU ≤198 compared with an initial threshold of PRU ≤237. Mean PRU values were higher in patients who died from all causes at 30 days than in survivors (p=0.031). No correlation was found between lower PRU values and hemorrhage. Aspirin reaction units did not correlate with outcome. Conclusions PRU ≤198 may be associated with a lower incidence of ischemic neurological sequela and death post-CAS. Prospective studies are needed to validate the relationship between antiplatelet assays and outcomes post-CAS.

Perioperative complications after carotid artery stenting: a contemporary experience from the university at buffalo neuroendovascular surgery team.

BACKGROUND Technological advances have resulted in diminishing perioperative complications reported during carotid artery stenting (CAS) trials. Because trial experience lags behind technological advances, an understanding of the incidence of perioperative complications after CAS remains in flux. OBJECTIVE In this single-arm, observational study, a contemporary experience of CAS at a high-volume academic training center for neuroendovascular surgeons was reviewed to assess perioperative morbidity. METHODS A prospectively maintained database of all neuroendovascular procedures was queried for all CAS procedures performed for stenotic atherosclerotic disease between 2009 and 2011. Each case was assessed for major perioperative (30 day) adverse events, including new acute ischemic stroke, postoperative symptomatic intracranial hemorrhage, myocardial infarction (MI), and mortality. RESULTS A total of 474 patients were identified. Perioperative adverse events were noted in 13 patients (2.7%). These included 4 ischemic strokes, 4 intracranial hemorrhages, 3 MIs, and 5 deaths. Most perioperative events occurred in symptomatic patients (10 of 239 symptomatic patients with events, 4.2% event incidence), whereas these events occurred rarely in asymptomatic patients (3 of 235 asymptomatic patients with events, 1.3% event incidence). CONCLUSION In this retrospective analysis of consecutive patients treated with CAS, the perioperative incidence of stroke (0.9%), MI (0.6%), and death (1.1%) was favorable.

Aspiration thrombectomy in concert with stent thrombectomy

In the SWIFT and TREVO 2 trials, aspiration thrombectomy was not able to be performed. Outside these studies, in post-market application, the interventionist can use aspiration thrombectomy in addition to stent device thrombectomy. This technique is described in detail in the present report. Combined aspiration/stentriever thrombectomy may improve recanalization efforts, simplify a second thrombectomy attempt if necessary and may limit distal embolization.

Advances in endovascular approaches to cerebral aneurysms.

Abstract Recent advancements in all phases of endovascular aneurysm treatment, including medical therapy, diagnostics, devices, and implants, abound. Advancements in endovascular technologies and techniques have enabled treatment of a wide variety of intracranial aneurysms. In this article, technical advances in endovascular treatment of cerebral aneurysms are discussed, with an effort to incorporate a clinically relevant perspective. Advancements in diagnostic tools, medical therapy, and implants are reviewed and discussed.Recent advancements in all phases of endovascular aneurysm treatment, including medical therapy, diagnostics, devices, and implants, abound. Advancements in endovascular technologies and techniques have enabled treatment of a wide variety of intracranial aneurysms. In this article, technical advances in endovascular treatment of cerebral aneurysms are discussed, with an effort to incorporate a clinically relevant perspective. Advancements in diagnostic tools, medical therapy, and implants are reviewed and discussed.

Cerebrovascular neurosurgery in evolution: the endovascular paradigm.

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.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.

Ruptured mycotic cerebral aneurysm development from pseudoocclusion due to septic embolism.

Background: Cerebral mycotic aneurysms are rare sequelae of systemic infections that can cause profound morbidity and mortality with rupture. Direct bacterial extension and vessel integrity compromise from septic emboli have been implicated as mechanisms for formation of these lesions. We report the 5-day development of a ruptured mycotic aneurysm arising from a septic embolism that caused a focal M1 pseudoocclusion. Case Description: A 14-year-old girl developed acute left-sided hemiparesis while hospitalized for subacute bacterial endocarditis that was found after she presented with a 2-week history of fever, myalgia, shortness of breath, and lethargy. Mitral valve vegetations were confirmed in the setting of hemophilus bacteremia. Brain magnetic resonance (MR) imaging and angiography confirmed middle cerebral artery infarct with focal pseudoocclusion of the distal M1 segment. Given that further middle cerebral artery territory was at risk, a trial of heparin was attempted for revascularization but required discontinuation owing to hemorrhagic conversion. Decline of the patients mental status necessitated craniectomy for decompression. Postoperatively, her mental status improved with residual left hemiparesis. On the third postoperative day (5 days after MR angiography), the patients neurologic condition acutely declined, with development of right-sided mydriasis. Computed tomography (CT) angiography revealed a ruptured 19 × 16 mm pseudoaneurysm arising from the M1 site of the previous occlusion. Emergent coiling of aneurysm and parent vessel followed by hematoma evacuation ensued. At discharge, the patient had residual left hemiparesis but intact speech and cognition. Conclusion: Focal occlusions due to septic emboli should be considered high-risk for mycotic aneurysm formation, prompting aggressive monitoring with neuroimaging and treatment when indicated.

Endovascular Nuances of the Treatment of Very Small Intracranial Aneurysms

he management of very small intracranial aneurysms, meaning aneurysms 3 mm or less in diameter, remains T an active topic of controversy in neurosurgery. A lack of consensus exists among relevant landmark trials that supports clear guidelines in their management. Therefore, this specific pathologic condition pushes the envelope between science and art, from which technological innovation will play an important role in influencing management. Results from the International Study of Unruptured Intracranial Aneurysms support conservative management for small aneurysms 7 mm, given the low 5-year risk of rupture (8), yet aneurysms sized 5 mm accounted for 52% of ruptured aneurysm treated in the International Subarachnoid Aneurysm Trial (7). Interpreting this opposing evidence for use in clinical practice becomes even more difficult when one recognizes that metrics other than size influence the transition from unruptured to ruptured. This aneurysm subset clearly requires further study in both epidemiology as well as optimal surgical management.