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Peter T. Kan, Kenneth V. Snyder, Parham Yashar, Adnan H. Siddiqui, L. Nelson Hopkins and Elad I. Levy

Computed tomography perfusion scanning generates physiological flow parameters of the brain parenchyma, allowing differentiation of ischemic penumbra and core infarct. Perfusion maps, along with the National Institutes of Health Stroke Scale score, are used as the bases for endovascular stroke intervention at the authors' institute, regardless of the time interval from stroke onset. With case examples, the authors illustrate their perfusion-based imaging guidelines in patient selection for endovascular treatment in the setting of acute stroke.

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Joshua E. Meyers, Grant C. Sorkin, Hakeem J. Shakir and Kenneth V. Snyder

With the use of endovascular techniques and indwelling catheters, potential complications can include embolization of fragments or components of various systems. The authors describe the surgical retrieval of a guidewire introducer from the right common carotid artery (CCA). A 64-year-old man was found to have a foreign body within the right CCA on CT angiography after he had presented with a transient ischemic attack. He had undergone a complex mitral valve repair several months before presenting to the authors' facility. That procedure involved a femoral artery cutdown and the insertion of an endovascular aortic balloon for cardiac bypass. As in most endovascular procedures, guidewire introducers were probably used to facilitate the introduction of the guidewire into the system during the procedure. Although rare, iatrogenic embolization of the introducer probably occurred during use of the guidewire. The guidewire introducer was successfully retrieved without complication by using a standard carotid cutdown approach. It is extraordinarily unusual for an extracorporeal part of an implantable system to embolize to the carotid circulation. To the authors' knowledge, this is the only reported case of an embolized guidewire introducer and the use of a carotid exposure to retrieve an intraluminal foreign body. This case demonstrates that a carotid cutdown approach can be used successfully for the retrieval of intraluminal extracranial carotid artery foreign bodies.

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Maxim Mokin, Peter Kan, Tareq Kass-Hout, Adib A. Abla, Travis M. Dumont, Kenneth V. Snyder, L. Nelson Hopkins, Adnan H. Siddiqui and Elad I. Levy

Intracerebral hemorrhage (ICH) secondary to intravenous and intraarterial revascularization strategies for emergent treatment of acute ischemic stroke is associated with high mortality. ICH from systemic thrombolysis typically occurs within the first 24–36 hours of treatment initiation and is characterized by rapid hematoma development and growth. Pathophysiological mechanisms of revascularization therapy-induced ICH are complex and involve a combination of several distinct processes, including the direct effect of thrombolytic agents, disruption of the blood-brain barrier secondary to ischemia, and direct vessel damage from wire and microcatheter manipulations during endovascular procedures. Several definitions of ICH secondary to thrombolysis currently exist, depending on clinical or radiological characteristics used. Multiple studies have investigated clinical and laboratory risk factors associated with higher rates of ICH in this setting. Early ischemic changes seen on noncontrast CT scanning are strongly associated with higher rates of hemorrhage. Modern imaging techniques, particularly CT perfusion, provide rapid assessment of hemodynamic parameters of the brain. Specific patterns of CT perfusion maps can help identify patients who are likely to benefit from revascularization or to develop hemorrhagic complications. There are no established guidelines that describe management of revascularization therapy–induced ICH, and great variability in treatment protocols currently exist. General principles that apply to the management of spontaneous ICH might not be as effective for revascularization therapy–induced ICH. In this article, the authors review current knowledge of risk factors and radiological predictors of ICH secondary to stroke revascularization techniques and analyze medical and surgical management strategies for ICH in this setting.

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Justin M. Cappuzzo, Ryan M. Hess, John F. Morrison, Jason M. Davies, Kenneth V. Snyder, Elad I. Levy and Adnan H. Siddiqui

OBJECTIVE

Idiopathic intracranial hypertension (IIH) is a commonly occurring disease, particularly among young women of child-bearing age. The underlying pathophysiology for this disease has remained largely unclear; however, the recent literature suggests that focal outflow obstruction of the transverse sinus may be the cause. The purpose of this study was to report one group’s early experience with transverse venous sinus stenting in the treatment of IIH and assess its effectiveness.

METHODS

The authors performed a retrospective chart review to identify patients who had undergone stenting of an outflow-obstructed transverse venous sinus for the treatment of IIH at Gates Vascular Institute between January 2015 and November 2017. Patient demographic data of interest included age, sex, BMI, and history of smoking, hypertension, obstructive sleep apnea, hormonal contraceptive use, and acetazolamide therapy. Each patient’s presenting signs and symptoms and whether those symptoms improved with treatment were reviewed. The average opening lumbar puncture (LP) pressure preprocedure, average pressure gradient across the obstructed segment prior to stenting, treatment failure rate (need for shunt placement), and mean follow-up period were calculated.

RESULTS

Of the 18 patients who had undergone transverse venous stenting for IIH, 16 (88.9%) were women. The mean age of all the patients was 38.3 years (median 38 years). Mean BMI was 34.2 kg/m2 (median 33.9 kg/m2). Presenting symptoms were headache (16 patients [88.9%]), visual disturbances (13 patients [72.2%]), papilledema (8 patients [44.4%]), tinnitus (3 patients [16.7%]), and auditory bruit (3 patients [16.7%]). The mean opening LP pressure pre-procedure was 35.6 cm H2O (median 32 cm H2O). The mean pressure gradient measured proximally and distally to the area of focal obstruction within the transverse sinus was 16.5 cm H2O (median 15 cm H2O). Postprocedurally, 14 patients (77.8%) continued to have headaches; 6 (33.3%) continued to have visual disturbances. No patients continued to have auditory bruit (0%) or papilledema (0%). One patient (5.6%) had new-onset tinnitus postprocedure. Overall improvement of symptoms was noted in 16 patients (88.9%) postprocedure, with 1 patient (5.6%) requiring shunt placement and 2 other patients (11.1%) requiring postprocedural LP to monitor intracranial pressure to determine candidacy for further surgical interventions to treat residual symptoms. The mean duration of follow-up was 194.2 days.

CONCLUSIONS

Transverse sinus stenting is a rapidly developing technique that has shown good effectiveness and safety in the literature. Authors of the present study found that stenting a flow-obstructed transverse sinus in patients with IIH was a safe and effective way to treat the condition.

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Leonardo Rangel-Castilla, Stephan A. Munich, Naser Jaleel, Marshall C. Cress, Chandan Krishna, Ashish Sonig, Kenneth V. Snyder, Adnan H. Siddiqui and Elad I. Levy

OBJECTIVE

The Pipeline Embolization Device (PED) has become increasingly used for the treatment of intracranial aneurysms. Given its high metal surface area coverage, there is concern for the patency of branch vessels that become covered by the device. Limited data exist regarding the patency of branch vessels adjacent to aneurysms that are covered by PEDs. The authors assessed the rate of intracranial internal carotid artery, anterior circulation branch vessel patency following PED placement at their institution.

METHODS

The authors retrospectively reviewed the records of 82 patients who underwent PED treatment between 2009 and 2014 and in whom the PED was identified to cover branch vessels. Patency of the anterior cerebral, posterior communicating, anterior choroidal, and ophthalmic arteries was evaluated using digital subtraction angiography preoperatively and postoperatively after PED deployment and at longer-term follow-up.

RESULTS

Of the 127 arterial branches covered by PEDs, there were no immediate postoperative occlusions. At angiographic follow-up (mean 10 months, range 3–34.7 months), arterial side branches were occluded in 13 (15.8%) of 82 aneurysm cases and included 2 anterior cerebral arteries, 8 ophthalmic arteries, and 3 posterior communicating arteries. No cases of anterior choroidal artery occlusion were observed. Patients with branch occlusion did not experience any neurological symptoms.

CONCLUSIONS

In this large series, the longer-term rate of radiographic side branch arterial occlusion after coverage by a flow diverter was 15.8%. Terminal branch vessels, such as the anterior choroidal artery, remained patent in this series. The authors' series suggests that branch vessel occlusions are clinically silent and should not deter aneurysm treatment with flow diversion.

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Leonardo Rangel-Castilla, Gary B. Rajah, Hakeem J. Shakir, Hussain Shallwani, Sirin Gandhi, Jason M. Davies, Kenneth V. Snyder, Elad I. Levy and Adnan H. Siddiqui

OBJECTIVE

Acute tandem occlusions of the cervical internal carotid artery and an intracranial large vessel present treatment challenges. Controversy exists regarding which lesion should be addressed first. The authors sought to evaluate the endovascular approach for revascularization of these lesions at Gates Vascular Institute.

METHODS

The authors performed a retrospective review of a prospectively maintained, single-institution database. They analyzed demographic, procedural, radiological, and clinical outcome data for patients who underwent endovascular treatment for tandem occlusions. A modified Rankin Scale (mRS) score ≤ 2 was defined as a favorable clinical outcome.

RESULTS

Forty-five patients were identified for inclusion in the study. The average age of these patients was 64 years; the mean National Institutes of Health Stroke Scale score at presentation was 14.4. Fifteen patients received intravenous thrombolysis before undergoing endovascular treatment. Thirty-seven (82%) of the 45 proximal cervical internal carotid artery occlusions were atherothrombotic in nature. Thirty-eight patients underwent a proximal-to-distal approach with carotid artery stenting first, followed by intracranial thrombectomy, whereas 7 patients underwent a distal-to-proximal approach (that is, intracranial thrombectomy was performed first). Thirty-seven (82%) procedures were completed with local anesthesia. For intracranial thrombectomy procedures, aspiration alone was used in 15 cases, stent retrieval alone was used in 5, and a combination of aspiration and stent-retriever thrombectomy was used in the remaining 25. The average time to revascularization was 81 minutes. Successful recanalization (thrombolysis in cerebral infarction Grade 2b/3) was achieved in 39 (87%) patients. Mean National Institutes of Health Stroke Scale scores were 9.3 immediately postprocedure (p < 0.05) (n = 31), 5.1 at discharge (p < 0.05) (n = 31), and 3.6 at 3 months (p < 0.05) (n = 30). There were 5 in-hospital deaths (11%); and 2 patients (4.4%) had symptomatic intracranial hemorrhage within 24 hours postprocedure. Favorable outcomes (mRS score ≤ 2) were achieved at 3 months in 22 (73.3%) of 30 patients available for follow-up, with an mRS score of 3 for 7 of 30 (23%) patients.

CONCLUSIONS

Tandem occlusions present treatment challenges, but high recanalization rates were possible in the present series using acute carotid artery stenting and mechanical thrombectomy concurrently. Proximal-to-distal and aspiration approaches were most commonly used because they were safe, efficacious, and feasible. Further study in the setting of a randomized controlled trial is needed to determine the best sequence for the treatment approach and the best technology for tandem occlusion.

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Jianping Xiang, Robert J. Damiano, Ning Lin, Kenneth V. Snyder, Adnan H. Siddiqui, Elad I. Levy and Hui Meng

OBJECT

Flow diversion via Pipeline Embolization Device (PED) represents the most recent advancement in endovascular therapy of intracranial aneurysms. This exploratory study aims at a proof of concept for an advanced device-modeling tool in conjunction with computational fluid dynamics (CFD) to evaluate flow modification effects by PED in actual, treated cases.

METHODS

The authors performed computational modeling of 3 PED-treated complex aneurysm cases. The patient in Case 1 had a fusiform vertebral aneurysm treated with a single PED. In Case 2 the patient had a giant internal carotid artery (ICA) aneurysm treated with 2 PEDs. Case 3 consisted of tandem ICA aneurysms (III-a and III-b) treated by a single PED. The authors’ recently developed high-fidelity virtual stenting (HiFiVS) technique was used to recapitulate the clinical deployment process of PEDs in silico for these 3 cases. Pretreatment and posttreatment aneurysmal hemodynamics studies performed using CFD simulation were analyzed. Changes in aneurysmal flow velocity, inflow rate, wall shear stress (WSS), and turnover time were calculated and compared with the clinical outcome.

RESULTS

In Case 1 (occluded within the first 3 months), the aneurysm had the most drastic flow reduction after PED placement; the aneurysmal average velocity, inflow rate, and average WSS were decreased by 76.3%, 82.5%, and 74.0%, respectively, whereas the turnover time was increased to 572.1% of its pretreatment value. In Case 2 (occluded at 6 months), aneurysmal average velocity, inflow rate, and average WSS were decreased by 39.4%, 38.6%, and 59.1%, respectively, and turnover time increased to 163.0%. In Case 3, Aneurysm III-a (occluded at 6 months) had a decrease by 38.0%, 28.4%, and 50.9% in average velocity, inflow rate, and average WSS, respectively, and turnover time increased to 139.6%, which was quite similar to Aneurysm II. Surprisingly, the adjacent Aneurysm III-b had more substantial flow reduction (a decrease by 77.7%, 53.0%, and 84.4% in average velocity, inflow rate, and average WSS, respectively, and an increase to 213.0% in turnover time) than Aneurysm III-a, which qualitatively agreed with angiographic observation at 3-month follow-up. However, Aneurysm III-b remained patent at both 6 months and 9 months. A closer examination of the vascular anatomy in Case 3 revealed blood draining to the ophthalmic artery off Aneurysm III-b, which may have prevented its complete thrombosis.

CONCLUSIONS

This proof-of-concept study demonstrates that HiFiVS modeling of flow diverter deployment enables detailed characterization of hemodynamic alteration by PED placement. Posttreatment aneurysmal flow reduction may be correlated with aneurysm occlusion outcome. However, predicting aneurysm treatment outcome by flow diverters also requires consideration of other factors, including vascular anatomy.

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Muhammad Zeeshan Memon, Sabareesh K. Natarajan, Jitendra Sharma, Marlon S. Mathews, Kenneth V. Snyder, Adnan H. Siddiqui, L. Nelson Hopkins and Elad I. Levy

Object

Experience with the use of platelet glycoprotein (GP) IIb–IIIa inhibitor eptifibatide in patients with ischemic stroke is limited. The authors report the off-label use of intraarterial eptifibatide during endovascular ischemic stroke revascularization procedures for reocclusion after documented recanalization or formed fresh thrombi in distal vessels that were inaccessible to endovascular devices.

Methods

Patients who received intraarterial eptifibatide were identified from a prospectively collected database of patients in whom endovascular revascularization for acute ischemic stroke was attempted between 2005 and 2008. Data were analyzed retrospectively. The intraarterial eptifibatide dose was a single-bolus dose of 180 μg/kg body weight. Primary outcome measures were angiographic recanalization (Thrombolysis in Myocardial Infarction Grade 2 or 3), symptomatic intracranial hemorrhage rate, overall mortality rate, and favorable 3-month modified Rankin Scale score (≤ 2).

Results

The study included 35 patients (mean age 62 years, range 18–85 years). The median presenting National Institutes of Health Stroke Scale score was 13. Two patients received intravenous tissue plasminogen activator before endovascular therapy. The median time from symptom onset to therapy initiation was 230 minutes (range 90–1370 minutes). Twelve patients (34%) received intraarterial tissue plasminogen activator without mechanical measures. Mechanical revascularization measures used were Merci retriever in 19 (54%), Penumbra device in 1 (3%), balloon angioplasty in 15 (43%), and stent placement in 22 (63%) patients. The mean dose of intraarterial eptifibatide was 11.6 mg (range 5–16.6 mg). Partial-to-complete recanalization (Thrombolysis in Myocardial Infarction Grade 2 or 3) was achieved in 27 patients (77%). Postprocedure intracranial hemorrhage occurred in 13 patients (37%), causing symptoms in 5 (14%). In the 5 symptomatic intracranial hemorrhage cases, all patients but one presented more than 8 hours after symptom onset and all received intraarterial recombinant tissue plasminogen activator. The median discharge National Institutes of Health Stroke Scale score was 7 (range 0–17). At 3 months postprocedure, 21 patients (60%) had a modified Rankin Scale score ≤ 2, and 8 patients (23%) had died.

Conclusions

Adjunctive intraarterial eptifibatide is a feasible option for salvage of reocclusion and thrombolysis of distal inaccessible thrombi during endovascular stroke revascularization. Its safety and efficacy need to be studied further in larger, multicenter, controlled studies.

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Travis M. Dumont, Ashish Sonig, Maxim Mokin, Jorge L. Eller, Grant C. Sorkin, Kenneth V. Snyder, L. Nelson Hopkins, Elad I. Levy and Adnan H. Siddiqui

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.