Endotheliitis and cytokine storm as a mechanism of clot formation in COVID-19 ischemic stroke patients: A histopathologic study of retrieved clots.

BACKGROUND: Studies during the COVID-19 pandemic have demonstrated an association between COVID-19 virus infection and the development of acute ischemic stroke, particularly large vessel occlusion (LVO). Studying the characteristics and immunohistochemistry of retrieved stroke emboli during mechanical thrombectomy for LVO may offer insights into the pathogenesis of LVO in COVID-19 patients. We examined retrieved COVID-19 emboli from the STRIP, EXCELLENT, and RESTORE registries and compared their characteristics to a control group. METHODS: We identified COVID-positive LVO patients from the STRIP, RESTORE, and EXCELLENT studies who underwent mechanical thrombectomy. These patients were matched to a control group controlling for stroke etiology based on Trial of Org 10172 in Acute Stroke Treatment criteria. All clots were stained with Martius Scarlet Blue (MSB) along with immunohistochemistry for interleukin-6 (IL-6), C-reactive protein (CRP), von Willebrand factor (vWF), CD66b, fibrinogen, and citrullinated Histone H3. Clot composition was compared between groups. RESULTS: Nineteen COVID-19-positive patients and 38 controls were included. COVID-19-positive patients had a significantly higher percentage of CRP and vWF. There was no difference in IL-6, fibrin, CD66b, or citrullinated Histone H3 between groups. Based on MSB staining, there was no statistically significant difference regarding the percentage of red blood cells, white blood cells, fibrin, and platelets. CONCLUSIONS: Our study found higher concentrations of CRP and vWF in retrieved clots of COVID-19-positive stroke patients compared to COVID-19-negative controls. These findings support the potential role of systemic inflammation as indicated by elevated CRP and endothelial injury as indicated by elevated vWF as precipitating factors in thrombus development in these patients.

Endovascular Acute Ischemic Stroke Treatment with FlowGate Balloon Guide Catheter: A Single-Center Observational Study of FlowGate Balloon Guide Catheter Use.

BACKGROUND: Treatment of large vessel occlusion acute ischemic stroke with mechanical thrombectomy has become the standard of care after recent clinical trials. However, the degree of recanalization with stent retrievers remains very important in overall outcomes. We sought to review the utility of a new balloon guide catheter (BGC) in improving the degree of recanalization in conjunction with mechanical thrombectomy. METHODS: The medical records of a prospectively collected endovascular ischemic stroke database were reviewed. All consecutive strokes when a FlowGate BGC was used with a thrombectomy stent retriever were identified. Use of a FlowGate BGC, number of passes, final Thrombolysis in Cerebral Infarction (TICI) score, trackability, and use of adjunct devices were all collected and analyzed. RESULTS: Use of a FlowGate BGC resulted in 64% (33/52) first-pass effect (FPE) of TICI 2b/3, and specifically 46% (24/52) TICI 3 FPE (true FPE). A total of 52/62 (84%) of thrombectomy cases were treated with BGCs. In the remaining 10, the BGC was not inflated or used due to the clot not being visualized or the lesions being distal and BGC use thus not deemed appropriate. Adjunct use of an aspiration catheter was seen in 12% (6/52) of cases. The overall success with FlowGate BGCs with one or more passes of TICI 2b/3 was 94% (49/52). Trackability was achieved in 92% (57/62) of cases. CONCLUSIONS: Use of the FlowGate BGC as an adjunct to mechanical thrombectomy was associated with good FPE and an overall recanalization of TICI 2b/3 of 94%.

Stroke vision, aphasia, neglect (VAN) assessment-a novel emergent large vessel occlusion screening tool: pilot study and comparison with current clinical severity indices.

BACKGROUND: Identification of emergent large vessel occlusion (ELVO) stroke has become increasingly important with the recent publications of favorable acute stroke thrombectomy trials. Multiple screening tools exist but the length of the examination and the false positive rate range from good to adequate. A screening tool was designed and tested in the emergency department using nurse responders without a scoring system. METHODS: The vision, aphasia, and neglect (VAN) screening tool was designed to quickly assess functional neurovascular anatomy. While objective, there is no need to calculate or score with VAN. After training participating nurses to use it, VAN was used as an ELVO screen for all stroke patients on arrival to our emergency room before physician evaluation and CT scan. RESULTS: There were 62 consecutive code stroke activations during the pilot study. 19 (31%) of the patients were VAN positive and 24 (39%) had a National Institutes of Health Stroke Scale (NIHSS) score of ≥6. All 14 patients with ELVO were either VAN positive or assigned a NIHSS score ≥6. While both clinical severity thresholds had 100% sensitivity, VAN was more specific (90% vs 74% for NIHSS ≥6). Similarly, while VAN and NIHSS ≥6 had 100% negative predictive value, VAN had a 74% positive predictive value while NIHSS ≥6 had only a 58% positive predictive value. CONCLUSIONS: The VAN screening tool accurately identified ELVO patients and outperformed a NIHSS ≥6 severity threshold and may best allow clinical teams to expedite care and mobilize resources for ELVO patients. A larger study to both validate this screening tool and compare with others is warranted.

Stenting and angioplasty for idiopathic intracranial hypertension: a case series with clinical, angiographic, ophthalmological, complication, and pressure reporting.

BACKGROUND: Previous studies have demonstrated that cerebral dural sinus stenosis (DSS) may be a potential patho-physiological cause of idiopathic intracranial hypertension (IIH). Endovascular therapy for DSS is emerging as a potential alternative to treat IIH. Here, we present the results of our case series. METHOD: We prospectively collected angiographic and manometric data on patients that underwent angioplasty/stenting for IIH. All patients had failed maximal medical therapy (MMT) and had confirmed sinus stenosis. Demographic, clinical and radiological presentation, and outcomes were collected retrospectively. RESULTS: A total of 18 patients underwent 25 procedures. Demographics revealed a mean age of 30 (range 15-59), 83% (15/18) were female, 72% (13/18) were white, and mean body mass index of 36 (range 23-59.2). All patients presented with classic IIH. Symptom improvement or resolution was reported in 94% (17/18) of patients. All patients had resolution and/or stabilization/improvement of their papilledema. Headaches related to increased pressure improved in 56% (10/18). Re-stenosis and retreatment occurred in 33% (6/18). No procedural related complications were reported. CONCLUSION: Dural sinus angioplasty and stenting is relatively safe, feasible, and clinically efficacious for patients with symptomatic sinus stenosis who have failed standard therapy. The long-term durability of patency and clinical improvement remains unknown.

Endovascular reconstruction for progressively worsening carotid artery dissection.

BACKGROUND: Carotid artery dissection is an important cause of stroke in young patients. Selection criteria for endovascular repair have not been well defined and limited data exist on long-term outcomes of stent reconstruction. OBJECTIVE: To report the immediate and long-term clinical and radiographic outcomes of patients treated with stent placement for progressively worsening symptomatic carotid arterial dissection despite antithrombotic therapy. METHODS: A single institution neuro-endovascular database was accessed to identify consecutive cases in which carotid artery dissection was treated with endovascular repair between 2006 and 2012. Clinical, demographic, radiographic, and procedural data were obtained through chart review. RESULTS: A total of 22 patients were identified and included 27 carotid artery dissection repairs with stent implantation. The mean age was 43 years (±8.7) with 13 patients being women. Traumatic dissections were seen in 9 (40.9%) patients and spontaneous dissections in 13 (59.1%) patients. All patients were symptomatic and were started on antithrombotic therapy on diagnosis. Most common indications for treatment included recurrent ischemia despite antithrombotic therapy in 15 (55.5%) arteries and enlarging dissecting aneurysm in 4 (14.8%) arteries. Mean degree of stenosis was 79.1%. Mean number of stents used was 1.88 (range 1-4). There was 1 (4.5%) asymptomatic peri-procedural thromboembolic event. Median clinical follow-up was 14 months (range 3-40) and median imaging follow-up was 14 months (range 3-38). There was 1 (4.5%) case of recurrent transient ischemic attack. There was no death, significant restenosis or stroke in the territory of the treated vessel during the duration of the follow-up. CONCLUSIONS: Endovascular stent reconstruction for the treatment of selected patients with progressively worsening carotid dissection despite medical management is feasible with acceptable immediate and long-term clinical and radiographic outcomes. To be able to draw more robust conclusions, further evaluation with larger number of patients and longer follow-up is needed.

Middle cerebral artery aneurysm endovascular and surgical therapies: comprehensive literature review and local experience.

The middle cerebral artery is a common location for cerebral aneurysms and is associated with a lower risk of rupture than aneurysms located in the anterior or posterior communicating arteries. No evidence supports the superiority of clipping over coiling to treat middle cerebral artery aneurysm (MCAA) or vice versa. The feasibility of treating the MCAA with endovascular therapy as the first choice of treatment in cohorts of nonselected aneurysms exceeds 90%. A randomized clinical trial comparing the 2 approaches in nonselected cases with long-term follow-up will shed light on which patients may benefit from one approach over another.

Endovascular management of intracranial atherosclerosis.

Intracranial atherosclerotic disease (ICAD) represents one of the most common causes of ischemic stroke worldwide, yet our understanding remains limited regarding the best treatment options for this complex disease with a high recurrence rate of stroke. Although medical therapy has proved to be effective in lowering the risk of stroke, certain high-risk ICAD patients may derive benefit from endovascular therapy. This review presents the current treatment options for the endovascular management of ICAD and highlights the recent relevant literature.

Safety and predictors of aneurysm retreatment for remnant intracranial aneurysm after initial endovascular embolization.

INTRODUCTION: Aneurysmal subarachnoid hemorrhage (SAH) is a rare but devastating form of stroke. Endovascular therapy has been criticized for its higher rate of recanalization and retreatment. The safety and predictors of retreatment are unknown. We report the clinical outcomes, imaging outcomes and predictors for aneurysm retreatment after initial endovascular embolization. METHOD: We identified patients who underwent endovascular retreatment from July 2005 through November 2011. Aneurysm and patient data were collected. Periprocedural complications were reported as intraoperative perforation (IOP) or thromboembolic event (TEE). Aneurysm and patient characteristics were compared between aneurysms requiring retreatment and those not requiring retreatment to evaluate aneurysm retreatment predictors. RESULTS: A total of 111/871 (13%) aneurysms underwent retreatment. Two (0.2%) were retreated for recurrent acute SAH, 82 (74%) aneurysms were located in the anterior circulation, 47 (42%) required stent and 5 (5%) required balloon assist during retreatment. There were a total of 5 (5%) IOP and 6 (5%) TEE from which 2 (2%) and 1 (1%) were symptomatic, respectively. Overall symptomatic events rate were 2.7%. Patients were followed up for an average of 15±14 months. Seven (0.8%) aneurysms required a second retreatment without any recurrent SAH. Multivariable analysis revealed an OR for aneurysms requiring retreatment of 2.965 for aneurysms presenting as aneurysmal SAH, 1.791 for aneurysms in the posterior circulation and 1.053 for aneurysms with large dome size. CONCLUSIONS: Aneurysm retreatment is a safe option without a significant increase in morbidity or mortality. SAH, posterior circulation aneurysms and larger aneurysm dome size are predictors of aneurysms requiring retreatment.

Need for performance protocols in TEE and TCD for detection of right to left shunts.

BACKGROUND AND PURPOSE: Although transesophageal echocardiography (TEE) is the gold standard for right to left shunt detection, we observed that transcranial Doppler (TCD) was more sensitive and sought an explanation. METHODS: We retrospectively evaluated results of TCD and TEE in 118 patients with cryptogenic stroke and transient ischemic attacks. TCDs were done as per modification of a published performance protocol and interpreted by a neurologist and radiologist. TEEs were performed and interpreted by five cardiologists without standardized protocol. Statistical methodology included χ(2) tests, Fisher exact tests, and ANOVA. RESULTS: Overall agreement between TCD and TEE was found for 76 of 118 patients. Sensitivities of TCD and TEE were 93.8% and 53.1%. Sensitivities for TCD interpreters were 61.1% and 64.1%. Sensitivities for TEE operators varied from 46.7% to 75.7%. We were unable to find a performance protocol for TEE microbubble studies in either published literature or certification organizations. CONCLUSIONS: TEEs and TCDs are operator dependent and thus subject to false negatives. The lower yield and interoperator variability in TEE results appear to reflect the lack of performance protocols and engender concern about false negatives in community use. Consensus performance protocols and certification criteria for both modalities should have an impact on accuracy of shunt detection.

Angiographic lumen changes associated with oversized intracranial stent implantation for aneurysm treatment.

BACKGROUND: The effect of oversized intracranial stent implantation, and potential excessive neointimal hyperplasia from the chronic outward radial force, has not been reported. We sought to compare the angiographic narrowing associated with implantation of oversized stents. METHODS: We reviewed an aneurysm database and identified patients treated with stent-assisted embolization involving a vessel size transition. Demographics and lesion characteristics were extracted. The relationship between lumen diameter and stent oversizing was compared. RESULTS: Twenty vessels were identified in 18 patients, providing 80 paired data points. Mean follow-up time was 8 months (SD 6). The average oversizing in the smaller diameter parent vessel landing-zone was 1.75 mm. Mean change in lumen size from pre-stent implantation was not significantly different for any of the four sites. There was a significant difference in change of lumen size at the stent tines when compared with the respective mid-stent segment for both the proximal (P = 0.02) and distal (P = 0.0004) landing zones. CONCLUSIONS: A small significant lumen loss occurs at stent tines when compared to midstent struts. However, there is no overall significant stenosis from highly oversized stents. Persistent luminal gain from the oversized stent radial force likely predominates over any neointimal hyperplasia.

Idiopathic Intracranial Hypertension. A Systematic Analysis of Transverse Sinus Stenting.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a disorder characterized by signs and symptoms of increased intracranial pressure without structural cause seen on conventional imaging. Hallmark treatment after failed medical management, has been CSF shunting or optic nerve fenestration with the goal of treatment being preservation of vision. Recently, there have been multiple case reports and case series on dural sinus stenting for this disorder. OBJECTIVE: We aim to review all published cases and case series of dural sinus stenting for IIH, with analysis of patient presenting symptoms, objective findings (CSF pressures, papilledema, pressure gradients across dural sinuses), follow-up of objective findings, and complications. METHODS: A Medline search was performed to identify studies meeting pre-specified criteria of a case report or case series of patients treated with dural sinus stent placement for IIH. The manuscripts were reviewed and data was extracted. RESULTS: A total of 22 studies were identified, of which 19 studies representing 207 patients met criteria and were included in the analysis. Only 3 major complications related to procedure were identified. Headaches resolved or improved in 81% of patients. Papilledema improved the (172/189) 90%. Sinus pressure decreased from an average of 30.3 to 15 mm Hg. Sinus pressure gradient decreased from 18.5 (n=185) to 3.2 mm Hg (n=172). Stenting had an overall symptom improvement rate of 87%. CONCLUSION: Although all published case reports and case series are nonrandomized, the low complication and high symptom improvement rate make dural sinus stenting for IIH a potential alternative surgical treatment. Standardized patient selection and randomization trials or registry are warranted.

Cross section of stat (emergent) EEG use. Who orders them? What do we find? What indications best predict finding seizures?

Stat electroencephalograms (sEEG) recorded over a one year period were analyzed to determine the rate of seizure or status epilepticus (SE) detection and the best predictors based on: ordering physician, clinical indication for study, and clinical history. All consecutive sEEG reports done over a year period at our institution were retrospectively reviewed. The following data were evaluated: sEEG findings, clinical history, clinical indication for study, requesting physician, location of patient, and demographics. Univariate analysis followed by a multivariate regression model analysis was performed. Of the 3,471 inpatient EEGs performed during the review period, 778 (22.4%) were sEEGs. 3.5% (n = 27) nonconvulsive status epilepticus (NCSE), 0.4% (n = 3) convulsive status epilepticus (CSE), and 1.1% (n = 9) had discrete electrographic seizures giving a total yield of 5.0% (39/778) patients with seizures or SE. A multivariate logistic retrospective model looking at ordering physician, clinical indication, and clinical history found that only clinical indications (overt continuous seizures/movements and witnessed seizure without return to baseline) were significant in the overall model. In our tertiary care institution sample, the rate of detecting status epilepticus or seizures among sEEG is low compared to prior studies. The best clinical predictors of finding SE or discrete seizures were overt continuous seizures/movements or witnessed seizure without return to baseline.

Pseudotumor cerebri presenting with ataxia and hyper-reflexia in a non-obese woman treated with sinus stenting.

AIM: To report a successful treatment of an atypical case of pseudotumor cerebri. BACKGROUND: Pseudotumor cerebri is a disorder of raised intracranial pressure. Multiple Case Series have been published about its treatment with sinus stenting. All these cases have had typical presentations. CASE: An atypical fulminant case of pseudotumor cerebri which was treated successfully with venous sinus stenting. CONCLUSION: Venous sinus stenting can be done effectively in atypical cases of pseudotumor cerebri.

Safety and feasibility of simultaneous ipsilateral proximal carotid artery stenting and cerebral aneurysm coiling.

Coexistence of cerebral aneurysm and carotid artery disease may be encountered in clinical practice. Theoretical increase in aneurysmal blood flow may increase risk of rupture if carotid artery disease is treated first. If aneurysm coiling is performed first, stroke risk may increase while repeatedly crossing the diseased artery. It is controversial which disease to treat first, and whether it is safe to treat both simultaneously via endovascular procedures. We document the safety and feasibility of such an approach. Review of collected neurointerventional database at our institution was performed for patients who underwent both carotid artery stenting (CAS) and aneurysm coil embolization (ACE) simultaneously. All patients underwent carotid stenting followed by aneurysm coiling in the same setting. Demographic, clinical data, and outcome measures including success rate and periprocedural complications were collected. Five hundred and ninety aneurysms coiling were screened for patients who underwent combined CAS and ACE. Ten patients were identified. Mean age was 67.7 years (range 51-89). The success rate for stenting and coiling was 100% with no immediate complications. The coiling procedure time was extended by an average of 45 min for performing both procedures jointly. No stroke, TIAs, or aneurysmal rebleeding was found on their most recent follow up. Our case series demonstrates that it is safe and feasible to perform CAS and ACE simultaneously as one procedure which may avoid unwanted risk of treating either disease at two separate time sessions.