Middle meningeal artery embolization for membranous versus non-membranous subdural hematomas: a retrospective and multicenter cohort study

BACKGROUND

Middle meningeal artery (MMA) embolization is a treatment option for chronic subdural hematoma (SDH). The theorized mechanism of MMA embolization is by devascularizing membranes that contribute to recurrence. In this study, we aimed to determine whether MMA embolization is more efficacious for SDH with radiographically visible membranes.

METHODS

A multicenter retrospective cohort study was performed of patients with SDHs who underwent MMA embolization alone or with burr hole drainage. Hematomas were categorized as membranous or non-membranous based on radiographic appearance. Patient characteristics and outcomes were compared between the two groups.

RESULTS

A total of 99 patients with 117 MMA embolization procedures were included. 73.7% of patients with membranous SDH and 61.0% with non-membranous SDH underwent MMA embolization alone. The remaining patients underwent MMA embolization in conjunction with burr hole evacuation. The overall recurrence rate was 10.7%. There was no significant difference in complications (p=0.417), recurrence (p=0.898), or retreatment (p=0.999) amongst the membranous and non-membranous groups.

CONCLUSION

To our knowledge, this is the first multi-center study evaluating the effect of membrane presence in SDH undergoing embolization. Membrane presence in patients undergoing MMA embolization did not correlate with recurrence or retreatment suggesting that membrane presence should not be used as the sole selection criteria for MMA embolization. While prospective studies amongst larger cohorts are needed, this study sheds light on the potential implications of membranes in determining the optimal treatment paradigm for SDH.

Abstract TMP4: BB-031 Reduces Platelet Reactivity And Attenuates Von Willebrand Factor Levels In A Large Vessel Occlusion Stroke Model

Introduction: Acute ischemic strokes (AIS) are a leading cause of death and long-term disability worldwide. Von Willebrand Factor (VWF) is an attractive target for anti-thrombotic therapeutics as it plays a pivotal role in platelet adhesion, activation, and aggregation with large vessel occlusion (LVO) stroke. VWF is stored in an ultra large form in platelet α-granules and Weibel-Palade bodies of endothelial cells from where it is released during injury or inflammation. BB-031 is an RNA aptamer that binds and inhibits VWF, and both prevents and lyses an occlusive thrombus.

Hypothesis: We hypothesize BB-031 treatment will inhibit VWF thereby reducing platelet reactivity and attenuating the increase in VWF levels in a canine model of LVO stroke.

Methods: A canine embolic MCAO model was used to assess BB-031 efficacy of VWF inhibition and platelet activity compared to placebo. After 6 hours of LVO with an autologous clot, intravenous treatment was initiated with placebo (n=7), or 0.5 (n=8), 1.0 (n=4), and 5.0 (n=4) mg/kg BB-031. Whole blood was collected at baseline, 6 hours after occlusion then at 10, 15, 20, 25, 30, 60 min after treatment and lastly, at time of sacrifice 9 hours after MCAO induction. Enzyme-linked immunosorbent assay (ELISA) was used to measure circulating VWF and platelet function analysis (PFA-100 Siemens) was utilized to determine platelet reactivity.

Results: VWF levels immediately after LVO in vehicle control were significantly attenuated within 10 minutes of administration with all BB-031 concentrations (p<0.05). Within 15 minutes after vehicle treatment, VWF levels increased by 3.102 ± .382 ng/ml whereas BB-031 administration of 0.5, 1.0, and 5.0 mg/kg reduced VWF levels by 0.223 ± .154 ng/ml, 0.269 ± .304 ng/ml and 1.053 ± .267 ng/ml respectively. Platelet reactivity to ADP/Collagen (PFA-100) revealed significantly increased platelet closing time in all BB-031 treated canines from immediately after administration through 60 minutes. (p<0.05).

Conclusion: BB-031 treatment demonstrated significant VWF inhibition and reduced platelet reactivity in a canine AIS LVO model compared to placebo. These findings indicate that BB-031 may offer a superior therapeutic treatment paradigm for ischemic stroke.

Utility of the novel guide catheter in mechanical thrombectomy for emergent large vessel occlusion stroke

BACKGROUND

A number of large bore guide catheters are currently available for use in neuroendovascular surgery. This study represents a multi-institutional retrospective series of patients undergoing mechanical thrombectomy with the use of a TracStar Large Distal Platform (LDP) guide catheter and assessed its performance in vivo in 107 patients.

OBJECTIVE

To review a multi-institutional initial experience with the TracStar LDP guide catheter during mechanical thrombectomy for emergent large vessel occlusion (ELVO).

METHODS

A retrospective review was performed at two level one stroke centres to include all patients who underwent mechanical thrombectomy and had the TracStar LDP guide catheter used during the intervention.

RESULTS

The TracStar LDP guide catheter was successfully used in 107 mechanical thrombectomies. In anterior circulation ELVO, the guide catheter advanced into the cavernous segment of the internal carotid artery in 62.6% (62/99) of cases. In posterior circulation cases, the guide catheter advanced to the basilar artery in 87.5% (7/8) of cases. A thrombolysis in cerebral infarction 2b or greater reperfusion was obtained in 90.7% (97/107). No complications occurred related to the TracStar LDP guide catheter. Three complications occurred with aspiration catheters including a small dissection that did not require further intervention and fracturing of the AXS Catalyst 6 catheter tip in two cases. No thromboembolic events occurred.

CONCLUSIONS

The TracStar LDP large bore guide catheter is safe and effective at navigating the tortuous vascular anatomy often encountered during mechanical thrombectomy for stroke. The flexible distal and stiffer proximal components provide a good combination of navigability and support for use in neuroendovascular interventions.

Sex differences in thrombosis as it affects acute ischemic stroke

Ischemic stroke is a devastating health problem, affecting approximately 800,000 patients in the US every year, making it the leading cause of combined death and disability in the country. Stroke has historically been thought of as predominantly impacting men, however it is becoming increasingly clear that stroke affects women to a greater degree than men. Indeed, women have worse outcomes compared to men following ischemic stroke. Recent clinical advances have shown great promise in acute stroke therapy, with the use of mechanical endovascular thrombectomy (with and without recombinant tissue plasminogen activator; rtPA) greatly improving outcomes. This observation makes it clear that removal of clots and reperfusion, either mechanically or pharmacologically, is critical for improving outcomes of patients following acute ischemic stroke. Despite these promising advances, long-term neurological sequelae persist in the post-stroke population. This review focuses on mechanisms of thrombosis (clot formation) as it pertains to stroke and important sex differences in thrombosis and responses to treatment. Finally, we describe recent data related to new therapeutic approaches to thrombolysis, with a particular focus on von Willebrand Factor (vWF).

Abstract 45: Vwf Inhibitor Lyses Middle Cerebral Artery Occlusion After 6 Hours Of Large Vessel Occlusion Stroke

Introduction: Acute ischemic stroke (AIS) is the leading cause of combined morbidity and mortality worldwide. Recombinant tissue plasminogen activator (rtPA) is the only FDA-approved drug to treat AIS, however, it is limited to treating patients within 4.5 hours of stroke onset because of the risk of intracranial hemorrhage. This limits rtPA administration to ~6% of patients. Moreover, it poorly lyses large vessel occlusion (LVO) stroke. Endovascular mechanical thrombectomy (MT) effectively recanalizes LVO but is limited to highly specialized hospitals, leaving the majority without acute therapy.

Hypothesis: We hypothesize that targeted von Willebrand Factor (VWF) inhibition by DTRI-031 will recanalize arterial thrombosis in a canine model of LVO stroke, and DTRI-031 activity will be rapidly reversed by DTRI-025, which is specifically designed to inhibit DTRI-031.

Methods: Utilizing a canine embolic middle cerebral artery occlusion (eMCAO) model of LVO stroke, we assessed DTRI-031 on vessel recanalization after 6 hours of LVO stroke by digital subtraction angiography (DSA). We also measured the effect of recanalization on infarct volume (efficacy) and hemorrhage (safety) using magnetic resonance imaging (MRI). Finally, we assessed the ability of DTRI-025, an oligonucleotide that binds DTRI-031 to reverse DTRI-031 activity.

Results: DTRI-031 administration after 6 hours of LVO stroke resulted in ≥TICI 2A in 62.5% and ≥TICI 2B in 50% of canines (n=8). The negative control group demonstrated no revascularization (n=7). Recanalization resulted in reduced infarct volume compared to the negative control (p<0.05, unpaired t-test). None of the animals that received DTRI-031 had an intracranial hemorrhage on MRI. Finally, DTRI-025 completely reversed the activity of DTRI-031 within 5 minutes of administration in both whole blood impedance aggregometry (WBA) and PFA-100. There was no difference in heart rate, blood pressure, or temperature among the 3 groups studied.

Conclusion: DTRI-031 effectively recanalizes LVO after 6 hours of stroke onset with reduced infarct volume and no incidence of hemorrhage. DTRI-025 rapidly reverses DTRI-031. This drug/reversal agent combination represents a robust yet safe approach to treat AIS.

Management of tandem occlusions in patients who receive rtPA

BACKGROUND

Tandem occlusions exist in 17-32% of large vessel occlusion (LVO) strokes. A significant concern is bleeding when carotid stenting is performed in tandem with thrombectomy due the administration of antiplatelet agents such as glycoprotein IIb/IIIa inhibitors (GP2b3aI) after receiving rtPA, but data are limited in this setting.

METHODS

A mutlicenter, retrospective chart review was conducted at two comprehensive stroke centers to assess the safety and efficacy of using GP2b3aI to facilitate carotid stent placement simultaneously with endovascular thrombectomy in patients who have received rtPA.

RESULTS

Overall, 32 patients were included in this study, with average age of 66.3 ± 10.4 years and predominantly male (87.5%). The cause of stroke was mostly large artery atherosclerosis (59.4%) and the thrombectomy target vessels were typically first- or second segment middle cerebral artery (37.5% and 31.3%). Time from symptom onset to rtPA bolus was 1.8 h [interquartile range (IQR) 1.5-2.7], rtPA bolus to first pass was 2 h [IQR 1.5-3.1], rtPA bolus to GP2b3aI bolus was 2 h [IQR 1.6-3.5], and rtPA bolus to aspirin and clopidogrel administration was 4.3 h [IQR 2.6-8.9] and 6.6 h [IQR 4.5-11.6] respectively. No patients had acute in-stent thrombosis or post-op bleeding from the access site. Two patients (6.3%) had significant hemorrhagic conversion.

CONCLUSION

The use of GP2b3aI in the setting of tandem occlusions that required emergent stent placement post-rtPA appears safe and effective. Given the small sample size, these findings should be interpreted cautiously, and need to be confirmed in a larger patient population.

The effect of different levels of ozone and ozonized water on biogenic amines in broiler chicken meat by HPLC

Biogenic amines (BA) are low molecular weight substances, formed mainly by decarboxylation of specific amino acids present in food through the action of enzymes during storage produced by some microorganisms, this fact can be used to relate BA as a bacteriological quality indicator. This study was aimed to evaluate the effects of an experimental ozone gaseous treatment and production of the biogenic amines’ putrescine and cadaverine. Amines were extracted with perchloric acid, derivative with dansyl chloride, separated using a reversed-phase high-performance liquid chromatographic method, and detected by fluorescence. The results showed that during the 7 days, the amount of putrescine had increased in all four experimental treatments. The highest increase was related to Group 1. The Duncan post hoc test showed that the highest amount of Cadaverine after killing was related to Group 1 (control) with 88.85 mg/kg and the lowest value for Group 2 is 12.03 mg/kg. Also, the results of Duncan's post hoc test for comparing Cadaverine seven days after slaughter among experimental treatments showed that the highest amount of Cadaverine after slaughter was related to Group 1 (control) with 135.6 mg/kg and the lowest value for the group is 94.83 mg/kg. The results of the test to compare the pH of the treatments showed that the highest amount of pH is for Group 4 and the lowest value for Group 1 (control). The results of this study showed that with increasing ozone gas concentration and decreasing the concentration of water, the biogenic amines’ putrescine and cadaverine in frozen poultry meat decreased. Putrescine and cadaverine levels appeared to be useful to control the effectiveness of the ozone treatment on meat quality and may be useful as a quality index to highlight the loss of poultry meat freshness.

Ischemic stroke in COVID-19-positive patients: an overview of SARS-CoV-2 and thrombotic mechanisms for the neurointerventionalist

Coronavirus disease 2019 (COVID-19) results from infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It was first reported in Wuhan, China in patients suffering from severe pneumonia and acute respiratory distress syndrome and has now grown into the first pandemic in over 100 years. Patients infected with SARS-CoV-2 develop arterial thrombosis including stroke, myocardial infarction and peripheral arterial thrombosis, all of which result in poor outcomes despite maximal medical, endovascular, and microsurgical treatment compared with non-COVID-19-infected patients. In this review we provide a brief overview of SARS-CoV-2, the infectious agent responsible for the COVID-19 pandemic, and describe the mechanisms responsible for COVID-19-associated coagulopathy. Finally, we discuss the impact of COVID-19 on ischemic stroke, focusing on large vessel occlusion.

Woven EndoBridge (WEB) device in the treatment of ruptured aneurysms

BACKGROUND

Wide-necked bifurcation aneurysms (WNBAs) present unique challenges for endovascular treatment. The Woven EndoBridge (WEB) device is an intrasaccular braided device, recently approved by the FDA for treatment of WNBAs. While treatment of intracranial aneurysms with the WEB device has been shown to yield an adequate occlusion rate of 85% at 1 year, few data have been published for patients with ruptured aneurysms.

OBJECTIVE

To present a multi-institutional series depicting the safety and efficacy of using the WEB device as the primary treatment modality in ruptured intracranial aneurysms.

METHODS

A multi-institutional retrospective analysis was conducted, assessing patients presenting with aneurysmal subarachnoid hemorrhage treated with the WEB between January 2014 and April 2020. Baseline demographics, aneurysm characteristics, adverse events, and long-term outcomes (occlusion, re-treatment, functional status) were collected. A descriptive analysis was performed, and variables potentially associated with aneurysm recurrence or re-treatment were assessed.

RESULTS

Forty-eight patients were included. Anterior communicating artery aneurysms were the most common (35.4%) location for treatment, followed by middle cerebral artery (20.8%) and basilar apex (16.7%). Procedural success was noted in 95.8% of patients, and clinically significant periprocedural adverse events occurred in 12.5%. After a median follow-up of 5.5 months, 54.2% of patients had follow-up angiographic imaging. Complete occlusion was seen in 61.5% of cases with adequate occlusion in 92.3%. Re-treatment was required in only 4.2% of patients during the study period. Tobacco use was significantly higher in patients with aneurysm recurrence (88.9% vs 35.7%; p=0.012). No other characteristics were associated with recurrence/re-treatment. At 30 days, 81.1% were functionally independent (modified Rankin Scale score ≤2).

CONCLUSION

Treatment of acutely ruptured aneurysms with the WEB device demonstrates both safety and efficacy on par with rates of conventional treatment strategies.

Endovascular Stenting of Tandem Carotid Artery Origin and Bifurcation Stenotic Lesions Using Flow Reversal

BACKGROUND

The treatment of tandem lesions involving severe stenosis of the internal carotid artery with concomitant stenosis of the ipsilateral common carotid artery (CCA) origin represents an ongoing challenge. Current options for the treatment of tandem carotid artery origin and bifurcation stenotic lesions include open surgical endarterectomy, endovascular stenting, balloon angioplasty, and hybrid procedures combining both modalities. However, these options are either associated with high peri-operative risks or not always anatomically feasible.

CASE DESCRIPTION

We report, for the first time in North America (to the best of our knowledge), an alternative treatment modality that involves obtaining access through a direct carotid cut-down, with serial treatment of the tandem lesions through a combination of retrograde and anterograde endovascular stenting.

CONCLUSION

This technique obviates the need for navigating the aortic arch in patients with difficult arch anatomy and permits the use of distal embolic protection devices, thus decreasing the risk of peri-operative ischemic events.

Extraction of antioxidants and caffeine from green tea (Camelia sinensis) leaves: kinetics and modeling

The effects of temperature (50, 60, 70, 80, 90 °C) and time (5, 10, 20, 40, 80 min) on catechins and caffeine solubility in water from Iranian green tea were investigated, The best combinations of temperature and time extraction with water were 20-40 min, 80 °C for epigallocatechin (EGC), epicatechin (EC) and caffeine (Caff), and 80 min, 90 °C for catechin (C), epicatechin gallate (ECG) and epigallocatechin gallate (EGCG). A mathematical model derived from Fick's second law was then used to calculate the diffusivity of the components, and to monitor the effect of temperature on the diffusivities. The extraction of these components is governed by two diffusion processes: fast and slow. The results showed that the intra-particle diffusion was the rate-governing step of the extraction process. The slow stage diffusivities of these components at their optimum extraction temperatures were calculated as: 1.94e-9 (EGC), 8.1e-10 (EC), 3.9e-10 (Caff), 1.34e-8 (C), 4.2e-9 (ECG) and 4.63e-9 (EGCG).

Familial syringomyelia: case report and review of the literature

BACKGROUND

Syringomyelia is an uncommon disease of the spinal cord, occurring sporadically. However, rare familial cases with autosomal dominant or recessive inheritance patterns are reported and their incidence quoted as approximately 2%. Only one previous report originated from the United States.

METHODS

We present a brother and sister with syringomyelia and associated Chiari type I malformation; both patients responded to surgical treatment. We review the world literature and briefly discuss pathogenetic theories of syringomyelia as well as the relevance of the histocompatibility leukocyte antigen profile.

RESULTS

Both genetic and environmental factors appear to be involved in familial syringomyelia.

CONCLUSION

We recommend that close relatives of patients affected with familial syringomyelia undergo routine neurologic and radiologic surveys.