Most Promising Approaches to Improve Brain AVM Management: ARISE I Consensus Recommendations

Brain arteriovenous malformations (bAVMs) are complex, and rare arteriovenous shunts that present with a wide range of signs and symptoms, with intracerebral hemorrhage being the most severe. Despite prior societal position statements, there is no consensus on the management of these lesions. ARISE (Aneurysm/bAVM/cSDH Roundtable Discussion With Industry and Stroke Experts) was convened to discuss evidence-based approaches and enhance our understanding of these complex lesions. ARISE identified the need to develop scales to predict the risk of rupture of bAVMs, and the use of common data elements to perform prospective registries and clinical studies. Additionally, the group underscored the need for comprehensive patient management with specialized centers with expertise in cranial and spinal microsurgery, neurological endovascular surgery, and stereotactic radiosurgery. The collection of prospective multicenter data and gross specimens was deemed essential for improving bAVM characterization, genetic evaluation, and phenotyping. Finally, bAVMs should be managed within a multidisciplinary framework, with clinical studies and research conducted collaboratively across multiple centers, harnessing the collective expertise and centralization of resources.

ARISE I Consensus Review on the Management of Intracranial Aneurysms

BACKGROUND

Intracranial aneurysms (IAs) remain a challenging neurological diagnosis associated with significant morbidity and mortality. There is a plethora of microsurgical and endovascular techniques for the treatment of both ruptured and unruptured aneurysms. There is no definitive consensus as to the best treatment option for this cerebrovascular pathology. The Aneurysm, Arteriovenous Malformation, and Chronic Subdural Hematoma Roundtable Discussion With Industry and Stroke Experts discussed best practices and the most promising approaches to improve the management of brain aneurysms.

METHODS

A group of experts from academia, industry, and federal regulators convened to discuss updated clinical trials, scientific research on preclinical system models, management options, screening and monitoring, and promising novel device technologies, aiming to improve the outcomes of patients with IA.

RESULTS

Aneurysm, Arteriovenous Malformation, and Chronic Subdural Hematoma Roundtable Discussion With Industry and Stroke Experts suggested the incorporation of artificial intelligence to capture sequential aneurysm growth, identify predictors of rupture, and predict the risk of rupture to guide treatment options. The consensus strongly recommended nationwide systemic data collection of unruptured IA radiographic images for the analysis and development of machine learning algorithms for rupture risk. The consensus supported centers of excellence for preclinical multicenter trials in areas such as genetics, cellular composition, and radiogenomics. Optical coherence tomography and magnetic resonance imaging contrast-enhanced 3T vessel wall imaging are promising technologies; however, more data are needed to define their role in IA management. Ruptured aneurysms are best managed at large volume centers, which should include comprehensive patient management with expertise in microsurgery, endovascular surgery, neurology, and neurocritical care.

CONCLUSIONS

Clinical and preclinical studies and scientific research on IA should engage high-volume centers and be conducted in multicenter collaborative efforts. The future of IA diagnosis and monitoring could be enhanced by the incorporation of artificial intelligence and national radiographic and biologic registries. A collaborative effort between academic centers, government regulators, and the device industry is paramount for the adequate management of IA and the advancement of the field.

Clinical presentation and treatment of 26 spinal epidural arteriovenous fistulas: a single-center experience

BACKGROUND

Spinal epidural arteriovenous fistulas (SEDAVFs) are rarely diagnosed vascular malformations that can cause spinal cord compression and congestive myelopathy.

METHODS

This is a single-center, retrospective case series of patients with SEDAVFs who underwent observation or treatment at UCLA medical center between 1993 and 2023.

RESULTS

Between 1993 and 2023 a total of 26 patients at UCLA were found to have a SEDAVF. The median age at treatment was 59 years (range 4 months to 91 years). Compared with sacral, lumbar, and thoracic SEDAVFs, patients with cervical SEDAVF were younger (41 years vs 63 years, P=0.016) and more likely to be female (66.7% vs 14.3%, P=0.006). Possible triggers for development of SEDAVFs may be prior spinal surgery or trauma (n=4), turning the neck (n=1), lifting a heavy box (n=1), a prolonged period of bending over (n=1), and neurofibromatosis type 1 (n=1). Of the 22 patients treated endovascularly, 18 (82%) were angiographically cured on the first attempt without complications. One patient underwent surgical treatment alone and had a failed surgery on the first attempt, and developed a surgical site infection after the second successful attempt at treatment. Of the 16 patients with adequate clinical follow-up, 11 (69%) demonstrated early improved clinical outcome (eg, improved strength on examination, absent bruit).

CONCLUSIONS

SEDAVFs are a rarely diagnosed disease that can be treated effectively and safely with endovascular embolization in most cases. Patients with sacral, lumbar, and thoracic SEDAVFs were older and more often male compared to patients with cervical SEDAVFs.

Arterial Bypass in the Treatment of Complex Middle Cerebral Artery Aneurysms: Lessons Learned from Forty Patients

OBJECTIVE

Complex middle cerebral artery (MCA) aneurysms incorporating parent or branching vessels are often not amenable to standard microsurgical clipping or endovascular embolization treatments. We aim to discuss the treatment of such aneurysms via a combination of surgical revascularization and aneurysm exclusion based on our institutional experience.

METHODS

Thirty-four patients with complex MCA aneurysms were treated with bypass and aneurysm occlusion, 5 with surgical clipping or wrapping only, and 1 with aneurysm excision and primary reanastomosis. Bypasses included superficial temporal artery (STA)-MCA, double-barrel STA-MCA, occipital artery-MCA, and external carotid artery-MCA. After bypass, aneurysms were treated by surgical clipping, Hunterian ligation, trapping, or coil embolization.

RESULTS

The average age at diagnosis was 46 years. Of the aneurysms, 67% were large and most involved the MCA bifurcation. Most bypasses performed were STA-MCA bypasses, 12 of which were double-barrel. There were 2 wound-healing complications. All but 2 of the aneurysms treated showed complete occlusion at the last follow-up. There were 3 hemorrhagic complications, 3 graft thromboses, and 4 ischemic insults. The mean follow-up was 73 months. Of patients, 83% reported stable or improved symptoms from presentation and 73% reported a functional status (Glasgow Outcome Scale score 4 or 5) at the latest available follow-up.

CONCLUSIONS

Cerebral revascularization by bypass followed by aneurysm or parent artery occlusion is an effective treatment option for complex MCA aneurysms that cannot be safely treated by standard microsurgical or endovascular techniques. Double-barrel bypass consisting of 2 STA branches to 2 MCA branches yields adequate flow replacement in most cases.

Proximal Internal Carotid Artery Occlusion and Extracranial-Intracranial Bypass for Treatment of Fusiform and Giant Internal Carotid Artery Aneurysms

OBJECTIVE

To discuss the treatment of intracranial fusiform and giant internal carotid artery (ICA) aneurysms via revascularization based on our institutional experience.

METHODS

An institutional review board-approved retrospective analysis was performed of patients with unruptured fusiform and giant intracranial ICA aneurysms treated from November 1991 to May 2020. All patients were evaluated for extracranial-intracranial (EC-IC) bypass and ICA occlusion.

RESULTS

Thirty-eight patients were identified. Initially, patients failing preoperative balloon test occlusion were treated with superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and concurrent proximal ICA ligation. We then treated them with STA-MCA bypass, followed by staged balloon test occlusion, and, if they passed, endovascular ICA coil occlusion. We treat all surgical medically uncomplicated patients with double-barrel STA-MCA bypass and concurrent proximal ICA ligation. The mean length of follow-up was 99 months. Symptom stability or improvement was noted in 85% of patients. Bypass graft patency was 92.1%, and all surviving patients had patent bypasses at their last angiogram. Aneurysm occlusion was complete in 90.9% of patients completing proximal ICA ligation. Three patients experienced ischemic complications and 4 patients experienced hemorrhagic complications.

CONCLUSIONS

Not all fusiform intracranial ICA aneurysms require intervention, except when life-threatening rupture risk is high or symptomatic management is necessary to preserve function and quality of life. EC-IC bypass can augment the safety of proximal ICA occlusion. The rate of complete aneurysm occlusion with this treatment is 90.9%, and long-term bypass graft-related complications are rare. Perioperative stroke is a major risk, and continued evolution of treatment is required.

First-in-human trial of a self-expandable, temporary dilation system for intracranial atherosclerotic disease in patients presenting with acute ischemic stroke

BACKGROUND

Intracranial atherosclerotic disease (ICAD) significantly contributes to ischemic stroke, especially among Asian populations. Large vessel occlusion (LVO) due to underlying ICAD accounts for 15-35% of acute ischemic stroke cases requiring endovascular therapy. However, the successful recanalization rate of ICAD-related LVO remains lower. The TG dilator is a self-expandable device, temporarily dilating ICAD-related blocked blood vessels.

OBJECTIVE

To demonstrate TG dilator safety and efficacy for ICAD-related acute ischemic stroke.

METHODS

This was a single-arm, open-label, non-randomized, prospective, multicenter, and investigator-initiated trial that involved patients undergoing TG dilator application for acute ischemic stroke caused by ICAD-related LVO or severe stenosis.

RESULTS

We enrolled 10 patients in this trial between November 2022 and April 2023. The median (IQR) age was 68 (59.3-75.3) years. Before using the dilator, seven patients received stent retriever treatment. All 10 patients were prescribed a loading dose of aspirin with prasugrel. The median application time was 10 (10-12) min. At the end of the procedure, we achieved significant recanalization immediately in all patients. The stenosis/occlusion decreased from 100% (100-100) to 68% (56.3-75.3). No patient experienced recurrent ischemic stroke or reocclusion within 90 days. We achieved a modified Rankin scale score of 0-2 in 8 patients by day 90. We detected no cases of intracranial hemorrhage, equipment failure, distal embolism, vasospasm, dissection, or perforation requiring intervention.

CONCLUSIONS

Acute revascularization using the TG dilator on patients with ICAD-related LVO or severe stenosis did not cause any significant adverse event, and consistently improved blood flow at 90 days.

Perfusion Collateral Index versus Hypoperfusion Intensity Ratio in Assessment of Collaterals in Patients with Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Perfusion-based collateral indices such as the perfusion collateral index and the hypoperfusion intensity ratio have shown promise in the assessment of collaterals in patients with acute ischemic stroke. We aimed to compare the diagnostic performance of the perfusion collateral index and the hypoperfusion intensity ratio in collateral assessment compared with angiographic collaterals and outcome measures, including final infarct volume, infarct growth, and functional independence.

MATERIALS AND METHODS

Consecutive patients with acute ischemic stroke with anterior circulation proximal arterial occlusion who underwent endovascular thrombectomy and had pre- and posttreatment MRI were included. Using pretreatment MR perfusion, we calculated the perfusion collateral index and the hypoperfusion intensity ratio for each patient. The angiographic collaterals obtained from DSA were dichotomized to sufficient (American Society of Interventional and Therapeutic Neuroradiology [ASITN] scale 3-4) versus insufficient (ASITN scale 0-2). The association of collateral status determined by the perfusion collateral index and the hypoperfusion intensity ratio was assessed against angiographic collaterals and outcome measures.

RESULTS

A total of 98 patients met the inclusion criteria. Perfusion collateral index values were significantly higher in patients with sufficient angiographic collaterals (P < .001), while there was no significant (P = .46) difference in hypoperfusion intensity ratio values. Among patients with good (mRS 0-2) versus poor (mRS 3-6) functional outcome, the perfusion collateral index of ≥ 62 was present in 72% versus 31% (P = .003), while the hypoperfusion intensity ratio of ≤0.4 was present in 69% versus 56% (P = .52). The perfusion collateral index and the hypoperfusion intensity ratio were both significantly predictive of final infarct volume, but only the perfusion collateral index was significantly (P = .03) associated with infarct growth.

CONCLUSIONS

Results show that the perfusion collateral index outperforms the hypoperfusion intensity ratio in the assessment of collateral status, infarct growth, and determination of functional outcomes.

In vitro comparison of manual and robotic endovascular thrombectomy for acute ischemic stroke

BACKGROUND

Robotic endovascular systems have the potential to reduce radiation exposure to physicians and expand timely neurointerventional access to patients in remote areas. The goal of the study was to determine the feasibility of robotic endovascular thrombectomy (EVT) in an in vitro model.

METHODS

In vitro procedures were conducted manually and robotically using the Corpath GRX robotic system in a human vascular simulator with an elastic ovine clot in the M1 segment of the left middle cerebral artery. Due to the limited device compatibility of the CorPath GRX, a simple technique with a stent retriever and guiding catheter without a balloon was used in the study. Seven robotic EVT and manual EVT were carried out in each group. Metrics including procedural time, success rate, and radiation dose were compared between the two groups.

RESULTS

In robotic EVT, the mean total preparation and procedural time was 892 s, which was significantly longer than manual operation at 357 (p = 0.0001). There was no significant difference in the success rate between the two approaches (robotic: 28.6% vs. manual 42.9%, p = 0.577). The mean radiation exposure to operating physicians was significantly lower during robotic operation compared to manual operation (0.02 μSv vs. 0.22 μSv, p < 0.0001).

CONCLUSIONS

Robotic EVT was feasible in our human vascular simulator with significantly reduced radiation exposure to the operating physicians, despite an increased length of procedure when compared to manual procedures. Future technological advancement is warranted for reducing procedural length using endovascular robotic techniques.

Devices and Techniques

This extensive review explores the intricacies of the three principal mechanical thrombectomy techniques: the stent retriever technique, contact aspiration technique, and a combined approach, and their application in managing acute ischemic stroke. Each technique operates uniquely on the thrombus, leading to differences in their efficacy. Factors including clot size, clot stiffness, vessel tortuosity, and the angle of interaction between the aspiration catheter and the clot significantly influence these differences. Clinical trials and meta-analyses have shown the overall equivalency of these techniques for the treatments of large vessel occlusion and distal medium vessel occlusions. However, there are nuanced differences that emerge under specific clinical circumstances, highlighting the absence of a one-size-fits-all strategy in acute ischemic stroke management. We emphasize the need for future investigations to elucidate these nuances further, aiming to refine procedural strategies and individualize patient care for optimal outcomes.

Rescue Intracranial Balloon Angioplasty with or without Stent Placement in Acute Strokes with Intracranial Atherosclerotic Disease

BACKGROUND

Optimal management of acute ischemic stroke (AIS) secondary to intracranial atherosclerotic disease (ICAD) refractory to conventional mechanical thrombectomy remains unclear. We aimed to investigate the clinical outcome of patients undergoing rescue intracranial balloon angioplasty with or without stent placement in the setting of AIS in our institution.

METHODS

This is a retrospective single-arm observational study to evaluate the efficacy and safety of rescue balloon angioplasty with or without stent placement in emergent large vessel occlusion (EVLO) strokes with underlying ICAD. We included all patients undergoing such rescue intervention within 24 hours of AIS presentation with EVLO between 2017 and 2021. We further evaluated stent or vessel reocclusion.

RESULTS

Of 20 patients undergoing rescue intervention, 3 cases achieved adequate recanalization of artery using balloon angioplasty alone. Seventeen patients required stent placement. Fourteen (70%) procedures resulted in National Institutes of Health Stroke Scale improvement in postprocedure and upon discharge. Among 6 (30%) procedures with worsening neurological measures, 3 had reoccluded stent 24-48 hours after procedure, 2 had symptomatic hemorrhagic conversion, and 1 had perforator occlusion. Nine patients (45%) had favorable functional outcome (modified Rankin Scale ≤2) at discharge, unchanged or improved at 3-month follow-up. The median modified Rankin Scale score was 4 (Interquartile range: 1.75-4) at discharge, improving to 3 (Interquartile range: 0-4) at 3-month follow-up. Two patients (10%) died during hospital stay.

CONCLUSIONS

Rescue angioplasty with or without stenting can lead to significant clinical improvement in patients with ICAD presenting with ELVO and refractory to thrombectomy; however, this procedure is associated with a high rate of morbidity in acute setting.

Robotic Diagnostic Cerebral Angiography: A Multicenter Experience of 113 Patients

BACKGROUND

Neurointerventional robotic systems have potential to reduce occupational radiation, improve procedural precision, and allow for future remote teleoperation. A limited number of single institution case reports and series have been published outlining the safety and feasibility of robot-assisted diagnostic cerebral angiography.

METHODS

This is a multicenter, retrospective case series of patients undergoing diagnostic cerebral angiography at three separate institutions - University of California, Davis (UCD); University of California, Los Angeles (UCLA); and University of California, San Francisco (UCSF). The equipment used was the CorPath GRX Robotic System (Corindus, Waltham, MA).

RESULTS

A total of 113 cases were analyzed who underwent robot-assisted diagnostic cerebral angiography from September 28, 2020 to October 27, 2022. There were no significant complications related to use of the robotic system including stroke, arterial dissection, bleeding, or pseudoaneurysm formation at the access site. Using the robotic system, 88 of 113 (77.9%) cases were completed successfully without unplanned manual conversion. The principal causes for unplanned manual conversion included challenging anatomy, technical difficulty with the bedside robotic cassette, and hubbing out of the robotic system due to limited working length. For robotic operation, average fluoroscopy time was 13.2 min (interquartile range (IQR), 9.3 to 16.8 min) and average cumulative air kerma was 975.8 mGY (IQR, 350.8 to 1073.5 mGy).

CONCLUSIONS

Robotic cerebral angiography with the CorPath GRX Robotic System is safe and easily learned by novice users without much prior manual experience. However, there are technical limitations such as a short working length and an inability to support 0.035" wires which may limit its widespread adoption in clinical practice.

First-in-human trial of Center Wire for neuroendovascular therapy to avoid guidewire-related complications

BACKGROUND

An exchange maneuver is useful for the delivery of devices to target vessels. However, hemorrhagic complications can occur due to vessel perforation during an exchange maneuver. In addition, the exchange is often challenging due to unfavorable anatomy. Center Wire is an exchange-length wire with a nondetachable stent that was developed to improve navigation and stability during exchange maneuvers. The aim of this study is to investigate the safety and efficacy of Center Wire of the anchor wire technique during neuroendovascular treatment.

METHODS

Ten patients with intracranial aneurysms were treated after signing a Certified Review Board-approved consent. Anchor wire technique was used in all patients to navigate catheters to the target vessel for aneurysm treatment.

RESULTS

Anchor wire technique was successfully applied in all 10 cases using Center Wire. One device-related incident of vasospasm occurred which was asymptomatic. No device-related dissection, perforation, or thromboembolic events occurred. One patient had intraoperative aneurysm rupture during coil placement which was treated immediately without clinical consequences. Two patients had postoperative ischemic strokes due to thrombotic occlusion of branches originating from the aneurysm which were unrelated to the device.

CONCLUSIONS

This first-in-human trial of Center Wire demonstrated the safety and efficacy of the anchor wire technique for neuroendovascular treatment in a strictly regulated prospective registry trial.

Republished: Robotic assistant spinal angiography: a case report and technical considerations

Robotic-assisted technology has shown to be promising in coronary and peripheral vascular interventions. Early case reports have also demonstrated its efficacy in neuro-interventions. However, there is no prior report demonstrating use of the robotic-assisted platform for spinal angiography. We report the feasibility of the robotic-assisted thoracic and lumbar spinal angiography.

First-in-human trial of Stabilizer device in neuroendovascular therapy

Objectives

Flow diverter or stent implantation to intracranial target lesion requires large inner diameter microcatheter navigation. The exchange method using stiff long wire is often necessary if it is difficult to navigate over the regular guidewire. However, this method has an intrinsic risk of vessel damage and may cause severe complications. We investigated the safety and efficacy of a new device, the Stabilizer device for navigation in a first-in-human clinical trial under the Certified Review Board agreement.

Materials and methods

The Stabilizer is a 320 cm length exchange wire with a stent for anchoring and is compatible with a 0.0165" microcatheter. The trial design is a prospective single-arm open-label registry. Inclusion criteria are elective flow diverter treatment or stent-assisted coiling, expected to be difficult to navigate a microcatheter with a regular micro guidewire, and obtained documented consent. The primary endpoint of the study was a hemorrhagic complication.

Results

Five patients were enrolled in this trial. The median age is 52 years, ranges from 41 to 70, and all patients were female. Three aneurysms were located on the internal carotid artery, one on the vertebral artery, and one on the basilar artery. Basilar artery aneurysm was treated by stent-assisted coiling and others were treated by flow diverter deployment. All cases successfully navigate microcatheter for the treatment by the trial method using Stabilizer device without any adverse event.

Conclusions

The results from this first-in-human consecutive five cases show the safety of the Stabilizer device in neuro-endovascular therapy for navigation of devices to the intracranial target lesion.

Abstract 96: Independent Adjudication Of Get With The Guidelines Thrombectomy Imaging And Angiography Data Reveals Major Discrepancies

Introduction: The Get with the Guidelines - Stroke (GWTG-Stroke) registry has been collecting endovascular thrombectomy (EVT) data on acute stroke interventions since 2015. The key variables associated with EVT, solely based on local site documentation, have never been independently adjudicated. We conducted a detailed analysis of single center EVT data as entered in the GWTG-Stroke registry.

Methods: Consecutive EVT cases entered into both GWTG-Stroke and an independent research database at a large academic comprehensive stroke center were sampled from 2020-2022. For each case, the following EMR and PACS imaging variables related to EVT efficacy and safety outcomes were compared between GWTG-Stroke and core lab independent readings, including: site of target occlusion (STO), first-pass time (FPT), time mTICI >=2b50 first documented (reperfusion time), final mTICI score (0, 1, 2a, 2b50, 3; FTICI), presence of post-intervention hemorrhagic transformation (HT), and subtype/extent of HT.

Results: The GWTG-Stroke registry EVT-imaging data variables document only 6/30 (20%) of the common data elements (CDEs) recommended by NINDS and 6/34 (18%) recommended by the FDA. Of the 80 cases sampled, 29 (36%) had discrepancies between GWTG-Stroke recorded data and independent core lab findings. In 4 cases (5%), reperfusion time was incorrect. In another 4 cases (5%), FTICI was incorrect, even when using the gross 2b50/3 categories. In 1 case (1.3%) STO was incorrect. In 2 cases (2.5%) patient data was not reported to GWTG-Stroke. In 21 cases (26%), HT was documented as not present, when in fact it was. Of those, 3 cases (4%) were PH2, while 18 cases (23%) were IPH of PH1 or less, SAH or SDH.

Conclusions: Detailed analysis of the GWTG-Stroke registry on EVT for acute ischemic stroke reveal major discrepancies in numerous variables. In addition, the majority of variables recommended by NINDS and FDA for routine collection in thrombectomy procedures are not captured in GWTG-Stroke. Even the minority of recommended thrombectomy CDEs currently captured in GWTG-Stroke further contain subject level discrepancies in imaging and angiography outcomes when centrally adjudicated.

Abstract TMP93: Middle Meningeal Artery Embolization - A Preliminary Analysis Of Efficacy In Acute Settings And Among Patients With Major Co-morbidities

Introduction: Middle meningeal artery (MMA) embolization is an therapy utilized in the management of subdural hematomas (SDH). Based on promising preliminary data, several clinical trials are underway to evaluate the efficacy of this endovascular approach in patients with chronic subdural hematomas. However, consensus for the efficacy of MMA embolization has not been well established in acute settings or among patients with major co-morbidities.

Methods: Patient data were gathered from consecutive cases performed at UCLA between 05/02/2018 and 08/26/2022. Retrospective chart review was performed to determine inpatient/outpatient status, mortality, co-morbidities, and time-to-death. Primary statistical analyses were performed to determine the proportion of patients.

Results: Among the 111 patients meeting study entry criteria, 44 (39.6%) had acute, inpatient MMA procedures performed and 66 (40.4%) had elective procedures in the setting of advanced or terminal diseases (e.g. malignancy, cirrhosis). After follow-up of median 31.9 months, mean 17.4 months years, 86 (77.5%) of patients were still living and 25 (22.5%) were deceased. The age for both deceased and living patients was the same, 71±13 vs 71±16.1 years old. Mortality during follow-up was more common among patients undergoing MMA as an inpatient (47.8% vs 6.1%). Among the 25 deceased patients, mortality occurred within 1 year in 64% and beyond 1 year in 36%. Co-morbidity frequencies among deceased compared with surviving patients were: 40% vs 22%; solid tumor cancer in 28% vs 14%; cirrhosis in 32% vs 6%; and hematologic malignancy in 4% vs 4%. Among those deceased, 14 of 25 (56%) were diagnosed with a major co-morbidity (hematologic condition, cancer, or liver cirrhosis) at the time of the procedure. Among those living, 19 of 86 (22.1%) were diagnosed with a major co-morbidity (hematologic condition, cancer, or liver cirrhosis) at the time of the procedure.

Conclusion: Patients with SDH undergoing MMA embolization on an acute inpatient basis have a high, nearly 50%, rate of mortality within the next 0.5-2 years, while patients electively treated despite major co-morbidities have a substantially higher survival rate.

Intermittent Orbital Pain due to Hemodynamic Collapse of an Orbital Varix: A Case Report

Orbital varices typically present with symptoms related to dilation or thrombosis. We describe a rare presentation of an orbital varix with pain caused by hemodynamic collapse of the varix. A woman in the third decade presented with position-dependent orbital pain and enophthalmos. She was found to have an intraorbital varix and a separate pterygoid varix. The patient underwent endovascular treatment of the pterygoid varix using coils and sclerosing agents which altered the venous outflow from the orbital varix. The patient had immediate resolution of symptoms after the procedure. Our findings suggest that extraorbital venous outflow abnormalities may be the cause of symptoms in selected cases of orbital varices. By understanding the venous structures on cerebral angiography and treating the extraorbital component, orbital intervention may be avoided, reducing the risk of complications.

Aneurysmal subarachnoid hemorrhage in pregnancy: National trends of treatment, predictors, and outcomes

INTRODUCTION

Aneurysmal subarachnoid hemorrhage (aSAH) is a rare event associated with significant pregnancy-associated maternal and neonatal morbidity and mortality. The optimal treatment strategy and clinical outcome of aSAH in pregnancy remains unclear. We aimed to investigate the treatment utilizations and outcomes of aSAH in pregnant people.

METHODS

Using the 2010-2018 National Inpatient Sample, we identified all birth hospitalizations of women between ages of 18 to 45 associated with subarachnoid hemorrhage and aneurysm treatment were included. Multivariate analyses were used to evaluate the effect of pregnancy state, mode of treatment of aneurysms, severity of subarachnoid hemorrhage on mortality and discharge destination of this cohort. Trends in mode of treatment utilized for aneurysmal treatment in this time interval was evaluated.

RESULTS

13,351 aSAH with treatment were identified, of which 440 were associated with pregnancy. There was no significant difference in mortality or rate of discharge to home in pregnancy related hospitalization. Worse aSAH severity, chronic hypertension, and smaller hospital size was associated with significantly higher rate of mortality from aSAH during pregnancy. Worse aSAH severity was associated with lower rate of discharge to home. Like the non-pregnant cohort, the treatment of ruptured aneurysms in pregnancy are increasingly through endovascular approaches. The mode of treatment does not change the mortality or discharge destination.

CONCLUSIONS

Pregnancy does not alter mortality or the discharge destination for aSAH. Ruptured aneurysms during pregnancy are increasingly treated endovascularly. Mode of aneurysm treatment does not affect mortality or discharge destination in pregnancy.

Modeling optimal patient transport in a stroke network capable of remote telerobotic endovascular therapy

BACKGROUND

Telerobotic endovascular therapy (EVT) has the potential to decrease time to treatment and expand existing networks of care to more rural populations. It is currently unclear how its implementation would impact existing stroke networks.

METHODS

Conditional probability models were generated to predict the probability of excellent outcome for patients with suspected large vessel occlusion (LVO). A baseline stroke network was created for California using existing intravenous thrombolysis (IVT) centers and comprehensive stroke centers (CSCs) capable of IVT and EVT. Optimal transport decisions and catchment areas were generated for the baseline model and three hypothetical scenarios through conversion of IVT centers at various distances from a CSC into centers capable of telerobotic EVT [i.e., hospitals ≥15 and <50 miles from a CSC were converted (Scenario 1), ≥50 and <100 miles (Scenario 2), and ≥100 miles (Scenario 3)]. Procedural times and success rates were varied systematically.

RESULTS

Telerobotic EVT centers decreased median travel time for LVO patients in all three scenarios. The estimated number of robotically treated LVOs per year in Scenarios 1, 2, and 3 were 2,172, 740, and 212, respectively. Scenario 1 (15-50 miles) was the most sensitive to robotic time delay and success rate, but all three scenarios were more sensitive to decreases in procedural success rate compared to time delay.

CONCLUSIONS

Telerobotic EVT has the potential to improve care for stroke patients outside of major urban centers. Compared to procedural time delays in robotic EVT, a decrease in procedural success rate would not be well tolerated.

A novel intracranial exchange guidewire improves the navigation of various endovascular devices: An in vitro study of challenging situations

OBJECTIVE

Neuroendovascular procedures rely on successful navigation and stable access to the target vessel. The Stabilizer is a 300 cm long exchange wire with a 0.014 diameter and a soft, flexible stent at the distal end designed to assist with navigation and device delivery. This study aims to assess the efficacy of the Stabilizer for navigation in a variety of challenging environments.

METHODS

The efficacy of the Stabilizer was evaluated using three challenging vascular models: a giant aneurysm model, a severe tortuosity model, and an M1 stenosis model. The Stabilizer was compared with a conventional wire during navigation in each model.

RESULTS

In the giant aneurysm model, there was no significant difference of success during straightening of a looped wire and significantly higher success rates when advancing an intermediate catheter with the Stabilizer beyond the aneurysm neck compared to a conventional guidewire. The Stabilizer also significantly increased success rates when advancing an intermediate catheter through a model with severe tortuosity compared to a conventional guidewire, as well as exchange maneuver for intracranial stenting in a stenosis model compared to an exchange wire.

CONCLUSIONS

In our experimental model, the Stabilizer significantly improved navigation and device delivery in a variety of challenging settings compared to conventional wires.

The "Bright Falx" Sign-Midline Embolic Penetration Is Associated With Faster Resolution of Chronic Subdural Hematoma After Middle Meningeal Artery Embolization: A Case Series

BACKGROUND

Chronic subdural hematomas (CSDHs) are common in the elderly population and patients taking antiplatelet/anticoagulation medications. Middle meningeal artery (MMA) embolization has become an adjunctive treatment to observation and surgery. Despite many embolization techniques, best practices for optimal CSDH resolution remain unknown.

OBJECTIVE

To report a retrospective case series of MMA embolization for CSDHs regarding rate of hematoma improvement and the significance of distal embolic penetration into the falx.

METHODS

Retrospective chart review was performed on all patients who underwent MMA embolization for CSDHs between January 2017 and June 2021. Patient demographics, clinical presentation, anticoagulant use, and radiographic features were collected. Pre-embolization and postembolization computed tomography scans were analyzed for volumetric changes and assessed for midline penetration of embolic material in the falx.

RESULTS

MMA embolization was performed in 37 patients and 53 hemispheres. Older patients took longer to obtain complete resolution of CSDHs (r = 0.47, P = .03). Patients with larger pre-embolization (r = 0.57, P = .007) and postembolization (r = 0.56, P = .008) CSDH volumes took longer to completely resolve. Patients who had n-butyl cyanoacrylate embolization with midline penetration, as evidenced by the "bright falx" sign, had faster improvement rates than those who did not (5.64 cm3/d vs 1.2 cm3/d, P = .02).

CONCLUSION

Distal penetration of embolic material, particularly n-butyl cyanoacrylate, into the falx may lead to more rapid improvement of CSDH.

Critical Angiographic and Sonographic Analysis of Intra Aneurysmal and Downstream Hemodynamic Changes After Flow Diversion

Introduction

Successful treatment of intracranial aneurysms after flow diversion (FD) is dependent on the flow modulating effect of the device. We aimed to investigate the intra-aneurysmal and parent vessel hemodynamic changes, as well as the incidence of silent emboli following treatment with various FD devices.

Methods

We evaluated the appearance of the eclipse sign in nine distinct phases of cerebral angiography before and immediately after FD placement in correlation with aneurysm occlusion. Angiographic and clinical data of consecutive procedures were analyzed retrospectively. Patients who had successful FD procedure without adjunctive coiling, visible eclipse sign on post embolization angiography, and reliable follow-up angiographic data were included in the analysis. Detailed analysis of hemodynamic data from transcranial doppler after FD was performed in selected patients, such as monitoring for silent emboli.

Results

Among all patients (N = 65) who met inclusion criteria, complete aneurysm occlusion at 12 months was achieved in 89% (58/65). Eclipse sign prior to FD was observed in 42% (27/65) with unchanged appearance in 4.6% (3/65) of the treated patients. None of these three patients achieved complete aneurysm occlusion. Among all analyzed variables, such as aneurysm size, device type used, age, and appearance of the eclipse sign pre- and post-FD, the most reliable predictor of permanent aneurysm occlusion at 12 months was earlier, prolonged, and sustained eclipse sign visibility in more than three angiographic phases in comparison to the baseline (p &lt; 0.001). Elevation in flow velocities within the ipsilateral vascular territory was noted in 70% (9/13), and bilaterally in 54% (7/13) of the treated patients. None of the patients had silent emboli.

Conclusions

Intra-aneurysmal and parent vessel hemodynamic changes after FD can be reliably assessed by the cerebral angiography and transcranial doppler with important implications for the prediction of successful treatment.

Complete robotic intervention for acute epistaxis in a patient with COVID-19 pneumonia: technical considerations and device selection tips

The use of robot-assisted technology is expanding in interventional laboratories with an increasing number of reports of effective treatment delivery in neurointerventional procedures. Here we report the feasibility of complete robot-assisted neurointervention including the guide catheter and microcatheter manipulations with subsequent embolization of the arterial source of hemorrhage in a patient hospitalized with severe COVID-19 complicated by acute epistaxis.

A technical guide to robotic catheter angiography with the Corindus CorPath GRX system

Robotic catheter angiography is an emerging technology with the opportunity to increase procedural precision and decrease occupational hazards.1-5 In this video, we present our initial experiences with the CorPath GRX Robotic System (Corindus, a Seimens Healthineers Company, Waltham, Massachusetts, USA), including various technical considerations such as set-up, operation, and recommended tools (video 1). We demonstrate that the robotic system can be used to reformat catheters and select cervical arteries without the need for manual conversion. Lastly, we discuss the commonly encountered robot-specific operational challenges, along with strategies to overcome them.neurintsurg;neurintsurg-2021-018347v1/V1F1V1Video 1.

Abstract TP108: Intracranial Artery Calcification: Frequency, Determinants, And Modification Of Outcomes From Endovascular Thrombectomy

Introduction: Intracranial artery calcification (ICAC) is a common finding on CTA in patients presenting with LVO acute ischemic stroke and could potentially serve as a useful biomarker of intracranial atherosclerosis and altered intracranial vessel pliability in patients undergoing endovascular thrombectomy (EVT). However, ICAC frequency, determinants, and outcome associations have not been well delineated.

Methods: In a prospectively maintained database, we analyzed consecutive patients undergoing CTA immediately prior to EVT from Mar 2016 - Aug 2020. Extent of ICAC in the intracranial ICA or VA proximal to the target vessel was scored using a validated grading scale (Babiarz et al, AJNR 2003: 5 levels for greatest calcific thickness and 5 levels for greatest circumferential extent). Example cases in Figure 1. Patients were stratified into low (0-2), medium (3-4), and high (5-6) ICAC groups.

Results: Among 91 patients, mean age was 73, 54% female, and mean NIHSS 17. Median ICAC score was 3 [IQR 0-4]. Baseline characteristics associated with higher ICAC scores were: CAD (3.8 vs. 2.4, p = 0.02), HTN (3.1 vs. 2.1, p = 0.07), and age ( r = 0.50, p < 0.001). There was a U-shaped association between ICAC score and successful reperfusion (mTICI 2b-3): 90.9%, 65.7%, and 95.0% in low, medium, and high ICAC score groups, respectively ( p = 0.006). Need for rescue intervention (angioplasty/stenting, IA thrombolysis, or GpIIb/IIIa inhibitor) was higher in the high ICAC group: 5.9% vs. 5.6% vs. 28.6% ( p = 0.01). Functional independence (mRS 0-2) at discharge (29.4% vs. 22.2% vs. 19.0%, p = 0.64) or 90 days (40.0% vs. 30.0% vs. 21.4%, p = 0.22) did not differ, nor did symptomatic intracranial hemorrhage ( p = 0.96).

Conclusions: Calcification of intracranial vessels is frequently seen on CTA in LVO patients and is associated with age and vascular risk factors. Degree of calcification has important associations with rates of successful reperfusion and need for rescue intervention during EVT.

A new aspiration device equipped with a hydro-separator for acute ischemic stroke due to challenging soft and stiff clots

OBJECTIVE

Fragile soft clots and stiff clots remain challenging in the treatment of acute ischemic stroke. This study aims to investigate the impact of clot stiffness on the efficacy of thrombectomy devices and a new aspiration catheter with a hydro-separator.

METHODS

The Neurostar aspiration catheter has a novel hydro-separator technology that macerates clots by a stream of saline inside the catheter. The Neurostar catheter and two commercially available devices, the SOFIA aspiration catheter and Solitaire stent retriever, were tested in this study. We evaluated the efficacy of each device on clots with various stiffness in a simple in vitro model. We also assessed single-pass recanalization performance in challenging situations with large erythrocyte-rich clots and fibrin-rich clots in a realistic vascular model.

RESULTS

We observed an inverse association between the clot stiffness and recanalization rates. The aspiration catheter, SOFIA ingested soft clots but not moderately stiff clots. When removing soft clots with the stent retriever, fragmentation was observed, although relatively stiff clots were well-integrated and removed. The Neurostar ingested soft clots similar to the aspiration catheter, and also aspirated stiff clots by continuous suction with hydro-separator. In the experiments with challenging clots, the Neurostar led to significantly higher recanalization rates than the stent retriever and aspiration catheter.

CONCLUSIONS

The stiffness of the clots affected the efficacy of endovascular thrombectomy based on the type of device. The Neurostar catheter with hydro-separator resulted in better success rates than a commercially available aspiration catheter and stent retriever in this experimental model.

Endovascular biopsy of a sigmoid sinus lesion using a stent retriever and aspiration catheter

A teenager with a history of acute myeloid leukemia presented with headache, nausea and blurry vision over a 2 week period. The MRI of the brain was concerning for the presence of a myeloid sarcoma within the right sigmoid sinus. For evaluation of venous obstruction and the underlying lesion the patient underwent a cerebral angiogram and transvenous biopsy of the sigmoid sinus lesion using a stent retriever and aspiration catheter. The tissue extracted was consistent with myeloid sarcoma. This pathologic finding was consistent with the recurrence of leukemia and guided the targeted oncologic treatment.

Engineering elastic sealants based on gelatin and elastin-like polypeptides for endovascular anastomosis

Cerebrovascular ischemia from intracranial atherosclerosis remains difficult to treat. Although current revascularization procedures, including intraluminal stents and extracranial to intracranial bypass, have shown some benefit, they suffer from perioperative and postoperative morbidity. To address these limitations, here we developed a novel approach that involves gluing of arteries and subsequent transmural anastomosis from the healthy donor into the ischemic recipient. This approach required an elastic vascular sealant with distinct mechanical properties and adhesion to facilitate anastomosis. We engineered two hydrogel-based glues: an elastic composite hydrogel based on methacryloyl elastin-like polypeptide (mELP) combined with gelatin methacryloyl (GelMA) and a stiff glue based on pure GelMA. Two formulations with distinct mechanical characteristics were necessary to achieve stable anastomosis. The elastic GelMA/mELP composite glue attained desirable mechanical properties (elastic modulus: 288 ± 19 kPa, extensibility: 34.5 ± 13.4%) and adhesion (shear strength: 26.7 ± 5.4 kPa) to the blood vessel, while the pure GelMA glue exhibited superior adhesion (shear strength: 49.4 ± 7.0 kPa) at the cost of increased stiffness (elastic modulus: 581 ± 51 kPa) and reduced extensibility (13.6 ± 2.5%). The in vitro biocompatibility tests confirmed that the glues were not cytotoxic and were biodegradable. In addition, an ex vivo porcine anastomosis model showed high arterial burst pressure resistance of 34.0 ± 7.5 kPa, which is well over normal (16 kPa), elevated (17.3 kPa), and hypertensive crisis (24 kPa) systolic blood pressures in humans. Finally, an in vivo swine model was used to assess the feasibility of using the newly developed two-glue system for an endovascular anastomosis. X-ray imaging confirmed that the anastomosis was made successfully without postoperative bleeding complications and the procedure was well tolerated. In the future, more studies are required to evaluate the performance of the developed sealants under various temperature and humidity ranges.

Focused Ultrasound Ablation of an Arteriovenous Malformation Model

Brain AVMs are rare but serious vascular lesions that often pose a management dilemma between the risk of various treatment modalities and uncertain natural history during observation. We describe preliminary data on the use of focused ultrasound as a novel therapeutic strategy. In an AVM model, one session of ultrasound gradually reduced flow through the lesion without inducing rupture. Due to its non-invasive yet immediate ablative effects, focused ultrasound may allow safer treatment of AVMs. However, further studies are needed to clarify its efficacy and side effect profile.

Frequency, Determinants, and Outcomes of Emboli to Distal and New Territories Related to Mechanical Thrombectomy for Acute Ischemic Stroke

[Figure: see text].

New Class of Radially Adjustable Stentrievers for Acute Ischemic Stroke: Primary Results of the Multicenter TIGER Trial

Supplemental Digital Content is available in the text.

Background and Purpose:

The Tigertriever is a novel, radially adjustable, fully visible, stentriever that permits the operator to align radial expansion with target vessel diameters. This multicenter trial compared the Tigertriever’s effectiveness and safety compared with established stent retrievers.

Methods:

Single arm, prospective, multicenter trial comparing the Tigertriever to efficacy and safety performance goals derived from outcomes in 6 recent pivotal studies evaluating the Solitaire and Trevo stent-retriever devices with a lead-in and a main-study phase. Patients were enrolled if they had acute ischemic stroke with National Institutes of Health Stroke Scale score ≥8 due to large vessel occlusion within 8 hours of onset. The primary efficacy end point was successful reperfusion, defined as core laboratory-adjudicated modified Thrombolysis in Cerebral Ischemia score 2b-3 within 3 passes of the Tigertriever. The primary safety end point was a composite of 90-day all-cause mortality and symptomatic intracranial hemorrhage. Secondary efficacy end points included 3-month good clinical outcome (modified Rankin Scale score 0–2) and first-pass successful reperfusion.

Results:

Between May 2018 and March 2020, 160 patients (43 lead-in, 117 main phase) at 17 centers were enrolled and treated with the Tigertriever. The primary efficacy end point was achieved in 84.6% in the main-study phase group compared with the 63.4% performance goal and the 73.4% historical rate (noninferiority P<0.0001; superiority P<0.01). The first pass successful reperfusion rate was 57.8%. After all interventions, successful reperfusion (modified Thrombolysis in Cerebral Ischemia score ≥2b) was achieved in 95.7% and excellent reperfusion (modified Thrombolysis in Cerebral Ischemia score 2c-3) in 71.8%. The primary safety composite end point rate of mortality and symptomatic intracranial hemorrhage was 18.1% compared with the 30.4% performance goal and the 20.4% historical rate (noninferiority P=0.004; superiority P=0.57). Good clinical outcome was achieved in 58% at 90 days.

Conclusions:

The Tigertriever device was shown to be highly effective and safe compared with Trevo and Solitaire devices to remove thrombus in patients with large-vessel occlusive stroke eligible for mechanical thrombectomy.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03474549.

Robotic assistant spinal angiography: a case report and technical considerations

Robotic-assisted technology has shown to be promising in coronary and peripheral vascular interventions. Early case reports have also demonstrated its efficacy in neuro-interventions. However, there is no prior report demonstrating use of the robotic-assisted platform for spinal angiography. We report the feasibility of the robotic-assisted thoracic and lumbar spinal angiography.

Abstract P348: Perfusion Collateral Index vs. Hypoperfusion Intensity Ratio in Assessment of Angiographic Collateral Scores in Patients With Acute Ischemic Stroke

Background and Purpose: In acute ischemic stroke (AIS), perfusion imaging, while not directly visualizing collateral vessels, can provide important insight into collateral robustness, indexed by perfusion lesion volume and by perfusion lesion heterogeneity. Two proposed perfusion lesion heterogeneity measures indexing collateral status are the Perfusion Collateral Index (PCI) and Hypoperfusion Intensity Ratio (HIR), but their accuracy compared with direct collateral assessment on DSA has been incompletely characterized.

Methods: Consecutive AIS patients with anterior circulation large vessel occlusion who underwent pre-endovascular thrombectomy MRI perfusion imaging were included. MRI measures analyzed were: 1) Perfusion Collateral Index ( PCI) - the volume of moderately hypoperfused tissue (arterial tissue delay time between 2 and 6 seconds: ATD 2-6sec ) multiplied by its corresponding relative cerebral blood volume using Olea software; 2) Hypoperfusion Intensity Ratio (HIR) ratio of moderate TMax >6 s lesion volume versus severe Tmax >10 s lesion volume with the RAPID software program. DSA collateral scores were evaluated by ASITN grading and dichotomized to inadequate (ASTIN <2) vs. adequate (ASTIN ≥3).

Results: Among 48 patients meeting entry criteria, age (mean ± SD) was 70 (± 15.2), 54% were female, and NIHSS (median, IQR) was 15 (10-19). For HIR, there was no significant difference in score values in patients with adequate vs inadequate collaterals: 0.35 ± 0.20 vs 0.39 ± 0.25, p=0.68. ROC analysis using previously described cut-off of 0.4 resulted in an AUC of 0.52 and sensitivity/specificity of 71% / 33%. For PCI, score values were significantly higher in patients with adequate vs inadequate collaterals, 117 ± 61 vs. 57 ± 41, p=0.002. ROC analysis using previously described cut-off of 62 resulted in an AUC of 0.8 and sensitivity/specificity of 84% / 78%.

Conclusion: Collateral status can be accurately assessed on perfusion MRI with the Perfusion Collateral Index, which outperformed the Hypoperfusion Intensity Ratio. MRI-PCI is an informative imaging biomarker of collateral status in patients with AIS.

Abstract MP10: Aneurysmal Subarachnoid Hemorrhage in Pregnancy: National Trends of Treatment and Outcomes

Introduction: Aneurysmal subarachnoid hemorrhage (aSAH) is a rare event associated with significant pregnancy-associated maternal and neonatal morbidity and mortality. With advances in neurosurgical and neurocritical care, there have been significant improvement in survival and clinical outcome of patients with aSAH. We aimed to investigate the treatment utilizations and outcomes of aSAH in pregnancy.

Methods: Retrospective analysis using the Nationwide Inpatient Sample identified women 18-45 years-old hospitalized between 2010-2015. We identified pregnancy state, subarachnoid hemorrhage, and aneurysm treatments in this cohort. The mode of aneurysm treatment, mortality, and discharge destination was compared in pregnant versus non-pregnant cohorts.

Results: 9,667 aSAH with treatment were identified, of which 341 were associated with pregnancy. Mortality in the pregnancy and non-pregnancy were not different (7.37% vs 7.39%, p=0.97). However, pregnancy-related admissions were more likely to be discharged to home or short-term facility (71.9% vs 63.8%, p=0.002). Endovascular treatment for aSAH was more prevalent in pregnancy vs non-pregnancy (73% vs 66.3%, p=0.004). During the study epoch, there was a significant increase in endovascular treatment in pregnancy related aSAH (p<0.001). Surgical clipping was associated with higher mortality in pregnancy compared to non-pregnancy (15.9% vs 6.8%, p<0.001). There was no difference in mortality following endovascular treatment in pregnancy vs non-pregnancy (6.1% vs 7.8%, p=0.26). Favorable discharge outcome was significantly higher for pregnancy vs non-pregnancy with endovascular treatment (75.8% vs 63.9%, p<0.001), whereas no significant difference was observed in rate of favorable outcome for pregnancy and non-pregnancy with surgical clipping (57.9% vs 61.2%, p=0.29).

Conclusions: Pregnancy does not alter mortality from aSAH. Among interventions for aSAH, surgical clipping is associated with higher mortality in pregnancy compared to non-pregnancy. However, pregnancy is associated with more favorable discharge outcomes (vs controls) and no change in mortality in this cohort. Consideration for endovascular intervention with aSAH in this cohort should be considered.

A Review of Robotic Interventional Neuroradiology

Robotic interventional neuroradiology is an emerging field with the potential to enhance patient safety, reduce occupational hazards, and expand systems of care. Endovascular robots allow the operator to precisely control guidewires and catheters from a lead-shielded cockpit located several feet (or potentially hundreds of miles) from the patient. This has opened up the possibility of expanding telestroke networks to patients without access to life-saving procedures such as stroke thrombectomy and cerebral aneurysm occlusion by highly-experienced physicians. The prototype machines, first developed in the early 2000s, have evolved into machines capable of a broad range of techniques, while incorporating newly automated maneuvers and safety algorithms. In recent years, preliminary clinical research has been published demonstrating the safety and feasibility of the technology in cerebral angiography and intracranial intervention. The next step is to conduct larger, multisite, prospective studies to assess generalizability and, ultimately, improve patient outcomes in neurovascular disease.

[Future of Cerebral Aneurysm Treatment]

There has been an increasing role in the low invasive endovascular treatment of intracranial aneurysms. In addition to the detachable coils, the development of intracranial stents that are capable of repairing the parent artery itself has induced a significant treatment paradigm shift from open surgical to endovascular intervention. Recent evidence suggests that chronic inflammation plays a critical role in the process of intracranial aneurysm formation and rupture. It is, therefore, a natural evolution to seek drug treatments for intracranial aneurysms for growth or rupture prevention rather than any mechanical intervention. The authors review the current preclinical efforts on aneurysm drug treatments and prospective. Also covered is an emerging technology such as robotic endovascular treatment. The robotic system is capable of performing a subset of endovascular procedures such as stent-assisted aneurysm coiling. Although a lot of work needs to be done, remote health care is no longer science fiction.

Impact of eloquent motor cortex-tissue reperfusion beyond the traditional thrombolysis in cerebral infarction (TICI) scoring after thrombectomy

Background

Targeted eloquence-based tissue reperfusion within the primary motor cortex may have a differential effect on disability as compared with traditional volume-based (thrombolysis in cerebral infarction, TICI) reperfusion after endovascular thrombectomy (EVT) in the setting of acute ischemic stroke (AIS).

Methods

We explored the impact of eloquent reperfusion (ER) within primary motor cortex (PMC) on clinical outcome (modified Rankin Scale, mRS) in AIS patients undergoing EVT. ER-PMC was defined as presence of flow on final digital subtraction angiography (DSA) within four main cortical branches, supplying the PMC (middle cerebral artery (MCA) – precentral, central, postcentral; anterior cerebral artery (ACA) – medial frontal branch arising from callosomarginal or pericallosal arteries) and graded as absent (0), partial (1), and complete (2). Prospectively collected data from two centers were analyzed. Multivariate analysis was conducted to assess the impact of ER-PMC on 90-day disability (mRS) among patients with anterior circulation occlusion who achieved partial reperfusion (TICI 2a and 2b).

Results

Among the 125 patients who met the study criteria, ER-PMC distribution was: absent (0) in 19/125 (15.2%); partial (1) in 52/125 (41.6%), and complete (2) in 54/125 (43.2%). TICI 2b was achieved in 102/125 (81.6%) and ER-PMC was substantially higher in those patients (P<0.001). In multivariate analysis, in addition to age and symptomatic intracranial hemorrhage, ER-PMC had a profound independent impact on 90-day disability (OR 6.10, P=0.001 for ER-PMC 1 vs 0 and OR 9.87, P<0.001 for ER-PMC 2 vs 0), while the extent of total partial reperfusion (TICI 2b vs 2a) was not related to 90-day mRS.

Conclusions

Eloquent PMC-tissue reperfusion is a key determinant of functional outcome, with a greater impact than volume-based (TICI) degree of partial reperfusion alone. PMC-targeted revascularization among patients with partial reperfusion may further diminish post-stroke disability after EVT.

Role of Intravenous Tissue Plasminogen Activator in Acute Ischemic Stroke with Large Vessel Occlusion

OBJECTIVE

The goal of the present study was to determine the safety and efficacy of intravenous tissue plasminogen activator (IVT) in patients with acute ischemic stroke (AIS) with large vessel occlusion (LVO) undergoing mechanical thrombectomy (MT).

METHODS

We performed a retrospective analysis of prospectively collected data gathered during a 3-year period for all our patients with AIS and LVO. We analyzed the stroke outcomes and complications between patients who had received a combination of IVT and MT and those who had undergone MT only. Standardized selection criteria, including the uniform use of perfusion imaging, were used for selection for MT, irrespective of IVT administration.

RESULTS

Of the patients who had received IVT, 10% had had successful reperfusion found at initial angiography and did not require MT. A door-to-puncture time within 1 hour of presentation was achieved in 19% of both groups. IVT+MT was not associated with an increased incidence of intracranial hemorrhage (IVT+MT, 47.1%; MT, 49%). Of the 73 patients in IVT+MT group, 8 had developed access-site hematomas compared with 9 of the 95 patients in the MT group (28.6% vs. 26.5%; P = 0.85). The IVT+MT group had a lower proportion of patients with a modified Rankin scale score of 5-6 at 90 days compared with the MT group (36% vs. 56%; P = 0.024). Both groups showed statistically similar proportions of patients with a Thrombolysis in Cerebral Infarction scale score of ≥2c (IVT+MT, 50%; MT, 43%; P = 0.58). The IVT+MT group had a greater proportion of patients with Thrombolysis in Cerebral Infarction scale score of 2c (IVT+MT, 29.6%; MT, 16.8%; P = 0.068).

CONCLUSIONS

Administration of IVT before MT to patients with AIS with LVO resulted in reperfusion before MT in 10% of patients, reduced the incidence of mortality and severe disability at 90 days, did not affect the door-to-puncture time, and was associated with a similar incidence of systemic and intracranial hemorrhage compared with MT only.

Reperfusion Therapy Frequency and Outcomes in Mild Ischemic Stroke in the United States

BACKGROUND AND PURPOSE

More than half of patients with acute ischemic stroke have minor neurological deficits; however, the frequency and outcomes of reperfusion therapy in regular practice has not been well-delineated.

METHODS

Analysis of US National Inpatient Sample of hospitalizations with acute ischemic stroke and mild deficits (National Institutes of Health Stroke Scale [NIHSS] score 0-5) from October 1, 2016, to December 31, 2017. Patient- and hospital-level characteristics associated with use and outcome of reperfusion therapies were analyzed. Primary outcomes included excellent discharge disposition (discharge to home without assistance); poor discharge disposition (discharge to facility or death); in-hospital mortality; and radiological intracranial hemorrhage.

RESULTS

Among 179 710 acute ischemic stroke admissions with recorded NIHSS during the 15-month study period, 103 765 (57.7%) had mild strokes (47.3% women; median age, 69 [interquartile range, 59-79] years; median NIHSS score of 2 [interquartile range, 1-4]). Considering reperfusion therapies among strokes with documented NIHSS, mild deficit hospitalizations accounted for 40.0% of IVT and 10.7% of mechanical thrombectomy procedures. Characteristics associated with IVT and with mechanical thrombectomy utilization were younger age, absence of diabetes, higher NIHSS score, larger/teaching hospital status, and Western US region. Excellent discharge outcome occurred in 48.2% of all mild strokes, and in multivariable analysis, was associated with younger age, male sex, White race, lower NIHSS score, absence of diabetes, heart failure, and kidney disease, and IVT use. IVT was associated with increased likelihood of excellent outcome (odds ratio, 1.90 [95% CI, 1.71-2.13], P<0.001) despite an increased risk of intracranial hemorrhage (odds ratio, 1.41 [95% CI, 1.09-1.83], P<0.001).

CONCLUSIONS

In national US practice, more than one-half of acute ischemic stroke hospitalizations had mild deficits, accounting for 4 of every 10 IVT and 1 of every 10 mechanical thrombectomy treatments, and IVT use was associated with increased discharge to home despite increased intracranial hemorrhage.

Efficient Multimodal MRI Evaluation for Endovascular Thrombectomy of Anterior Circulation Large Vessel Occlusion

BACKGROUND

MRI and CT modalities are both current standard-of-care options for initial imaging in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). MR provides greater lesion conspicuity and spatial resolution, but few series have demonstrated multimodal MR may be performed efficiently.

METHODS

In a prospective comprehensive stroke center registry, we analyzed all anterior circulation LVO thrombectomy patients between 2012-2017 who: (1) arrived directly by EMS from the field, and (2) had initial NIHSS ≥6. Center imaging policy was multimodal MRI (including DWI/GRE/MRA w/wo PWI) as the initial evaluation in all patients without contraindications, and multimodal CT (including CT with CTA, w/wo CTP) in the remainder.

RESULTS

Among 106 EMS-arriving endovascular thrombectomy patients, initial imaging was MRI 62.3%, CT in 37.7%. MRI and CT patients were similar in age (72.5 vs 71.3), severity (NIHSS 16.4 v 18.2), and medical history, though MRI patients had longer onset-to-door times. Overall, door-to-needle (DTN) and door-to-puncture (DTP) times did not differ among MR and CT patients, and were faster for both modalities in 2015-2017 versus 2012-2014. In the 2015-2017 period, for MR-imaged patients, the median DTN 42m (IQR 34-55) surpassed standard (60m) and advanced (45m) national targets and the median DTP 86m (IQR 71-106) surpassed the standard national target (90m).

CONCLUSIONS

AIS-LVO patients can be evaluated by multimodal MR imaging with care speeds faster than national recommendations for door-to-needle and door-to-puncture times. With its more sensitive lesion identification and spatial resolution, MRI remains a highly viable primary imaging strategy in acute ischemic stroke patients, though further workflow efficiency improvements are desirable.

Predictors and Functional Outcomes of Fast, Intermediate, and Slow Progression Among Patients With Acute Ischemic Stroke

BACKGROUND AND PURPOSE

We aimed to delineate the determinants of the initial speed of infarct progression and the association of speed of infarct progression (SIP) with procedural and functional outcomes.

METHODS

From a prospectively maintained stroke center registry, consecutive anterior circulation ischemic stroke patients with large artery occlusion, National Institutes of Health Stroke Scale score ≥4, and multimodal vessel, ischemic core, and tissue-at-risk imaging within 24 hours of onset were included. Initial SIP was calculated as ischemic core volume at first imaging divided by the time from stroke onset to imaging.

RESULTS

Among the 88 patients, SIP was median 2.2 cc/h (interquartile range, 0-8.7), ranging most widely within the first 6 hours after onset. Faster SIP was positively independently associated with a low collateral score (odds ratio [OR], 3.30 [95% CI, 1.25-10.49]) and arrival by emergency medical services (OR, 3.34 [95% CI, 1.06-10.49]) and negatively associated with prior ischemic stroke (OR, 0.12 [95% CI, 0.03-0.50]) and coronary artery disease (OR, 0.32 [95% CI, 0.10-1.00]). Among the 67 patients who underwent endovascular thrombectomy, slower SIP was associated with a shift to reduced levels of disability at discharge (OR, 3.26 [95% CI, 1.02-10.45]), increased substantial reperfusion by thrombectomy (OR, 8.30 [95% CI, 0.97-70.87]), and reduced radiological hemorrhagic transformation (OR, 0.34 [95% CI, 0.12-0.94]).

CONCLUSIONS

Slower SIP is associated with a high collateral score, prior ischemic stroke, and coronary artery disease, supporting roles for both collateral robustness and ischemic preconditioning in fostering tissue resilience to ischemia. Among patients undergoing endovascular thrombectomy, the speed of infarct progression is a major determinant of clinical outcome.

Increased Rate of Successful First Passage Recanalization During Mechanical Thrombectomy for M2 Occlusion

BACKGROUND

Mechanical thrombectomy (MT) is the standard of care for the treatment of acute ischemic stroke (AIS) caused by anterior circulation large-vessel occlusion. However, the true safety and efficacy of MT in medium-size vessel occlusions such as the M2 segment of the middle cerebral artery have yet to be completely defined. In this study, we analyze the safety and efficacy of MT in M2 occlusions compared with M1 occlusions.

METHODS

A retrospective analysis was performed of patients with AIS secondary to M1 and M2 occlusions between 2011 and 2018. The inclusion criteria were 1) AIS secondary to M1 or M2 occlusion, 2) MT performed by stentrieval technique alone, aspiration technique, or combined stentrieval-aspiration techniques. Basic patient characteristics, number of passages, first passage recanalization success (≥TICI [Thrombolysis in Cerebral Ischemia] grade 2b), total recanalization success, hemorrhagic complications (including intracerebral hemorrhage [ICH] and subarachnoid hemorrhage), and clinical outcomes were compared between both groups.

RESULTS

Two hundred and sixty patients met the inclusion criteria; 171 patients had M1 occlusion versus 89 with M2 occlusion. First passage recanalization success rate was significantly higher in the M2 group (55.1% vs. 39.2%; P = 0.015). Total recanalization success rate was higher in the M2 group but did not reach significance (83% vs. 75%; P = 0.128). Subarachnoid hemorrhage rate was significantly higher in the M2 group (25% vs. 12%; P = 0.010) but there was no difference for ICH complications (14.6% vs. 16.4%; P = 0.711).

CONCLUSIONS

MT for M2 occlusions has similar overall efficacy to that for M1 occlusions, but with higher first-pass successful recanalization rates. MT for M2 occlusions has a higher risk of associated subarachnoid hemorrhage.

Abstract WMP27: PAT Model Accurately Predicts Aneurysm Enlargement in 16 Growing Aneurysm Cases

Objective: Imaging technology for unruptured intracranial aneurysms (UIA) has improved detection of such aneurysms. However, there is limited information on UIA change over time, and how to predict the rate of enlargement. The objective of this study was to quantify the accuracy of the Predicted Aneurysm Trajectory (PAT) model recently developed by Chien et al. (J Neurosurgery. 2019; Mar 1:1-11).

Methods: Patients diagnosed with UIA were prospectively enrolled at the UCLA Medical Center, and followed through serial imaging. 16 UIA cases exhibiting growth across multiple follow-ups were included in this study. Prior images and medical records were collected. Characteristics relevant to the PAT model (mean ± stdev), including initial UIA size (7.26 ± 6.38), patient age (67.4 ± 9.48 yrs.), sex (4 male), history of smoking (n=5), hypothyroidism (n=4), and follow-up duration (36.5 ± 50.0 mos.) were used to predict UIA size at each follow-up. Predicted and actual UIA sizes at follow-up were compared using symmetric mean absolute percentage error (SMAPE) with percentage error ranging from 0-100%.

Results: The 16 UIA cases were split by initial UIA size. For UIA smaller than 7 mm (10 cases, 23 follow-up), SMAPE = 11.13%. For UIA greater than 7 mm (6 cases, 15 follow-up), SMAPE = 8.07%. For all UIA cases (16 cases, 38 follow-up), SMAPE = 9.92%.

Conclusions: The PAT model predicts the rate of enlargement for UIA, as opposed to whether or not UIA will grow. With this new sample of data, we found the predicted UIA size at follow-up to be quite accurate, deviating in the range of 10% from the actual, measured size. Patient characteristics such as the demographics and behavior included in the model influence the growth of UIA, which allows prediction of growth to optimize treatment and management in future cases.

Abstract WP59: Cerebral Blood Flow Increase After Endovascular Thrombectomy on Perfusion Weighted Image is Associated With Hemorrhagic Transformation

Introduction: The role of increased CBF after endovascular thrombectomy in post-ischemic hyperperfusion has not been studied in detail. We aimed to investigate the timing of CBF increases on PWI after thrombectomy in association with hemorrhagic transformation.

Methods: We analyzed prospectively collected data in consecutive patients treated with endovascular thrombectomy. Inclusion criteria were: (1) patients with ICA or M1 occlusion, and (2) PWI and GRE obtained within 12 hours and 12-48 hours after thrombectomy. We compared each rCBF with early hemorrhage (within 12 hours after thrombectomy), late hemorrhage (12-48 hour) and non-hemorrhage in basal ganglia (BG) and MCA cortical or subcortical (CS) region. In each PWI dataset, ROIs were placed in two slice levels of the BG and three slice levels of the CS region.

Results: Fifty-three patients met inclusion criteria. Early BG hemorrhages were noted in 13 patients, with 4 late BG hemorrhage, 8 early CS hemorrhage and 3 late CS hemorrhage. There were no significant differences on rCBF in PWI within 12 hours after thrombectomy between early hemorrhage, late hemorrhage and non-hemorrhage groups. In contrast, rCBF on 12-48 hours PWI in the BG region was significantly higher in the early BG hemorrhage than non-BG hemorrhage (lower BG slice 1.36 vs 1.01, p<0.001, upper BG slice 1.33 vs 0.96, p<0.001) and rCBF in CS region were significantly higher in early CS hemorrhage than non-CS hemorrhage (lower CS slice 1.55 vs 0.98, p=0.001, middle CS slice 1.31 vs 0.92, p=0.018). There were no significant differences in rCBF on 12-48 hours PWI between the late hemorrhage and non-hemorrhage group.

Conclusions: Most intracerebral hemorrhages after thrombectomy were seen within 12 hours after intervention. A rCBF increase in hemorrhage cases was not seen on PWI within 12 hours after thrombectomy. rCBF increases on PWI 12-48 hours after thrombectomy, however, was associated with post-thrombectomy hemorrhage within 12 hours.

Abstract TP7: Association of Retrieved Thrombus Composition With Measures of Thrombectomy Success

Introduction: Emboli retrieved from stroke patients undergoing mechanical thrombectomy vastly differ in histopathologic appearance, likely reflecting varying etiologies of stroke. We investigated whether clot components correlated with clinical features and thrombectomy outcomes.

Methods: Retrieved thrombi from endovascular thrombectomy in consecutive AIS-LVO patients at 2 academic medical centers were fixed in formalin and sections stained by hematoxylin and eosin. The RBC, WBC and fibrin percentages of the clot were quantified by a neuropathologist blinded to the clinical details. We evaluated the association of these clot components, patient demographic and clinical features, with TICI score (both ordinal and dichotomized at 2c), AOL score, number of thrombectomy passes, and first-pass substantial recanalization (≥TICI 2b result on the first thrombectomy device pass). Non-parametric values were computed via Spearman correlation and pairwise interaction of clinical features was analyzed by ordinal logistic regression.

Results: Among the 75 analyzed patients, mean age was 71.4 (SD 17.7), 50.7% were female and presenting NIHSS mean was 16.1 (SD 7.6). Devices employed were stent retrievers in 71% of patients, aspiration in 10%, and both stent retrievers and aspiration in 19%. Number of passes per procedure was mean 2.16 (SD 1.21). Substantial reperfusion (TICI 2B-3) was achieved in 88% and excellent reperfusion (TICI 2C-3) in 44%. In retrieved thrombi, mean RBC% was 44.8% (SD 31.9) and mean fibrin% was 49.8% (SD 31.4). Rates of first-pass substantial reperfusion, final substantial reperfusion, and final excellent reperfusion were homogenous across wide ranges of retrieved thrombus RBC% and fibrin% in correlation analysis.

Conclusion: RBC and fibrin composition range widely among retrieved thrombi causing acute ischemic stroke. Current generation thrombectomy devices perform well across a broad range of clot compositions.

Abstract TP62: Frequency, Characteristics, and Outcomes of Acute Ischemic Stroke Patients With “Total Mismatch” on Penumbral Imaging Before Reperfusion Therapy

Background: When penumbral imaging shows “total mismatch” (large perfusion lesion and no irreversibly infarcted core), the entirety of jeopardized brain is still salvageable and the benefits of reperfusion therapy may be enhanced. The frequency, characteristics, and reperfusion therapy outcomes of total mismatch patients has not been well-characterized.

Methods: Analysis of consecutive acute cerebral ischemia patients in anterior circulation undergoing CT or MR penumbral imaging prior to intravenous thrombolysis (IVT) and/or endovascular thrombectomy (EVT). Patients were classified in four groups: 1) total mismatch (core 0% of perfusion lesion), 2) non-total but substantial mismatch (core 1-20% of perfusion lesion), 3) moderate or no mismatch (core 20-100% of perfusion lesion), and 4) small perfusion lesion (perfusion lesion volume <10 ml).

Results: Among 180 patients, pretreatment imaging patterns were: total mismatch 28.9%, substantial mismatch 22.8%, moderate or no mismatch 22.8%, and small perfusion lesion 25.6%. Among total mismatch patients, the Tmax>6 sec perfusion lesion volume was 56.5 ml (IQR 28.3-85.6) and time from last known well to imaging was 89 mins (IQR 65-296). Compared to moderate patients, clinical features of total mismatch patients were: older (76.0 vs 65.9, p=0.006), lower NIHSS (median 12 vs 18, p=0.019), and more cardioembolism (76.9% vs 48.8%, p=0.005). Total mismatch patients more often had CT than MR (65.4% vs 14.6%, p=0.000), less ICA occlusion (15.4% vs 34.1%, p=0.035), and smaller perfusion lesions (median 56.5 vs 82.1 ml, p=0.007). Total mismatch patients were treated with combined IVT+EVT in 32.7%, IVT alone in 26.9%, and EVT alone in 40.4%. Freedom from disability (mRS 0-1) at discharge was more frequent, 35.6% vs 16.2%, p=0.049 and disability levels at day 90 were lower in total mismatch patients, mean mRS 2.7 vs 3.9, p=0.029.

Conclusion: Total mismatch is present in one-quarter of patients undergoing reperfusion therapy, more often in older patients with cardioembolism as etiology of stroke. Total mismatch patients have better disability outcomes from reperfusion therapy, but more than half show disability indicating need for more complete reperfusion.

Abstract 170: Impact of Eloquent Motor Cortex-Tissue Reperfusion Beyond the Traditional TICI Scoring After Thrombectomy

Background: Targeted eloquence-based tissue reperfusion within the primary motor cortex may have differential effect on disability as compared to the traditional volume-based (TICI) reperfusion after endovascular thrombectomy (EVT) in setting of acute ischemic stroke (AIS).

Methods: We explored the impact of eloquent reperfusion (ER) within primary motor cortex (PMC) on clinical outcome (mRS) in AIS patients undergoing EVT. ER was defined as presence of flow on final digital subtraction angiography (DSA) within four main cortical branches, supplying the PMC (MCA - precentral, central, anterior parietal; ACA- pericallosal) and graded as absent (0), partial (1), and complete (2). Prospectively collected data from two centers were analyzed. Multivariable analysis was conducted to assess the impact of ER on 90-day disability (mRS) among patients with anterior circulation occlusion who achieved partial reperfusion (TICI 2 a and b).

Results: Among the 125 patients who met study criteria, median age was 73, median NIHSS was 16, median ASPECTS was 7, 48% (60/125) were female, and 36.8% achieved functional independence (mRS 0-2) at 90 days. ER distribution was: Absent (0) in 19/125 (15.2%); Partial (1) in 52/125 (41.6%), and Complete (2) in 54/125 (43.2%). TICI 2b was achieved in 102/125 (81.6%) and ER was substantially higher in those patients (p<0.001). In multivariate analysis, in addition to age and sICH, ER had a profound independent impact on 90-day disability (OR 6.10, p=0.001 for ER 1 vs 0; and OR 9.87, p<0.001 for ER 2 vs 0). In contrast, extent of total partial reperfusion (TICI 2b vs 2a) was not related to 90-day disability.

Conclusions: Our findings support that eloquent PMC-tissue reperfusion is a major determinant of functional outcome, more impactful than volume-based degree of partial reperfusion. More aggressive, PMC-targeted revascularization among patients with non-eloquent partial reperfusion may further improve post-stroke disability after EVT.

Abstract WP66: Impaired Collaterals Are Associated With Intracranial Thrombus Extension: Evidence From MRI, Catheter Angiography, and Retrieved Thrombus Composition

Background: Clot propagation after initial occlusion may increase target thrombus burden and its pathophysiologic basis has not been extensively studied in acute human ischemic stroke. We investigated whether clot characteristics on MRI, catheter angiography, and thrombus histopathology indicated that impaired collaterals may be associated with extension of acute intracranial occlusions via stasis clotting in slow flow arterial segments.

Methods: Analysis of consecutive AIS-LVO endovascular thrombectomy patients at 2 academic medical centers with: 1) pretreatment MRI, and 2) retrieved thrombi. GRE MR susceptibility vessel sign presence and extent of ASITN collateral scores were rated by blinded assessors. Extracted clots were fixed in formalin, stained by hematoxylin and eosin, and RBC, WBC and fibrin percent composition quantified by a neuropathologist blinded to clinical details. We evaluated the correlation of collateral grade with clot size by susceptibility vessel sign (SVS) and clot composition by RBC%. Non-parametric values were computed via Spearman correlation.

Results: Among the 48 patients, mean age was 71.4 (SD 17.7), 56.3% female, and mean presenting NIHSS was 15.5 (SD 7.41). A susceptibility vessel sign was present in 65%, with mean SVS length 15.6 mm (SD 8.3). Collateral scores were mean 2.3 (SD 1.2). The number of passes per procedure was mean 1.98 (SD 1.30) The presence of a susceptibility vessel sign correlated with higher RBC% in retrieved thrombi (r s =0.36 p=0.011). Worse collateral grades correlated with longer SVS length (r s =-0.50 p=0.004) and greater SVS width (r s =-0.54 p=0.002). Worse collateral grade also trended toward correlation with higher RBC% in retrieved clots (r s =-0.19 p=0.18).

Conclusion: Impaired angiographic collaterals are associated with longer RBC-rich thrombi on susceptibility imaging and trend toward association with higher RBC% in retrieved thrombi. These findings support that, in LVO acute ischemic stroke, clot propagation after initial occlusion occurs by stasis clotting accelerated by impaired collaterals.

Abstract WP111: The Role of Intravenous Tissue Plasminogen Activator in Acute Ischemic Stroke With Large Vessel Occlusion

Introduction: Current guidelines recommend administration of intravenous tissue plasminogen activator (IVT) for all eligible patients with acute ischemic stroke (AIS) with large vessel occlusion (LVO). Recent observational data question the safety and efficacy of IVT in AIS patients with LVO undergoing mechanical thrombectomy (MT).

Methods: Retrospective analysis using prospectively collected database on all AIS patients with LVO treated at our institution over 3 consecutive years. Stroke outcomes and adverse events were compared between patients who underwent IVT+MT versus MT only. Stroke outcomes were adjusted for known comorbidities, last know well time and core volume on pretreatment imaging.

Results: 158 AIS patients with LVO were treated. 69 patients had treatment strategy of IVT+MT, 89 patients MT only. 7 (10%) patients treated with IVT had successful reperfusion before MT. IVT+MT, compared with MT alone, was associated with reduced 90day mortality (22.4% vs 40.8%, p:0.03) and reduced 90day severe disability or death (mRS 4-6: 48% vs 67%, p:0.03). Door-to-puncture time (DTP) was longer with IVT. IVT was not associated with increased intracranial hemorrhage but was associated with increased access site hematomas (16.9% vs 5.7%, p:0.03). Both groups showed similar proportion of patients ≥TICI2c (IVT+MT: 48% vs MT: 47%), however IVT+MT patients had greater proportion of TICI2c than TICI3. (IVT+MT TICI2c:30.4% vs MT TICI2c:17%)

Conclusions: IVT before MT in AIS with LVO, results in reperfusion prior to thrombectomy in 10% of patients, and is associated with reduced mortality and severe disability at 90days. However, IVT+MT is associated with more access site hematomas and increased TICI 2C vs TICI 3 reperfusion, suggesting increased distal embolization due to thrombus fragmentation. The use of balloon guide for proximal flow arrest and aspiration during thrombectomy should be considered.