Abstract Number ‐ 123: Retained microvascular wire during acute stroke thrombectomy and stenting.

Introduction There is limited information on retained wires during neuro interventional ischemic cases, although there is a wealth of information on cardiac cases. Retained wires can present with thrombosis, perforation, or may be followed for longer period of time, with no complications. Changes in outcome vary on the ability of the wire to migrate, the size of the vessel adjacent to the wire, and the difficulty in retrieving the retained item. Methods We present a case report on a 56‐year‐old man who presented in 2018 with a left internal carotid occlusion horizontal petrous level, with no early signs of stroke on CT, and 106 mL penumbra on CT perfusion (CTP), with dense expressive and receptive aphasia. Results Patient developed hemiparesis while sitting sitting up, and drops in blood pressure, below the presenting blood pressure of 200 over 100 mmHg. The patient was taken for emergent thrombectomy. Patient underwent petrous thrombectomy with a residual high grade stenosis. This was followed by cavernous angioplasty, and Wingspan stenting. We attempted to cross the stenosis with a Gateway balloon and Synchro2 microwire. The wire tip was trapped and separated after extensive rotation, with a retained 5 mm tip. After inspecting the wire, there is no clear evidence of any a retained product. The tip was secured with a Wingspan stent. After thrombectomy and stenting aphasia improved. Four days later the patient developed worsening aphasia, and was found to have stent reocclusion. During CT angiography (CTA) it became apparent that a small wire extended from the left internal carotid petrous segment at the level of the wingspan stent down to the descending aorta. CT angiography of the chest and abdomen after reperfusion found that the wire was anchored in the left internal carotid, and extended down to the renal artery. Thrombus was aspirated, and ICA reconstructed with coronary stents in the petrous, and self‐expanding stents in the cervical segments, with TICI 3 reperfusion. Follow‐up imaging with CT chest and abdomen at six months, one year, and four years found the wire to be still anchored to the left internal carotid stent, and stable in the superior mesenteric artery. There is no evidence of thrombus formation, or distal embolization. We examined a Synchro2 microwire ex vivo were able to detach the tip, and have the inner core unravel up to a meter in length. Given that the wire shaft did not appear to be altered, the retained product was likely an unraveled inner core. Conclusions Retained neurovascular products can predispose to reocclusion, and should be secured. Once secured the course can be benign. When a wire with a wound core is fractured, unwound core can remain behind with the wire appearing as if it has been fully retrieved

Abstract 1122‐000027: Bilateral Vertebral Artery Occlusion and Involvement of the Posterior Circulation

Introduction: Rationale: Bilateral vertebral artery occlusion with collateral reconstitution is a rare finding. Compared to patients with acute occlusion, symptom progression may be much slower [1]. Atherosclerotic risk factors lead to occlusion, including hypertension and hyperlipidemia, but it is unclear what leads to collateral reconstitution [2]. These patients may have collateral circulation from anterior and posterior circulation sources that are well developed [1] [2]. Sufficient collateral flow correlates with lower rates of hemorrhagic transformation following recanalization [3] [4]. However, given the risk of spontaneous hemorrhage from microvascular collaterals, the hemorrhagic risk associated with thrombolytic therapy in patients with moyamoya collaterals, due to the fragility of these vessels [5], must be balanced with the benefit of therapy in the presence of severe neurologic deficits along with the mortality and morbidity that may stem from the occlusion. Patient concerns: 67 year old Caucasian male with past medical history of coronary artery disease, abdominal aortic aneurysm, hypertension, history of tobacco use and type 2 diabetes mellitus presents with acute right‐sided weakness. Methods: Diagnoses: On admission, CTA Head and Neck suggested chronic total occlusion of bilateral V4 segments from their origin to the midportion with tandem bilateral high‐grade stenoses throughout the imaged distal V2 and V3 segments bilaterally. MRI could not be obtained because of old lumbar fusion spinal hardware. Cerebral angiography showed microvascular reconstitution, analogous to moyamoya, with slow mid basilar flow, which could be either due to occlusion or competitive flow from top of the basilar collaterals. Interventions: Patient received intra‐arterial integrilin and tPA thrombolysis with TICI 1 reperfusion. Results: Outcomes: Patient presented with NIHSS 18 notable for right sided weakness (2/5 strength in his right upper extremity and 1/5 strength in RLE), bilateral hemianopia, severe dysarthria and right gaze preference. Patient had significant improvement in his exam the next day following thrombolysis. Notably, patient had 5/5 strength in his right upper and right lower extremities compared to his strength on presentation. Repeat head CT on the following day after thrombolysis showed left pontine infarct. Repeat NIHSS was 3 at 24 hours for partial hemianopia, minor nasolabial flattening and mild dysarthria. Conclusions: Conclusion: Bilateral intracranial vertebral artery stenosis and occlusion commonly occurs distal to PICA and near the vertebrobasilar junction [2]. Proximal (specifically areas supplied by PICA) and distal territories within the posterior circulation are often infarcted [2], which can yield a unique exam upon presentation that can help accurately guide diagnosis and treatment when appropriately recognized. The involvement of collateral circulation can play a crucial role in patients undergoing endovascular revascularization therapy [6]. In the setting of bilateral vertebral occlusion with microvascular reconstitution, patients can still undergo catheter based thrombolysis, but not thrombectomy

Abstract 1122‐000021: Delayed Vasospasm and Cerebral Ischemia Following Mild Traumatic Brain Injury

Introduction: Post‐traumatic vasospasm (PTV) is a significant cause of morbidity and mortality following traumatic brain injury (TBI).1 Delayed PTV is thought to occur due to inflammation from SAH.1 The risk of symptomatic PTV is associated with the severity of TBI.1,2,3 Treatment of PTV traditionally involves agents used in aneurysmal vasospasm such as Nimodipine. Intra‐arterial and intravenous verapamil and milrinone have been utilized to treat PTV.4 We present a rare case of delayed cerebral ischemia caused by PTV without SAH treated with intra‐arterial milrinone and oral verapamil. Methods: This is a case report of a case of a 16‐day delay of cerebral ischemia secondary to PTV. Results: A 19‐year‐old female without significant medical history presented to the emergency room as the restrained driver in a motor vehicle collision involving a car versus a tree. The patient’s Glasgow Coma Scale score was 13 and the initial head CT did not demonstrate SAH with a Rotterdam score of 0. There were multiple fractures and soft tissue contusions noted on imaging which required surgical correction and splinting. The patient’s hospital stay was complicated by a large retroperitoneal hematoma requiring blood transfusions and surgical evacuation. 16 days after admission, the patient experienced sudden‐onset right upper extremity paralysis and weakness of the right leg. CT head demonstrated loss of gray‐white differentiation in the left middle cerebral artery (MCA) territory and CT angiography demonstrated 70% stenosis of the left supra‐clinoid internal carotid artery (ICA) and proximal left MCA. Cerebral angiography demonstrated 60% stenosis left supra‐clinoid ICA and 60% stenosis at the origin of the left MCA consistent with PTV. Left MCA stenosis improved to 20% post 10 mg intra‐arterial milrinone in the left ICA (Figure 1). The patient also received verapamil orally. Transcranial doppler demonstrated elevated peak systolic velocities at 298 cm/s in the left MCA and 276 cm/s in the left ICA. Six days later this improved to 150 cm/s in the left MCA and 151 cm/s in the left ICA. The patient continued to be unable to move her right side against gravity with dense expressive aphasia and dysarthria at discharge to inpatient rehabilitation. At follow‐up 4 weeks later, her right hemiparesis had improved significantly to being able to stand with assistance and her expressive aphasia had improved from one word to occasionally forming several word sentences. Conclusions: PTV is a potentially devastating complication of TBI. As our case demonstrates, the presence of mild TBI and absence of SAH may be falsely reassuring.2 Additionally, our case report demonstrates that intra‐arterial milrinone causes radiographic improvement in PTV. Further studies are needed for the best screening and diagnostic exams for PTV and therapeutic interventions

Abstract Number ‐ 26: Results from Flat‐Panel CT as a predictor following Mechanical Thrombectomy

Introduction Flat‐panel CT provides quick and effective parenchymal cross‐sectional imaging. Pre‐thrombectomy, flat‐panel can be obtained to evaluate ischemic stroke patients for thrombectomy candidacy in cases where the traditional CT scanner is bypassed. Post‐thrombectomy images obtained from flat‐panel CT are also effective in evaluating complications such as contrast extravasation, hemorrhage, or increased core size. Findings on flat‐panel CT may provide information to guide decisions such as blood pressure goals, antiplatelet or anticoagulation regimen, thrombolytic reversal, and the need for emergent neurosurgical intervention in rare cases. Methods We analyzed 93 thrombectomy cases from 2021 to 2022, where flat‐panel CT was obtained, with follow‐up CT and MRI. Demographics were reviewed for this series of cases. Cases where stratified and compared depending on results on flat‐panel CT. Medical records were reviewed for changes in management. The local IRB approved the project, and consent was waived according to institutional guidelines. Results For our patient population, the median age was 70; race was 59% Caucasian, 40% African American, and 1% Hispanic; and gender was 46% female and 54% male. From the flat‐panel CT, we had the following results: Flat‐panel CT was normal in 68% of cases, 20% had contrast extravasation, 9% showed evidence of contrast extravasation vs. hemorrhage, 2% had hemorrhage during the procedure, and 1% had contrast retained in the vessels. On follow‐up CT, 35% had no change, 16% had contrast extravasation, 8% had SAH, 4% had contrast extravasation vs. hemorrhage, 3% had hemorrhagic transformation, 1% had IVH, 1% had petechial hemorrhages, and 31% had no follow‐up CT. On MRI, 20% had hemorrhagic transformation, 41% had no hemorrhage, 6% had microhemorrhages, 10% had petechial hemorrhages, 2% had ICH, 1% had 1 IVH, 1% had SAH, 1% had contrast extravasation, 17% of the cases had no follow‐up MRI. Based on flat‐panel CT, results for normal and contrast extravasation were as follows (Table 1.). Therapy was altered by the flat‐panel CT results in 10 cases. The main change in therapy was a delay in restarting antiplatelet and anticoagulation therapy, which took place in 9 cases. Conclusions Post thrombectomy flat‐panel CT is a useful screen post thrombectomy for high‐risk findings such as contrast extravasation and hemorrhagic transformation. Further studies are needed to determine ideal management in cases of contrast extravasation or hemorrhage on flat‐panel CT

CF45-1, a Secreted Protein Which Participates in Dictyostelium Group Size Regulation

Developing Dictyostelium cells aggregate to form fruiting bodies containing typically 2 × 10(4) cells. To prevent the formation of an excessively large fruiting body, streams of aggregating cells break up into groups if there are too many cells. The breakup is regulated by a secreted complex of polypeptides called counting factor (CF). Countin and CF50 are two of the components of CF. Disrupting the expression of either of these proteins results in cells secreting very little detectable CF activity, and as a result, aggregation streams remain intact and form large fruiting bodies, which invariably collapse. We find that disrupting the gene encoding a third protein present in crude CF, CF45-1, also results in the formation of large groups when cells are grown with bacteria on agar plates and then starve. However, unlike countin(−) and cf50(−) cells, cf45-1(−) cells sometimes form smaller groups than wild-type cells when the cells are starved on filter pads. The predicted amino acid sequence of CF45-1 has some similarity to that of lysozyme, but recombinant CF45-1 has no detectable lysozyme activity. In the exudates from starved cells, CF45-1 is present in a ∼450-kDa fraction that also contains countin and CF50, suggesting that it is part of a complex. Recombinant CF45-1 decreases group size in colonies of cf45-1(−) cells with a 50% effective concentration (EC(50)) of ∼8 ng/ml and in colonies of wild-type and cf50(−) cells with an EC(50) of ∼40 ng/ml. Like countin(−) and cf50(−) cells, cf45-1(−) cells have high levels of cytosolic glucose, high cell-cell adhesion, and low cell motility. Together, the data suggest that CF45-1 participates in group size regulation in Dictyostelium

Stent Retriever-Mediated Manual Aspiration Thrombectomy for Acute Ischemic Stroke

BACKGROUND AND PURPOSE: Stent retriever thrombectomy and manual aspiration thrombectomy (MAT) have each been shown to lead to high rates of recanalization as single-modality endovascular stroke therapy. We sought to describe the safety and efficacy of a multimodal approach combining these two techniques termed \u27stent retriever-mediated manual aspiration thrombectomy\u27 (SMAT) and compared them to MAT alone. METHODS: Retrospective review of a prospectively acquired acute endovascular stroke database. RESULTS: 195 consecutive patients with large-vessel occlusion were identified between July 2013 and April 2015. Occlusion distribution was as follows: 52% middle cerebral artery segment 1 (M1), 6% M2, 29% internal carotid artery, and 13% vertebrobasilar. Median onset to treatment time was 278 min. Intravenous rtPA was administered in 33% of cases, whereas 34% of cases had symptom onset beyond 8 h. Effective recanalization (TICI 2b/3) was achieved in 91% of patients and in 49% of patients, only a single pass was necessary. Median groin puncture to recanalization time was 40 min. Symptomatic intracerebral hemorrhage occurred in 5% of patients. Favorable outcomes defined as a modified Rankin Scale score of 0-2 were noted in 42% of patients. Compared with MAT alone, SMAT achieved a similar rate of effective recanalization (91 vs. 88%, p = n.s.) but was associated with faster access to reperfusion times (49 vs. 77 min, p \u3c 0.00001). CONCLUSIONS: SMAT is a safe and efficacious method to achieve rapid revascularization that leads to faster recanalization compared to manual aspiration alone. Future prospective comparisons are necessary to establish the most clinically effective therapy for acute thrombectomy

Perfusion imaging predicts favorable outcomes after basilar artery thrombectomy

Objective: Perfusion imaging identifies anterior circulation stroke patients who respond favorably to endovascular thrombectomy (ET), but its role in basilar artery occlusion (BAO) is unknown. We hypothesized that BAO patients with limited regions of severe hypoperfusion (time to reach maximum concentration in seconds [Tmax] &gt; 10) would have a favorable response to ET compared to patients with more extensive regions involved. Methods: We performed a multicenter retrospective cohort study of BAO patients with perfusion imaging prior to ET. We prespecified a Critical Area Perfusion Score (CAPS; 0-6 points), which quantified severe hypoperfusion (Tmax &gt; 10) in cerebellum (1 point/hemisphere), pons (2 points), and midbrain and/or thalamus (2 points). Patients were dichotomized into favorable (CAPS ≤ 3) and unfavorable (CAPS &gt; 3) groups. The primary outcome was a favorable functional outcome 90 days after ET (modified Rankin Scale = 0-3). Results: One hundred three patients were included. CAPS ≤ 3 patients (87%) had a lower median National Institutes of Health Stroke Scale score (NIHSS; 12.5, interquartile range [IQR] = 7-22) compared to CAPS &gt; 3 patients (13%; 23, IQR = 19-36; p = 0.01). Reperfusion was achieved in 84% of all patients, with no difference between CAPS groups (p = 0.42). Sixty-four percent of reperfused CAPS ≤ 3 patients had a favorable outcome compared to 8% of nonreperfused CAPS ≤ 3 patients (odds ratio [OR] = 21.0, 95% confidence interval [CI] = 2.6-170; p &lt; 0.001). No CAPS &gt; 3 patients had a favorable outcome, regardless of reperfusion. In a multivariate regression analysis, CAPS ≤ 3 was a robust independent predictor of favorable outcome after adjustment for reperfusion, age, and pre-ET NIHSS (OR = 39.25, 95% CI = 1.34-&gt;999, p = 0.04). Interpretation: BAO patients with limited regions of severe hypoperfusion had a favorable response to reperfusion following ET. However, patients with more extensive regions of hypoperfusion in critical brain regions did not benefit from endovascular reperfusion. ANN NEUROL 2022;91:23-32.</p

Streamlining door to recanalization processes in endovascular stroke therapy

BACKGROUND: In acute stroke due to large vessel occlusion, faster reperfusion leads to better outcomes. We analyzed the effect of optimization steps aimed to reduce treatment delays at our center. METHODS: Consecutive patients with ischemic stroke treated with endovascular therapy were prospectively analyzed. We divided the patients into pre-optimization (20 April 2012 to 8 October 2013) and post-optimization (9 October 2013 to 29 July 2014) periods. The main interventions included: (1) continuous feedback; (2) standardized immediate emergency department attending to stroke attending communication with interventional team activation for all potential interventions; (3) pre-notification by the emergency medical service; (4) minimizing additional diagnostic testing; (5) direct transport to the CT scanner; (6) transport directly from the CT scanner to the angiography suite. The main metric used to measure improvement was door to groin puncture time (D2P). RESULTS: We included a total of 286 patients (178 pre-optimization, 108 post-optimization). There were no significant differences between major baseline characteristics between the groups with the exception of higher median CT Alberta Stroke Program Early CT Score in the pre-optimization group (p=0.01). Median D2P improved from 105 min pre-optimization to 67 min post-optimization (p=0.0002). Rates of good clinical outcomes (modified Rankin Scale 0-2 at 3 months) were similar in both groups, with a trend toward a better outcome in the post-optimization group in a subgroup analysis of patients with anterior circulation occlusion who received intravenous tissue plasminogen activator. CONCLUSIONS: This pilot study demonstrates that D2P times can be significantly reduced with a standardized multidisciplinary approach. There was no significant difference in the rate of 3-month good outcome, which is most likely due to the small sample size and confounding baseline patient characteristics