Hamed Farid

Sequence-specific MR Imaging Findings That Are Useful in Dating Ischemic Stroke

Patients may present to the hospital at various times after an ischemic stroke. Many present weeks after a neurologic deficit has occurred, as is often the case with elderly patients and those in a nursing home. The ability to determine the age of an ischemic stroke provides useful clinical information for the patient, his or her family, and the medical team. Many times, perfusion imaging is not performed, and pulse sequence-specific magnetic resonance (MR) imaging findings may help determine the age of the infarct. The findings seen at apparent diffusion coefficient mapping and diffusion-weighted, fluid-attenuated inversion recovery (FLAIR) and unenhanced and contrast material-enhanced T1- and T2-weighted gradient-echo and susceptibility-weighted MR imaging may help determine the relative age of a cerebral infarct. Strokes may be classified and dated as early hyperacute, late hyperacute, acute, subacute, or chronic. Recent data indicate that in many patients with restricted diffusion and no change on FLAIR images, it is more likely than was initially thought that the stroke is less than 6 hours old. The time window to administer intravenous tissue plasminogen activator is currently 4.5 hours from the time when the patient was last seen to be normal, and for anterior circulation strokes, the time window for administering intraarterial tissue plasminogen activator is 6 hours from when the patient was last seen to be normal. For this reason, accurate dating is important in patients with ischemic stroke.

Mechanical embolectomy for treatment of large vessel acute ischemic stroke in children.

Background and purpose The three largest adult stroke trials investigating mechanical embolectomy retrieval devices in acute stroke (the Merci, Multi Merci and Penumbra Pivotal Stroke Trials) excluded children. There is a need to expand the literature on mechanical embolectomy in large vessel pediatric arterial ischemic stroke. This paper reports the use of two mechanical embolectomy devices cleared by the Federal Drug Administration (FDA) in four consecutive cases. Methods Our pediatric stroke database from 2002 to the present was reviewed retrospectively. Patients were included if they were diagnosed with an acute large vessel occlusion, were <18 years of age and underwent recanalization with a device cleared by the FDA. Clinical and radiographic results were abstracted from medical record review. The Pediatric National Institutes of Health Stroke Scale (PedNIHSS) score at presentation and at discharge and a pediatric-modified Rankin Scale (Ped-mRS) at approximately 90 days were scored retrospectively based on documented examinations. Results Four patients aged 4–17 years with a PedNIHSS score at presentation ranging from 2 to 17 points underwent mechanical embolectomy for reperfusion of the basilar artery (n=3), M1 segment of the right middle cerebral artery (n=1) and right internal carotid artery terminus (n=1). Thrombolysis in cerebral infarction (TICI) grade 3 was achieved in four vessels and TICI grade 2A was achieved in one vessel; there was one asymptomatic intraparenchymal hemorrhage. Intra-arterial tissue plasminogen activator was administered in two vessels. The PedNIHSS score at discharge ranged from 0 to 16 points and the Ped-mRS score at approximately 90 days ranged from 0 to 3 with 75% achieving a Ped-mRS score of ≤2. Conclusion Mechanical embolectomy using the Merci and Penumbra systems may be a feasible therapeutic option in the treatment of large vessel pediatric arterial ischemic stroke.

Transvenous embolization of a pediatric pial arteriovenous fistula

Pial arteriovenous fistulas (AVFs) are a rare, although clinically significant, vascular anomaly affecting the pediatric population. There are few retrospective case series describing their epidemiological, clinical and radiographic characteristics as well as technical elements of treatment. Combined transarterial and transvenous embolization of a 12 month old female with a multi-hole pial AVF is described. The patient underwent treatment in a staged fashion and without neurological complication.

TREVO stent-retriever mechanical thrombectomy for acute ischemic stroke secondary to large vessel occlusion registry

Background Recent randomized clinical trials (RCTs) demonstrated the efficacy of mechanical thrombectomy using stent-retrievers in patients with acute ischemic stroke (AIS) with large vessel occlusions; however, it remains unclear if these results translate to a real-world setting. The TREVO Stent-Retriever Acute Stroke (TRACK) multicenter Registry aimed to evaluate the use of the Trevo device in everyday clinical practice. Methods Twenty-three centers enrolled consecutive AIS patients treated from March 2013 through August 2015 with the Trevo device. The primary outcome was defined as achieving a Thrombolysis in Cerebral Infarction (TICI) score of ≥2b. Secondary outcomes included 90-day modified Rankin Scale (mRS), mortality, and symptomatic intracranial hemorrhage (sICH). Results A total of 634patients were included. Mean age was 66.1±14.8 years and mean baseline NIH Stroke Scale (NIHSS) score was 17.4±6.7; 86.7% had an anterior circulation occlusion. Mean time from symptom onset to puncture and time to revascularization were 363.1±264.5 min and 78.8±49.6 min, respectively. 80.3% achieved TICI ≥2b. 90-day mRS ≤2 was achieved in 47.9%, compared with 51.4% when restricting the analysis to the anterior circulation and within 6 hours (similar to recent AHA/ASA guidelines), and 54.3% for those who achieved complete revascularization. The 90-day mortality rate was 19.8%. Independent predictors of clinical outcome included age, baseline NIHSS, use of balloon guide catheter, revascularization, and sICH. Conclusion The TRACK Registry results demonstrate the generalizability of the recent thrombectomy RCTs in real-world clinical practice. No differences in clinical and angiographic outcomes were shown between patients treated within the AHA/ASA guidelines and those treated outside the recommendations.

Zygomatico-orbital intra-arterial melphalan infusion for intraocular retinoblastoma

Retinoblastoma is a rare and curable malignancy affecting the pediatric population. For advanced stage intraocular retinoblastoma, enucleation remains the primary treatment modality, although the use of laser photocoagulation, cryotherapy, radiotherapy and chemotherapy are frequently used, particularly in the setting of bilateral disease. Intravenous chemotherapy is the long-standing method of delivery, but local administration (subtenon, intravitreal or intra-arterial) is gaining in popularity because of the reduced side effects related to systemic administration. Of these newer methods, intra-arterial infusion has demonstrated technical feasibility, few procedural complications and robust tumor response. A case is described where a collateral supply to the affected ophthalmic artery was via the zygomatico-orbital branch of the ipsilateral superficial temporal artery. Melphalan infusion was performed via this pathway without incident.

O-004 Analysis of M2 Occlusions within TREVO Acute Ischemic Stroke (TRACK) stent-retriever Thrombectomy Registry

Background and purpose Several recent randomized clinical trials have demonstrated the safety and efficacy of mechanical thrombectomy with stent retrievers for acute ischemic stroke patients with anterior circulation occlusions. However, these trials have limited enrollment of patients with M2 occlusions. Here, we sought to examine the clinical and angiographic outcomes of patients with M2 occlusions in the Trevo Acute Ischemic Stroke (TRACK) stent-retriever thrombectomy multicenter registry. Methods Data from the investigator-initiated TRACK Registry (631 consecutive AIS patients, 23 clinical centers) was used to examine and compare demographic, clinical, and angiographic outcomes of patients with M1 versus M2 occlusions who were treated with TREVO as first treatment device. Results Of the 631 patients enrolled in the TRACK registry, 84 (13.3%) had M2 and 344 (54.5%) had M1 occlusions. Mean age was similar between the M1 and M2 cohorts, 66.5 ± 14.4 and 64.7 ± 3.8 years (p = 0.34), respectively. M2 patients had a lower median baseline NIHSS at presentation (14 (IQR 7–9) versus 18(IQR 14–22), p ≤ 0.0001). Time of onset to groin puncture (347 ± 237.4 and 361 ± 232.3, p = 0.63) and total procedural time (85.9 ± 49.9 and 78.3 ± 64.5, p = 0.4) was similar between the M1 and M2 cohorts. The number of passes with TREVO device was greater in the M1 cohort (Median, 2 (IQR 1–3) versus 1(IQR 1–2), p = 0.01) as well as use of rescue therapy (20.2% versus 9.8%, p = 0.03). Patients with M2 occlusions achieved a higher rate of TICI 3 revascularization after the 1st pass with TREVO device compared to those with M1 occlusions (55.8% versus 40.4%, p = 0.01). There was no significant difference in time to revascularization (78.6 ± 50.7 versus 71.6 ± 45.3, p = 0.2), revascularization success (≥TICI 2 b) (80.5% versus 76.2%, p = 0.4), symptomatic intracranial hemorrhage (5.6% versus 6.0%, p = 0.9), 90 day modified Rankin Scale score 0–2 (51.0% versus 57.4%, p = 0.35), or mortality (16.1% versus 13.2%, p = 0.6) between the M1 and M2 groups, respectively. Conclusions Patients with M2 Occlusions are more likely to achieve complete recanalization from the first pass with Trevo stent retriever device than M1 occlusion. In addition, the M2 cohort had a numerically higher rate of good clinical outcome and less rate of mortality than M1 group. This substudy is limited by lack of a control M2 group without mechanical thrombectomy. Disclosures A. Castonguay: None. R. Nogueira: None. J. English: None. S. Satti: None. H. Farid: None. E. Veznedaroglu: None. M. Binning: None. A. Puri: None. N. Vora: None. R. Budzik: None. G. Dabus: None. I. Linfante: None. V. Janardhan: None. A. Alshekhlee: None. M. Abraham: None. R. Edgell: None. M. Taqi: None. R. El Khoury: None. M. Mokin: None. M. Mokin: None. A. Majjhoo: None. M. Kabbani: None. M. Froehler: None. I. Finch: None. S. Ansari: None. R. Novakovic: None. T. Nguyen: None. O. Zaidat: None.

Real-world stent retriever thrombectomy for acute ischemic stroke beyond 6 hours of onset: analysis of the NASA and TRACK registries

Background The DEFUSE 3 and DAWN trials have shown the benefit of thrombectomy beyond 6 hours of stroke symptom onset in carefully selected patients. Objective To evaluate the real-world outcomes of stent retriever thrombectomy beyond 6 hours of stroke onset using combined individual patient data from the North American Solitaire Stent Retriever Acute Stroke (NASA) and Trevo Stent-Retriever Acute Stroke (TRACK) registries. Methods Pooled analysis of individual patient data of all cases of anterior circulation acute ischemic stroke (AIS) from NASA and TRACK was performed to compare outcomes of patients presenting within the first hours 6 or beyond 6 hours of stroke symptom onset. Results Of 830 patients with anterior circulation AIS from the NASA and TRACK registries, 32.7% (271 patients) underwent thrombectomy beyond the first 6 hours of symptom onset. The rates of good clinical outcome (modified Rankin scale score of 0–2 at 90 days), mortality, and symptomatic intracranial hemorrhage were similar: 48.1%, 20.6%, and 8.0% within 0–6 hours, 46.2%, 21.6%, and 10.9% within 6–16 hours, and 38.9%, 33.3%, and 5% within 16–24 hours (p=0.8, 0.6, and 0.5, respectively). The rates of successful recanalization (Thrombolysis in Cerebral Infarction 2b/3) were 79.4% in patients with stroke within 0–6 hours, 72.6% within 6–16 hours, and 85.0% within 16–24 hours (p=0.04). Conclusions Real-world experience with patients with anterior circulation AIS treated with the Solitaire and Trevo thrombectomy devices beyond the first 6 hours of symptom onset proved to be equally safe and effective as for patients with symptom onset within the first 6 hours.

Sequenzspezifische MR-Bildgebungsbefunde als Hilfsmittel zur Datierung des ischämischen Schlaganfalls

Nach einem ischamischen Schlaganfall kommen Patienten zu unterschiedlichen Zeitpunkten ins Krankenhaus. Viele werden erst Wochen nach Auftreten von neurologischen Ausfallerscheinungen vorstellig. Dies ist oft bei alteren Patienten und Patienten in Pflegeheimen der Fall. Die Altersbestimmung eines ischamischen Schlaganfalls bietet Patienten, deren Familien und dem medizinischen Team hilfreiche klinische Informationen. Haufig wird keine Perfusionsbildgebung durchgefuhrt; dann konnen die Befunde der pulssequenzspezifischen Magnetresonanzbildgebung dazu beitragen, das Alter des Infarkts zu bestimmen. Die beim Apparent-Diffusion-Coefficient-Mapping, in diffusionsgewichteten und in Fluid-attenuated-Inversion-Recovery-Sequenzen sowie in der nativen und kontrastmittelverstarkten T1-gewichteten und der T2-gewichteten Gradientenecho- und suszeptibilitatsgewichteten Magnetresonanzbildgebung beobachteten Befunde konnen die Bestimmung des relativen Alters eines Hirninfarkts unterstutzen. Schlaganfalle lassen sich in folgende Gruppen einteilen und datieren: fruh hyperakut, spat hyperakut, akut, subakut oder chronisch. Jungere Daten lassen darauf schliesen, dass ein weniger als 6 h zuruckliegender Zeitpunkt des Schlaganfalls bei vielen Patienten mit Diffusionseinschrankungen und keinen Veranderungen auf Fluid-attenuated-Inversion-Recovery-Aufnahmen wahrscheinlicher als zunachst angenommen ist. Das Zeitfenster fur die intravenose Verabreichung eines Gewebeplasminogenaktivators betragt derzeit 4,5 h ab dem letzten Beobachtungszeitpunkt vor Beginn der ersten Symptome. Bei Infarkten im vorderen Stromgebiet betragt das Zeitfenster fur die intraarterielle Verabreichung des Gewebeplasminogenaktivators 6 h ab dem letzten Beobachtungszeitpunkt vor Beginn der ersten Symptome. Aus diesem Grund ist die Bestimmung des genauen Zeitpunkts bei Patienten mit ischamischem Schlaganfall wichtig.

E-037 Endovascular treatment of traumatic pediatric posterior circulation pseudoaneurysms

Introduction and purpose Traumatic intracranial aneurysms are rare and represent fewer than 1% of all intracranial aneurysms. They may develop as the result of blunt or penetrating head trauma and are associated with a significant mortality of up to 50%. Traumatic aneurysms typically involve the anterior circulation or the internal carotid artery at the level of the skull base. They rarely involve the posterior circulation. We present three pediatric patients with traumatic aneurysms in the posterior circulation and describe their clinical presentation, angiographic findings and clinical outcome after being treated by endovascular technique. Materials and methods We retrospectively reviewed the angiographic and clinical findings in three pediatric patients, aged 12 years and younger, with traumatic pseudoaneurysms occurring in the posterior circulation in a variety of locations: one in the basilar artery, one in the posterior cerebral artery and one in the superior cerebellar artery. Results Three patients with three posterior circulation pseudoaneurysms (two male patients and one female patient; aged 3–12 years) were admitted during the past 2 years. All three patients underwent endovascular coil embolization. No complications were noted from these procedures. All patients improved clinically after treatment. Conclusions Contemporary endovascular techniques can be used effectively to treat posterior circulation pseudoaneurysms in the pediatric population. Treatment efficacy may be improved if there are bony confines around the aneurysm or if therapy takes place in the subacute period, when the wall of the pseudoaneurysm has matured and stabilized.