Follow-up Vascular Imaging Research Articles

Stereotactic radiosurgery for intracranial dural arteriovenous fistulas: patient outcomes and lessons learned over a 3-decade single-center experience.

The role of stereotactic radiosurgery (SRS) in the management of intracranial dural arteriovenous fistula (dAVF) is unclear given the rarity of this lesion and the variability in treatment paradigms. This study describes a 3-decade experience with the SRS technique and its outcomes for patients with dAVF. The authors conducted a retrospective analysis of patients with dAVF who had undergone single-fraction SRS in the period from 1990 to 2021. The imaging modality initially used for targeting was angiography alone, then angiography plus MRI, and most recently MRI alone. Two hundred twenty-two patients underwent SRS alone (n = 56, 25%) or SRS plus embolization (n = 166, 75%), depending on the severity of symptoms or the presence of cortical venous drainage (CVD). Most patients were women (64%), and the median patient age was 60 years. Common presenting symptoms were pulsatile bruit (55%), visual change or chemosis (21%), headache (10%), and intracerebral hemorrhage (5%). The most frequent dAVF location was the transverse or sigmoid sinus (44%), followed by the cavernous sinus (24%), jugular bulb (9%), and torcula (5%). CVD was noted in 28% of cases, and venous ectasia in 5%. Borden dAVF types among the patients were I (72%), II (20%), and III (8%). Cognard dAVF types among the patients were I (44%), IIa (27%), IIb (5%), IIa+b (15%), III (4%), and IV (5%). The median SRS treatment volume was 7.6 cm3; the median margin and maximum doses were 18 and 36 Gy, respectively. Follow-up after SRS was available for 209 patients (median follow-up 31 months). Obliteration was noted in 75% of the patients (110/147) with follow-up vascular imaging; the median time to obliteration was 37 months. Multivariate analysis revealed that a cavernous sinus dAVF location was predictive of radiological obliteration (HR 1.86, 95% CI 1.08-3.18, p = 0.024). The absence of CVD was predictive of obliteration in subgroup analysis of non-cavernous sinus dAVF (HR 0.53, 95% CI 0.29-0.98, p = 0.04). Symptoms resolved in 86% of patients (160/185) with clinical follow-up. Twelve patients (5.4%) had complications related to angiography for SRS planning (n = 2, 0.9%), embolization (n = 3, 1.4%), post-SRS hemorrhage (n = 1, 0.5%), delayed sinus thrombosis (n = 1, 0.5%), radiation-induced tumors (n = 2, 0.9%), and chronic encapsulated expanding hematoma (n = 3, 1.4%). SRS alone or in conjunction with embolization provided obliteration and symptom relief for the majority of patients with dAVF, with a low rate of procedure-related morbidity. Patients are at risk for late radiation-related complications, which can require treatment many years after SRS.

Safety and efficacy of endovascular recanalization for symptomatic non-acute atherosclerotic intracranial large artery occlusion.

The optimal treatment for patients with symptomatic non-acute atherosclerotic intracranial large artery occlusion (ILAO) despite medical treatment is not well established. We aimed to assess the safety, efficacy, and feasibility of angioplasty and stenting for these patients. A total of 251 consecutive patients with symptomatic non-acute atherosclerotic ILAO treated with interventional recanalization were retrospectively collected in our center from March 2015 to August 2021. The rate of successful recanalization, perioperative complications, and follow-up outcomes were evaluated. Successful recanalization was achieved in 88.4% (222/251) of the patients. A total of 24 (24/251, 9.6%) symptomatic complications occurred among 251 procedures. In the 193 patients with clinical follow-up during 19.0 ± 14.7 months, 11 (11/193, 5.7%) patients developed ischemic stroke and four (4/193, 2.1%) patients developed transient ischemic attack (TIA). In the 106 patients with vascular imaging follow-up during 6.8 ± 6.6 months, seven (7/106, 6.6%) patients had restenosis and 10 (10/106, 9.4%) patients had reocclusion. This study suggests that interventional recanalization may be a feasible, basically safe, and an effective alternative in carefully selected patients with symptomatic non-acute atherosclerotic ILAO who have failed medical management.

Impact of cerebral small vessel disease on symptomatic in-stent restenosis in intracranial atherosclerosis.

Cerebral small vessel disease (CSVD) commonly coexists with intracranial atherosclerotic stenosis (ICAS). In-stent restenosis (ISR) affects the nonprocedural outcome of severe symptomatic ICAS after intracranial stenting. However, only 8%-27% of ISR patients are symptomatic, which highlights the importance of the investigation of risk factors associated with symptomatic ISR (SISR) to improve long-term functional outcome. Whether CSVD is associated with SISR remains unclear. The authors tested the hypothesis that CSVD is associated with SISR in ICAS patients after intracranial stenting. This retrospective study enrolled 97 patients who were symptomatic due to severe anterior circulation ICAS treated with intracranial stenting. SISR was evaluated with clinical and vascular imaging follow-up. CSVD subtypes, including white matter hyperintensities (WMHs), enlarged perivascular spaces, and chronic lacunar infarctions, were evaluated. Cox regression analysis was used to compare the incidence of SISR between patients with and without CSVD. Of the enrolled patients, 58.8% had CSVD. The 1- and 2-year ISR rates were 24.7% and 37.1%, respectively. Of the CSVD subtypes, SISR was associated with deep WMHs (DWMHs; HR 5.39, 95% CI 1.02-28.44). DWMH Fazekas scale grades 2 (HR 85.54, 95% CI 2.42-3018.93) and 3 (HR 66.24, 95% CI 1.87-2352.32) were associated with SISR, but DWMH Fazekas grades 0 and 1 were not. The proportions of SISR in patients with DWMH Fazekas grades 0, 1, 2, and 3 were 16.7%, 33.3%, 50%, and 100%, respectively. Patients with CSVD have a higher risk of SISR than those without CSVD. Of the CSVD subtypes, patients with DWMHs are associated with SISR. The DWMH Fazekas scale score is considered to be a predictor for SISR.

Abstract 54: Incidence And Predictors Of Dural Arteriovenous Fistulae After Cerebral Venous Sinus Thrombosis: Analysis Of ACTION-CVT

Background: Intracranial dural arteriovenous fistulae (DAVF) are uncommon vascular anomalies with a reported incidence of 0.2 per 100,000 person years. An association between cerebral venous thrombosis (CVT) and DAVF has been reported; however, the direction of causality between the two remains uncertain. We aimed to identify the incidence and predictors of development of DAVF among patients with CVT. Methods: This is a post-hoc analysis of Anticoagulation in the Treatment of Cerebral Venous Thrombosis (ACTION-CVT), a multicenter retrospective study comparing outcomes of CVT patients treated with warfarin versus direct oral anticoagulants (DOACs) from 2015 to 2020. Patients were included in this analysis if they did not have DAVF on initial imaging and had follow-up vascular imaging during the study. Clinical, imaging, and anticoagulation characteristics of patients who developed DAVF were compared to those who did not. Stepwise binary logistic regression including important variables (achieving p<0.1 on univariate analyses) was used to determine predictors of DAVF development. Results: A total of 751 patients (median age 43, 66% female) met inclusion criteria of whom 13 (1.7%) developed DAVF with an estimated rate of 2.40 per 100 patient years. Patients with DAVF were less likely to have headache at presentation (53.8% vs 79.3%, p=0.037), but more likely to have no venous recanalization on follow-up imaging (46.2% vs 14.8%, p=0.008), baseline cortical vein thrombosis (15.4% vs 2.7%, p=0.053), and received warfarin (vs. DOACs) as initial oral anticoagulant (84.6% vs 58.7%, p=0.085) but the latter two missed the statistical significance threshold. In stepwise binary logistic regression analysis, cortical vein thrombosis (OR 7.98, 95% CI 1.40-45.35, p=0.02) and lack of venous recanalization (OR 4.93, 95% CI 1.48-16.39, p=0.01) were associated with development of DAVF. Conclusion: In this large multicenter study of CVT, the incidence of DAVF development was higher than the previously reported rate in the general population. The presence of cortical vein thrombosis and lack of venous recanalization were associated with increased risk of development of DAVF.

Natural history and nonoperative management of penetrating cerebrovascular injury

IntroductionThere is a modern precedent for nonoperative management of select penetrating cerebrovascular injuries (PCVIs); however, there is minimal data to guide management. Patients and methodsThis study assessed treatments, radiographic injury progression, and outcomes for all patients with PCVIs managed at an urban Level I trauma center from 2016 to 2021 that underwent initial nonoperative management (NOM). ResultsFourteen patients were included. There were 11,635 trauma admissions, 378 patients with blunt cerebrovascular injury, and 18 patients with operatively-managed PCVI during this timeframe. All patients received antithrombotic therapy, but this was delayed in some due to concomitant injuries. Three patients had stroke (21%): two before antithrombotic initiation, and one with unclear timing relative to treatment. Three patients underwent endovascular interventions. On follow-up imaging, 14% had injury resolution, 36% were stable, 21% worsened, and 29% had no follow-up vascular imaging. One patient died (7%), one had a bleeding complication (7%), and no patient required delayed operative intervention. DiscussionEarly initiation of antithrombotic therapy, early surveillance imaging, and selective use of endovascular interventions are important for nonoperative management of PCVI.

Drug-Coated Balloon for the Treatment of Nonacute Symptomatic Intracranial Carotid Artery Terminus Occlusion: Initial Experience and Follow-Up Outcome.

BackgroundStudies on the recanalization for occlusion of the internal carotid artery terminus are scattered. Recently, drug-coated balloon (DCB) has been increasingly applied in the intracranial artery occlusion and achieved encouraging results. However, there seems no convincing data for the nonacute symptomatic internal carotid artery terminus occlusion (sICATO).ObjectiveTo assess the feasibility and effectiveness (safety) of DCB for patients with nonacute sICATO refractory to medical therapy.ApproachThis study included 30 patients with nonacute sICATO treated with DCBs and/or remedial stenting. The rate of successful recanalization, periprocedural complications, and clinical and vascular imaging follow-up outcomes were retrospectively analyzed.ResultsDrug-coated balloon (DCB) dilatation of nonacute sICATO gives a 100% rate of successful recanalization, with a low complication rate (10.00%), good clinical outcomes (86.20%), low restenosis/reocclusion rate (3.45%), and one asymptomatic ipsilateral infarction (3.45%).ConclusionDrug-coated balloon dilation seems to be the promising treatment option for nonacute sICATO considering its safety and feasibility.

Abstract 1122‐000138: De Novo Intracranial Stenosis after Mechanical Thrombectomy with Stent Retrievers

Introduction : Increased vascular damage with the use of stent‐retrievers (SR) has been shown on histopathological analysis of the vascular tissue immediately after mechanical thrombectomy (MT) in animal models. We hypothesized that intraoperative endovascular damage‐intimal injury could result in fibrosis and de novo vascular stenosis (dnVS). The purpose of the study is to identify de novo or worsening intracranial stenosis (wICS) of the treated vessel(s) on patients who underwent MT for the treatment of acute ischemic stroke with SR, on follow‐up vascular imaging (FVI). Methods : This was a retrospective chart review. Patients who underwent MT with SR at two centers from January 2015‐December 2020, who had FVI (CTA, MRA or cerebral angiogram) were included. Patient characteristics, procedural details, timing for FVI and clinical outcomes were collected. Two neuroradiologists reviewed baseline angiograms and FVI to assess for the presence of dnVS or wICS, and graded each stenosis and collateral scores (CS), when stenosis was present. CS were calculated using the multiphase CT angiography collateral score (mCTA). Fischer exact test and Mann‐Whitney U test were used to assess for differences in categorical and continuous variables, respectively. Statistical analysis was performed using SPSS 28.0 (IBM Corp.). Results : Forty‐six patients within this cohort had FVI with 9 patients developing dnVS or wICS in the follow‐up period (19.6%) with a median follow‐up of 113 days. Five of these patients demonstrated a complete occlusion of the target vessel on FVI. Of the remaining 4 patients, mean degree of stenosis was 55%. Only 2 of these patients had underlying stenosis on baseline post‐treatment angiogram: one with 44% stenosis which progressed to 95% in 2 months. Another with mild stenosis that progressed to complete occlusion in 50 days. Adequate revascularization, defined as TICI score >2b was achieved in 88.8% of patients with dnVS or wICS, and in 89.2% of patients with stable FVI. No significant differences were observed in baseline demographics, NIHSS score at presentation or initial ASPECTS. Median number of passes was identical between patients who developed dnVS or wICS (median 1, IQR [1, 2], p = 0.683). Mean CS for dnVS or wICS was 3. No significant differences were observed in discharge or follow‐up NIHSS scores, mRS, mortality, or recurrent stroke or TIA between the two cohorts. Conclusions : MT with SR can be associated with dnVS or wICS in some patients. The number of passes with SR did not seem to have an impact on this. Patients with dnVS or wICS did not have a higher incidence of recurrent stroke or TIA. This could be due to the development of new collaterals in this population. Our study is limited by a small cohort, however, larger studies might be challenging as standardized radiological follow up of these patients has not been implemented.

Vascular Imaging Techniques to Diagnose and Monitor Patients with Takayasu Arteritis: A Review of the Literature.

Takayasu arteritis (TA) is a large vessel vasculitis that causes stenosis, occlusion, and sometimes the aneurysm of the aorta and its major branches. TA often occurs in young women, and because the symptoms are not obvious in the early stages of the disease, diagnosis is difficult and often delayed. In approximately 10% to 20% of patients, TA is reportedly complicated by ischemic stroke or transient ischemic attack. It is important to diagnose TA early and provide appropriate treatment to prevent complications from stroke. Diagnostic imaging techniques to visualize arterial stenosis are widely used in clinical practice. Even if no signs of cerebrovascular events are present at the time of the most recent evaluation of patients with TA, follow-up vascular imaging is important to monitor disease progression and changes in the cerebrovascular risk. However, the optimal imaging technique for monitoring of TA has not been established. Therefore, the purpose of this review is to describe newly available evidence on the usefulness of conventional imaging modalities (digital subtraction angiography, computed tomography angiography, magnetic resonance imaging/angiography, duplex ultrasound, and positron emission tomography) and novel imaging modalities (optical coherence tomography, infrared thermography, contrast-enhanced ultrasonography, and superb microvascular imaging) in the diagnosis and monitoring of TA.

Flow Diversion in Acute Sub Arachnoid Haemorrhage: A Single Centre Five Year Experience

ObjectivesThe role of flow-diversion in acute sub-arachnoid haemorrhage (SAH) is controversial. Many of the published data warns of high rates of procedure-related complications and aneurysmal rebleed. This study evaluates the safety, efficacy, clinical and angiographic outcomes of acute flow-diversion at our institute. MethodsThe institutional database from June 2015 to June 2020 was retrospectively reviewed for aneurysmal SAH (aSAH) treated with flow diversion. Clinical presentation, procedural details, complications, anti-platelet usage, rebleeding and aneurysm occlusion rates and outcomes were recorded. Results22 (59% females; median age 56 years) consecutive patients were identified. None of them were on regular antiplatelets/anticoagulation in the 15-days preceding the treatment. The mean aneurysm diameter was 5.4 mm and the median delay to flow-diversion was 2 days. Almost 73% (16/22) of patients had adjunctive coiling in the same session. There was no aneurysmal rebleed at a median follow up of 8.5 months and 86.3% (19/22 patients) had good clinical outcomes (3-month MRS 0–2). Adverse events related to the flow diversion procedure were seen in 3 patients; none of them had a medium to long-term clinical consequence. Three patients died from complications of SAH, unrelated to the procedure. Vascular imaging follow-up was available for 20 patients and the complete aneurysm occlusion rate was 95%. ConclusionFlow-diversion could be a reasonably safe and effective technique for treating ruptured aneurysms in appropriately selected patients when conventional options of surgical clipping and coiling are considered challenging.

Clinical outcomes of adjunct sinus stenting in dural arteriovenous fistulas

This study investigated the clinical outcomes and follow-up results of venous sinus stenting (VSS) for constrictive dural sinus restoration in patients with intracranial dural arteriovenous fistulas (DAVFs). We hypothesized that this treatment would have durable benefits in such patients. Patients who underwent VSS for DAVFs with cortical venous reflux between January 2008 and June 2020 were identified after aretrospective review (n=18). Clinical and endovascular treatment data and follow-up information were reviewed. The mean age of the 18patients was 59.9 years. Stents were implanted in 10 previously occluded sinuses and 9 stenotic sinuses in addition to endovascular embolization. One patient received bilateral VSS. Subdural hemorrhage occurred in one patient after recanalization for embolization, followed by uneventful stenting. In 17patients with clinical follow-up, the median follow-up time was 59.5 months (interquartile range 18 to 84months). Of these, sixteen patients had follow-up vascular imaging, revealing AVF obliteration in 6patients (38%) and stent patency in11 (69%). Retreatment was performed for8 (50%) patients. The mean follow-up modified Rankin scale score was 1.28. All patients had longstanding symptomatic improvement. Restoration of sinus flow in DAVFs with cortical venous reflux through VSS has an acceptable complication rate and long-term symptomatic control; however, retreatment is often required, and stent occlusion is not uncommon.

Long-term clinical and angiographic follow-up results of the dual-layer flow diverter device (FRED) for the treatment of intracranial aneurysms in a multicenter study.

Our aim was to determine the long-term safety and efficacy of the Flow Re-Direction Endoluminal Device (FRED) in this multicenter study with prospective design. This study included 136 consecutive patients with 155 aneurysms treated between March 2013 and June 2016 in 10 centers. Twenty-two (16.2%) patients presented with rupture of the index aneurysm. Large/giant aneurysms comprised 1/3 of the cohort. Adjuvant coil use during the treatment was 15.5%. The effectiveness measure in the study was the percentage of aneurysms with stable occlusion at follow-up. Vascular imaging follow-up was performed at least once in 131/136 (96.3%) patients with 148/155 (95.5%) aneurysms up to 75months (mean: 37.3months; median: 36months according to latest follow-up), and 102/155(65.8%) aneurysms in 90/136 (66.2%) patients had ≥ 24-month control. According to the latest controls, the overall stable occlusion rate was 91.9% (95% CI, 87.5 to 96.3%). Three out of 148 aneurysms with follow-up were retreated (2%, 95% CI 0.0 to 4.3%). Adverse events were noted in 19/136 (14%, 95% CI, 9 to 21%) patients with a morbidity of 1.5% (95% CI, 0.0 to 3.5%). Mortality was 1/136 (0.7%, 95% CI, 0.02 to 2.2%) and was unrelated to aneurysm treatment. In-stent stenosis (ISS) was detected in 10/131 of the patients with follow-up (7.6%, 95% CI; 3.1 to 12.2%), only one being symptomatic. No adverse events have occurred in any of the patients with follow-up after 24months, except the one resulting from ISS. In the treatment of cerebral aneurysms which were candidates for flow diversion technique, this study showed long-term efficacy of FRED with good safety and occlusion rates.

Thrombus Migration and Fragmentation After Intravenous Alteplase Treatment: The INTERRSeCT Study.

There is interest in what happens over time to the thrombus after intravenous alteplase. We study the effect of alteplase on thrombus structure and its impact on clinical outcome in patients with acute stroke. Intravenous alteplase treated stroke patients with intracranial internal carotid artery or middle cerebral artery occlusion identified on baseline computed tomography angiography and with follow-up vascular imaging (computed tomography angiography or first run of angiography before endovascular therapy) were enrolled from INTERRSeCT study (Identifying New Approaches to Optimize Thrombus Characterization for Predicting Early Recanalization and Reperfusion With IV Alteplase and Other Treatments Using Serial CT Angiography). Thrombus movement after intravenous alteplase was classified into complete recanalization, thrombus migration, thrombus fragmentation, and no change. Thrombus migration was diagnosed when occlusion site moved distally and graded according to degrees of thrombus movement (grade 0-3). Thrombus fragmentation was diagnosed when a new distal occlusion in addition to the primary occlusion was identified on follow-up imaging. The association between thrombus movement and clinical outcome was also evaluated. Among 427 patients in this study, thrombus movement was seen in 54% with a median time of 123 minutes from alteplase administration to follow-up imaging, and sub-classified as marked (thrombus migration grade 2-3 + complete recanalization; 27%) and mild to moderate thrombus movement (thrombus fragmentation + thrombus migration grade 0-1; 27%). In patients with proximal M1/internal carotid artery occlusion, marked thrombus movement was associated with a higher rate of good outcome (90-day modified Rankin Scale, 0-2) compared with mild to moderate movement (52% versus 27%; adjusted odds ratio, 5.64 [95% CI, 1.72-20.10]). No difference was seen in outcomes between mild to moderate thrombus movement and no change. In M1 distal/M2 occlusion, marked thrombus movement was associated with improved 90-day good outcome compared with no change (70% versus 56%; adjusted odds ratio, 2.54 [95% CI, 1.21-5.51]). Early thrombus movement is common after intravenous alteplase. Marked thrombus migration leads to good clinical outcomes. Thrombus dynamics over time should be further evaluated in clinical trials of acute reperfusion therapy.

The WOVEN trial: Wingspan One-year Vascular Events and Neurologic Outcomes

BackgroundPrior studies evaluating the Wingspan stent for treatment of symptomatic intracranial atherosclerotic disease have included patients with a spectrum of both on-label and off-label indications for the stent. The WEAVE...

Management of Extracranial Blunt Cerebrovascular Injuries: Experience with an Aspirin-Based Approach

Optimal management of patients with extracranial blunt cerebrovascular injury (BCVI) remains controversial, with both anticoagulation and antiplatelet therapy being recommended. The purpose of this study was to evaluate the efficacy and safety of using acetylsalicylic acid (ASA) in the management of BCVI. Patients with BCVI were identified from the registry of a Level 1 trauma center between 2010 and 2017. Digital imaging and electronic medical records were reviewed for patient information including demographic characteristics, injury type, therapy, outcomes, and follow-up. Over the study period, 13,578 patients were admitted following blunt trauma, with 94 (0.7%) having confirmed BCVI (mean age, 42 years; 72% male). Mean Injury Severity Score and Glasgow Coma Score were 27 and 10, respectively. BCVI was identified in 130 vessels with Biffl grade I (38%) and grade II injury (29%) being most common. Twelve (13%) patients experienced an ischemic event, but only 3 events occurred after diagnosis. ASA was primary treatment for 56 (60%) patients. Thirty patients (32%) received no treatment; 21 patients died within 24 hours of primary injury. Only 4 patients had ASA contraindications. Four patients (7%) had ASA-related complications; there were 2 cases of intracranial hemorrhage progression and 2 cases of gastrointestinal bleeding. Follow-up vascular imaging at a mean of 36 days demonstrated stable or improved levels of BCVI in 94% of patients. An ASA-based management strategy for BCVI was efficacious and relatively safe in this study. This approach may be the preferred treatment for BCVI, but confirmation is needed.

Significance of the absent vertebral artery T2 flow void on cervical spine MRI in atraumatic patients without acute neurological symptoms.

Loss of the T2 vertebral artery flow void can be an ominous sign in patients with trauma. However, the significance of an absent vertebral artery flow void is less clear when discovered incidentally in patients without trauma or acute neurological symptoms. The purpose of this study was to review retrospectively the results of additional imaging and clinical evaluation in atraumatic patients without acute neurological symptoms found to have an incidentally discovered absent vertebral artery flow void on magnetic resonance imaging. An imaging database was reviewed for absent vertebral artery flow voids in atraumatic cervical spine magnetic resonance images. Imaging and long-term clinical follow-up were recorded. Fifty-four patients were included in the study. All patients had clinical follow-up and 22 patients (40% of cases) had vascular imaging follow-up. Nine patients had a hypoplastic but patent vertebral artery on follow-up vascular imaging, and no further action was taken. Ten patients had evidence of stenosis or occlusion of the vertebral artery on follow-up imaging, none with acute neurological symptoms or new symptoms/subsequent change in management during follow-up. Three additional patients had vertebral artery dissections on follow-up imaging, but all of them had acute neurological symptoms at the time of imaging and acute infarcts on current or subsequent magnetic resonance imaging. The other 32 patients had clinical follow-up and remained asymptomatic throughout the study period, without change in management. In the absence of trauma or acute neurological symptoms an absent vertebral artery flow void has a low likelihood of altering patient management.

Drug-coated balloons for the treatment of symptomatic intracranial atherosclerosis: initial experience and follow-up outcome

BackgroundThe optimal treatment for patients with symptomatic severe intracranial atherosclerotic disease is not well established. Angioplasty and stenting have been attempted, with controversial results, mainly attributed to perioperative complications and...

Multicenter Experience with Stenting for Symptomatic Carotid Web

Background: A carotid web (CaW) is a shelf-like lesion in the posterior aspect of the internal carotid bulb and represents an intimal variant of fibromuscular dysplasia. CaW has been associated with recurrent strokes and conventionally treated with surgical excision. We report a multicenter experience of stenting in patients with symptomatic CaWs. Methods: Retrospective review of consecutive patients admitted to 5 comprehensive stroke centers who were identified to have a symptomatic CaW and treated with carotid stenting. A symptomatic CaW was defined by the presence of a shelf-like/linear, smooth filling defect in the posterior aspect of the carotid bulb diagnosed by neck CT angiography (CTA) and confirmed with conventional angiography in patients with negative stroke workup. Results: Twenty-four patients with stented symptomatic CaW were identified (stroke in 83% and transient ischemic attack in 17%). Their median age was 47 years (IQR 41–61), 14 (58%) were female, and were 17 (71%) black. The degree of stenosis by NASCET was 0% (range 0–11). All patients were placed on dual antiplatelets and stented at a median of 9 days (IQR 4–35) after the last event. Closed-cell stents were used in 18 (75%) of the cases. No periprocedural events occurred with the exception of 2 cases of asymptomatic hypotension/bradycardia. Clinical follow-up after stent placement occurred for a median of 12 months (IQR 3–19) with no new cerebrovascular events noted. Functional independence at 90 days was achieved in 22 (91%) patients. Follow-up vascular imaging (ultrasound n = 18/CTA n = 5) was performed at a median of 10 months (IQR 3–18) and revealed no stenosis. Conclusions: Stenting for symptomatic CaW appears to be a safe and effective alternative to surgical resection. Further studies are warranted.

Rescue Stenting for Failed Mechanical Thrombectomy in Acute Ischemic Stroke: A Multicenter Experience.

Effective rescue treatment has not yet been suggested in patients with mechanical thrombectomy (MT) failure. This study aimed to test whether rescue stenting (RS) improved clinical outcomes in MT-failed patients. This is a retrospective analysis of the cohorts of the 16 comprehensive stroke centers between September 2010 and December 2015. We identified the patients who underwent MT but failed to recanalize intracranial internal carotid artery or middle cerebral artery M1 occlusion. Patients were dichotomized into 2 groups: patients with RS and without RS after MT failure. Clinical and laboratory findings and outcomes were compared between the 2 groups. It was tested whether RS is associated with functional outcome. MT failed in 148 (25.0%) of the 591 patients with internal carotid artery or middle cerebral artery M1 occlusion. Of these 148 patients, 48 received RS (RS group) and 100 were left without further treatment (no stenting group). Recanalization was successful in 64.6% (31 of 48 patients) of RS group. Compared with no stenting group, RS group showed a significantly higher rate of good outcome (modified Rankin Scale score, 0-2; 39.6% versus 22.0%; P=0.031) without increasing symptomatic intracranial hemorrhage (16.7% versus 20.0%; P=0.823) or mortality (12.5% versus 19.0%; P=0.360). Of the RS group, patients who had recanalization success had 54.8% of good outcome, which is comparable to that (55.4%) of recanalization success group with MT. RS remained independently associated with good outcome after adjustment of other factors (odds ratio, 3.393; 95% confidence interval, 1.192-9.655; P=0.022). Follow-up vascular imaging was available in the 23 (74.2%) of 31 patients with recanalization success with RS. The stent was patent in 20 (87.0%) of the 23 patients. Glycoprotein IIb/IIIa inhibitor was significantly associated with stent patency but not with symptomatic intracranial hemorrhage. RS was independently associated with good outcomes without increasing symptomatic intracranial hemorrhage or mortality. RS seemed considered in MT-failed internal carotid artery or middle cerebral artery M1 occlusion.

Abstract TP128: Multicenter Experience With Stenting for Carotid Webs

Background: Carotid web is a shelf-like lesion in the posterior aspect of the internal carotid bulb and represents an intimal variant of fibromuscular dysplasia. Carotid webs have been associated with recurrent strokes and traditionally treated with surgical excision. We report a multicenter experience of stenting in patients with symptomatic carotid webs. Methods: Retrospective review of patients admitted to three comprehensive stroke centers identified to have a carotid web with otherwise negative stroke workup that underwent stenting. A carotid web was defined by the presence of a shelf-like/linear, smooth filling defect in the posterior aspect of the carotid bulb diagnosed by neck CT/MR angiography and confirmed with conventional angiography. Results: Twenty patients with symptomatic (80% Stroke/20% TIA) carotid webs were stented. Median age was 48[41-61] years, 7(35%) were male, and 15(75%) Black. Median NIHSS was 11[2-16] while ASPECTS 8[7-8]. Eight (40%) received intravenous thrombolysis and 10 (50%) thrombectomy. All patients were stented on dual antiplatelets (aspirin and clopidogrel[17] or ticagrelor[3]) at a median 9[4-30]days after the last vascular event. Closed-cell stents were used in 75% of cases (XACT [14] and Wallstent [1]) while open-cell stents in 25% (Acculink[5]). No cases required angioplasty for residual stenosis had to be performed. DIstal embolic protection was used in 19 cases (SpiderFX[18] and Emboshield_NAV6[1]) while proximal protection in 1 (MoMa). No periprocedural events occurred with the exception of two cases of hypotension/bradycardia (one requiring 24-hour vasopressors). No parenchymal hematomas were observed but one patient developed vaginal hemorrhage requiring discontinuation of one antiplatelet at 2 months. Modified Rankin Scale 0-2 (independence) at 90 days was recorded in 95% of patients. Clinical follow-up post stent occurred for a median of 4 [2-12] months and no follow-up cerebrovascular events were noted. Follow-up vascular imaging was performed in 95% patients at a median of 3[2-12]months and were all unremarkable. Conclusions: Stenting for symptomatic carotid web appears to be a valid, safe, and effective alternative to surgical piecemeal resection. Further studies are warranted.

Abstract TP10: Prediction of Thrombolytic Efficacy: Usefulness of Measurement of Enhancement in the Thrombus on Thin-reconstructed Perfusion CT

Purpose: To directly measure enhancement in acute thrombi using thin-reconstructed perfusion CT images for prediction thrombolytic efficacy. Materials and Methods: Prior to administration of tissue plasminogen activator (tPA), noncontrast CT (NCCT), 60-second 70-kVp adaptive 4D spiral CT (CTP), and CT angiography (CTA) were prospectively obtained and reconstructed at 1-mm thickness. Length and Hounsfield unit ratio (HUr) of thrombus were measured using 1-mm NCCT. Collateral circulation was assessed on dynamic CTA that were reconstructed from 1-mm CTP images. Good collateral circulation was defined as the criteria that were used for ESCAPE trial. After spatial motion correction of 1-mm CTP images, circular regions of interest were drawn in the central portion and each end of thrombus to measure the level of HU increase from baseline on time-attenuation curves (TAC). Recanalization was assessed on follow-up vascular imaging studies that were obtained within 24 hours after tPA. Modified TICI 2b or 3 was considered successful recanalization. Thrombus length, HUr, collaterals, and minimum increase of HU on TAC (HUmin) were compared between the recanalized and non-recanalized groups. Results: Of 57 patients who received tPA therapy, 31 patients (female, 13; mean age, 66.5 years) with occlusions in ICA (n=7), M1 (n=8), M1-M2 (n=6), and M2 (n=10) were only assessed. Thrombus length ranged 3-45 mm (median, 12 mm; IQR, 7). HUr was measured from 1.03 to 1.69 (median, 1.26; IQR, 0.19). Good collaterals were noted in 27 patients. HUmin ranged 3-70 HU (median, 15; IQR, 12), and showed negative correlation with thrombus length (rho=-0.410, P=0.022), but not with HUr. HUmin was significantly higher in the recanalized group (n=19) than the non-recanalized group (mean HUmin 23.79 vs 7.83; P<0.0001) independent of thrombus location. Thrombus length, HUr, or collateral status was not significantly different between the two groups. HUmin > 13 was determined with sensitivity of 89.5%, specificity of 91.7%, and AUC of 0.961 for prediction of recanalization. Conclusion: HUmin of thrombus was significantly higher in patients with successful recanalization after tPA therapy.