A comparative analysis between intravascular guidewire-obtained and computational fluid dynamic (CFD) flow velocity and pressure data using simplified carotid stenosis models was performed. This information was used to evaluate the viability of using guidewire pressure data to provide inlet conditions for CFD flow, and to study the relationship between stenotic length and hemodynamic behavior. Carotid stenosis models differing in diameter and length were prepared and connected to a vascular pulsatile flow simulator. Time-dependent flow velocity and pressure measurements were taken by microcatheter guidewires and compared with CFD data. Guidewire and CFD-generated pressure profiles matched closely in all measurement locations. The guidewire was unable to reliably measure flow velocity at areas associated with higher CFD flow velocities (r = 0.92). CFD results showed that an increased length of stenosis generated expansive regions of elevated wall shear stress (WSS) within and distal to the stenosis. Low WSS was found immediately outside the stenosis outlet. An increase in stenotic length produced higher flow velocities with minimal lengthening of the distal high velocity flow jet due to faster dissipation of translational kinetic energy through turbulence. We found the accuracy of guidewire-obtained velocity measurements is limited to regions unaffected by disturbed flow. WSS and turbulence behavior distal to the stenosis may be important markers to evaluate the severity of atherosclerotic progression as a function of stenotic length.

Dural arteriovenous fistulas involving the cavernous sinus can lead to orbital pain, vision loss and, in the setting of associated cortical venous reflux, intracranial hemorrhage. The treatment of dural arteriovenous fistulas has primarily become the role of the endovascular surgeon. The venous anatomy surrounding the cavernous sinus and venous sinus thrombosis that is often associated with these fistulas contributes to the complexity of these interventions. The current report gives a detailed description of the alternate endovascular routes to the cavernous sinus based on a single center's experience as well as a literature review supporting each approach. A comprehensive understanding of the anatomy and approaches to the cavernous sinus available to the endovascular surgeon is vital to the successful treatment of this condition.

BACKGROUND: Patterns of change in cerebrovascular (CV) morphology associated with aging are highly relevant to the incidence and progression of CV disease, particularly stroke. Intracranial aneurysms (IA), a leading cause of hemorrhagic stroke, are linked with factors such as blood flow, arterial stiffness, and inflammation that may also drive other changes in CV morphology. We worked with a cohort of longitudinally-imaged IA patients to construct the first longitudinal atlas of CV morphology and studied its relationship with disease. METHODS: 110 IA patients, ranging from 19 to 84 years old at IA detection, were monitored using 3D magnetic resonance angiography (MRA) for a mean of 6.11 (2.60) years with 3.6 (1.3) scans per patient. Using 405 image studies, we applied a machine learning diffeomorphic shape analysis to construct a longitudinal atlas of the cerebral arteries which defined a general trajectory of CV morphological change vs. age. This was paired with a centerline analysis to verify changes in individual arteries. RESULTS: Patient characteristics influenced the speed of CV shape change (e.g. diabetes mellitus, faster, p = 0.016), while other factors mapped to older CV age (e.g. hypertension, p = 0.0004). In parallel, we found that groups including autosomal dominant polycystic kidney disease (p = 0.0004), sex (p = 0.005), smoking (p = 0.046), and IA growth (p = 0.020) shared CV morphology characteristics. The centerline analysis validated changes consistent with the longitudinal atlas. CONCLUSION: A general CV trajectory of increasing artery length and tortuosity over a period of several decades was found. Although specific IA characteristics were not found to significantly affect this trajectory, these changes in the CV may contribute to increases in IA risk with aging. While our longitudinal findings were consistent with previous cross-sectional studies of individuals without IA, it remains to be determined whether the pattern of morphological change we observed is representative of aging within the general population. The model we developed provides a basis for integrating CV morphological change into understanding of aging and disease.

Background and purpose

Degree of stent retriever engagement with target thrombi may be reflected by (1) immediate reperfusion (IR) on first deployment, indicating displacement of clot toward the vessel wall, and (2) by early loss of IR (ELOIR), indicating penetration of retriever struts through the thrombus. The relation of these early findings to final reperfusion and clinical outcomes has not been well delineated.

Methods

We investigated IR and ELOIR in patients undergoing stent retriever mechanical thrombectomy at an academic medical center between March 2012 and June 2014.

Results

Among 56 patients, IR itself was not associated with final successful reperfusion, which occurred in 66.7% of IR patients and 71.4% of non-IR patients (P=0.999). However, ELOIR was associated with a higher rate of final successful reperfusion (92% versus 44%; P=0.046). Patients with ELOIR had a higher nominal rate of final favorable outcome (42% versus 22%; P=0.64).

Conclusions

ELOIR during the embedding period after deployment of stent retrievers is associated with successful final reperfusion, likely because of greater thrombus engagement with the stent retriever. ELOIR may be a useful finding to guide duration of embedding time in clinical practice and design of novel stent retrievers.

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 < 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.

BACKGROUND: Cerebral vasospasm is a serious sequela of traumatic brain injury (TBI) which leads to further neurologic injury subsequent to the initial trauma. The natural history and associated risk factors are not well understood. The objective of this study is to evaluate the clinical and radiographic characteristics of patients with TBI. METHODS: This is a descriptive case series of all patients with TBI who underwent cerebral angiogram for evaluation and rescue therapy for posttraumatic arterial vasospasm (PTV) between October 2017 and November 2019. The association of clinical and radiographic characteristics with cumulative severity of angiographic vasospasm was evaluated. The clinical characteristics comprised of age, sex, Glascow Coma Scale (GCS) and need for surgery. The radiographic characteristics were presence of subarachnoid hemorrhage (SAH), location of SAH, presence of contusion, presence of subdural hemorrhage (SDH), and presence of pseudoaneurysm. RESULTS: Twenty-two patients with PTV were identified requiring 69 cerebral angiograms (mean: 3.2; range: 1-9 angiograms per patient) during this period. The average age upon presentation was 40 years old, 81% of the patients were male sex, and the average GCS was 6.8. 67% of the patients underwent craniotomy or craniectomy. All patients had SAH, although only 60% had cisternal SAH. Parenchymal contusion was noted on 90% as well as SDH in 90%. The PTV was noted between 3 and 19 days after trauma. There was more vasospasm involving proximal arteries and higher severity of vasospasm in patients with cisternal SAH. Otherwise, there was no strong association between the clinical or radiographic characteristics and cumulative severity noted on the angiograms for each patient. CONCLUSION: Posttraumatic vasospasm can be detected as early as posttrauma day 3-19 in patients with TBI and SAH. The absence of cisternal SAH does not rule out the occurrence of the vasospasm during the course of treatment.

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.

The interval appearance of cerebral microbleeds (CMBs) after endovascular treatment has never been described. We investigated the frequency and predictors of new CMBs that developed shortly after mechanical thrombectomy for acute ischemic stroke, and its impact on clinical outcome.We retrospectively analyzed patients with large-vessel occlusion strokes treated with Merci Retriever, Penumbra System, or stent-retriever devices. Serial T2*-weighted gradient-recall echo (GRE) magnetic resonance imaging (MRI) before and 48 h after endovascular thrombectomy were assessed to identify new CMBs. We examined independent factors associated with new CMBs after mechanical thrombectomy. We analyzed the association of the presence, burden, and distribution of new CMBs with clinical outcome.A total of 187 consecutive patients with serial GRE were enrolled in this study. CMBs were evident in 36 (19.3%) patients before mechanical thrombectomy. New CMBs occurred in 41 (21.9%) patients after mechanical thrombectomy. Of the 68 new CMBs, 45 appeared in the lobar location, 18 in the deep location and 5 in the infratentorial location. The presence of baseline CMBs was associated with new CMBs after mechanical thrombectomy (OR 5.38; 95% CI 2.13-13.59; P < 0.001), no matter whether the patients were treated primarily with mechanical thrombectomy or with intravenous thrombolysis followed by mechanical thrombectomy. Patients with new CMBs did not have increased rates of hemorrhagic transformation, in-hospital mortality, and modified Rankin Scale score 4 to 6 at discharge.New CMBs are common after mechanical thrombectomy in one-fifth of patients with acute ischemic stroke. Baseline CMBs before mechanical thrombectomy predicts the development of new CMBs. New CMBs after mechanical thrombectomy do not influence clinical outcome.

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.

Background

The influence of cerebral microbleeds (CMBs) on post-thrombolytic hemorrhagic transformation (HT) in patients with acute ischemic stroke remains controversial.

Objective

To investigate the association of CMBs with HT and clinical outcomes among patients with large-vessel occlusion strokes treated with mechanical thrombectomy.

Methods

We analyzed patients with acute stroke treated with Merci Retriever, Penumbra system or stent-retriever devices. CMBs were identified on pretreatment T2-weighted, gradient-recall echo MRI. We analyzed the association of the presence, burden, and distribution of CMBs with HT, procedural complications, in-hospital mortality, and clinical outcome.

Results

CMBs were detected in 37 (18.0%) of 206 patients. Seventy-three foci of microbleeds were identified. Fourteen patients (6.8%) had ≥2 CMBs, only 1 patient had ≥5 CMBs. Strictly lobar CMBs were found in 12 patients, strictly deep CMBs in 12 patients, strictly infratentorial CMBs in 2 patients, and mixed CMBs in 11 patients. There were no significant differences between patients with CMBs and those without CMBs in the rates of overall HT (37.8% vs 45.6%), parenchymal hematoma (16.2% vs 19.5%), procedure-related vessel perforation (5.4% vs 7.1%), in-hospital mortality (16.2% vs 18.3%), and modified Rankin Scale score 0-3 at discharge. CMBs were not independently associated with HT or in-hospital mortality in patients treated with either thrombectomy or intravenous thrombolysis followed by thrombectomy.

Conclusions

Patients with CMBs are not at increased risk for HT and mortality following mechanical thrombectomy for acute stroke. Excluding such patients from mechanical thrombectomy is unwarranted. The risk of HT in patients with ≥5 CMBs requires further study.