Tenzing 7 delivery catheter with or without a leading microwire for single pass aspiration thrombectomy: A multicenter experience.

INTRODUCTION: Aspiration mechanical thrombectomy traditionally includes use of an inner microcatheter and leading microwire to navigate an aspiration catheter (AC) to the site of occlusion. Early clinical experience suggests that a leading microwire is often not needed with the Tenzing 7 (T7, Route 92 Medical, San Mateo, CA), a soft tapered tip ledge-reducing delivery catheter. This multicenter experience aims to describe AC delivery success in single-pass thrombectomy using T7 with and without a leading microwire. METHODS: A retrospective review was conducted of consecutive patients who underwent single-pass thrombectomy with T7 at six institutions between 2020 and 2022. We examined the percentage of successful AC delivery, puncture-to-revascularization time, and procedural complication rate. RESULTS: A leading microwire with T7 was used in 19/89 (21%) of patients, and it was not used with T7 in 70/89 (79%) of patients. Successful AC delivery was similar with and without microwires (97% vs. 90%, p = 0.15). Median puncture-to-revascularization times were similar (17 min microwire vs. 16 min no-microwire, p = 0.12). No complications were associated with microwire use; one (1.4%) patient had a T7-related vasospasm resolved with verapamil during thrombectomy without a leading microwire. Differences in complication rates were not statistically significant (p = 0.46). CONCLUSION: In our real-world clinical experience, leading microwire use was infrequently necessary with the T7 delivery catheter. Successful AC delivery and complication rates were similar with and without microwire use in single-pass T7 thrombectomies. Initial pass with T7 may be performed without use of leading microwire, reserving microwire use for refractory cases or known difficult-to-navigate vasculature.

Improved catheter delivery for aspiration thrombectomy using Tenzing 7 ledge reducing catheter and FreeClimb 70.

PURPOSE: Previous comparative mechanical thrombectomy device trials reported a substantial crossover rate from first-line aspiration to stent-retriever thrombectomy. A specialized delivery catheter may help track large-bore aspiration catheters to target occlusions. We report our multicenter experience of aspiration thrombectomy of intracranial large vessel occlusions using the FreeClimbTM 70 and Tenzing® 7 delivery catheter (Route 92, San Mateo, CA). METHODS: After local Institutional Review Board approval, we retrospectively reviewed the clinical, procedural, and imaging data of patients who underwent mechanical thrombectomy with the FreeClimb 70 and Tenzing 7. RESULTS: FreeClimb 70 was successfully delivered using Tenzing 7 to target occlusion in 30/30 (100%) patients (18 M1, 6 M2, 4 ICA-terminus, and 2 basilar artery occlusions), without the use of a stent-retriever for anchoring. In 21/30 (70%) cases, a leading microwire was not needed to advance the Tenzing 7 to the target. Median (interquartile range) time from groin puncture to first pass was 12 (interquartile range 8-15) minutes. Overall first pass effect, or first pass effect (modified thrombolysis in cerebral ischemia 2C-3), was achieved 16/30 (53%). For M1 occlusions, first pass effect was 11/18 (61%). Successful reperfusion (modified thrombolysis in cerebral ischemia ≥ 2B) was achieved in 29/30 (97%) cases after a median of 1 pass (interquartile range 1-3). Median groin puncture to reperfusion time was 16 (interquartile range 12-26) minutes. There were no procedural complications or symptomatic intracranial hemorrhage. Average improvement in National Institutes of Health Stroke Scale at discharge was 6.6 ± 7.1. There were three patient deaths (renal failure, respiratory failure, and comfort care). CONCLUSIONS: Initial data support the use of Tenzing 7 with FreeClimb 70 catheter for reliable access to rapid, effective, and safe aspiration thrombectomy of large vessel occlusions.

AXS Vecta 0.071-0.074 Inch Aspiration Catheters for Mechanical Thrombectomy: Case Series and Literature Review.

Aspiration catheters are widely used for thrombectomy either alone or in combination with a stent-retriever, with a distal inner diameter and trackability keys to their success. In an illustrative case series, we report our clinical experience with AXS Vecta (Stryker Neurovascular, Fremont, CA, USA), available in both 0.071-inch and 0.074-inch distal inner diameters, including the first 2 Vecta 74 cases reported. A literature review on AXS Vecta is also provided. In our series, 9 thrombectomies were performed (Vecta 71: 2 M1, 5 M2 occlusions; Vecta 74: 1 M1 and 1 ICA-terminus occlusion). The AXS Vecta was successfully delivered to the target site in all cases. In 7 of 9 cases, the catheter was delivered over a Tenzing 7 delivery catheter (Route 92 Medical, San Mateo, CA, USA). For 2 of 9 combination approach cases, Vecta was delivered using the stent-retriever wire as a rail. The median improvement in NIHSS score during hospitalization was 9 (IQR 5-12). Successful mTICI 2C or 3 recanalization was achieved in 8 of 9 (89%) patients after a median 2 (IQR 1-2) passes. Our median groin-to-reperfusion time was 23 (IQR 12.5-32) minutes, with no procedural complications. Two previous clinical studies of a total of 29 patients treated with Vecta 71 reported successful mTICI 2b-3 recanalization in 89-90% of cases. The Median groin-to-reperfusion time was 30 minutes. Complications were seen in 2 of 29 (6.9%) cases (vessel perforation and/or intracerebral hemorrhage). These data support the efficacy, deliverability, and safety of AXS Vecta for mechanical thrombectomy.

International controlled study of revascularization and outcomes following COVID-positive mechanical thrombectomy.

BACKGROUND AND PURPOSE: Previous studies suggest that mechanisms and outcomes in patients with COVID-19-associated stroke differ from those in patients with non-COVID-19-associated strokes, but there is limited comparative evidence focusing on these populations. The aim of this study, therefore, was to determine if a significant association exists between COVID-19 status with revascularization and functional outcomes following thrombectomy for large vessel occlusion (LVO), after adjustment for potential confounding factors. METHODS: A cross-sectional, international multicenter retrospective study was conducted in consecutively admitted COVID-19 patients with concomitant acute LVO, compared to a control group without COVID-19. Data collected included age, gender, comorbidities, clinical characteristics, details of the involved vessels, procedural technique, and various outcomes. A multivariable-adjusted analysis was conducted. RESULTS: In this cohort of 697 patients with acute LVO, 302 had COVID-19 while 395 patients did not. There was a significant difference (p < 0.001) in the mean age (in years) and gender of patients, with younger patients and more males in the COVID-19 group. In terms of favorable revascularization (modified Thrombolysis in Cerebral Infarction [mTICI] grade 3), COVID-19 was associated with lower odds of complete revascularization (odds ratio 0.33, 95% confidence interval [CI] 0.23-0.48; p < 0.001), which persisted on multivariable modeling with adjustment for other predictors (adjusted odds ratio 0.30, 95% CI 0.12-0.77; p = 0.012). Moreover, endovascular complications, in-hospital mortality, and length of hospital stay were significantly higher among COVID-19 patients (p < 0.001). CONCLUSION: COVID-19 was an independent predictor of incomplete revascularization and poor functional outcome in patients with stroke due to LVO. Furthermore, COVID-19 patients with LVO were more often younger and had higher morbidity/mortality rates.

Characteristics of a COVID-19 Cohort With Large Vessel Occlusion: A Multicenter International Study.

BACKGROUND: The mechanisms and outcomes in coronavirus disease (COVID-19)-associated stroke are unique from those of non-COVID-19 stroke. OBJECTIVE: To describe the efficacy and outcomes of acute revascularization of large vessel occlusion (LVO) in the setting of COVID-19 in an international cohort. METHODS: We conducted an international multicenter retrospective study of consecutively admitted patients with COVID-19 with concomitant acute LVO across 50 comprehensive stroke centers. Our control group constituted historical controls of patients presenting with LVO and receiving a mechanical thrombectomy between January 2018 and December 2020. RESULTS: The total cohort was 575 patients with acute LVO; 194 patients had COVID-19 while 381 patients did not. Patients in the COVID-19 group were younger (62.5 vs 71.2; P < .001) and lacked vascular risk factors (49, 25.3% vs 54, 14.2%; P = .001). Modified thrombolysis in cerebral infarction 3 revascularization was less common in the COVID-19 group (74, 39.2% vs 252, 67.2%; P < .001). Poor functional outcome at discharge (defined as modified Ranklin Scale 3-6) was more common in the COVID-19 group (150, 79.8% vs 132, 66.7%; P = .004). COVID-19 was independently associated with a lower likelihood of achieving modified thrombolysis in cerebral infarction 3 (odds ratio [OR]: 0.4, 95% CI: 0.2-0.7; P < .001) and unfavorable outcomes (OR: 2.5, 95% CI: 1.4-4.5; P = .002). CONCLUSION: COVID-19 was an independent predictor of incomplete revascularization and poor outcomes in patients with stroke due to LVO. Patients with COVID-19 with LVO were younger, had fewer cerebrovascular risk factors, and suffered from higher morbidity/mortality rates.

Acute ischaemic stroke associated with SARS-CoV-2 infection in North America.

BACKGROUND: To analyse the clinical characteristics of COVID-19 with acute ischaemic stroke (AIS) and identify factors predicting functional outcome. METHODS: Multicentre retrospective cohort study of COVID-19 patients with AIS who presented to 30 stroke centres in the USA and Canada between 14 March and 30 August 2020. The primary endpoint was poor functional outcome, defined as a modified Rankin Scale (mRS) of 5 or 6 at discharge. Secondary endpoints include favourable outcome (mRS ≤2) and mortality at discharge, ordinal mRS (shift analysis), symptomatic intracranial haemorrhage (sICH) and occurrence of in-hospital complications. RESULTS: A total of 216 COVID-19 patients with AIS were included. 68.1% (147/216) were older than 60 years, while 31.9% (69/216) were younger. Median [IQR] National Institutes of Health Stroke Scale (NIHSS) at presentation was 12.5 (15.8), and 44.2% (87/197) presented with large vessel occlusion (LVO). Approximately 51.3% (98/191) of the patients had poor outcomes with an observed mortality rate of 39.1% (81/207). Age >60 years (aOR: 5.11, 95% CI 2.08 to 12.56, p<0.001), diabetes mellitus (aOR: 2.66, 95% CI 1.16 to 6.09, p=0.021), higher NIHSS at admission (aOR: 1.08, 95% CI 1.02 to 1.14, p=0.006), LVO (aOR: 2.45, 95% CI 1.04 to 5.78, p=0.042), and higher NLR level (aOR: 1.06, 95% CI 1.01 to 1.11, p=0.028) were significantly associated with poor functional outcome. CONCLUSION: There is relationship between COVID-19-associated AIS and severe disability or death. We identified several factors which predict worse outcomes, and these outcomes were more frequent compared to global averages. We found that elevated neutrophil-to-lymphocyte ratio, rather than D-Dimer, predicted both morbidity and mortality.

ASPECTS estimation using dual-energy CTA-derived virtual non-contrast in large vessel occlusion acute ischemic stroke: a dose reduction opportunity for patients undergoing repeat CT?

PURPOSE: Recent studies have shown the feasibility of dual-energy CT (DECT) virtual non-contrast (VNC) for determining infarct extent. In this study, patients presenting with large-vessel occlusion (LVO) acute ischemic stroke (AIS), we assess whether ASPECTS on DECTA-VNC differs from non-contrast CT (NCCT). METHODS: After IRB approval, LVO-AIS patients undergoing NCCT and DECTA between October 2016 and September 2018 were retrospectively reviewed. DECTA-VNC images were derived using Syngo.via (Siemens, Erlangen, Germany). ASPECTS was scored by two blinded neuroradiologists. Square-weighted kappa statistic, diagnostic performance, Wilcoxon signed-rank tests between groups, and CT doses were calculated. RESULTS: Fifty-one patients met inclusion criteria, with median age of 76 (IQR 67-82); 26/51 (51%) were female. Median time between last-known-well and CT was 120 min (IQR 60-252). DECTA-VNC ASPECTS score differed by ≤ 1 from consensus NCCT in 49/51 (96%) patients for reader 1 and in 46/51 (90%) for reader 2. ASPECTS on DECTA-SI and consensus NCCT differed by ≤ 1 in 45/51 (88%) for both readers. On a per ASPECTS-region basis, DECTA-VNC had 87% sensitivity, 95% specificity, 0.82% PPV, and 0.96% NPV. ASPECTS inter-rater agreement was highest for DECTA-VNC (κ = 0.71), DECTA-SI (κ = 0.48), and NCCT (κ = 0.40). NCCT median CTDIvol was 63.7 mGy (IQR 60.7-67.2); DLP was 1060.0 mGy·cm (IQR 981.0-1151.5). DECTA-VNC dose was lower: median CTDIvol was 20.9 mGy (IQR 19.8-22.2); DLP was 804.1 (IQR 691.6-869.4), p < 0.0001. CONCLUSION: DECTA-derived VNC yielded similar ASPECTS scores as NCCT and is therefore non-inferior in early ischemia-related low attenuation edema/infarct detection in acute LVO-AIS patients. Further evaluation of the role of DECTA-VNC in AIS imaging is warranted.

Age and Acute Ischemic Stroke Outcome in North American Patients With COVID-19.

Background Acute ischemic stroke (AIS) in the context of COVID-19 has received considerable attention for its propensity to affect patients of all ages. We aimed to evaluate the effect of age on functional outcome and mortality following an acute ischemic event. Methods and Results A prospectively maintained database from comprehensive stroke centers in Canada and the United States was analyzed for patients with AIS from March 14 to September 30, 2020 who tested positive for SARS-CoV-2. The primary outcome was Modified Rankin Scale score at discharge, and the secondary outcome was mortality. Baseline characteristics, laboratory values, imaging, and thrombectomy workflow process times were assessed. Among all 126 patients with COVID-19 who were diagnosed with AIS, the median age was 63 years (range, 27-94). There were 35 (27.8%) patients with AIS in the aged ≤55 years group, 47 (37.3%) in the aged 56 to 70 group, and 44 (34.9%) in the aged >70 group. Intravenous tissue plasminogen activator and thrombectomy rates were comparable across these groups, (P=0.331 and 0.212, respectively). There was a significantly lower rate of mortality between each group favoring younger age (21.9% versus 45.0% versus 48.8%, P=0.047). After multivariable adjustment for possible confounders, a 1-year increase in age was significantly associated with fewer instances of a favorable outcome of Modified Rankin Scale 0 to 2 (odds ratio [OR], 0.95; 95 CI%, 0.90-0.99; P=0.048) and higher mortality (OR, 1.06; 95 CI%, 1.02-1.10; P=0.007). Conclusions AIS in the context of COVID-19 affects young patients at much greater rates than pre-pandemic controls. Nevertheless, instances of poor functional outcome and mortality are closely tied to increasing age.

Acute ischemic stroke endovascular therapy.

Endovascular therapy (EVT) has become the standard treatment for large-vessel occlusion (LVO) acute ischemic stroke (AIS). EVT is now indicated in patients up to 24h from their last known well, provided that the patient meets specific clinical and imaging criteria. Improvements in thrombectomy devices, techniques, and operator experience have allowed successful EVT of ICA terminus, M1-MCA occlusions as well as proximal M2-MCA, basilar artery occlusions, and revascularization of tandem lesions. Mechanical thrombectomy failures still occur due to several factors, however, highlighting the need for further device and technical improvements. An ongoing debate exists regarding the need for pre-EVT thrombolytic agents, thrombectomy techniques, distal occlusions, anesthesia methods, the role of advanced neuroimaging, the treatment of patients with larger infarct core, and those presenting with milder stroke symptoms. Many of these questions are the subject of current or upcoming clinical trials. This review aims to provide an outline and discussion about the established recommendations and emerging topics regarding EVT for LVO AIS.

Advanced vascular imaging techniques.

This chapter outlines recent advances in imaging of disorders of the cervicocerebral vasculature that permit evaluation of the lumen, the vessel wall, and the patterns of blood flow within the vessel. Noninvasive MR techniques to evaluate the vessel lumen, such as noncontrast time-of-flight magnetic resonance angiography and contrast-enhanced magnetic resonance angiography (CEMRA) are routinely used in diagnosis, planning, and posttreatment follow-up. More recently, high-resolution vessel wall imaging MRI (VWMRI) has been developed, which provides additional information about the vessel wall or aneurysm wall. VWMRI wall signal and enhancement patterns may permit differentiation between vasculopathies and between stable and unstable unruptured aneurysms. In addition, the study of blood flow patterns using phase-contrast MRI (4D flow MRI) and image-based computational fluid dynamics has been used to characterize flow and wall shear stress within aneurysms, flow within arteriovenous malformations (AVMs) and pulsatile tinnitus. Digital subtraction angiography (DSA), however, remains the gold standard in the evaluation and treatment of neurovascular diseases. New adjunctive DSA techniques, such as 4D-DSA reconstruction and color flow analysis, are also covered. These new MRI and DSA techniques increase diagnostic accuracy, improve understanding of the pathophysiology and natural history of neurovascular disease, inform and guide treatment, and may provide risk stratification for patients being considered for therapy.

3MAX catheter for thromboaspiration of downstream and new territory emboli after mechanical thrombectomy of large vessel occlusions: initial experience.

Distal emboli and emboli to new territories occur in up to 14% and 11% of large vessel occlusion mechanical thrombectomies, respectively. A retrospective review was conducted of 18 consecutive patients with large vessel occlusion acute stroke undergoing mechanical thrombecomy, subsequently developing distal emboli and/or emboli to new territory for which thromboaspiration using the 3MAX catheter was performed. Eighteen distal emboli and two emboli to new territory in 18 patients were treated in the distal M2 and M3 middle cerebral artery, pericallosal and callosomarginal arteries, and P2 posterior cerebral artery (all arteries ≥1.5 mm in diameter). 3MAX thromboaspiration was successful in 13/18 distal emboli and 2/2 emboli to new territory (total 15/20, 75%). 3MAX thromboaspiration resulted in improvement in the final modified treatment in cerebral ischaemia (mTICI) score in 14/18 patients (78%) compared with the initial mTICI score after large vessel occlusion thrombectomy. A shift towards higher final mTICI scores was seen with 3MAX catheter aspiration of distal emboli in this series. The initial mTICI score after large vessel occlusion thrombectomy was 2A in 4/18 (22%) patients and 2B in 14/18 (78%) patients. The final mTICI score after distal emboli/emboli to new territory aspiration improved to 2B in 7/18 (39%) patients, 2C in 3/18 (17%) patients and 3 in 8/18 (44%) patients. No procedural complications were noted. In 13 patients with successful distal emboli/emboli to new territory thromboaspiration, a 90-day modified Rankin score of 0-2 was seen in 10 patients (77%). In five patients with unsuccessful distal emboli/emboli to new territory aspiration, a 90-day modified Rankin score of 0-2 was seen in three patients (60%). 3MAX thromboaspiration of select distal emboli and emboli to new territories is feasible. Larger prospective studies are needed to establish the clinical benefit and safety of this approach.

Improving mechanical thrombectomy time metrics in the angiography suite: Stroke cart, parallel workflows, and conscious sedation.

Purpose Earlier reperfusion of large-vessel occlusion (LVO) stroke improves functional outcomes. We hypothesize that use of a stroke cart in the angiography suite, containing all commonly used procedural equipment in a mechanical thrombectomy, combined with parallel staff workflows, and use of conscious sedation when possible, improve mechanical thrombectomy time metrics. Methods We identified 47 consecutive LVO patients who underwent mechanical thrombectomy at our center, retrospectively and prospectively from implementation of these three workflow changes (19 pre- and 28 post-). For each patient, last known normal, NIHSS, angiography suite in-room time, type of anesthesia, groin puncture time, on-clot time, recanalization time, LVO location, number of passes, device(s) used, mTICI score, and outcome (mRS) were recorded. Between-group comparisons of time metrics and multivariate regression were performed. Results Stroke cart, parallel workflows, and primary use of conscious sedation decreased in-room time to groin puncture (-21.3 min, p < 0.0001), in-room to on-clot time (-24.1 min, p = 0.001), and in-room to reperfusion time (-29.5 min, p = 0.01). In a multivariate analysis, endotracheal intubation and general anesthesia were found to significantly increase in-room to on-clot time ( p = 0.01), in-room to reperfusion time ( p = 0.01), and groin puncture to on-clot time ( p = 0.05). The number of patients achieving a good outcome (mRS 0-2), however, did not significantly differ between the two groups (9/18 (47%) vs 14/28 (50%), p = 0.60). Conclusions Use of a stroke cart, parallel workflows by neurointerventionalists, technologists, and nursing staff, and use of conscious sedation may be useful to other institutions in efforts to improve procedural times.

Technical factors affecting outcomes following endovascular treatment of posterior circulation atherosclerotic lesions.

BACKGROUND: Atherosclerotic disease of the vertebrobasilar system causes significant morbidity and mortality. All lesions require aggressive medical management, but the role of endovascular interventions remains unsettled. This study examines such endovascular interventions for vertebrobasilar atherosclerosis. METHODS: Retrospective review was performed of prospectively maintained procedure logs at three hospitals with comprehensive neurointerventional services. Patients with angiographically-proven stenosis undergoing elective stent placement were selected for analysis of demographic factors, lesion characteristics, and treatment details. Multivariate analysis was performed to evaluate for associations with ischemic stroke, death, and functional status as measured by modified Rankin scale at multiple intervals. RESULTS: One hundred and twenty-three lesions were treated in 110 patients. A total of 43 (58.1%) lesions caused stroke, while 66 (89.2%) caused transient ischemic attacks (TIAs). Forty lesions (32.5%) were at the vertebral origin; 97 (60.2%) were intracranial. A total of 112 (91.1%) were treated successfully. 4 (3.3%) of 10 (8.1%) procedural complications were symptomatic. Intracranial lesions were associated with death at 1 and 2 years (OR 24.91, P < 0.001) and mRS >2 at last contact (OR 12.83, P < 0.001). Stenting treatment with conjunctive angioplasty had lower rates of death (OR 0.303, P = 0.046) and mRS >2 at last contact (OR 0.234, P = 0.018) when angioplasty was performed with a device other than that packaged with the stent. CONCLUSION: Endovascular treatment of vertebrobasilar atherosclerosis can be performed safely, particularly for vertebral origin lesions. Higher rates of technical failure and complication may be acceptable for certain intracranial lesions due to their refractory nature and the morbidity caused by such lesions. Treatment should be tailored to features of each individual lesion.

Interventional magnetic resonance imaging guided carotid embolectomy using a novel resonant marker catheter: demonstration of preclinical feasibility.

To assess the visualization and efficacy of a wireless resonant circuit (wRC) catheter system for carotid artery occlusion and embolectomy under real-time MRI guidance in vivo, and to compare MR imaging modality with x-ray for analysis of qualitative physiological measures of blood flow at baseline and after embolectomy. The wRC catheter system was constructed using a MR compatible PEEK fiber braided catheter (Penumbra, Inc, Alameda, CA) with a single insulated longitudinal copper loop soldered to a printed circuit board embedded within the catheter wall. In concordance with IACUC protocol (AN103047), in vivo carotid artery navigation and embolectomy were performed in four farm pigs (40-45 kg) under real-time MRI at 1.5T. Industry standard clots were introduced in incremental amounts until adequate arterial occlusion was noted in a total of n=13 arteries. Baseline vasculature and restoration of blood flow were confirmed via MR and x-ray imaging, and graded by the Thrombolysis in Cerebral Infarction (TICI) scale. Wilcoxon signed-rank tests were used to analyze differences in recanalization status between DSA and MRA imaging. Successful recanalizations (TICI 2b/3) were compared to clinical rates reported in literature via binomial tests. The wRC catheter system was visible both on 5° sagittal bSSFP and coronal GRE sequence. Successful recanalization was demonstrated in 11 of 13 occluded arteries by DSA analysis and 8 of 13 by MRA. Recanalization rates based on DSA (0.85) and MRA (0.62) were not significantly different from the clinical rate of mechanical aspiration thrombectomy reported in literature. Lastly, a Wilcoxon signed rank test indicated no significant difference between TICI scores analyzed by DSA and MRA. With demonstrated compatibility and visualization under MRI, the wRC catheter system is effective for in vivo endovascular embolectomy, suggesting progress towards clinical endovascular interventional MRI.

Transvenous ethanol sclerotherapy of feeding arteries for treatment of a dural arteriovenous fistula.

Dural arteriovenous fistulas (DAVFs) can be complex lesions that require a well trained eye for proper characterization and management decisions. With numerous possible arteries to supply and veins to drain them, DAVFs are often complex lesions. To best treat these complex lesions, the neurointerventionalist should be adept at treating them with multiple techniques. This report describes a unique case in which a DAVF was treated with arterial sclerotherapy using ethanol from a transvenous approach.

Intra-Arterial MR Perfusion Imaging of Meningiomas: Comparison to Digital Subtraction Angiography and Intravenous MR Perfusion Imaging.

BACKGROUND AND PURPOSE: To evaluate the ability of IA MR perfusion to characterize meningioma blood supply. METHODS: Studies were performed in a suite comprised of an x-ray angiography unit and 1.5T MR scanner that permitted intraprocedural patient movement between the imaging modalities. Patients underwent intra-arterial (IA) and intravenous (IV) T2* dynamic susceptibility MR perfusion immediately prior to meningioma embolization. Regional tumor arterial supply was characterized by digital subtraction angiography and classified as external carotid artery (ECA) dural, internal carotid artery (ICA) dural, or pial. MR perfusion data regions of interest (ROIs) were analyzed in regions with different vascular supply to extract peak height, full-width at half-maximum (FWHM), relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and mean transit time (MTT). Linear mixed modeling was used to identify perfusion curve parameter differences for each ROI for IA and IV MR imaging techniques. IA vs. IV perfusion parameters were also directly compared for each ROI using linear mixed modeling. RESULTS: 18 ROIs were analyzed in 12 patients. Arterial supply was identified as ECA dural (n = 11), ICA dural (n = 4), or pial (n = 3). FWHM, rCBV, and rCBF showed statistically significant differences between ROIs for IA MR perfusion. Peak Height and FWHM showed statistically significant differences between ROIs for IV MR perfusion. RCBV and MTT were significantly lower for IA perfusion in the Dural ECA compared to IV perfusion. Relative CBF in IA MR was found to be significantly higher in the Dural ICA region and MTT significantly lower compared to IV perfusion.

Transvenous ethanol sclerotherapy of feeding arteries for treatment of a dural arteriovenous fistula.

Dural arteriovenous fistulas (DAVFs) can be complex lesions that require a well trained eye for proper characterization and management decisions. With numerous possible arteries to supply and veins to drain them, DAVFs are often complex lesions. To best treat these complex lesions, the neurointerventionalist should be adept at treating them with multiple techniques. This report describes a unique case in which a DAVF was treated with arterial sclerotherapy using ethanol from a transvenous approach.

Initial clinical experience with near-infrared spectroscopy in assessing cerebral tissue oxygen saturation in cerebral vasospasm before and after intra-arterial verapamil injection.

Cerebral vasospasm is a devastating complication after subarachnoid hemorrhage. The use of cerebral tissue oxygen saturation (SctO2) to non-invasively assess changes in cerebral tissue perfusion induced by intra-arterial (IA) verapamil treatment has not been described to our knowledge. A total of 21 consecutive post-craniotomy patients scheduled for possible IA verapamil treatment of cerebral vasospasm were recruited. The effect of IA verapamil injection on SctO2 being continuously monitored on both the left and right forehead was investigated. Comparisons between changes in SctO2 monitored on the ipsilateral and contralateral forehead in relationship to the side of internal carotid artery (ICA) injection were performed. A total of 47 IA verapamil injections (15 left ICA, 18 right ICA, and 14 vertebral artery injections) during 18 neurointerventional procedures in 13 patients were analyzed. IA verapamil administration led to both increases and decreases in SctO2. Changes in SctO2 ipsilateral to the ICA injection side were more pronounced (p=0.02 and 0.07 for left and right ICA injections, respectively) and favored compared to contralateral SctO2 changes. We were unable to obtain reliable measurements on the side ipsilateral to the craniotomy during four procedures in three patients, presumably secondary to pneumocephalus. The local cerebral vasodilating effect of IA verapamil injection is suggested by the differential changes in SctO2 ipsilateral and contralateral to the ICA injection side. The inconsistent changes in SctO2 and the limitations of applying cerebral oximetry in this patient population needs to be recognized.

Monitoring cerebral tissue oxygen saturation at frontal and parietal regions during carotid artery stenting.

Cerebral oximetry is normally placed on the upper forehead to monitor the frontal lobe cerebral tissue oxygen saturation (SctO2). We present a case in which the SctO2 was simultaneously monitored at both frontal and parietal regions during internal carotid artery (ICA) stenting. Our case involves a 79-year-old man who presented after a sudden fall and was later diagnosed with a watershed ischemic stroke in the distal fields perfused by the left middle cerebral artery. He had diffuse atherosclerotic occlusive lesions in the carotid and cerebral arterial systems including an 85 % stenotic lesion in the left distal cervical ICA. The brain territory perfused by the left ICA was devoid of collateral flow from anterior and posterior communicating arteries due to an abnormal circle of Willis. During stenting, the SctO2 monitored at both frontal and parietal regions tracked the procedure-induced acute flow change. However, the baseline SctO2 values of frontal and parietal regions differed. The SctO2-MAP correlation was more consistent on the stroked hemisphere than the non-stroked hemisphere. This case showed that SctO2 can be reliably monitored at the parietal region, which is primarily perfused by the ICA. SctO2 of the stroked brain is more pressure dependent than the non-stroked brain.