Analysis of cerebral venous sinus stenosis by flat panel angiographic CT (FP-CT) to guide treatment for idiopathic intracranial hypertension.

INTRODUCTION: Cerebral venous sinus stenting (CVSS) is an effective treatment for idiopathic intracranial hypertension (IIH) secondary to dural venous sinus stenosis. Traditional selection of patients for CVSS has been made by microcatheter manometry, but pressure measurements are often equivocal. Here we present the results of a series of cases in which venous flat-panel CT (FP-CT) was used as an adjunct to microcatheter manometry to improve decision making and precise stent placement during CVSS. METHODS: Ten consecutive patients with IIH underwent angiography with microcatheter manometry and venous FP-CT, with CVSS if indicated by the results. Cross-sectional measurements of the narrowed sinus were obtained on FP-CT before and after stenting. After the procedure, clinical outcomes were tracked. Follow-up with quantitative MRA with sinus flow measurements was also performed, when available. RESULTS: There was an exponential correlation between measured pressure gradient and degree of stenosis calculated using venous FP-CT. All patients with both a high degree of stenosis measured by FP-CT and a high pressure gradient across the stenosis showed a clinical benefit from stenting. CONCLUSIONS: True measurement of the cross-sectional area of the dural sinus, made by venous phase FP-CT, has a high degree of correlation with elevated venous pressure gradient across the point of stenosis. Even in a limited series of cases, we found an exponential decrease in flow with increasing severity of stenosis. Furthermore, patients with both an elevated venous pressure gradient and critical stenosis of the sinus on FP-CT showed symptomatic improvement after stenting.

The effect of intravenous thrombolysis in stroke patients with unsuccessful thrombectomy.

BACKGROUND: The benefit of intravenous thrombolysis (IVT) is well established. We aim to study the benefits of IVT in acute ischemic stroke (AIS) patients with large vessel occlusion (LVO) who underwent unsuccessful mechanical thrombectomy (MT). METHODS: We included AIS patients who underwent MT for anterior circulation LVO with failed recanalization (modified treatment in cerebral ischemia [mTICI] score ≤ 2A). Patients who received IVT prior to MT were compared to those who received MT alone. Propensity score matching using demographic, clinical, radiographic and procedural variables was used to match patients with and without IVT. The primary outcome was favorable 90-day good functional outcome (defined as modified Rankin scale of 0-2), and secondary outcomes included intracranial hemorrhage (ICH), symptomatic ICH (sICH), and 90-day mortality. RESULTS: Totally, 610 AIS patients with unsuccessful MT were included. After propensity matching, 219 patients were identified in each group. Median age was 70 years and 73 years in the IVT + MT and MT alone groups, respectively. In the IVT + MT group, final mTICI scores of 0, 1, and 2A were achieved in 92 (42.0%), 33 (15.1%), and 94 (42.9%) patients, respectively, versus 76 (34.7%), 29 (13.2%), and 114 (52.1%) in the MT alone group. The IVT + MT group had greater odds of 90-day good functional outcome (adjusted odds ratio 2.54, 95% confidence interval 1.53-4.32). There were no significant differences in secondary outcomes. CONCLUSIONS: IVT is associated with improved functional outcomes in AIS patients with LVO despite unsuccessful MT.

Part 1: Pushing the boundaries of neurointerventional surgery: A historical review of the work of Dr Gerard Debrun.

French-American neurointerventionalist and pioneer, Dr Gerard Debrun, laid the groundwork for treatments which have become irreplaceable in neurointerventional surgery today. This article aims to outline the career of Dr Debrun while highlighting his accomplishments and contributions to the field of neurointerventional surgery. We selected relevant articles from PubMed authored or co-authored by Dr Debrun between 1941 and 2023. All included articles discuss the accomplishments and contributions of Dr Debrun. Dr Debrun began his career in France by investigating neurointerventional techniques, most notably the intravascular Detachable Balloon Catheter (DBC). His work was recognized by renowned neurosurgeon Dr Charles Drake, who recruited him to London, Ontario. Dr Debrun created the foundation for homemade manufacturing of DBCs, building on one of the largest series for use of DBCs in cerebrovascular disease. Dr Debrun spent time as faculty at Massachusetts General Hospital (MGH) and Johns Hopkins Hospital, before arriving at the University of Illinois Chicago (UIC) where he remained until his retirement. Dr Debrun's subsequent contributions included the calibrated-leak balloon catheter, pioneering of glue embolization, setting the foundation for preoperative AVM embolizations, and as an early adopter of the Guglielmi detachable coil (GDC), including mastering the balloon remodeling technique for wide neck aneurysms. Dr Debrun established the first integrated neurointerventional surgery program at UIC, establishing a well sought-after fellowship program. Dr Debrun lectured extensively and was a prolific writer on neurointerventional surgery throughout this career. His contributions established the foundation for several techniques which have since become standard practice in present-day neurointerventional surgery.

Clinical and radiographic outcomes after mechanical thrombectomy in medium-vessel posterior cerebral artery occlusions: Subgroup analysis from STAR.

BACKGROUND: Whereas mechanical thrombectomy (MT) has become standard-of-care treatment for patients with salvageable brain tissue after acute stroke caused by large-vessel occlusions, the results of MT in patients with medium-vessel occlusions (MEVOs), particularly in the posterior cerebral artery (PCA), are not well known. METHODS: Using data from the international Stroke Thrombectomy and Aneurysm Registry (STAR), we assessed presenting characteristics and clinical outcomes for patients who underwent MT for primary occlusions in the P2 PCA segment. As a subanalysis, we compared the PCA MeVO outcomes with STAR's anterior circulation MeVO outcomes, namely middle cerebral artery (MCA) M2 and M3 segments. RESULTS: Of the 9812 patients in STAR, 43 underwent MT for isolated PCA MeVOs. The patients' median age was 69 years (interquartile range 61-79), and 48.8% were female. The median NIH Stroke Scale score was 9 (range 6-17). After recanalization, 67.4% of patients achieved successful recanalization (modified treatment in cerebral infarction score [mTICI] ≥ 2b), with a first-pass success rate of 44.2%, and 39.6% achieved a modified Rankin score of 0-2 at 90 days. Nine patients (20.9%) had died by the 90-day follow-up. In comparison with M2 and M3 MeVOs, there were no differences in presenting characteristics among the three groups. Patients with PCA MeVOs were less likely to undergo intra-arterial thrombolysis (4.7% PCA vs. 10.1% M2 vs. 16.2% M3, p = 0.046) or to achieve successful recanalization (mTICI ≥ 2b, 67.4%, 86.7%, 82.3%, respectively, p < 0.001); however, there were no differences in the rates of successful first-pass recanalization (44.2%, 49.8%, 52.3%, respectively, p = 0.65). CONCLUSIONS: We describe the STAR experience performing MT in patients with PCA MeVOs. Our analysis supports that successful first-pass recanalization can be achieved in PCA MEVOs at a rate similar to that in MCA MeVOs, although further study and possible innovation may be necessary to improve successful PCA MeVO recanalization rates.

Part 2: The development and advancement of the detachable balloon catheter; a historical and technical review.

The detachable balloon catheter (DBC) was a revolutionary technique for the treatment of cerebrovascular pathologies. It was used to treat carotid cavernous fistulas (CCFs), vertebro-jugular fistulas, arteriovenous malformations (AVMs), and aneurysms. The DBC became the foundation for neurointerventional techniques, leading to the development of coil embolization and bioactives. Our team selected relevant articles from PubMed published between 1974 and 2023. Articles were excluded if they did not discuss the use or development of the detachable balloon catheter or subsequent technologies. The DBC was used to occlude vessels, either temporarily or permanently. Dr Gerard Debrun implemented findings from Dr Fedor Serbinenko's research to develop an intravascular detachable balloon technique. He developed many variations using type I and type II balloon catheters that differed in size, length, and material, allowing for the personalization of treatment based on the lesion. This revolutionary thinking showed that every pathology has a different shape and anatomy that require a unique approach. The DBC would offer the first alternative to the conventional practice of carotid occlusion in CCF treatment at the time. The DBC would later be used in aneurysm occlusion and the embolization of AVMs, with additional benefit in traumatic vascular sacrifice. Although the DBC has largely been replaced, it is still useful in a small subset of patients, and has financial incentive as it is more affordable than coils. This technique was a monumental stride in the history of neurointervention and helped propel the specialty to the current era of patient-specific interventions.

Comparison of combined intravenous and intra-arterial thrombolysis with intravenous thrombolysis alone in stroke patients undergoing mechanical thrombectomy: a propensity-matched analysis.

BACKGROUND: A combination of intravenous (IVT) or intra-arterial (IAT) thrombolysis with mechanical thrombectomy (MT) for acute ischemic stroke due to large vessel occlusion (AIS-LVO) has been investigated. However, there is limited data on patients who receive both IVT and IAT compared with IVT alone before MT. METHODS: STAR data from 2013 to 2023 was utilized. We performed propensity score matching between the two groups. The primary outcomes were symptomatic intracranial hemorrhage (sICH) and 90-day modified Rankin Scale (mRS) score 0-2. Secondary outcomes included successful recanalization (modified treatment in cerebral infarction (mTICI) ≥2B, ≥2C), early neurological improvement, any intracranial hemorrhage (ICH), and 90-day mortality. RESULTS: A total of 2454 AIS-LVO patients were included. Propensity matching yielded 190 well-matched patients in each group. No significant differences were observed between the groups in either ICH or sICH (odds ratio (OR): 0.80, 95% confidence interval (CI) 0.51-1.24, P=0.37; OR: 0.60, 95% CI 0.29 to 1.24, P=0.21, respectively). Rates of successful recanalization and early neurological improvement (ENI) were significantly lower in MT+IVT + IAT. mRS 0-1 and mortality were not significantly different between the two groups. However, the MT+IVT + IAT group demonstrated superior rates of good functional outcomes (90-day mRS 0-1) compared with patients in the MT+IVT group who had mTICI ≤2B, (OR: 2.18, 95% CI 1.05 to 3.99, P=0.04). CONCLUSION: The combined use of IAT and IVT thrombolysis in AIS-LVO patients undergoing MT is safe. Although the MT+IVT+ IAT group demonstrated lower rates of recanalization and early neurological improvement, long-term functional outcomes were favorable in this group suggesting a potential delayed benefit of IAT.

Temporal Changes on Postgadolinium MR Vessel Wall Imaging Captures Enhancement Kinetics of Intracranial Atherosclerotic Plaques and Aneurysms.

BACKGROUND AND PURPOSE: Analysis of vessel wall contrast kinetics (ie, wash-in/washout) is a promising method for the diagnosis and risk-stratification of intracranial atherosclerotic disease plaque (ICAD-P) and the intracranial aneurysm walls (IA-W). We used black-blood MR imaging or MR vessel wall imaging to evaluate the temporal relationship of gadolinium contrast uptake kinetics in ICAD-Ps and IA-Ws compared with normal anatomic reference structures. MATERIALS AND METHODS: Patients with ICAD-Ps or IAs who underwent MR vessel wall imaging with precontrast, early postcontrast (5-15 minutes), and delayed postcontrast (20-30 minutes) 3D T1-weighted TSE sequences were retrospectively studied. ROIs of a standardized diameter (2 mm) were used to measure the signal intensities of the cavernous sinus, pituitary infundibulum, temporalis muscle, and choroid plexus. Point ROIs were used for ICAD-Ps and IA-Ws. All ROI signal intensities were normalized to white matter signal intensity obtained using ROIs of 10-mm diameter. Measurements were acquired on precontrast, early postcontrast, and delayed postcontrast 3D T1 TSE sequences for each patient.ajnr;45/9/1206/T1T1T1Table 1:MR-VWI parameters for ICAD-Ps and IAsParameterValueSequence3D TSEScan planeAxialFOV (mm)160TR/TE (ms)800/28-32BW (Hx/pixel)370θ120Acceleration2ETL42Matrix acquisition0.5 mm ×0.5 mmMatrix recon0.5 mm ×0.5 mmNo. of slices/thick120/0.5Note:-FOV indicates field of view; TR, the repetition time; TE, the echo time; BW, bandwidth; ETL, echo train length; Matrix recon, matrix reconstruction. RESULTS: Ten patients with 17 symptomatic ICAD-Ps and 30 patients with 34 IA-Ws were included and demonstrated persisting contrast uptake (P < .001) of 7.21% and 10.54% beyond the early phase (5-15 minutes postcontrast) and in the delayed phase (20-30 minutes postcontrast) on postcontrast MR vessel wall imaging. However, normal anatomic reference structures including the pituitary infundibulum and cavernous sinus demonstrated a paradoxical contrast washout in the delayed phase. In both ICAD-Ps and IA-Ws, the greatest percentage of quantitative enhancement (>70%-90%) occurred in the early phase of postcontrast imaging, consistent with the rapid contrast uptake kinetics of neurovascular pathology. CONCLUSIONS: Using standard MR vessel wall imaging techniques, our results demonstrate the effects of gadolinium contrast uptake kinetics in ICAD-Ps and IA-Ws with extended accumulating enhancement into the delayed phase (> 15 minutes) as opposed to normal anatomic reference structures that conversely exhibit decreasing enhancement. Because these relative differences are used to assess qualitative patterns of ICAD-P and IA-W enhancement, our findings highlight the importance of standardizing acquisition time points and MR vessel wall imaging protocols to interpret pathologic enhancement for the risk stratification of cerebrovascular pathologies.

Earlier Endovascular Thrombectomy and Mortality in Patients with Anterior Circulation Large Vessel Occlusion: A Propensity-Matched Analysis of the Stroke Thrombectomy and Aneurysm Registry.

BACKGROUND: The definitive impact of onset to arterial puncture time (OPT) on 90-day mortality after endovascular thrombectomy (EVT) in patients with acute ischemic stroke (AIS) caused by anterior circulation large vessel occlusion (LVO) remains unknown. The present study aimed to evaluate the influence of OPT on 90-day mortality in anterior circulation AIS-LVO patients who underwent EVT. METHODS: Data from 33 international centers were retrospectively analyzed. The receiver operating characteristic curve analysis was used to identify a cutoff for OPT. A propensity score-matched analysis was performed. The primary outcome was 90-day mortality (modified Rankin Scale [mRS] 6). Secondary outcomes included mortality at discharge, 90-day good outcome (mRS 0-2), 90-day poor outcome (mRS 5-6), successful recanalization (defined as postprocedure modified Thrombolysis in Cerebral Infarction scale ≥2b), and intracranial hemorrhage. RESULTS: A total of 2842 AIS-LVO patients with EVT were included. The cutoff for OPT for 90-day mortality was 180 min. Of these 378 patients had OPT <180 min and 378 patients had OPT ≥180 min in the propensity score-matched cohort (n = 756). Patients with OPT <180 min were less likely to have 90-day mortality (odds ratio [OR] 0.70, 95% confidence interval [CI] 0.51-0.96) and poor outcome (OR 0.71, 95% CI 0.53-0.96), and more likely to have 90-day good outcome (OR 1.55, 95% CI 1.16-2.08). Other outcomes showed no significant differences. CONCLUSIONS: This study showed that OPT <180 min was less related to 90-day mortality and poor outcome, and more to 90-day good outcome in AIS-LVO patients who underwent EVT.

Neuropsychological Test Performance Differentiates Subgroups of Individuals With Adult Moyamoya Disease: A Cross-Sectional Clinical Study.

BACKGROUND AND OBJECTIVES: Moyamoya disease (MMD) is a rare noninflammatory disorder involving progressive intracranial vasculopathy and impaired cerebral blood flow in the anterior circulation, resulting in stroke and cognitive impairment. We aimed to characterize cognitive impairment and the possible predictive value of sociodemographic and clinical characteristics of adults with MMD. METHODS: This cross-sectional study examined neurocognitive performance in a group of 42 consecutive adult patients (mean age = 40.52 years; 69% female) referred for a presurgical neuropsychological evaluation. Neuropsychological functioning was assessed with a comprehensive battery, and cognitive dysfunction was defined as 1.5 SDs below the mean. Neurocognitive performance correlated with clinical/demographic characteristics and disease markers. RESULTS: Most patients (91%) had a history of stroke, and 45% had cognitive deficits, most notably on measures of attention/speed (48%), executive functioning (47%), visuoconstruction (41%), and memory (31%-54%). Only higher educational attainment and poor collateral blood flow in the right hemisphere differentiated cognitively impaired (n = 19) and intact groups (n = 23), and MMD-related characteristics (eg, disease duration, stroke history) did not differentiate the 2 groups. CONCLUSION: Consistent with previous work, frontal-subcortical cognitive deficits (eg, deficits in mental speed, attention, executive functioning) were found in nearly half of patients with MMD and better cognitive performance was associated with factors related to cognitive reserve. Angiographic metrics of disease burden (eg, Suzuki rating, collateral flow) and hemodynamic reserve were not consistently associated with poorer cognitive outcomes, suggesting that cognition is a crucial independent factor to assess in MMD and has relevance for treatment planning and functional status.

Endovascular Versus Medical Management in Distal Medium Vessel Occlusion Stroke: The DUSK Study.

BACKGROUND: Endovascular treatment (EVT) is part of the usual care for proximal vessel occlusion strokes. However, the safety and effectiveness of EVT for distal medium vessel occlusions remain unclear. We sought to compare the clinical outcomes of EVT to medical management (MM) for isolated distal medium vessel occlusions. METHODS: This is a retrospective analysis of prospectively collected data from seven comprehensive stroke centers. Patients were included if they had isolated distal medium vessel occlusion strokes due to middle cerebral artery M3/M4, anterior cerebral artery A2/A3, or posterior cerebral artery P1/P2 segments. Patients treated with EVT or MM were compared with multivariable logistic regression and inverse probability of treatment weighting. The primary outcome was the shift in the degree of disability as measured by the modified Rankin Scale (mRS) at 90 days. Secondary outcomes included 90-day good (mRS score, 0-2) and excellent (mRS score, 0-1) outcomes. Safety measures included symptomatic intracranial hemorrhage and 90-day mortality. RESULTS: A total of 321 patients were included in the analysis (EVT, 179; MM, 142; 40.8% treated with intravenous thrombolysis). In the inverse probability of treatment weighting model, there were no significant differences between EVT and MM in terms of the overall degree of disability (mRS ordinal shift; adjusted odds ratio [aOR], 1.25 [95% CI, 0.95-1.64]; P=0.110), rates of good (mRS score, 0-2; aOR, 1.32 [95% CI, 0.97-1.80]; P=0.075) and excellent (aOR, 1.32 [95% CI, 0.94-1.85]; P=0.098) outcomes, or mortality (aOR, 1.20 [95% CI, 0.78-1.85]; P=0.395) at 90 days. The multivariable regression model showed similar findings. Moreover, there was no difference between EVT and MM in rates of symptomatic intracranial hemorrhage in the multivariable regression model (aOR, 0.57 [95% CI, 0.21-1.58]; P=0.277), but the inverse probability of treatment weighting model showed a lower likelihood of symptomatic intracranial hemorrhage (aOR, 0.46 [95% CI, 0.24-0.85]; P=0.013) in the EVT group. CONCLUSIONS: This multicenter study failed to demonstrate any significant outcome differences among patients with isolated distal medium vessel occlusions treated with EVT versus MM. These findings reinforce clinical equipoise. Randomized clinical trials are ongoing and will provide more definite evidence.

Anesthesia modality in endovascular treatment for distal medium vessel occlusion stroke: intention-to-treat propensity score-matched analysis.

BACKGROUND: The optimal anesthesia modality during endovascular treatment (EVT) for distal medium vessel occlusion (DMVO) stroke is uncertain. We aimed to evaluate the association of the anesthesia modality with procedural and clinical outcomes following EVT for DMVO stroke. METHODS: This is a multicenter retrospective analysis of a prospectively collected database. Patients were included if they had DMVO involving the middle cerebral artery-M3/4, anterior cerebral artery-A2/3, or posterior cerebral artery-P1/P2-3, and underwent EVT. The cohort was divided into two groups, general anesthesia (GA) and non-general anesthesia (non-GA), and compared based on the intention-to-treat principle as primary analysis. We used propensity scores to balance the two groups. The primary outcome was the shift in the degree of disability as measured by the 90-day modified Rankin Scale (mRS). Secondary outcomes included successful reperfusion, as well as excellent (mRS 0-1) and good (mRS 0-2) clinical outcomes at 90 days. Safety measures included procedural complications, symptomatic intracerebral hemorrhage (sICH), and 90-day mortality. RESULTS: Among 366 DMVO thrombectomies, 61 matched pairs were eligible for analysis. Median age and National Institutes of Health Stroke Scale score as well as other baseline demographic and clinical characteristics were balanced between both groups. The GA group had no difference in the overall degree of disability (common OR 1.19, 95% CI 0.52 to 2.86, P=0.67) compared with the non-GA arm. Likewise, the GA group had comparable rates of successful reperfusion (OR 2.38, 95% CI 0.80 to 7.07, P=0.12), good/excellent clinical outcomes (OR 1.14, 95% CI 0.44 to 2.96, P=0.79/(OR 0.65, 95% CI 0.24 to 1.81, P=0.41), procedural complications (OR 1.00, 95% CI 0.19 to 5.16, P>0.99), sICH (OR 3.24, 95% CI 0.83 to 12.68, P=0.09), and 90-day mortality (OR 1.43, 95% CI 0.48 to 4.27, P=0.52) compared with the non-GA group. CONCLUSIONS: In patients with DMVO, our study showed that GA and non-GA groups had similar procedural and clinical outcomes, as well as safety measures. Further larger controlled studies are warranted.

Glue embolization of ruptured pseudoaneurysm secondary to reversible cerebral vasoconstriction syndrome: An illustrative case.

BACKGROUND: Reversible cerebral vasoconstriction syndrome (RCVS) is an increasingly recognized condition characterized by thunderclap headache with or without other neurological deficits and diffuse vasoconstriction of cerebral arteries. Altered cerebrovascular tone may produce hemorrhage or stroke. METHODS: A retrospective review of patients with RCVS at our institution (2000-2023) yielded one case of pseudoaneurysm secondary to RCVS. RESULTS: Diagnostic cerebral angiogram demonstrated diffuse multifocal segmental narrowing consistent with RCVS and a left M4 pseudoaneurysm in proximity to the cortical hemorrhage. The pseudoaneurysm was treated with branch vessel sacrifice using nBCA glue in a 1 : 3 ratio with ethiodized oil. After securing the source of hemorrhage, the patient received an intra-arterial infusion of Verapamil. CONCLUSION: This unique presentation of pseudoaneurysm secondary to RCVS in this patient highlights the impact of hemodynamic alteration as a possible source of bleeding and demonstrates a potential management strategy. Endovascular management with nBCA glue embolization successfully treated this lesion.

Revisiting the normal perfusion pressure breakthrough phenomenon in the era of endovascular treatment of cerebral arteriovenous malformations.

Post-operative cerebral edema and hemorrhage are common after resection of cerebral arteriovenous malformations. This has traditionally been attributed to normal perfusion pressure breakthrough, a phenomenon of pathologic vasoreactivity in the surrounding brain caused by chronic oligemia from the nearby shunt. As endovascular techniques for arteriovenous malformation treatment have advanced, more arteriovenous malformations are being treated without open surgery, even to the point of cure. Here we revisit the concept of normal perfusion pressure breakthrough as applied to the hemodynamic changes after arteriovenous malformation embolization, which we propose is responsible for the persistent rate of hemorrhagic complications seen after these procedures.

Predictors of angiographic resolution in patients with presumed reversible cerebral vasoconstriction syndrome.

INTRODUCTION: Reversible cerebral vasoconstriction syndrome is a complex neurovascular syndrome that presents with varying neurological deficits as well as segmental vasoconstriction of the small and medium cerebral arteries. There is limited literature on pathologies that mimic reversible cerebral vasoconstriction syndrome, so this study aims to understand what factors may impact the angiographic confirmation of reversible cerebral vasoconstriction syndrome on follow-up and play a role in establishing the diagnosis. METHODS: The Clinical Research Data Warehouse at this institution was employed to search the medical records for patients with diagnosis and treatment of reversible cerebral vasoconstriction syndrome between January 2010 and May 2021. After screening, 32 patients met the inclusion criteria for a presumed diagnosis of reversible cerebral vasoconstriction syndrome with both angiography on presentation and at three-month follow-up after treatment. Patients were divided into two categories: those with complete angiographic resolution, versus partial or no improvement on follow-up. Clinical and radiographic data were analyzed. RESULTS: Patients who had partial or no resolution were more likely to have a history of hypertension (p = 0.001), higher systolic blood pressure on admission (p = 0.047), and present with a recurrent thunderclap headache (p = 0.038). Binary logistic regression selected for hypertension (odds ratio [OR] 18.35 [95% CI, 1.37-245.1]) as predictive of not having reversible cerebral vasoconstriction syndrome, as can be seen by partial or no resolution on follow-up angiography (p = 0.028). CONCLUSION: Complete resolution on follow-up angiography is a distinguishing factor of reversible cerebral vasoconstriction syndrome. Our analysis revealed that a history of hypertension is the most significant predictor of confirming that a patient may not have reversible cerebral vasoconstriction syndrome. This is due, in part, to increased atherosclerotic or hypertensive cerebral arterial changes, which can mimic reversible cerebral vasoconstriction syndrome and present as partial or no resolution on angiography.

Refinement of nBCA embolization technique in treatment of metastatic spinal tumors: Case series and technical report.

BACKGROUND AND OBJECTIVES: Preoperative embolization of metastatic spinal tumors (MSTs) has proven advantageous in limiting intraoperative blood loss (IBL) during resection. N-butyl cyanoacrylate (nBCA) is a liquid embolic agent known for its rapid hemostatic effects. However, nBCA is associated with a higher risk of distal nontarget embolization. This study highlights the refinement of the embolization technique and assesses its efficacy in performing an initial distal segmental artery plug with concentrated nBCA followed by proximal diluted nBCA for MSTs. METHODS: A retrospective review of patients with MST (2018-2023) was performed. Patients who underwent preoperative nBCA endovascular embolization prior to tumor resection and spinal instrumentation were included. Baseline standard spinal angiography was performed. RESULTS: Sixteen patients (13 men, 3 women; 56.0 ± 12.4 years) met inclusion criteria. And 43.75% (7 of 16) had thoracic levels, 37.5% (6 of 16) lumbar, and 18.75% (3 of 16) sacral. The most common primary tumor was renal cell carcinoma (43.75%, 7 of 16). A total of 43 pedicles were embolized (median 3), resulting in complete/near complete obliteration of the tumor blush. Most pedicles (83.7%, 36 of 43) received a single dilute concentration of nBCA; however, 16.3% (7 of 43) received two separate concentrations of nBCA, a denser concentration distally into the segmental artery and a diluted concentration proximally into the tumor bed. Mean IBL was 1150 ± 1201 mL in 3 distal plug patients distal plug patients versus 1625 ± 681 mL in 12 other patients. There were no complications related to embolization. CONCLUSION: Performing a distal, concentrated nBCA plug during preoperative nBCA embolization of MSTs may increase tumor penetration and reduce IBL.

The natural history of aneurysms incompletely occluded by placement of a flow diverter: a multiinstitutional study.

OBJECTIVE: Treatment of intracranial aneurysms by flow diversion is safe and effective and is increasingly popular. However, the correct treatment paradigm for aneurysms incompletely treated by initial placement of a flow diverter has not been established, nor have the subsequent natural history and occlusion rates of such aneurysms. The authors sought to outline the natural history of such aneurysms, which to date have been considered partially treated. METHODS: The authors retrospectively reviewed consecutive cases from 6 high-volume neurointerventional services, including all cases in which the first follow-up imaging after placement of a flow diverter showed incomplete occlusion of the aneurysm, and for which subsequent clinical and/or radiological follow-up was available. All included patients were treated with the Pipeline Flex embolization device or the Pipeline Flex embolization device with Shield Technology. Subsequent radiographic and clinical outcome data were collected and analyzed using the Kaplan-Meier survival function. RESULTS: A total of 263 patients with persistently patent aneurysms on first follow-up imaging after flow diversion were identified. Of these, 204 had clinical follow-up and 152 had additional imaging follow-up. Of this final cohort, 148 aneurysms were unruptured, and 4 were ruptured. The average aneurysm size by maximum dimension was 10.8 mm. The average recorded follow-up was 27.8 months in the cohort, with some patients followed for as long as 9 years from treatment. Over the course of 403 person-years of follow-up, no delayed aneurysm ruptures were recorded. Both with and without retreatment, aneurysms showed a trend toward progressive occlusion over time. Complications related to device placement were low. CONCLUSIONS: Aneurysms that have been incompletely treated by flow diversion have a benign natural history with progression toward occlusion over time, with or without retreatment.

Are hemodynamics responsible for inflammatory changes in venous vessel walls? A quantitative study of wall-enhancing intracranial arteriovenous malformation draining veins.

OBJECTIVE: Signal enhancement of vascular walls on vessel wall MRI might be a biomarker for inflammation. It has been theorized that contrast enhancement on vessel wall imaging (VWI) in draining veins of intracranial arteriovenous malformations (AVMs) may be associated with disease progression and development of venous stenosis. The aim of this study was to investigate the relationship between vessel wall enhancement and hemodynamic stressors along AVM draining veins. METHODS: Eight AVM patients with 15 draining veins visualized on VWI were included. Based on MR venography data, patient-specific 3D surface models of the venous anatomy distal to the nidus were segmented. The enhanced vascular wall regions were manually extracted and mapped onto the venous surface models after registration of image data. Using image-based blood flow simulations applying patient-specific boundary conditions based on phase-contrast quantitative MR angiography, hemodynamics were investigated in the enhanced vasculature. For the shear-related parameters, time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT) were calculated. Velocity, oscillatory velocity index (OVI), and vorticity were extracted for the intraluminal flow-related hemodynamics. RESULTS: Visual observations demonstrated overlap of enhancement with local lower shear stresses resulting from decreased velocities. Thus, higher RRT values were measured in the enhanced areas. Furthermore, nonenhancing draining veins showed on average slightly higher flow velocities and TAWSS. Significant decreases of 55% (p = 0.03) for TAWSS and of 24% (p = 0.03) for vorticity were identified in enhanced areas compared with near distal and proximal domains. Velocity magnitude in the enhanced region showed a nonsignificant decrease of 14% (p = 0.06). Furthermore, increases were present in the OSI (32%, p = 0.3), RRT (25%, p = 0.15), and OVI (26%, p = 0.3) in enhanced vessel sections, although the differences were not significant. CONCLUSIONS: This novel multimodal investigation of hemodynamics in AVM draining veins allows for precise prediction of occurring shear- and flow-related phenomena in enhanced vessel walls. These findings may suggest low shear to be a local predisposing factor for venous stenosis in AVMs.

A patient-specific circle of Willis blood flow model in predicting outcomes of balloon test occlusion.

BACKGROUND AND PURPOSE: Balloon test occlusion (BTO) evaluates cerebral ischemic tolerance before internal carotid artery (ICA) sacrifice but carries risks like dissection and thrombosis. This study introduces a new approach using a patient-specific circle of Willis (COW) blood flow model, based on non-invasive quantitative MR angiography (qMRA) measurements, to predict the outcomes of BTO. METHODS: We developed individualized COW blood flow models for 43 patients undergoing BTO. These models simulated blood flow and pressure under normal conditions and with the ICA occlusion. We then compared the model's predictions of blood flow changes due to the simulated ICA occlusion to actual qMRA measurements before the BTO. RESULTS: For all 31 BTO failures, the ipsilateral hemisphere showed an average flow decrease of 15 ± 10% (mean ± standard deviation), compared to 3 ± 2% in the contralateral hemisphere. In all 12 BTO passes, these figures were 6 ± 3% and 1 ± 0.8%, respectively. Notably, all BTO passes had less than a 10% reduction in the ipsilateral hemisphere. In contrast, 65% of BTO failures and 67% single-photon emission computed tomography (SPECT) failures exhibited a decrease of 10% or more in the same region. CONCLUSION: Blood flow reduction exceeding 10% in the ipsilateral hemisphere during BTO is a strong predictor of failure in both BTO and SPECT. Our patient-specific COW blood flow models, incorporating detailed flow and arterial geometry data, offered valuable insights for predicting BTO outcomes. These models are especially beneficial for situations where conducting BTO or SPECT is clinically impractical.

Dural arteriovenous fistulas are not observed to convert to a higher grade after partial embolization.

OBJECTIVE: Borden-Shucart type I dural arteriovenous fistulas (dAVFs) lack cortical venous drainage and occasionally necessitate intervention depending on patient symptoms. Conversion is the rare transformation of a low-grade dAVF to a higher grade. Factors associated with increased risk of dAVF conversion to a higher grade are poorly understood. The authors hypothesized that partial treatment of type I dAVFs is an independent risk factor for conversion. METHODS: The multicenter Consortium for Dural Arteriovenous Fistula Outcomes Research database was used to perform a retrospective analysis of all patients with type I dAVFs. RESULTS: Three hundred fifty-eight (33.2%) of 1077 patients had type I dAVFs. Of those 358 patients, 206 received endovascular treatment and 131 were not treated. Two (2.2%) of 91 patients receiving partial endovascular treatment for a low-grade dAVF experienced conversion to a higher grade, 2 (1.5%) of 131 who were not treated experienced conversion, and none (0%) of 115 patients who received complete endovascular treatment experienced dAVF conversion. The majority of converted dAVFs localized to the transverse-sigmoid sinus and all received embolization as part of their treatment. CONCLUSIONS: Partial treatment of type I dAVFs does not appear to be significantly associated with conversion to a higher grade.

Comparison between transradial and transfemoral mechanical thrombectomy for ICA and M1 occlusions: insights from the Stroke Thrombectomy and Aneurysm Registry (STAR).

BACKGROUND: The role for the transradial approach for mechanical thrombectomy is controversial. We sought to compare transradial and transfemoral mechanical thrombectomy in a large multicenter database of acute ischemic stroke. METHODS: The prospectively maintained Stroke Thrombectomy and Aneurysm Registry (STAR) was reviewed for patients who underwent mechanical thrombectomy for an internal carotid artery (ICA) or middle cerebral artery M1 occlusion. Multivariate regression analyses were performed to assess outcomes including reperfusion time, symptomatic intracerebral hemorrhage (ICH), distal embolization, and functional outcomes. RESULTS: A total of 2258 cases, 1976 via the transfemoral approach and 282 via the transradial approach, were included. Radial access was associated with shorter reperfusion time (34.1 min vs 43.6 min, P=0.001) with similar rates of Thrombolysis in Cerebral Infarction (TICI) 2B or greater reperfusion (87.9% vs 88.1%, P=0.246). Patients treated via a transradial approach were more likely to achieve at least TICI 2C (59.6% vs 54.7%, P=0.001) and TICI 3 reperfusion (50.0% vs 46.2%, P=0.001), and had shorter lengths of stay (mean 9.2 days vs 10.2, P<0.001). Patients treated transradially had a lower rate of symptomatic ICH (8.0% vs 9.4%, P=0.047) but a higher rate of distal embolization (23.0% vs 7.1%, P<0.001). There were no significant differences in functional outcome at 90 days between the two groups. CONCLUSIONS: Radial and femoral thrombectomy resulted in similar clinical outcomes. In multivariate analysis, the radial approach had improved revascularization rates, fewer cases of symptomatic ICH, and faster reperfusion times, but higher rates of distal emboli. Further studies on the optimal approach are necessary based on patient and disease characteristics.