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Introduction: The major mechanism of morbidity of delayed cerebral ischemia after subarachnoid hemorrhage (SAH) is considered to be severe vasospasm. Quantitative MRA (QMRA) provides direct measurements of vessel-specific volumetric blood flow and may permit a clinically relevant assessment of the risk of ischemia secondary to cerebral vasospasm. Purpose: To evaluate the utility of QMRA as an alternative imaging technique for the assessment of cerebral vasospasm after SAH. Methods: QMRA volumetric flow rates of the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) were compared with vessel diameters on catheter-based angiography. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of QMRA for detecting cerebral vasospasm was determined by receiver-operating characteristic curves. Spearman correlation coefficients were calculated for QMRA flow versus angiographic vessel diameter. Results: Sixty-six vessels (10 patients) were evaluated with QMRA and catheter-based angiography. The median percent QMRA flow of all vessels with angiographic vasospasm (55.0%, IQR 34.3–71.6%) was significantly lower than the median percent QMRA flow of vessels without vasospasm (91.4%, IQR 81.4–100.4%) (p < 0.001). Angiographic vasospasm reduced QMRA-assessed flow by 23 ± 5 (p = 0.018), 95 ± 12 (p = 0.042), and 16 ± 4 mL/min (p = 0.153) in the ACA, MCA, and PCA, respectively, compared to vessels without angiographic vasospasm. The sensitivity, specificity, PPV, and NPV of QMRA for the discrimination of cerebral vasospasm was 84%, 72%, 84%, and 72%, respectively, for angiographic vasospasm >25% and 91%, 60%, 87%, and 69%, respectively, for angiographic vasospasm >50%. The Spearman correlation indicated a significant association between QMRA flows and vessel diameters (rs = 0.71, p < 0.001). Conclusion: Reduction in QMRA flow correlates with angiographic vessel narrowing and may be useful as a non-invasive imaging modality for the detection of cerebral vasospasm after SAH. [ABSTRACT FROM AUTHOR]

Cerebrospinal fluid (CSF) fistulas have recently been recognized as a cause of spontaneous intracranial hypotension (SIH), predominantly presenting with headaches, especially positional headaches. Atypical presentations like tinnitus and cranial nerve symptoms have also been reported. SIH has been linked to venous sinus thrombosis; however, to our knowledge, no prior cases describe a CSF venous fistula causing SIH that leads to cerebral venous thrombosis and coma. We report a patient who developed progressive venous sinus thrombosis, leading to coma, and was found to have low intracranial pressure indicative of SIH. Invasive monitoring and imaging confirmed the low intracranial pressure, prompting a dynamic myelogram that revealed a T2/3 CSF venous fistula. The patient underwent transvenous embolization of the fistula, which resulted in the resolution of symptoms and almost immediate improvement in both venous thrombosis and intracranial hypotension. CSF venous fistulae as a cause of SIH is a recently recognized entity, with ongoing research into its treatment through transvenous embolization. Most documented cases focus on patients with headaches. This case highlights a novel presentation, emphasizing the importance of thorough diagnostic workup in patients with cerebral venous thrombosis. Early detection and treatment of this condition can lead to significant clinical improvement, including the resolution of coma. [ABSTRACT FROM AUTHOR]

Introduction: Quantitative magnetic resonance angiography and non-invasive optimal vessel analysis serve as powerful tools to collect and analyze hemodynamic data from pipeline embolization patients. At our institution, patients receive post-embolization quantitative magnetic resonance angiography within 24 h of treatment and within 6 months for follow-up to evaluate pipeline patency. Here, we aim to elucidate the long-term hemodynamic changes following pipeline embolization device placement and report two cases in which in-stent stenosis was detected. Methods: Medical records of patients who underwent pipeline embolization device placement for an internal carotid artery aneurysm between 2017 and 2019 were reviewed. Patients who received post-procedure NOVA and follow-up NOVA were included in the study (n = 32). Location and size of aneurysm, number of pipeline embolization device deployed, and complications were collected along with the non-invasive optimal vessel analysis report (flow volume rate (ml/min), mean, systolic, and diastolic flow velocities (cm/s), and vessel diameter (mm)). Internal carotid artery vessel flow rate was measured proximal to the pipeline embolization device. Derivations of hemodynamic parameters (pulsatility index, Lindegaard ratio, and wall shear stress) were calculated. Results: The middle cerebral artery mean and diastolic flow velocities were significantly lower on the follow-up NOVA compared to the post-procedure NOVA. Moreover, follow-up NOVA demonstrated lower middle cerebral artery wall shear stress on the side with flow diversion compared to the post-procedure NOVA. In-stent stenosis, requiring intervention, was detected in two patients on follow-up NOVA. One patient had a successful balloon angioplasty of the stented internal carotid artery that resolved her stenosis. However, the second patient developed progressive stenosis and expired despite intervention. Conclusion: Long-term hemodynamic adaptations post-pipeline embolization device demonstrate decreased wall shear stress and decreased mean and diastolic flow velocities in the distal middle cerebral artery, which suggest decreasing velocity of blood flow with endothelialization of the device. Furthermore, follow-up NOVA is a useful tool for detecting potential flow-related complications such as in-stent stenosis. [ABSTRACT FROM AUTHOR]

Introduction: Delayed intraparenchymal hemorrhage is a known complication of the Pipeline Embolization device (PED); however, its etiology is unclear and some have suggested it is a flow related phenomenon. Quantitative magnetic resonance angiography (QMRA) serves as a powerful tool to collect and analyze hemodynamic data. We report a detailed characterization of short-term hemodynamics after PED placement. Methods: Patients who underwent PED placement for a distal internal carotid artery (ICA) aneurysm between 2017 to 2019 with post embolization QMRA were reviewed. Aneurysm characteristics, flow volume rate (ml/min), mean, systolic, and diastolic flow velocities (cm/s), vessel diameter (mm), pulsatility index, Lindegaard ratio, and wall shear stress (WSS) were collected. Results: A total of 67 patients were included. Post-procedure patients were found to have a significantly lower ICA flow on the side with flow diversion when compared to the side without flow diversion (218 vs. 236.3; P < 0.05). Average ICA flow after flow diversion for aneurysms >2 cm was significantly lower when compared to the untreated side (187.7 vs. 240.4; P < 0.05). There was no difference in MCA or ACA flow or velocity. WSS was significantly lower in the treated ICA (8.2 vs. 9.0; P < 0.05). Lindegaard ratio was not different in the treated vs. contralateral untreated sides. Conclusion: PED placement for distal ICA aneurysms results in lower flow, mean velocity, and WSS when compared to the contralateral untreated ICA. This is not demonstrated distal to the Pipeline device in the ACA or MCA territories. Ultimately these findings suggest hemodynamic changes are not a cause of PED complications. [ABSTRACT FROM AUTHOR]

Introduction: The concurrent use of endoluminal flow diversion with coils is a viable option when treating complex or large aneurysms. Alternatives to coil embolization as an adjunctive treatment are currently limited. The Food and Drug Administration recently approved the Woven EndoBridge (WEB) device (Microvention, Aliso Viejo, California) as an intrasaccular flow diverter for wide-neck bifurcation aneurysms. We present the technical aspects of combined WEB device plus endoluminal flow diversion for the treatment of complex wide-necked intracranial aneurysms. Methods: A retrospective chart review of all patients treated via intrasaccular flow diversion at a single institution over the last 12 months was performed. Results: In total, seven patients underwent treatment of eight aneurysms via combined intrasaccular and endoluminal flow diversion. Of the seven patients, six were treated in a single setting. The most common aneurysm location was the posterior communicating artery. The majority of the aneurysms required steam shaping of the Via deployment catheter to place the WEB device orthogonally to the aneurysm dome. There were no complications. Conclusions: We believe this is one of the first series reporting the combined use of the WEB device and endoluminal flow diversion for the treatment of intracranial aneurysms. This series demonstrates that the concurrent use of the WEB device with endoluminal flow diversion is safe for achieving immediate aneurysm treatment and may enhance the long-term durability in complex aneurysms. [ABSTRACT FROM AUTHOR]

The Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke (VERiTAS) study determined patients with low flow in their vertebrobasilar (VB) system are at increased risk of recurrent stroke. Endovascular interventions such as angioplasty and stenting are reserved for patients with refractory symptoms; however, few series to date have demonstrated either hemodynamic or clinical outcomes in this high-risk patient group. We present our combined institutional series of patients with symptomatic VB atherosclerotic disease and low-flow state who underwent angioplasty and stenting.Retrospective chart review of patients undergoing angioplasty and stenting for symptomatic VB atherosclerotic disease at two institutions was performed. Clinical and radiographical outcomes were collected including flow rates using quantitative MRA (QMRA) pre- and post-stenting.Seventeen patients underwent angioplasty and stenting for symptomatic VB atherosclerotic disease and met VERiTAS low-flow state criteria. There were four cases (23.5%) of periprocedural stroke, two of which were minor and transient. The stent was placed intracranially in 82.4% of patients. Basilar and bilateral posterior cerebral artery (PCA) flows significantly improved post-stenting (p < 0.05) and normalized based upon VERiTAS criteria in all patients. Fourteen patients had delayed QMRA at mean follow-up 20 months demonstrating appropriate patency and flow post-stenting. Two patients (10%) had recurrent stroke, one from medication nonadherence and in-stent thrombosis, and the other from a procedural dissection that subsequently became symptomatic.Our series demonstrates angioplasty and stenting significantly improve intracranial flow over long-term. Angioplasty and stenting may improve the natural history of low-flow VB atherosclerotic disease. [ABSTRACT FROM AUTHOR]

Endovascular coiling of small, intracranial aneurysms remains controversial and difficult, despite advances in technology.We retrospectively reviewed data for 62 small aneurysms (<3.99 mm) in 59 patients. Occlusion rates, complications rates, and coil packing densities were compared between subgroups based upon coil type and rupture status.Ruptured aneurysms predominated (67.7%). Aneurysms measured 2.99 ± 0.63 mm by 2.51 ± 0.61 mm with an aspect ratio of 1.21 ± 0.34 mm. Brands included Optima (Balt) (29%), MicroVention Hydrogel (24.2%), and Penumbra SMART (19.4%) coil systems. Average packing density was 34.3 ± 13.5 mm3. Occlusion rate was 100% in unruptured aneurysms; 84% utilized adjuvant devices. For ruptured aneurysms, complete occlusion or stable neck remnant was achieved in 88.6% while recanalization occurred in 11.4%. No rebleeding occurred. Average packing density (p = 0.919) and coil type (p = 0.056) did not impact occlusion. Aspect ratio was smaller in aneurysms with technical complications (p = 0.281), and aneurysm volume was significantly smaller in those with coil protrusion (p = 0.018). Complication rates did not differ between ruptured and unruptured aneurysms (22.6 vs. 15.8%, p = 0.308) or coil types (p = 0.830).Despite advances in embolization devices, coiling of small intracranial aneurysms is still scrutinized. High occlusion rates are achievable, especially in unruptured aneurysms, with coil type and packing density suggesting association with complete occlusion. Technical complications may be influenced by aneurysm geometry. Advances in endovascular technologies have revolutionized small aneurysm treatment, with this series demonstrating excellent aneurysm occlusion especially in unruptured aneurysms. [ABSTRACT FROM AUTHOR]

Objective: The authors sought to determine the predictors of late neurological and hospital-acquired medical complications (HACs) in patients with low-grade aneurysmal subarachnoid hemorrhage (aSAH)., Methods: The authors conducted a retrospective study of 424 patients with low-grade aSAH admitted to their institution from 2008 to 2015. Data collected included patient comorbidities, Hunt and Hess (HH) grade, ICU length of stay (LOS), and complications. A logistic regression analysis was performed to determine the predictors for neurological and hospital-associated complications., Results: Out of 424 patients, 50 (11.8%) developed neurological complications after the first week, with a mean ICU stay of 16.3 ± 6.5 days. Of the remaining 374 patients without late neurological complications, 83 (22.2%) developed late HACs with a mean LOS of 15.1 ± 7.6 days, while those without medical complications stayed 11.8 ± 6.2 days (p = 0.001). Of the 83 patients, 55 (66.3%) did not have any HACs in the first week. Smoking (p = 0.062), history of cardiac disease (p = 0.043), HH grade III (p = 0.012), intraventricular hemorrhage (IVH) (p = 0.012), external ventricular drain (EVD) placement (p = 0.002), and early pneumonia/urinary tract infection (UTI)/deep vein thrombosis (DVT) (p = 0.001) were independently associated with late HACs. Logistic regression showed early pneumonia/UTI/DVT (p = 0.026) and increased HH grade (p = 0.057) to be significant risk factors for late medical complications., Conclusions: While an extended ICU admission allows closer monitoring, low-grade aSAH patients develop HACs despite being at low risk for neurological complications. The characteristics of low-grade aSAH patients who would benefit from early discharge are reported in detail.