Mid-term assessment of transverse sinus stent patency in 104 patients treated for intracranial hypertension secondary to dural sinus stenosis.

BACKGROUND: Transverse sinus (TS) stenting is a valid treatment alternative for patients with intracranial hypertension caused by underlying bilateral TS stenoses. Its mid-term patency has, however, not been well documented. OBJECTIVE: To assess the 6-month patency of TS stenting using subtracted CT venography (CTV). METHODS: A retrospective analysis of a prospectively collected database of patients undergoing TS stenting was performed. The cohort was a single-center, single-operator series of 125 consecutive patients treated between 2008 and 2018. Mid-term follow-up 320-row detector CTV was available for review in 104 patients. RESULTS: Follow-up CTV was obtained on average 6 months after stenting. Stents in all patients (100%) were patent. Subtracted reconstructions showed no intraluminal thrombus or neointimal hyperplasia. Native reconstructions confirmed the structural integrity of the stents. De novo stenosis proximal to the stent was noted in 10 cases (10%). A total of 10 patients (10%) received additional treatment due to recurrent symptoms. In univariate analysis, both high body mass index and stent size (>6 mm) were associated with development of de novo stenoses: OR 1.12 (95% CI 1.01 to 1.25, p=0.037) and OR 5.63 (95% CI 1.16 to 27.22, p=0.032), respectively. In multivariate analysis, only stent size (>6 mm) remained significant: OR 7.19 (95% CI 1.03 to 50.01, p=0.046). CONCLUSION: TS stenting is an effective treatment for intracranial hypertension secondary to dural sinus stenosis in an appropriately selected patient population. A 320-row dynamic CTV is a high-quality non-invasive imaging method that can assess both the physical integrity of the stent and its patency. At mid-term follow-up, all imaged stents were patent. The occurrence of de novo stenoses proximal to the stent (10%) correlated with stent size (>6 mm).

General Anesthesia Alters Intracranial Venous Pressures During Transverse Sinus Stenting.

INTRODUCTION: Pressure gradients across venous stenosis are used as a marker for physiologically significant narrowing in idiopathic intracranial hypertension. Performing such measurements under conscious sedation (CS) more likely reflects physiologic conditions, but can be uncomfortable, leading some operators to perform measurement under general anesthesia (GA), though this may not be equivalent. METHODS: We performed a retrospective analysis of patients who received endovascular transverse sinus stenting due to idiopathic intracranial hypertension between August 2013 and May 2017. Patients' demographics and anesthetic parameters were collected along with venous pressure measurements. RESULTS: We identified 15 patients (14 women). The mean (SD) age was 30.5 (9.0) years and the mean body mass index (SD) was 39.5 (9.6) kg/m2. After measurements during CS, GA was induced with propofol and maintained with a volatile anesthetic. The median [IQR; range] transverse sinus pressure gradient under CS was 18 [12, 25; 6-38] mmHg compared with 14 [8, 21; 3-26] mm Hg under GA. The median [IQR; range] pressure gradient change after initiation of GA was -3 [-12, 0; -22 to 9] mm Hg (P = 0.014). After correction for increases in internal jugular vein pressures associated with assumption of GA, the median [IQR; range] gradient change was -11 [-12.5, -5; -22 to 0] mm Hg (P < 0.001). CONCLUSIONS: The transition from CS to GA results in clinically meaningful reductions in transverse sinus gradients in idiopathic intracranial hypertension. Correction for increases in the internal jugular vein pressures reveals even more dramatic reductions in transverse sinus gradients.

High-resolution compressed-sensing time-of-flight MRA in a case of acute ICA/MCA dissection.

PURPOSE: Acute, isolated intracranial dissection (ICD) represents a rare and challenging cause of acute stroke. DSA is considered to be the gold standard imaging modality in patients with ICD. The role of novel, high-resolution (HR) compressed-sensing (CS) time-of-flight (TOF) MRA techniques in ICDs is unclear. METHODS: A 22-year-old male patient with an isolated right ICA/MCA intracranial dissection underwent "conventional" 3-T TOF MRA, HR CS TOF MRA and also DSA including digital rotational angiography. RESULTS: Unlike the "conventional" TOF MRA, HR CS TOF MRA provided comparable image quality to rotational angiography and a dissection membrane was clearly visible in both techniques. CONCLUSION: In this single case study, we demonstrated the feasibility of a novel HR CS TOF in a case of an acute isolated intracranial ICA/MCA dissection, which needs to be validated in a larger case series.

Susceptibility weighted imaging in infants with staged embolization of vein of Galen aneurysmal malformations.

BACKGROUND AND PURPOSE: The vein of Galen aneurysmal malformation (VGAM) is a rare congenital vascular malformation with a higher morbidity and mortality, especially in neonates. Ultrasound, CT and MR are usually used in diagnosis and treatment monitoring of these disorders. In this current study, we aim to examine utility of SWI in evaluation of treatment response in infants with VGAM. MATERIALS AND METHODS: We performed a retrospective chart analysis of children with VGAM in our institution between January 2008 and December 2016. Inclusion criteria included; confirmed VGAM on DSA; available SWI sequence at baseline and at follow up after at least a single embolization session; age at initial MR of 18 years or younger. Signal intensity and Angioarchitecture of VGAM and cerebral veins on SWI, as well as hydrocephalus and clinical outcome were evaluated. RESULTS: Of 11 patients identified with VGAM in our institution, 5 children (3 males and 2 females) satisfied the inclusion criteria. The average age at initial MR was 29 days (range 1-120). Fourteen MRI were available for review. All children had VGAM of mural type. Intramedullary veins were dilated and SWI-hypointense in all children, while subependymal and sulcal veins were dilated and SWI-hypointense in 4 patients on initial MRI. On the first available follow up MRI, cerebral veins have mostly normalized in 4 children and remained mostly dilated and SWI-hypointense in 1 child; even after complete treatment of the VGAM. CONCLUSION: Our preliminary findings show that SWI seems to offer a beneficial non-invasive tool in evaluating passive venous congestion patterns in pediatric patients with VGAM. It remains to be determined in larger studies, the clinical significance of these SWI changes.

Treatment of hemorrhagic head and neck lesions by direct puncture and n-BCA embolization.

Life-threatening bleeding in the head and neck region requires urgent management. These hemorrhagic lesions, for example, a ruptured pseudoaneurysm, are often treated by transarterial embolization (TAE), but prior intervention or surgery, inflammation, anatomic variants, and vessel tortuosity may render an endovascular approach challenging, time-consuming, and sometimes impossible. We report two cases of severe head and neck hemorrhages successfully embolized with n-butyl cyanoacrylate via direct puncture, and propose this approach as a fast, safe, and effective alternative to TAE.

Helistroke: neurointerventionalist helicopter transport for interventional stroke treatment: proof of concept and rationale.

BACKGROUND AND PURPOSE: It is increasingly recognized that time is one of the key determinants in acute stroke outcome when interventional stroke therapy is applied. With increasing device efficacy and understanding of imaging triage options, reducing pre-treatment time loss may be a critical component of improving interventional stroke outcomes for the population at large. Time sensitive procedures such as organ harvest have transported physicians to the patient site to improve time to procedure. Applying this same principle to interventional stroke management may be a valid paradigm. METHODS: Previous logistical deliberation with hospital and Medevac companies was carried out to provide the rationale and funding for helicopter transfer of a neurointerventionalist to an in-network hospital with an on-site angiographic suite. An appropriate patient with large vessel occlusion and an NIH Stroke Scale score >8 was identified. MRI was performed, then the Medevac transport system was activated and the intervention was carried out. Times were collected during the case and assessed for time efficiency. RESULTS: The proof of concept case was identified and Medevac was consulted at 12:13 after verifying that no in-house emergencies would prevent physician departure. Weather clearance was obtained and stroke intervention confirmed as a go at 12:24. Groin puncture occurred at 13:07 and the intervention was completed at 13:41. The total time from decision-to-treat to groin puncture was 43 min and groin closure was completed at 77 min from decision-to-treat. CONCLUSIONS: This proof of concept case is presented for logistical, financial and use-case analysis. As it is a first case, times can likely be improved. We assert that this model may be another option in the spoke-and-hub design of stroke systems of care.

Treatment of hemorrhagic head and neck lesions by direct puncture and nBCA embolization.

Life-threatening bleeding in the head and neck region requires urgent management. These hemorrhagic lesions, for example, a ruptured pseudoaneurysm, are often treated by transarterial embolization (TAE), but prior intervention or surgery, inflammation, anatomic variants, and vessel tortuosity may render an endovascular approach challenging, time-consuming, and sometimes impossible. We report two cases of severe head and neck hemorrhages successfully embolized with n-butyl cyanoacrylate via direct puncture, and propose this approach as a fast, safe, and effective alternative to TAE.

The yield of initial conventional MRI in 115 cases of angiographically confirmed spinal vascular malformations.

MRI is the primary screening tool for patients with myelopathy. The decision to obtain additional imaging, notably spinal angiography, is generally based on initial MRI findings. This study retrospectively analyzed the yield of initial MRI in a cohort of patients with angiographically confirmed vascular malformations. MRI obtained at symptom onset was available in 115 patients with either high-flow (29 cases) or low-flow (86 cases) vascular malformations. MRI was classified as "positive" when the report mentioned a vascular malformation or "negative" when considered normal or when another diagnosis was suggested. Initial MRI was positive in 61 patients (53.0%), correctly identifying 28 high-flow (96.6%) but only 33 low-flow (38.4%) lesions. Flow voids were noted in 96.6% of the high-flow lesions and 38.4% of the low-flow ones. T2-signal anomalies (77.4%) and parenchymal enhancement (54.5%) were also common in low-flow anomalies. Patients with negative MRI had an average delay of 111 days before angiography and 239 days before therapy; these intervals were 27 and 76 days for those with positive MRIs. In summary, MRI shows a high yield for high-flow vascular malformations, i.e., characterized by prominent flow voids on T2-weighted images, but misdiagnosed over 60% of low-flow lesions. The percentage of correctly identified anomalies matched the percentage of observed flow voids in both groups, indicating over-reliance on this sign for the diagnosis of slow-flow lesions. MRI findings in slow-flow vascular malformation overlap with other conditions, notably transverse myelitis, which was initially misattributed to 40% of the slow-flow lesions in our cohort.

Predictors for venous sinus stent retreatment in patients with idiopathic intracranial hypertension.

BACKGROUND: Venous sinus stenting for dural sinus stenoses is an emerging alternative to cerebrospinal fluid diversion in cases of medically refractory idiopathic intracranial hypertension. Juxta-stent 're-stenoses' have been reported and managed alternatively with ventricular shunting or stent revision. Identification of factors that might predispose patients to recurrent narrowing may help to select or exclude patients with idiopathic intracranial hypertension for venous sinus stenting. METHODS: We retrospectively reviewed a prospectively maintained database spanning December 2011 to May 2015 of all patients with idiopathic intracranial hypertension who were screened for possible venous sinus stenting, including only patients who received a stent, noting symptomatic improvements, changes in opening lumbar puncture pressure, demographic characteristics, and any subsequent intervention after stent placement. Fisher's exact test and logistic regression were used to test each of seven potential predictors for retreatment. RESULTS: There were eight revisions in 31 patients (25.8%). Among Caucasians, 8.0% required a revision compared with 100% of African-Americans (p<0.001). The c-index for race was 0.857. Body mass index (BMI) was also a significant predictor of revision (p=0.031): among class III obese patients the revision rate was 46.2% compared with 16.7% among class I and II obese patients and 0% among overweight to normal weight patients. CONCLUSIONS: BMI was a significant predictor of revision, suggesting that higher BMI may have a higher risk of revision. The small number of African-Americans in the study makes interpretation of the practical significance of the revision rate in these patients uncertain. None of the other studied factors was statistically significant.

Novel in vitro assays for the characterization of EMT in tumourigenesis.

BACKGROUND: Two novel assays quantifying Epithelial to Mesenchymal Transition (EMT) were compared to traditional motility and migration assays. TGF-beta1 treatment of AY-27 rat bladder cancer cells acted as a model of EMT in tumourigenesis. METHODS: AY-27 rat bladder cancer cells incubated with 3 ng/ml TGF-beta1 or control media for 24 or 48 h were assessed using novel and traditional assays. The Spindle Index, a novel measure of spindle phenotype, was derived from the ratio of maximum length to maximum width of cells. The area covered by cells which migrated from a fixed coverslip towards supplemented agarose was measured in a novel chemoattractant assay. Motility, migration and immunoreactivity for E-cadherin, Vimentin and cytokeratin were assessed. RESULTS: TGF-beta1 treated cells had increased "spindle" phenotype together with decreased E-cadherin, decreased Cytokeratin-18 and increased Vimentin immunoreactivity. After 48 h, the mean Spindle Index of TGF-beta1 treated cells was significantly higher than Mock (p=0.02, Bonferroni test) and there were significant differences in migration across treatment groups measured using the novel chemoattractant assay (p=0.02, Chi-square). TGF-beta1 significantly increased matrigel invasion. CONCLUSION: The Spindle Index and the novel chemoattractant assay are valuable adjunctive assays for objective characterization of EMT changes during tumourigenesis.