Delivery Assist Catheters : A new Device Class and Initial Experience in Mechanical Thrombectomy in Acute Ischemic Stroke Patients.

PURPOSE: To report in vivo experience of a delivery assist catheter as ascending aid for a large-bore catheter for intracranial thromboaspiration. METHODS: Retrospective data collection and analysis of stroke databases of two comprehensive stroke centers focusing on technical and angiographic parameters - primary endpoint defined as reaching the occlusion with a large-bore reperfusion catheter - from patients receiving endovascular stroke treatment using an AXS Offset™ delivery assist catheter (Stryker, Fremont, CA, USA) between May 2017 and November 2017. RESULTS: Using the delivery assist catheter, a 6F catheter could be advanced to an intracranial occlusion for direct thromboaspiration in 30 (88.2%) out of a total of 34 patients (male: n = 14 out of 34 [41.2%], age in years: mean [SD]: 75 [11], median baseline NIHSS [National Institutes of Health stroke scale]: 16 [interquartile range, IQR 12-21]). In 4 out of 34 (11.7%) cases the occlusion could not be reached with the aspiration catheter because of a preceding non-occlusive arteriosclerotic plaque (n = 1, 2.9%) or because of severe elongation and tortuosity of the arterial access route (n = 3, 8.8%). After thromboaspiration mTICI (modified thrombolysis in cerebral infarction) 2b­3 was reached in 14 out of 30 (46.7%) patients. In 21 out of 34 (61.8%) patients stent-retriever-maneuvers (median: 1 [IQR: 0­2]) were needed. In 28 out of 34 (82.3%) patients final mTICI 2b-3 could be achieved. CONCLUSION: Delivery assist catheters can be used as ascending aid for large-bore catheters for thromboaspiration in acute ischemic stroke, in particular to overcome vessel tortuosity and anatomic obstacles.

Multimodal imaging findings during severe attacks of familial hemiplegic migraine type 2.

BACKGROUND: Familial hemiplegic migraine (FHM) is a rare monogenic form of migraine with aura with three distinct genetic subtypes (FHM1-3). Imaging studies during acute FHM attacks are scarce in the literature. This is particularly true for the FHM2 subtype. PATIENTS AND METHODS: In this monocentric study, we retrospectively evaluated imaging data of four different patients with genetically confirmed FHM2. Analysis comprised a total of eight cMRI and two CT perfusion studies, which were obtained during a total of six different attacks. RESULTS: cMRI investigations at all available time-points were without evidence of cytotoxic edema. The most prominent finding (four attacks in three patients) was swelling and/or cortical hyperintensity of the affected cerebral hemisphere on T2/FLAIR-weighted MRI. Further changes, encountered only in a few patients, included increased perfusion of the affected hemisphere (as assessed by perfusion CT) as well as dilatation of the middle cerebral artery. CONCLUSION: Our data from a sizeable cohort of FHM2 patients highlight that swelling / cortical hyperintensity of the clinically affected cerebral hemisphere - which has been previously reported mainly in FHM1 - can be observed also in FHM2. Further, they suggest that these changes, which tend to be present not in the very beginning, but rather later on during attacks, may be a possible correlate of the prolonged attack duration in our patients.

Cerebral vein thrombosis: clinical manifestation and diagnosis.

BACKGROUND: Cerebral venous thrombosis (CVT) is a disease with a wide spectrum of symptoms and severity. In this study we analysed the predictive value of clinical signs and symptoms and the contribution of D-dimer measurements for diagnosis. METHODS: We evaluated consecutive patients admitted with suspected CVT receiving non-invasive imaging. Symptoms and symptom combination as well as D-dimer levels were evaluated regarding their diagnostic value. RESULTS: 239 patients were included in this study, 170 (71%) were females. In 39 patients (16%) a CVT was found. For identifying a CVT patients underwent either a venous CT-angiography or MR-angiography or both. No combination of symptoms either alone or together with the D-dimer measurements had a sensitivity and positive predictive value as well as negative predictive value and specificity high enough to serve as red flag. D-dimer testing produced rates of 9% false positive and of 24% false negative results. For D-dimer values a Receiver Operating Characteristic curve (ROC) and the area under the curve (AUC = 0.921; CI: 0.864-0.977) were calculated. An increase of sensitivity above 0.9 results in a relevant decrease in specificity; a sensitivity of 0.9 matches a specificity value of 0.9. This corresponds to a D-dimer cut-off level of 0.16 µg/ml. CONCLUSION: Imaging as performed by venous CT-angiography or MR-angiography has a 1 to 2 in 10 chance to detect CVT when typical symptoms are present. D-dimer measurements are of limited clinical value because of false positive and negative results.

Preoperative embolization of intracranial arteriovenous malformations with Onyx.

OBJECTIVE: Preoperative embolization in accordance with multimodal therapies for cerebral arteriovenous malformations (AVMs) is generally the first step in treatment and may result in complete obliteration. The Onyx liquid embolic system (Micro Therapeutics, Inc., Irvine, CA) may offer advantages for intranidal targeted embolization and microsurgical resection. We present our experience in the combined treatment of intracranial AVMs using Onyx embolization and neurosurgical resection. METHODS: We treated a total of 47 patients for compact intracranial AVMs that were located in the frontal or frontoparietal area (16 patients); temporal, temporoparietal, or temporo-occipital regions (12 patients); parietal or parieto-occipital areas (8 patients); occipital regions (8 patients); had basal ganglia involvement (2 patients); and was cerebellar (1 patient). The Spetzler-Martin grading scale values were as follows: 25 patients were Grades I or II, 10 patients were Grade III, and 12 patients were Grades IV or V. Twenty-three AVMs were located in eloquent brain regions. RESULTS: After we performed final embolizations, the mean nidus reduction was 84%. Seven patients had new, nondisabling neurological deficits, and four patients had new, disabling neurological deficits after embolization. Periprocedurally, five vessel perforations and four stuck microcatheters were encountered without clinical deficits. In two patients, delayed hemorrhage after embolization occurred with good clinical outcome. We completely resected 46 AVMs; in one patient, we detected an AVM on postoperative angiography. The mean operative time was 4.7 hours, and the mean blood loss was 455 mL. Clinical status worsened postoperatively in 14 patients. Angiographic and clinical follow-up examinations were available for 42 patients (89%); the average follow-up period was 13 months. We found no relapse of arteriovenous shunt. Fourteen patients improved clinically after discharge. Of the 42 patients followed up, 23 individuals had no neurological deficit, 16 had a nondisabling deficit, and three had a disabling deficit. CONCLUSION: Preoperative use of the Onyx liquid embolic system in cerebral AVM treatment allows profound occlusion by targeted embolization and provides a basis for safe neurosurgical resection.

Treatment and follow-up of 22 unruptured wide-necked intracranial aneurysms of the internal carotid artery with Onyx HD 500.

BACKGROUND AND PURPOSE: The purpose of this study was to demonstrate endovascular treatment of wide-necked aneurysms of the internal carotid artery with the liquid embolic agent Onyx HD 500. METHODS: Twenty-two wide-necked, large or giant aneurysms of the internal carotid artery (ICA) were treated in 22 patients with Onyx HD 500 (15 ophthalmic, 1 clinoid, and 6 cavernous aneurysms). Sixteen patients were asymptomatic, and mass effect of the aneuryms caused cranial nerve palsy in 6. Seven aneurysms showed regrowth after prior endovascular coiling. RESULTS: Postinterventional angiography demonstrated total occlusion in 18 aneurysms, and a small remnant was left in 4. Clinical and angiographic follow-up data are available in 19 patients (average follow-up, 13 months; range, 5-36 months). Total occlusion was demonstrated in 17 aneurysms (91%), and a partial recanalization was seen in 2. There were 2 ICA occlusions and 1 ICA stenosis. Clinical follow-up demonstrated a transient ischemic attack in 1 patient; 2 with cranial nerve palsy were unchanged, and 2 showed improved symptoms compared with the findings before treatment. The remaining 14 patients were clinically asymptomatic. There was no permanent severe morbidity and no mortality at follow-up. CONCLUSION: The endovascular treatment of wide-necked, large or giant ICA aneurysms with Onyx HD 500 is a treatment option in these selected cases. The benefit is a primary high and stable occlusion rate and good clinical outcome. ICA occlusion caused by Onyx migration in the parent artery is a typical problem, with a benign clinical course in this series.

Dynamic spin labeling angiography in extracranial carotid artery stenosis.

BACKGROUND AND PURPOSE: Similar to digital subtraction angiography, dynamic spin labeling angiography (DSLA) provides time-resolved measurements of the influx of blood into the cerebral vascular tree. We determined whether DSLA may help in assessing the degree of stenosis and whether it provides information about intracerebral collateralization and allows us to monitor the hemodynamic effects of vascular interventions. METHODS: We developed a segmented DSLA sequence that allowed the formation of images representing inflow delays in 41-ms increments. Thirty patients with unilateral carotid artery stenosis and 10 control subjects underwent DSLA. Arrival times of the labeled arterial blood bolus were measured in the carotid siphon (CS) and the middle cerebral artery (MCA) on both sides, and the corresponding side-to-side arrival time differences (ATDs) were calculated. ATDs before and after carotid endarterectomy or percutaneous angioplasty were studied in 10 patients. RESULTS: The degree of stenosis was significantly correlated with ATD in the cerebral vessels. Receiver operating characteristic analysis yielded a cutoff CS ATD of 110 ms to separate stenoses <70% from those > or =70%, with a sensitivity of 90% and a specificity of 67%. In one third of patients, ATD was higher in the MCA than in the CS; this finding suggested an absence of collateralization. Most patients had reduced ATD in the MCA. The degree of ATD reduction was regarded as a quantitative measure of collateralization. Successful intervention resulted in normalized ATDs. CONCLUSION: DSLA is a promising method that allowed us to noninvasively quantify the hemodynamic effect of extracranial carotid stenosis and the resulting intracranial collateralization.

Influence of recanalization on outcome in dural sinus thrombosis: a prospective study.

BACKGROUND AND PURPOSE: Recanalization in dural sinus thrombosis (DST) has been observed previously; however, systematic prospective data are lacking. The influence of recanalization on DST outcome has not yet been thoroughly evaluated. METHODS: Thirty-seven consecutive patients with DST were prospectively examined. Neurological deficits were graded with the National Institutes of Health Stroke Scale (NIHSS) on hospital admission and discharge. Functional outcome was assessed with the modified Rankin Scale (mRS) on hospital discharge and after 12 months. All patients were treated with intravenous heparin in the acute stage of illness, followed by oral anticoagulation for 12 months. Imaging follow-up with MR angiography and, in a few cases, with CT or conventional angiography was performed on hospital discharge and after 6 and 12 months. RESULTS: Twelve-month functional outcome was excellent in 89% of patients with an mRS of 0 or 1. A recanalization rate of 60% was already observed on hospital discharge (22+/-6 days); thereafter, recanalization rates increased insignificantly. Early recanalization was not related to NIHSS score on hospital discharge or an mRS of 0 on discharge or after 12 months. CONCLUSIONS: We found a high frequency of early recanalization but without influence on clinical outcome parameters. Frequent imaging follow-ups in DST are not useful because they provide no information on patient outcome.

Effect of glacial acetic acid and ethiodized oil concentration on embolization with N-butyl 2-cyanoacrylate: an in vivo investigation.

BACKGROUND AND PURPOSE: Precise control of the polymerization dynamics of cyanoacrylate mixtures used in the embolization of cerebral arteriovenous malformations is required to achieve a safe and permanent obliteration of the lesion. In this study, in vivo embolization using mixtures of Histoacryl, Lipiodol Ultra-Fluid, and glacial acetic acid (GAA) was investigated. The present study investigated whether increased ethiodized oil concentration or the addition of GAA increased rate of embolization. METHODS: Using embolic mixtures containing Histoacryl (N-butyl 2-cyanoacrylate [NBCA]), the embolization process in the femoral and subclavian arteries of the rabbit was examined. Various embolic agents composed of ethiodized oil and N-BCA mixtures, either with or without the addition of minute quantities of GAA, were injected. Blood flow through the aforementioned arteries was measured during embolization. The transient decay of blood flow to zero was modeled, and an optimized model parameter, termed the time elapsed to flow arrest (TEFA) factor, was compared with the experimental data related to the embolization process. RESULTS: The TEFA factor was independent of the variation of the ethiodized oil concentration in the mixture (P >.05). In contradistinction, the addition of GAA significantly increased the TEFA factor (P <.05). Moreover, a linear relation between the TEFA factor and the quantity of GAA in the mixture was discerned. CONCLUSION: Predictable control of the embolization process with N-BCA in vivo is attained by varying the amount of GAA in the embolic mixture.