Endovascular treatment is a highly effective therapy for acute ischemic stroke due to large vessel occlusion and has recently revolutionized stroke care. Oftentimes, ischemic core extent on baseline ...imaging is used to determine endovascular treatment-eligibility. There are, however, 3 fundamental issues with the core conceptFirst, computed tomography and magnetic resonance imaging, which are mostly used in the acute stroke setting, are not able to precisely determine whether and to what extent brain tissue is infarcted (core) or still viable, due to variability in tissue vulnerability, the phenomenon of selective neuronal loss and lack of a reliable gold standard. Second, treatment decision-making in acute stroke is multifactorial, and as such, the relative importance of single variables, including imaging factors, is reduced. Third, there are often discrepancies between core volume and clinical outcome. This review will address the uncertainty in terminology and proposes a direction towards more clarity. This theoretical exercise needs empirical data that clarify the definitions further and prove its value.
Abstract Background Recent reports have revealed a worsening of aneurysm occlusion between WEB treatment baseline and angiographic follow-up due to “compression” of the device. Objective We utilized ...computational fluid dynamics (CFD) in order to determine whether the underlying mechanism of this worsening is flow related. Methods We included data from all consecutive patients treated in our institution with a WEB for unruptured aneurysms located either at the middle cerebral artery or basilar tip. The CFD study was performed using pre-operative 3D rotational angiography. From digital subtraction follow-up angiographies patients were dichotomized into two groups: one with WEB “compression” and one without. We performed statistical analyses to determine a potential correlation between WEB compression and CFD inflow ratio. Results Between July 2012 and June 2015, a total of 22 unruptured middle cerebral artery or basilar tip aneurysms were treated with a WEB device in our department. Three patients were excluded from the analysis and the mean follow-up period was 17 months. Eleven WEBs presented “compression” during follow-up. Interestingly, device “compression” was statistically correlated to the CFD inflow ratio ( P = 0.018), although not to aneurysm volume, aspect ratio or neck size. Conclusion The mechanisms underlying the worsening of aneurysm occlusion in WEB-treated patients due to device compression are most likely complex as well as multifactorial. However, it is apparent from our pilot study that a high arterial inflow is, at least, partially involved. Further theoretical and animal research studies are needed to increase our understanding of this phenomenon.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Introduction
Endovascular treatment of dural arteriovenous malformation is challenging especially if the related dural venous sinus is patent and might be usable for normal venous drainage.
Methods
A ...new particular venous balloon remodeling technique was described in the treatment of transverse–sigmoid dural arteriovenous malformation by using transarterial Onyx. The goal was obliteration of the malformation with preservation of the dural sinus. Two illustrative cases with 6-month follow-up result were narrated.
Results
The penetration of Onyx in the dural arterial feeders was well achieved. Obliteration of the malformation with preservation of the dural sinus was finally demonstrated.
Conclusion
Transvenous balloon assistance is a useful and feasible technique in the treatment of dural arteriovenous malformation when sinus preservation is in concern.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, VSZLJ, ZAGLJ
Wastelands are likely to host a significant part of urban floristic diversity but have received limited attention because they are not considered interesting green zones. Here, we explore the ...potential role of wastelands in maintaining urban biodiversity to help define effective urban management plans. We quantified floristic diversity in 98 wasteland sites of Hauts-de-Seine, one of the most densely populated areas in France, and characterized the environmental parameters and spatial distribution of sites to identify some of the factors that influence plant species composition and to explore the impact of urban environment on the floristic interest of wastelands. Their floristic richness represented 58% of the total richness observed in the whole study area. Site richness depended on site area (the largest sites were the richest) and site age, with a maximum in sites of intermediate age (4-13 years). In the largest sites only (>2,500 m²), the floristic distance among sites was positively correlated with geographic distance, which suggests that migration of species among large sites partly controls local floristic composition. In contrast, the environmental distance among sites was not correlated with floristic distance. Finally, we showed that the presence of collective and individual dwellings within 200 m of a wasteland decreased its floristic rarity, whereas the presence of rivers or ponds increased it. We derive several recommendations to optimize the management of wastelands with respect to conservation of urban biodiversity.
The endovascular treatment of wide-neck bifurcation aneurysms can be challenging and often requires the use of adjunctive techniques and devices.
We report our first experience of using a waffle-cone ...technique adapted to the Woven Endoluminal Bridge (WEB) device in a large-neck basilar tip aneurysm, suitable in cases where the use of Y stenting or other techniques is limited due to anatomic restrictions.
The procedure was complete, and angiographic occlusion of the aneurysm was achieved 24 hours post treatment, as confirmed by digital subtraction angiography. No complications occurred.
The case reported here was not suitable for Y stenting or deployment of the WEB device alone, due to the small caliber of both posterior cerebral arteries and their origin at the neck level. The main advantage of this technique is that both devices have a controlled detachment system and are fully independent. To our knowledge, this technique has not been reported previously and this modality of treatment has never been described in the literature.
•The goal of this paper is to expose a new endovascular solution of treatment for large neck aneurysms in which bifurcation branches cannot support stenting due to small diameter, and the neck is larger or equal with the dome. In this situation a “waffle cone” technique using a WEB device represents a possible treatment strategy.•The advantages of both devices used (Solitaire AB + WEB device) are that both of them have a controlled detachment system and readjustments if needed can easily be performed.•Bifurcation aneurysms will always represent a huge challenge in our field, and more technical solutions are needed in order to safely treat this type of lesion in the future.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Five trials published in 2015 showed the benefit of endovascular thrombectomy (ET) in patients with stroke and large vessel occlusion, extending the treatment window has become an obsession of all ...physicians. In 2018, the DAWN and DEFUSE-3 trials showed that, with careful selection of patients, the procedure could be carried out up to 24 hours after symptom onset with good outcomes. In addition, there have been cases where the DAWN criteria were met, and treatment occurred >24 hours after symptom onset. We present the case of a 68-year-old female whose groin puncture occurred 52 hours after the time last known well (TLKW), after neurological worsening of the initial situation, with a large mismatch ratio observed on magnetic resonance imaging, achieving TICI (the Thrombolysis in Cerebral Infarction scale) grade 3 recanalization. Five days after the procedure, the patient was discharged with NIHSS (National Institutes of Health Stroke Scale) score of 3. Some types of collateral circulation (slow progressors and "turtle" progressors, our term for very slow progressors) can extend the treatment window beyond 24 hours of the TLKW but can lead to a hyperperfusion-like syndrome immediately after the ET. Further studies are needed to evaluate the reproducibility of this hypothetical syndrome.
Flow-diverter stent (FDS) placement for treatment of intracranial aneurysms can cause flow changes in the covered branches.
To assess the impact of the treatment of carotid siphon aneurysms with FDS ...on the posterior communicating artery (PComA) flow.
Between February 2011 and January 2015, 125 carotid siphon aneurysms were treated with FDS. We retrospectively analyzed all cases with PComA ostial coverage. The circle of Willis anatomy was also studied as the flow changes in PComA postoperatively and during angiographic follow-up. Data from neurological examination were also collected.
Eighteen aneurysms of the carotid siphon in 17 patients were treated with FDS covering the ostium of the PComA. Based on the initial angiography, patients were divided into two groups: the first with a P1/PComA size ratio >1 (10 cases) and the second with a ratio ≤1 (8 cases). Follow-up angiography (mean time of 10 months) showed 90% of PComA flow changes in group 1 but only 12.5% in group 2. There was a significant difference between the two groups (p=0.002). Nevertheless, no patient had new symptoms related to these flow changes during the follow-up period.
In our experience, covering the PComA by FDS when treating carotid siphon aneurysms appeared safe and the P1/PComA ratio is a good predictor of flow changes in PComA.
PDF
