Association Between Aneurysmal Haemodynamics and Device Microstructural Characteristics After Flow-Diversion Treatments With Dual Stents of Different Sizes: A Numerical Study.
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ABSTRACT: Objectives
Treating intracranial aneurysms with flow-diverting stents sometimes requires deployment of a second device. Herein we quantify the sizing effects of devices in dual-stent treatments upon the final stent microstructure and the post-treatment aneurysmal haemodynamics.Methods
Fifteen sidewall ICA aneurysm geometries were included. Using a virtual stenting technique, we implanted either one or two stents for each aneurysm treatment considered, with each stent specified as one of two different sizes, yielding a total of two single-stent and fouir dual-stent treatment scenarios for each aneurysm. Three stent microstructural parameters and nine aneurysmal haemodynamic parameters were quantified and systematically compared across the 90 treatment scenarios.Results
Deployment of a second stent further reduced the aneurysmal inflow rate (IR) and energy loss (EL) by, respectively, 14 ± 11% (p = 0.001) and 9 ± 12% (p = 0.056), relative to the untreated condition. Sizing effects of the earlier-deployed stent led to largest differences of 6.9% for the final IR reduction and 11.1% for the EL, whereas sizing effects from the later-deployed stent were minor (≤2.1%). The change in stent pore size was the only microstructural parameter demonstrating a strong correlation with the reduction in the post-treatment aneurysmal haemodynamics, in terms of the IR (r = 0.50, p < 0.001) and pressure drop (r = 0.63, p < 0.001).Conclusion
Size of the earlier-deployed stent has substantial effects on the final haemodynamic outcomes after dual-stent treatment. The average pore size of stent wires at the aneurysm orifice shows promise as a potential index for predicting the efficacy of flow-diversion treatments.
SUBMITTER: Zhang M
PROVIDER: S-EPMC8185279 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Background and purposeAlthough grading scales for angiography outcomes following cerebral aneurysm treatment with flow diversion have been published, physicians have not widely adopted these scales in practice. The aim of this study is to propose and validate a novel Flow diversion Predictive Score (4F-FPS) grading scale based on previously established scales that is simple and reliable.MethodsWe retrospectively analyzed consecutive patients who underwent endovascular treatment for cerebral aneurysms with flow diversion between January 2014 and September 2019. The included patients were randomly divided into the derivation and validation group in a 70/30 ratio, respectively. Aneurysms were classified as incomplete or complete occlusion based on final angiography outcomes. 4F-FPS was derived to predict aneurysm occlusion from multivariate logistic regression analyses in the derivation group and validated with previously published grading scales in the validation group.ResultsOverall, 662 patients [mean age, 53.8 years; 72.5% (480/662) female] with 662 aneurysms treated with the PipelineTM flow diverter were included [69.9% (463/662) derivation group, 30.1% (199/662) validation group]. The incidence of aneurysm occlusion was 82.7%. 4F-FPS demonstrated significant discrimination in 10-fold cross validation [mean receiver operating characteristic (ROC) area, 0.862 ± 0.055] and calibration (Cox & Snell R 2, 0.251; Nagelkerke R 2, 0.413) in the derivation group. The ROC area of 4F-FPS score in both the derivation and validation groups is the largest compared with previously published grading scales/scores (p < 0.05), which shows better sensitivity and specificity. The 4F-FPS score showed excellent prediction, discrimination, and calibration properties.ConclusionThe 4F-FPS score is a simple and reliable tool to predict angiography outcome after flow diversion treatment. If widely adopted, it may provide a common language to be used in future reporting of flow diversion results for clinical trials and daily practice.Clinical trial registrationhttp://www.clinicaltrials.gov. Unique identifier: NCT03831672.
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Project description:Uptake of flow-diverting technology is rapidly outpacing the availability of clinical evidence. Most current usage is off-label, and the endovascular community is nearer the beginning than the end of the learning curve, given the number of devices in development. A comprehensive overview of technical specifications alongside key outcome data is essential both for clinical decision-making and to direct further investigations. Most-studied has been the Pipeline Embolization Device, which has undergone a transition to the Pipeline Flex for which outcome data are sparse or heterogeneous. Alternative endoluminal devices do not appear to be outperforming the Pipeline Embolization Device to date, though prospective studies and long-term data mostly are lacking, and between-study comparisons must be treated with caution. Nominal technical specifications may be unrelated to in situ performance, emphasizing the importance of correct radiologic sizing and device placement. Devices designed specifically for bifurcation aneurysms also lack long-term outcome data or have only recently become available for clinical use. There are no major studies directly comparing a flow-diverting device with standard coiling or microsurgical clipping. Data on flow-diverting stents are too limited in terms of long-term outcomes to reliably inform clinical decision-making. The best available evidence supports using a single endoluminal device for most indications. Recommendations on the suitability and choice of a device for bifurcation or ruptured aneurysms or for anatomically complex lesions cannot be made on the basis of current evidence. The appropriateness of flow-diverting treatment must be decided on a case-by-case basis, considering experience and the relative risks against standard approaches or observation.
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Project description:BackgroundTransradial access for neurointerventions offers advantages of fewer access-site complications, reduced procedure time, and greater patient comfort over transfemoral access. Data about transradial access for flow diversion are limited. We share our early experience with transradial access for flow diversion in a relatively large case series.MethodsConsecutive patients who underwent Pipeline embolization device (Medtronic) deployment via transradial access were included in the study, irrespective of location and laterality of the intracranial aneurysm. The cases were performed between July 2016 and October 2019. Demographics, aneurysm characteristics, and procedure-related details (including catheter systems used) were recorded and statistically evaluated.ResultsThirty-five transradial flow diversion procedures were attempted in 32 patients, of which 33 procedures were successful. In two cases involving left common carotid artery and internal carotid artery access, guide catheter herniation into the aortic arch led to abandonment of transradial access in favor of transfemoral access. The most common aneurysm locations in the transradial access procedures were the posterior communicating artery (n = 7), ophthalmic artery (n = 7), and superior hypophyseal artery (n = 7). Most transradial access procedures (66.7%) were performed using a biaxial catheter system. 6-French Benchmark (Penumbra) and Phenom 27 (Medtronic) were the most commonly utilized guide- and microcatheters, respectively. One patient had intraprocedural subarachnoid hemorrhage. No access-site complications occurred.ConclusionThis study demonstrates safety and feasibility of transradial access for Pipeline embolization device deployment and shows the versatility of this approach for different catheter systems. Tortuosity and acute angulation of the left common carotid artery and internal carotid artery were associated with approach failure.
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