Immediate Flow Disruption as a Prognostic Factor After Flow Diverter Treatment: Long-Term Experience with the Pipeline Embolization Device

Dodier, Philippe; Frischer, Josa M.; Wang, Wei-Te; Auzinger, Thomas; Mallouhi, Ammar; Serles, Wolfgang; Gruber, Andreas; Knosp, Engelbert; Bavinzski, Gerhard

doi:10.1016/j.wneu.2018.02.096

Cited by 6 publications

(4 citation statements)

References 29 publications

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“…We systematically reviewed: patients' demographics: age, sex; IAs' characteristics: type, location, configuration (saccular unilobular or complex [10] fusiform, dysmorphic, multilobular), sizing, neck ratio (NR) [11] (ratio of diameters of the neck and the parent artery), ruptured or unruptured IA, indication (first treatment, recanalization), presence of a side-branch artery incorporated into the IA, and contrast agent stagnation at venous phase; parent artery' characteristics: diameters (5 mm upstream to the neck and 5 mm downstream), diameters ratio (PDR), curvature of the parent artery in relation to the tangent passing through the neck of the IA (acute angle: concavity, no angle: straightness, obtuse angle: convexity), and inflow angle [12]; as well as devices' characteristics: type, number, and associate coiling.…”

Section: Patientsmentioning

confidence: 99%

“…Several studies have already shown the existence of factors predictive of aneurysmal occlusion after FDS placement. However, these studies have very varied methodologies: silicon flow models [4], animal models [4,5], computational fluid dynamics (CFD) models [6,7], digital subtraction angiography (DSA)-based optical flow approach [8], or patient cohort studies [9,10]. To the best of our knowledge there is no pre-treatment predictive score available in the literature for complete occlusion of IAs treated by FDS.…”

Section: Introductionmentioning

confidence: 99%

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Predictive score for complete occlusion of intracranial aneurysms treated by flow-diverter stents using machine learning

Guédon

Thepenier

Shotar

et al. 2020

J NeuroIntervent Surg

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BackgroundComplete occlusion of an intracranial aneurysm (IA) after the deployment of a flow-diverter stent is currently unpredictable. The aim of this study was to develop a predictive occlusion score based on pretreatment clinical and angiographic criteria.MethodsConsecutive patients with ≥6 months follow-up were included from 2008 to 2019 and retrospectively analyzed. Each IA was evaluated using the Raymond–Roy occlusion classification (RROC) and dichotomized as occluded (A) or residual (B/C); 80% of patients were randomly assigned to the training sample. Feature selection and binary outcome prediction relied on logistic regression and threshold maximizing class separation selected by a CART tree algorithm. The feature selection was addressed by a genetic algorithm selected from the 30 pretreatment available variables.ResultsThe study included 146 patients with 154 IAs. Feature selection yielded a combination of six variables with a good cross-validated accuracy on the test sample, a combination we labeled DIANES score (IA diameter, indication, parent artery diameter ratio, neck ratio, side-branch artery, and sex). A score of more than −6 maximized the ability to predict RROC=A with sensitivity of 87% (95% CI 79% to 95%) and specificity of 82% (95% CI 64% to 96%) in the training sample. Accuracy was 86% (95% CI 79% to 94%). In the test sample, sensitivity and specificity were 89% (95% CI 77% to 98%) and 60% (95% CI 33% to 86%), respectively. Accuracy was 81% (95% CI 69% to 91%).ConclusionA score was developed as a grading scale for prediction of the final occlusion status of IAs treated with a flow-diverter stent.

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Section: Patientsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Predictive score for complete occlusion of intracranial aneurysms treated by flow-diverter stents using machine learning

Guédon

Thepenier

Shotar

et al. 2020

J NeuroIntervent Surg

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“…[8][9][10][11][12][13][14] The treatment of aneurysms with flow diverters is particularly amenable to such analysis because (a) the reduction of intraaneurysmal flow remains a central hypothesis of treatment success; (b) flow diversion does not require (dense) intra-saccular device implantation, thus allowing for X-ray visualization of contrast transport within the aneurysm; and (c) instead of the need for extraction of absolute flow parameters, the change in intraaneurysmal contrast transport from pre-device implantation to post-device implantation can potentially be used to predict aneurysm occlusion. Current angiographic methods used to generate predictive values of flow diversion success are generally based on grading scales, 15 quantification of aneurysmal time-density curves (TDC), 8,12,16 or optical flow 10,14 methods. Irrespective of which parameter is derived, these methods acquire angiographic sequences before and immediately after flow diverter deployment while keeping the injection and imaging parameters constant.…”

Section: Introductionmentioning

confidence: 99%

Angiographic assessment of the efficacy of flow diverter treatment for cerebral aneurysms

et al. 2019

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Background The recent growth of neuro-endovascular treatment has rekindled interest in the use of angiographic techniques for flow assessment. Aneurysm treatment with flow diverters is particularly amenable to such analysis. We analyze contrast time–density curves — recorded within aneurysms before (pre) and immediately after (post) flow diverter implantation to estimate six-month treatment outcomes. Methods Fifty-six patients with 65 aneurysms were treated with flow diverters at two institutions. A region of interest was drawn around the aneurysm perimeter in image sequences taken both pre and post angiography, and the temporal variation in grayscale intensity within the aneurysm (time–density curve) was recorded. Eleven parameters were quantified from each time–density curve. Aneurysm occlusion status was recorded six months post treatment. The change in parameters from pre to post treatment was statistically evaluated between aneurysm occluded and non-occluded groups. Results Of the 11 parameters, eight were significantly different before and immediately after flow diversion. Considering the entire data set, none of the parameters was statistically different between the occluded and non-occluded groups. However, subgroup analyses showed that four variables were significantly different between the aneurysm occluded and non-occluded groups. The sensitivity of these variables to predict aneurysm occlusion at six months ranged from 60% to 89%, while the specificity ranged from 55% to 70%. Conclusions Device-induced intra-aneurysmal flow alterations quantified by simple aneurysmal time–density curves can potentially be used to predict long-term outcomes of flow diversion. Large multi-center studies will be required to confirm these findings. Patient-to-patient variability in coagulation may need to be incorporated for clinically relevant predictive values.

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“…In the era of flow diversion, neurosurgeons frequently face the paradox that, even in specialized centers, the caseload of clipping procedures declines while the case complexity is simultaneously increasing. 2,20,21 Moreover, the global trend of reducing working hours for medical professionals and the growing limitations on traditional cadaveric training further add to the challenges for cerebrovascular neurosurgeons. 22 The lack of frequent hands-on microsurgical clipping experience might even compromise the maintenance of already acquired expert skills, leading to increasing demands on alternative training options.…”

Section: Introduction Of a Novel Training Platform Combining Physical...mentioning

confidence: 99%

An evaluation of physical and augmented patient-specific intracranial aneurysm simulators on microsurgical clipping performance and skills: a randomized controlled study

Dodier,

Civilla,

Mallouhi

et al. 2024

Neurosurgical Focus

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OBJECTIVE In the era of flow diversion, there is an increasing demand to train neurosurgeons outside the operating room in safely performing clipping of unruptured intracranial aneurysms. This study introduces a clip training simulation platform for residents and aspiring cerebrovascular neurosurgeons, with the aim to visualize peri-aneurysm anatomy and train virtual clipping applications on the matching physical aneurysm cases. METHODS Novel, cost-efficient techniques allow the fabrication of realistic aneurysm phantom models and the additional integration of holographic augmented reality (AR) simulations. Specialists preselected suitable and unsuitable clips for each of the 5 patient-specific models, which were then used in a standardized protocol involving 9 resident participants. Participants underwent four sessions of clip applications on the models, receiving no interim training (control), a video review session (video), or a video review session and holographic clip simulation training (video + AR) between sessions 2 and 3. The study evaluated objective microsurgical skills, which included clip selection, number of clip applications, active simulation time, wrist tremor analysis during simulations, and occlusion efficacy. Aneurysm occlusions of the reference sessions were assessed by indocyanine green videoangiography, as well as conventional and photon-counting CT scans. RESULTS A total of 180 clipping procedures were performed without technical complications. The measurements of the active simulation times showed a 39% improvement for all participants. A median of 2 clip application attempts per case was required during the final session, with significant improvement observed in experienced residents (postgraduate year 5 or 6). Wrist tremor improved by 29% overall. The objectively assessed aneurysm occlusion rate (Raymond-Roy class 1) improved from 76% to 80% overall, even reaching 93% in the extensively trained cohort (video + AR) (p = 0.046). CONCLUSIONS The authors introduce a newly developed simulator training platform combining physical and holographic aneurysm clipping simulators. The development of exchangeable, aneurysm-comprising housings allows objective radio-anatomical evaluation through conventional and photon-counting CT scans. Measurable performance metrics serve to objectively document improvements in microsurgical skills and surgical confidence. Moreover, the different training levels enable a training program tailored to the cerebrovascular trainees’ levels of experience and needs.

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Immediate Flow Disruption as a Prognostic Factor After Flow Diverter Treatment: Long-Term Experience with the Pipeline Embolization Device

Cited by 6 publications

References 29 publications

Predictive score for complete occlusion of intracranial aneurysms treated by flow-diverter stents using machine learning

Predictive score for complete occlusion of intracranial aneurysms treated by flow-diverter stents using machine learning

Angiographic assessment of the efficacy of flow diverter treatment for cerebral aneurysms

An evaluation of physical and augmented patient-specific intracranial aneurysm simulators on microsurgical clipping performance and skills: a randomized controlled study

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