Ostium Ratio and Neck Ratio Could Predict the Outcome of Sidewall Intracranial Aneurysms Treated with Flow Diverters

Paliwal, Nikhil; Tutino, Vincent M.; Shallwani, Hussain; Beecher, Jeffrey S.; Damiano, Robert J.; Shakir, Hakeem J; Atwal, Gursant; Fennell, Vernard S.; Natarajan, Sabareesh K.; Levy, Elad I.; Siddiqui, Adnan H.; Davies, Jason M; Meng, Hui

doi:10.3174/ajnr.a5953

Cited by 20 publications

(17 citation statements)

References 35 publications

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“…This prospective study compared geometric and hemodynamic parameters in unruptured sidewall intracranial aneurysms for different FD treatment responses at 2 follow-up time points. Other studies have reported on the parameters for differentiation of the aneurysm response, 15,16 but we highlighted the relationship between in vivo aneurysm hemodynamics and the treatment responses, and tried to give a hemodynamic explanation for the delayed occlusion. Our results showed geometric and hemodynamic differences between the occlusion and remnant groups at 6 and 12 months.…”

Section: Discussionmentioning

confidence: 99%

“…[12][13][14] Nevertheless, to our knowledge, few reports have investigated the relationship between the ostium and FD treatment response. 15,16 We hypothesized that different FD treatment responses were related to aneurysm features, and our study focused on the aneurysm geometries and hemodynamics at the ostium. The aim of this study was to perform an in vivo investigation of the relationship between aneurysm features, particularly the geometric and hemodynamic parameters and their impact on FD treatment responses.…”

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confidence: 99%

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Large Neck and Strong Ostium Inflow as the Potential Causes for Delayed Occlusion of Unruptured Sidewall Intracranial Aneurysms Treated by Flow Diverter

Su¹,

Reymond²,

Brina³

et al. 2020

AJNR Am J Neuroradiol

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BACKGROUND AND PURPOSE: Flow diverter-induced hemodynamic change plays an important role in the mechanism of intracranial aneurysm occlusion. Our aim was to explore the relationship between aneurysm features and flow-diverter treatment of unruptured sidewall intracranial aneurysms. MATERIALS AND METHODS: MR imaging, 4D phase-contrast, was prospectively performed before flow diverter implantation in each patient with unruptured intracranial aneurysm. Two postprocedure follow-ups were scheduled at 6 and 12 months. Responses were grouped according to whether the aneurysms were occluded or remnant. Preprocedural aneurysm geometries and ostium hemodynamics in 38 patients were compared between the 2 groups at 6 and 12 months. Receiver operating characteristic curve analyses were performed for significant geometric and hemodynamic continuous parameters. RESULTS: After the 6-month assessment, 21 of 41 intracranial aneurysms were occluded, and 9 additional aneurysms were occluded at 12 months. Geometrically, the ostium maximum diameter was significantly larger in the remnant group at 6 and 12 months (both P , .001). Hemodynamically, the proximal inflow zone was more frequently observed in the remnant group at 6 months. Several preprocedural ostium hemodynamic parameters were significantly higher in the remnant group. As a prediction for occlusion, the areas under the curve of the ostium maximum diameter (for 6 and 12 months), systolic inflow rate ratio (for 6 months), and systolic inflow area (for 12 months) reached 0.843, 0.883, 0.855, and 0.860, respectively. CONCLUSIONS: Intracranial aneurysms with a large ostium and strong ostium inflow may need a longer time for occlusion. Preprocedural 4D flow MR imaging can well illustrate ostium hemodynamics and characterize aneurysm treatment responses.

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Section: Discussionmentioning

confidence: 99%

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confidence: 99%

Large Neck and Strong Ostium Inflow as the Potential Causes for Delayed Occlusion of Unruptured Sidewall Intracranial Aneurysms Treated by Flow Diverter

Su¹,

Reymond²,

Brina³

et al. 2020

AJNR Am J Neuroradiol

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“…This means that a larger portion of the parent vessel was the opening into the aneurysms in this group, which allowed more flow into the aneurysmal sac. 40 In these cases, use of alternative strategies like overlapping FDs, compacted FD or FDs with adjunctive coils could be more beneficial for successful outcome, namely occlusion. 9,38 In the ideal case, our models will identify IAs that may not occlude with a single, uniformly implanted FD, promoting the interventionalist to consider these alternative methods.…”

Section: Discussionmentioning

confidence: 99%

Outcome prediction of intracranial aneurysm treatment by flow diverters using machine learning

Paliwal

Jaiswal²,

Tutino

et al. 2018

Neurosurgical Focus

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OBJECTIVEFlow diverters (FDs) are designed to occlude intracranial aneurysms (IAs) while preserving flow to essential arteries. Incomplete occlusion exposes patients to risks of thromboembolic complications and rupture. A priori assessment of FD treatment outcome could enable treatment optimization leading to better outcomes. To that end, the authors applied image-based computational analysis to clinically FD-treated aneurysms to extract information regarding morphology, pre- and post-treatment hemodynamics, and FD-device characteristics and then used these parameters to train machine learning algorithms to predict 6-month clinical outcomes after FD treatment.METHODSData were retrospectively collected for 84 FD-treated sidewall aneurysms in 80 patients. Based on 6-month angiographic outcomes, IAs were classified as occluded (n = 63) or residual (incomplete occlusion, n = 21). For each case, the authors modeled FD deployment using a fast virtual stenting algorithm and hemodynamics using image-based computational fluid dynamics. Sixteen morphological, hemodynamic, and FD-based parameters were calculated for each aneurysm. Aneurysms were randomly assigned to a training or testing cohort in approximately a 3:1 ratio. The Student t-test and Mann-Whitney U-test were performed on data from the training cohort to identify significant parameters distinguishing the occluded from residual groups. Predictive models were trained using 4 types of supervised machine learning algorithms: logistic regression (LR), support vector machine (SVM; linear and Gaussian kernels), K-nearest neighbor, and neural network (NN). In the testing cohort, the authors compared outcome prediction by each model trained using all parameters versus only the significant parameters.RESULTSThe training cohort (n = 64) consisted of 48 occluded and 16 residual aneurysms and the testing cohort (n = 20) consisted of 15 occluded and 5 residual aneurysms. Significance tests yielded 2 morphological (ostium ratio and neck ratio) and 3 hemodynamic (pre-treatment inflow rate, post-treatment inflow rate, and post-treatment aneurysm averaged velocity) discriminants between the occluded (good-outcome) and the residual (bad-outcome) group. In both training and testing, all the models trained using all 16 parameters performed better than all the models trained using only the 5 significant parameters. Among the all-parameter models, NN (AUC = 0.967) performed the best during training, followed by LR and linear SVM (AUC = 0.941 and 0.914, respectively). During testing, NN and Gaussian-SVM models had the highest accuracy (90%) in predicting occlusion outcome.CONCLUSIONSNN and Gaussian-SVM models incorporating all 16 morphological, hemodynamic, and FD-related parameters predicted 6-month occlusion outcome of FD treatment with 90% accuracy. More robust models using the computational workflow and machine learning could be trained on larger patient databases toward clinical use in patient-specific treatment planning and optimization.

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“…All morphology parameters were previously defined,15 except for 3D neck ratio (NR 3D ), which we introduce in this study as the ratio of average neck dimension to average parent vessel diameter, both measured in 3D. It is a 3D version of our previously introduced two-dimensional (2D) neck ratio, NR 2D , which was found to be significantly associated with outcomes of flow diverter (FD)-treated IAs 16…”

Section: Methodsmentioning

confidence: 99%

Aneurysm characteristics, coil packing, and post-coiling hemodynamics affect long-term treatment outcome

Damiano

Tutino

Paliwal

et al. 2019

J NeuroIntervent Surg

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BackgroundRecurrence of intracranial aneurysms after endovascular coiling is a serious clinical concern.ObjectiveWe hypothesized that recurrence is associated with aneurysm morphology and flow, as well as the coil intervention and the induced flow modifications.MethodsWe collected 52 primary-coiling aneurysm cases that were either occluded (n=34) or recurrent (n=18) at >1 year follow-up. We created aneurysm models from pre-coiling digital subtraction angiographic images, calculated aneurysm morphology, simulated pre-coiling hemodynamics, modeled coil deployment, and obtained post-coiling hemodynamics for each case. We performed univariable analysis on 26 morphologic, treatment-specific, and hemodynamic parameters to distinguish between recurrent and occluded groups, and multivariable analysis to identify independently significant parameters associated with recurrence. Univariable analysis was also performed on ruptured and unruptured aneurysm subcohorts separately to investigate if they shared specific significant parameters.ResultsRecurrence was associated with pre-coiling aneurysm morphologic and flow parameters including larger size (maximum dimension and volume), larger neck (diameter, area, and neck-to-parent-artery ratio), and higher flow momentum and kinetic energy. Recurrence was also associated with lower coil packing (packing density and uncoiled volume), higher post-treatment flow (velocity, momentum, and kinetic energy), lower post-treatment washout time, and higher post-treatment impingement force at the neck. Multivariable analysis identified two aneurysmal characteristics (neck diameter and pre-coiling flow kinetic energy), one coil packing parameter (uncoiled volume), and one post-treatment hemodynamic parameter (flow momentum) that were independently associated with recurrence. In ruptured aneurysms, recurrence was associated with larger neck (diameter and area), whereas in unruptured aneurysms, recurrence was associated with larger size (maximum dimension and volume). In both subcohorts, recurrence was associated with higher post-coiling flow momentum and kinetic energy.ConclusionRecurrence at >1 year after coil treatment is associated with intrinsic aneurysm characteristics, coiling itself, and flow changes induced by coiling. Larger aneurysm size and neck, less coil packing, and higher intra-aneurysmal flow before and after coiling predict recurrence.

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Ostium Ratio and Neck Ratio Could Predict the Outcome of Sidewall Intracranial Aneurysms Treated with Flow Diverters

Cited by 20 publications

References 35 publications

Large Neck and Strong Ostium Inflow as the Potential Causes for Delayed Occlusion of Unruptured Sidewall Intracranial Aneurysms Treated by Flow Diverter

Large Neck and Strong Ostium Inflow as the Potential Causes for Delayed Occlusion of Unruptured Sidewall Intracranial Aneurysms Treated by Flow Diverter

Outcome prediction of intracranial aneurysm treatment by flow diverters using machine learning

Aneurysm characteristics, coil packing, and post-coiling hemodynamics affect long-term treatment outcome

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