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Belanger BL, Morrish R, McClarty D, Barnstable C, Muir W, Ghazizadeh S, Eesa M, Fiorella D, Wong JH, Sadasivan C, Mitha AP. In vitro flow diversion effect of the ReSolv stent with the shelf technique in a bifurcation aneurysm model. J Neurointerv Surg 2024; 16:296-301. [PMID: 37188503 DOI: 10.1136/jnis-2022-020023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 04/17/2023] [Indexed: 05/17/2023]
Abstract
BACKGROUND Flow-diverting stents are not currently indicated for the treatment of bifurcation aneurysms, and some case series have demonstrated low occlusion rates, possibly due to a lack in neck coverage. The ReSolv stent is a unique hybrid metal/polymer stent that can be deployed with the shelf technique in order to improve neck coverage. METHODS A Pipeline, unshelfed ReSolv, and shelfed ReSolv stent were deployed in the left-sided branch of an idealized bifurcation aneurysm model. After determining stent porosity, high-speed digital subtraction angiography runs were acquired under pulsatile flow conditions. Time-density curves were created using two region of interest (ROI) paradigms (total aneurysm and left/right), and four parameters were extracted to characterize flow diversion performance. RESULTS The shelfed ReSolv stent demonstrated better aneurysm outflow alterations compared to the Pipeline and unshelfed ReSolv stent when using the total aneurysm as the ROI. On the left side of the aneurysm, there was no significant difference between the shelfed ReSolv stent and the Pipeline. On the right side of the aneurysm, however, the shelfed ReSolv stent had a significantly better contrast washout profile than the unshelfed ReSolv stent and the Pipeline stent. CONCLUSIONS The ReSolv stent with the shelf technique demonstrates the potential to improve flow diversion outcomes for bifurcation aneurysms. Further in vivo testing will help to determine whether the additional neck coverage leads to better neointimal scaffolding and long-term aneurysm occlusion.
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Affiliation(s)
- Brooke L Belanger
- Department of Clinical Neurosciences, University of Calgary, Foothills Medical Centre, Calgary, Alberta, Canada
| | - Rosalie Morrish
- Department of Clinical Neurosciences, University of Calgary, Foothills Medical Centre, Calgary, Alberta, Canada
| | - Davis McClarty
- Department of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Colette Barnstable
- Department of Clinical Neurosciences, University of Calgary, Foothills Medical Centre, Calgary, Alberta, Canada
| | - Warren Muir
- Department of Clinical Neurosciences, University of Calgary, Foothills Medical Centre, Calgary, Alberta, Canada
| | - Soheil Ghazizadeh
- Department of Biomedical Engineering, University of Calgary, Calgary, Alberta, Canada
| | - Muneer Eesa
- Department of Clinical Neurosciences, University of Calgary, Foothills Medical Centre, Calgary, Alberta, Canada
| | - David Fiorella
- Department of Neurosurgery, Stony Brook University, Stony Brook, New York, USA
| | - John H Wong
- Department of Clinical Neurosciences, University of Calgary, Foothills Medical Centre, Calgary, Alberta, Canada
| | - Chandar Sadasivan
- Department of Neurosurgery, Stony Brook University, Stony Brook, New York, USA
| | - Alim P Mitha
- Department of Clinical Neurosciences, University of Calgary, Foothills Medical Centre, Calgary, Alberta, Canada
- Department of Biomedical Engineering, University of Calgary, Calgary, Alberta, Canada
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Zhang Z, Albadawi H, Fowl RJ, Mayer JL, Chong BW, Oklu R. Treatment of Ruptured Wide-Necked Aneurysms using a Microcatheter Injectable Biomaterial. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2305868. [PMID: 37579579 PMCID: PMC10843457 DOI: 10.1002/adma.202305868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 08/03/2023] [Indexed: 08/16/2023]
Abstract
Ruptured wide-neck aneurysms (WNAs), especially in a setting of coagulopathy, are associated with significant morbidity and mortality. It is shown that by trapping a sub-millimeter clinical catheter inside the aneurysm sac using a flow diverter stent (FDS), instant hemostasis can be achieved by filling the aneurysm sac using a novel biomaterial, rescuing catastrophic bleeding in large-animal models. Multiple formulations of a biomaterial comprising gelatin, nanoclay (NC), and iohexol are developed, optimized, and extensively tested in vitro to select the lead candidate for further testing in vivo in murine, porcine, and canine models of WNAs, including in a subset with aneurysm rupture. The catheter-injectable and X-ray visible versions of the gel embolic agent (GEA) with the optimized mechanical properties outperform control groups, including a subset that receive a clinically used liquid embolic (Onyx, Medtronic), with and without aneurysm rupture. A combinatorial approach to ruptured WNAs with GEA and FDS may change the standard of medical practice and save lives.
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Affiliation(s)
- Zefu Zhang
- Division of Vascular & Interventional Radiology, Laboratory for Patient Inspired Engineering, Mayo Clinic, 13400 East Shea Blvd., Scottsdale, Arizona 85259. USA
| | - Hassan Albadawi
- Division of Vascular & Interventional Radiology, Laboratory for Patient Inspired Engineering, Mayo Clinic, 13400 East Shea Blvd., Scottsdale, Arizona 85259. USA
| | - Richard J. Fowl
- Chair Emeritus, Division of Vascular and Endovascular Surgery, Emeritus Professor of Surgery, Mayo Clinic, 5777 East Mayo Blvd., Phoenix, Arizona 85054, USA
| | - Joseph L. Mayer
- Division of Vascular & Interventional Radiology, Laboratory for Patient Inspired Engineering, Mayo Clinic, 13400 East Shea Blvd., Scottsdale, Arizona 85259. USA
| | - Brian W. Chong
- Department of Neurological Surgery and Radiology Mayo Clinic, 5777 East Mayo Blvd., Phoenix, Arizona 85054, USA
| | - Rahmi Oklu
- Division of Vascular & Interventional Radiology, Laboratory for Patient Inspired Engineering, Mayo Clinic, 13400 East Shea Blvd., Scottsdale, Arizona 85259. USA
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Muram S, Corcoran R, Cooke J, Forrester K, Lapins E, Morrish R, Cheema OZA, Goyal M, Eesa M, Fiorella D, Wong JH, Sadasivan C, Mitha AP. Immediate flow-diversion characteristics of a novel primarily bioresorbable flow-diverting stent. J Neurosurg 2022; 137:1794-1800. [PMID: 35364565 DOI: 10.3171/2022.1.jns212975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 01/31/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Flow-diverting stents with a resorbable component have significant theoretical benefits over full metal stents, although currently there are none in clinical use. In this study, the authors sought to determine the immediate flow-diversion characteristics of a novel primarily bioresorbable flow-diverting stent. METHODS Bioresorbable stents were deployed into glass tube models to determine porosity and pore density. In vitro flow diversion behavior was evaluated using high frame rate angiography under pulsatile flow conditions in a patient-specific silicone aneurysm model treated with the resorbable stent as well as the Surpass Evolve stent. In vivo flow diversion was characterized by deployment into 20 rabbit saccular aneurysm models, and grading was based on the O'Kelly-Marotta scale and the 4F-flow diversion predictive score. RESULTS Porosities and pore densities of the bioresorbable stent were in the flow-diverting range for all target vessel diameters. Quantified results of immediate angiography after placement of the bioresorbable stent into a silicone aneurysm model demonstrated greater flow diversion compared to the Evolve stent. Bioresorbable stent placement in saccular aneurysm models resulted in an immediate O'Kelly-Marotta grade of A3 or better and a 4F-flow diversion predictive score of 4 or better in all cases. CONCLUSIONS The bioresorbable stent has immediate flow-diversion characteristics that are comparable to commercially available metal stents. Longer-term studies are underway to determine the ability of the resorbable fibers to act as a neointimal scaffold and result in long-term aneurysm occlusion.
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Affiliation(s)
- Sandeep Muram
- 1Department of Clinical Neurosciences, University of Calgary
| | | | | | | | - Elana Lapins
- 1Department of Clinical Neurosciences, University of Calgary
| | - Rosalie Morrish
- 1Department of Clinical Neurosciences, University of Calgary
| | | | - Mayank Goyal
- 1Department of Clinical Neurosciences, University of Calgary.,5Department of Radiology, University of Calgary, Alberta, Canada; and
| | - Muneer Eesa
- 1Department of Clinical Neurosciences, University of Calgary.,5Department of Radiology, University of Calgary, Alberta, Canada; and
| | - David Fiorella
- 6Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, New York
| | - John H Wong
- 1Department of Clinical Neurosciences, University of Calgary.,4Hotchkiss Brain Institute, University of Calgary.,5Department of Radiology, University of Calgary, Alberta, Canada; and
| | - Chander Sadasivan
- 6Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, New York
| | - Alim P Mitha
- 1Department of Clinical Neurosciences, University of Calgary.,3Biomedical Engineering Program, University of Calgary.,4Hotchkiss Brain Institute, University of Calgary.,5Department of Radiology, University of Calgary, Alberta, Canada; and
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4
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Simgen A, Mayer C, Kettner M, Mühl-Benninghaus R, Reith W, Yilmaz U. Retrospective analysis of intracranial aneurysms after flow diverter treatment including color-coded imaging (syngo iFlow) as a predictor of aneurysm occlusion. Interv Neuroradiol 2021; 28:190-200. [PMID: 34107790 DOI: 10.1177/15910199211024056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
PURPOSE Flow Diverters (FD) have immensely extended the treatment of cerebral aneurysms in the past years. Complete aneurysm occlusion is a process that often takes a certain amount of time and is usually difficult to predict. Our aim was to investigate different syngo iFlow parameters in order to predict aneurysm occlusion. METHODS Between 2014 and 2018 patients with unruptured cerebral aneurysms treated with a FD were reviewed. Aneurysm occlusion and complication rates have been assessed.In addition, various quantitative criteria were assessed using syngo iFlow before, after the intervention, and after short and long-term digital subtraction angiography (DSA). RESULTS A total of 66 patients hosting 66 cerebral aneurysms were included in this study. 87.9% (n = 58) aneurysms in the anterior and 12.1% (n = 8) in the posterior circulation were treated. Adequate aneurysm occlusion at long-term follow-up (19.05 ± 15.1 months) was achieved in 90.9% (n = 60). Adequately occluded aneurysm revealed a significantly greater peak intensity delay (PI-D, p = 0.008) and intensity decrease ratio (ID-R, p < 0.001) compared to insufficiently occluded aneurysms. Increased intra-aneurysmal contrast agent intensity (>100%) after FD implantation resulted in an ID-R < 1, which was associated with aneurysm growth during follow-up DSA. Retreatment with another FD due to foreshortening and/or aneurysm growth was performed in 10.6% (n = 7). Overall morbidity and mortality rates were 1.5% (n = 1) and 0%. CONCLUSION The applied syngo iFlow parameters were found to be useful in predicting adequate aneurysm occlusion and foresee aneurysm growth, which might indicate the implantation of another FD.
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Affiliation(s)
- Andreas Simgen
- Departments of Neuroradiology, Saarland University Hospital, Homburg/Saar, Germany
| | - Christine Mayer
- Departments of Neuroradiology, Saarland University Hospital, Homburg/Saar, Germany
| | - Michael Kettner
- Departments of Neuroradiology, Saarland University Hospital, Homburg/Saar, Germany
| | | | - Wolfgang Reith
- Departments of Neuroradiology, Saarland University Hospital, Homburg/Saar, Germany
| | - Umut Yilmaz
- Departments of Neuroradiology, Saarland University Hospital, Homburg/Saar, Germany
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5
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Guédon A, Thépenier C, Shotar E, Gabrieli J, Mathon B, Premat K, Lenck S, Degos V, Sourour N, Clarençon F. Predictive score for complete occlusion of intracranial aneurysms treated by flow-diverter stents using machine learning. J Neurointerv Surg 2020; 13:341-346. [PMID: 33219150 DOI: 10.1136/neurintsurg-2020-016748] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/26/2020] [Accepted: 11/03/2020] [Indexed: 11/04/2022]
Abstract
BACKGROUND Complete 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. METHODS Consecutive 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. RESULTS The 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%). CONCLUSION A 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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Affiliation(s)
- Alexis Guédon
- Biosurgical Research Lab (Carpentier Foundation), European Georges-Pompidou Hospital, INSERM UMR_S 1140, University of Paris, Paris, France.,Department of Anatomy, University of Paris, Paris, France
| | - Cédric Thépenier
- French Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France.,Department of Experimental Neuropathology, Institut Pasteur, Paris, France
| | - Eimad Shotar
- Department of Neuroradiology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | - Joseph Gabrieli
- Department of Neuroradiology, University of Padova Faculty of Medicine and Surgery, Padova, Veneto, Italy
| | - Bertrand Mathon
- Department of Neurosurgery, Pitié-Salpêtrière Hospital, AP-HP, Paris, France.,Sorbonne University, Paris, Île-de-France, France
| | - Kévin Premat
- Department of Neuroradiology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France.,Sorbonne University, Paris, Île-de-France, France
| | - Stéphanie Lenck
- Department of Neuroradiology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | - Vincent Degos
- Sorbonne University, Paris, Île-de-France, France.,Department of Neuro-anesthesiology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | - Nader Sourour
- Department of Neuroradiology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | - Frédéric Clarençon
- Department of Neuroradiology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France .,Sorbonne University, Paris, Île-de-France, France
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What is the hemodynamic effect of the Woven EndoBridge? An in vivo quantification using time-density curve analysis. Neuroradiology 2020; 62:1043-1050. [PMID: 32170371 PMCID: PMC7366603 DOI: 10.1007/s00234-020-02390-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/26/2020] [Indexed: 12/20/2022]
Abstract
Purpose Using the Woven EndoBridge (WEB) for aneurysm treatment has emerged as endovascular approach aiming for flow disruption in aneurysm sac. Since quantifiable data confirming the hemodynamic effect are lacking, we investigated in vivo aneurysmal flow alterations using time-density curve (TDC) analysis. Additionally, we evaluated whether flow parameters could be identified as independent factor to predict aneurysm occlusion. Methods Forty cerebral aneurysm patients treated with WEB were enrolled. Pre- and postinterventional digital subtraction angiography series were postprocessed and TDCs generated. TDCs were quantified calculating the parameters aneurysmal inflow velocity, outflow velocity, mean flow velocity, and relative time-to-peak (rTTP) of aneurysm filling. Pre- and postinterventional values were compared and related to occlusion rate. Results WEB implanting induced highly significant rTTP prolongation by 52% (p = 0.001) and highly significant decrease of aneurysmal inflow, outflow, and mean flow velocity (p < 0.001). While outflow velocity was reduced by 49%, inflow velocity was reduced by 33% only. No statistically significant difference between the occluded and the non-occluded group was observed. No flow parameter reached significance level concerning predicting aneurysm occlusion. Conclusion Flow quantification confirms a significant flow-disrupting effect of WEB reducing more the outflow than the inflow velocity. In our small cohort, no flow parameter reached statistical significance to show predictive value regarding complete aneurysm occlusion. The hemodynamic effect of WEB is on comparable level to flow-diverting stents meaning that aneurysm closure can be delayed. In case of only slight inflow changes and high aneurysmal hemodynamic stress, some aneurysms might not be adequately protected in the short term.
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Sadasivan C, Fiorella D. Preliminary in vitro angiographic comparison of the flow diversion behavior of Evolve and Pipeline devices. J Neurointerv Surg 2019; 12:616-620. [DOI: 10.1136/neurintsurg-2019-015455] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/29/2019] [Accepted: 10/31/2019] [Indexed: 11/04/2022]
Abstract
Background and purposeFlow diverters are increasingly used to treat a broad category of cerebral aneurysms. We conducted an in vitro study to angiographically compare the flow diversion effect of Surpass Evolve from Stryker Neurovascular with the Pipeline Shield Embolization Device from Medtronic Neurovascular.MethodsThree copies each of three carotid aneurysm geometries were manufactured from silicone. Evolve and Pipeline flow diverters were deployed in one copy of each geometry; the third copy was used as Control. High-speed angiography was acquired under pulsatile flow in each replica, contrast concentration-time curves within the aneurysms were recorded, and the curves were quantified with six parameters. The parameters were statistically evaluated to compare the flow diversion effect of both devices.ResultsThe Evolve showed greater flow diversion trends in almost all intra-geometry comparisons than the Pipeline. When aggregated over the three geometries, the Evolve was statistically significantly better than the Pipeline in four of the six parameters, and about the same or better (not statistically significant) than the Pipeline in the other two parameters.ConclusionsThe Evolve device demonstrated greater in vitro flow diversion effects than Pipeline. Comparative efficacy of the devices will need to be adjudicated based on clinical outcomes.
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8
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Sadasivan C, Dholakia R, Peeling L, Gölitz P, Doerfler A, Lieber BB, Fiorella DJ, Woo HH. Angiographic assessment of the efficacy of flow diverter treatment for cerebral aneurysms. Interv Neuroradiol 2019; 25:655-663. [PMID: 31296064 DOI: 10.1177/1591019919860829] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
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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Affiliation(s)
- Chander Sadasivan
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, USA
| | - Ronak Dholakia
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, USA
| | - Lissa Peeling
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, USA
| | - Philipp Gölitz
- Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Arnd Doerfler
- Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Baruch B Lieber
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, USA
| | - David J Fiorella
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, USA
| | - Henry H Woo
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, USA
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Ishibashi T, Toyama S, Miki K, Karakama J, Yoshino Y, Ishibashi S, Tomita M, Nemoto S. Effects of propofol versus sevoflurane on cerebral circulation time in patients undergoing coiling for cerebral artery aneurysm: a prospective randomized crossover study. J Clin Monit Comput 2019; 33:987-998. [PMID: 30610516 DOI: 10.1007/s10877-018-00251-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 12/31/2018] [Indexed: 11/28/2022]
Abstract
Many neuroendovascular treatments are supported by real-time anatomical and visual hemodynamic assessments through digital subtraction angiography (DSA). Here we used DSA in a single-center prospective randomized crossover study to assess the intracranial hemodynamics of patients undergoing coiling for cerebral aneurysm (n = 15) during sevoflurane- and propofol-based anesthesia. Color-coded DSA was used to define time to peak density of contrast medium (TTP) at several intravascular regions of interest (ROIs). Travel time at a particular ROI was defined as the TTP at the selected ROI minus TTP at baseline position on the internal carotid artery (ICA). Travel time at the jugular bulb on the anterior-posterior view was defined as the cerebral circulation time (CCT), which was divided into four segmental circulation times: ICA, middle cerebral artery (MCA), microvessel, and sinus. When bispectral index values were kept between 40 and 60, CCT (median [interquartile range]) was 10.91 (9.65-11.98) s under propofol-based anesthesia compared with 8.78 (8.32-9.45) s under sevoflurane-based anesthesia (P < 0.001). Circulation times for the ICA, MCA, and microvessel segments were longer under propofol-based anesthesia than under sevoflurane-based anesthesia (P < 0.05 for all). Our results suggest that, relative to sevoflurane, propofol decreases overall cerebral perfusion.
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Affiliation(s)
- Tomoko Ishibashi
- Department of Anesthesiology, Graduate School of Medicine and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Satoshi Toyama
- Department of Critical Care and Anesthesia, National Center for Child Health and Development, 2-10-1 Okura, Setagaya-Ku, Tokyo, 157-8535, Japan.
| | - Kazunori Miki
- Department of Endovascular Surgery, Graduate School of Medicine and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Jun Karakama
- Department of Endovascular Surgery, Graduate School of Medicine and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Yoshikazu Yoshino
- Department of Endovascular Surgery, Graduate School of Medicine and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Satoru Ishibashi
- Department of Neurology, Graduate School of Medicine and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Makoto Tomita
- Clinical Research Center, Graduate School of Medicine and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Shigeru Nemoto
- Department of Endovascular Surgery, Graduate School of Medicine and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan
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10
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Dholakia RJ, Kappel AD, Pagano A, Woo HH, Lieber BB, Fiorella DJ, Sadasivan C. In vitro angiographic comparison of the flow-diversion performance of five neurovascular stents. Interv Neuroradiol 2017; 24:150-161. [PMID: 29239685 DOI: 10.1177/1591019917748317] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background and purpose Data differentiating flow diversion properties of commercially available low- and high-porosity stents are limited. This in vitro study applies angiographic analysis of intra-aneurysmal flow to compare the flow-diversion performance of five neurovascular devices in idealized sidewall and bifurcation aneurysm models. Methods Five commercial devices (Enterprise, Neuroform, LVIS, FRED, and Pipeline) were implanted in silicone sidewall and bifurcation aneurysm models under physiological average flow of blood analog fluid. High-speed angiographic images were acquired pre- and post-device implantation and contrast concentration-time curves within the aneurysm were recorded. The curves were quantified with five parameters to assess changes in contrast transport, and thus aneurysm hemodynamics, due to each device. Results Inter-device flow-diversion performance was more easily distinguished in the sidewall model than the bifurcation model. There were no obvious overall statistical trends in the bifurcation parameters but the Pipeline performed marginally better than the other devices. In the sidewall geometry, overall evidence suggests that the LVIS performed better than the Neuroform and Enterprise. The Pipeline and FRED devices were statistically superior to the three stents and Pipeline was superior to FRED in all sidewall parameters evaluated. Conclusions Based on this specific set of experiments, lower-porosity flow diverters perform significantly better in reducing intra-aneurysmal flow activity than higher-porosity stents in sidewall-type geometries. The LVIS device is potentially a better flow diverter than the Neuroform and Enterprise devices, while the Pipeline is potentially better than the FRED.
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Affiliation(s)
- Ronak J Dholakia
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Ari D Kappel
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Andrew Pagano
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Henry H Woo
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Baruch B Lieber
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - David J Fiorella
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Chander Sadasivan
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
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11
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Treatment Evaluation of Flow-Limiting Stenoses of the Superficial Femoral and Popliteal Artery by Parametric Color-Coding Analysis of Digital Subtraction Angiography Series. Cardiovasc Intervent Radiol 2017; 40:1147-1154. [PMID: 28488106 DOI: 10.1007/s00270-017-1670-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 04/24/2017] [Indexed: 12/16/2022]
Abstract
PURPOSE To evaluate the hemodynamic effect of percutaneous transluminal intervention (PTI) on stenosis of the superficial femoral (SFA) and popliteal arteries (PA) using time-density curves (TDCs) derived from digital subtraction angiography (DSA) series in correlation with ultrasound peak systolic velocity ratio (PSVR) and ankle brachial index (ABI). MATERIALS AND METHODS DSA series of SFA or PA of patients with symptomatic peripheral arterial occlusive disease was obtained with a flat-panel angiography system with intention-to-treat. In DSA series acquired before and after PTI, TDCs were analyzed proximal and distal of each stenosis using parametric color coding (PCC). For correlation, ABI and PSVR measurements pre- and post-PTI were recorded for all patients. RESULTS In total, 25 stenoses of the SFA or PA were treated by PTI in 22 patients (17 male, 5 female, mean age 68 years). After treatment, peak-to-peak (PTP) times between TDCs proximal and distal to the treated vessel segment decreased statistically significantly (p = 0.01) on average from PTP = 1.9 ± 1.7 s to mean PTP = 1 ± 1 s. ABI and PSVR also changed statistically significantly after treatment (pretreatment ABI = 0.7 ± 0.2, PSVR = 4.2 ± 1.9; post-ABI = 0.9 ± 0.2, PSVR = 1.3 ± 0.4, both p < 0.05). Correlation parameters did not show a strong correlation between change in TDC and clinical parameters ABI and PSVR. CONCLUSION Using PCC for analyzing contrast medium dynamics in DSA series is clinically useful for evaluating stenoses of the SFA and PA and for immediate treatment control after PTA. LEVEL OF EVIDENCE Case series, IV.
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Dholakia R, Sadasivan C, Fiorella DJ, Woo HH, Lieber BB. Hemodynamics of Flow Diverters. J Biomech Eng 2017; 139:2569375. [DOI: 10.1115/1.4034932] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Indexed: 01/17/2023]
Abstract
Cerebral aneurysms are pathological focal evaginations of the arterial wall at and around the junctions of the circle of Willis. Their tenuous walls predispose aneurysms to leak or rupture leading to hemorrhagic strokes with high morbidity and mortality rates. The endovascular treatment of cerebral aneurysms currently includes the implantation of fine-mesh stents, called flow diverters, within the parent artery bearing the aneurysm. By mitigating flow velocities within the aneurysmal sac, the devices preferentially induce thrombus formation in the aneurysm within hours to days. In response to the foreign implant, an endothelialized arterial layer covers the luminal surface of the device over a period of days to months. Organization of the intraneurysmal thrombus leads to resorption and shrinkage of the aneurysm wall and contents, eventually leading to beneficial remodeling of the pathological site to a near-physiological state. The devices' primary function of reducing flow activity within aneurysms is corollary to their mesh structure. Complete specification of the device mesh structure, or alternately device permeability, necessarily involves the quantification of two variables commonly used to characterize porous media—mesh porosity and mesh pore density. We evaluated the flow alteration induced by five commercial neurovascular devices of varying porosity and pore density (stents: Neuroform, Enterprise, and LVIS; flow diverters: Pipeline and FRED) in an idealized sidewall aneurysm model. As can be expected in such a model, all devices substantially reduced intraneurysmal kinetic energy as compared to the nonstented case with the coarse-mesh stents inducing a 65–80% reduction whereas the fine-mesh flow diverters induced a near-complete flow stagnation (∼98% reduction). We also note a trend toward greater device efficacy (lower intraneurysmal flow) with decreasing device porosity and increasing device pore density. Several such flow studies have been and are being conducted in idealized as well as patient-derived geometries with the overarching goals of improving device design, facilitating treatment planning (what is the optimal device for a specific aneurysm), and predicting treatment outcome (will a specific aneurysm treated with a specific device successfully occlude over the long term). While the results are generally encouraging, there is poor standardization of study variables between different research groups, and any consensus will only be reached after standardized studies are conducted on collectively large datasets. Biochemical variables may have to be incorporated into these studies to maximize predictive values.
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Affiliation(s)
- Ronak Dholakia
- Department of Neurological Surgery, Stony Brook University Medical Center, Stony Brook, NY 11794
| | - Chander Sadasivan
- Department of Neurological Surgery, Stony Brook University Medical Center, Stony Brook, NY 11794
| | - David J. Fiorella
- Department of Neurological Surgery, Stony Brook University Medical Center, Stony Brook, NY 11794
| | - Henry H. Woo
- Department of Neurological Surgery, Stony Brook University Medical Center, Stony Brook, NY 11794
| | - Baruch B. Lieber
- Professor Department of Neurological Surgery, Stony Brook University Medical Center, HSC T12, Room 080, 100 Nicolls Road, Stony Brook, NY 11794-8122 e-mail:
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Gölitz P, Struffert T, Hoelter P, Eyüpoglu I, Knossalla F, Doerfler A. Flow-diverting stents allow efficient treatment of unruptured, intradural dissecting aneurysms of the vertebral artery: An explanatory approach using in vivo flow analysis. Interv Neuroradiol 2015; 22:76-83. [PMID: 26515700 DOI: 10.1177/1591019915609166] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 08/09/2015] [Indexed: 12/26/2022] Open
Abstract
OBJECT Our study aimed to evaluate the efficiency of flow-diverting stents (FDS) in treating unruptured, intradural dissecting aneurysms of the vertebral artery (VADAs). Additionally, the effect of FDS on the aneurysmal flow pattern was investigated by performing in vivo flow analysis using parametric color coding (PCC). METHODS We evaluated 11 patients with unruptured, intradural VADAs, treated with FDS. Pre- and postinterventional DSA-series were postprocessed by PCC, and time-density curves were calculated. The parameters aneurysmal inflow-velocity, outflow-velocity and relative time-to-peak (rTTP) were calculated. Pre- and postinterventional values were compared and correlated with the occlusion rate after six months. RESULTS Follow-up DSA detected 10 aneurysms occluded, meaning an occlusion rate of 91%. No procedure-related morbidity and mortality was found. Flow analyses revealed a significant reduction of aneurysmal inflow- velocity and prolongation of rTTP after FDS deployment. Concerning aneurysm occlusion, the postinterventional outflow-velocity turned out to be a marginally statistically significant predictor. A definite threshold value (-0.7 density change/s) could be determined for the outflow-velocity that allows prediction of complete aneurysm occlusion with high sensitivity and specificity (100%). CONCLUSIONS Using FDS can be considered an efficient and safe therapy option in treating unruptured, intradural VADA. From in vivo flow analyses the postinterventional aneurysmal outflow-velocity turned out to be a potential predictor for later complete aneurysm occlusion. Here, it might be possible to determine a threshold value that allows prediction of aneurysm occlusion with high specificity and sensitivity. As fast, applicable and easy-to-handle tool, PCC could be used for procedural monitoring and might contribute to further treatment optimization.
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Affiliation(s)
- Philipp Gölitz
- Department of Neuroradiology, University of Erlangen-Nuremberg, Germany
| | - Tobias Struffert
- Department of Neuroradiology, University of Erlangen-Nuremberg, Germany
| | - Philip Hoelter
- Department of Neuroradiology, University of Erlangen-Nuremberg, Germany
| | - Ilker Eyüpoglu
- Department of Neurosurgery, University of Erlangen-Nuremberg, Germany
| | - Frauke Knossalla
- Department of Neurology, University of Erlangen-Nuremberg, Germany
| | - Arnd Doerfler
- Department of Neuroradiology, University of Erlangen-Nuremberg, Germany
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Fernandez H, Macho JM, Blasco J, Roman LS, Mailaender W, Serra L, Larrabide I. Computation of the change in length of a braided device when deployed in realistic vessel models. Int J Comput Assist Radiol Surg 2015; 10:1659-65. [PMID: 26062795 DOI: 10.1007/s11548-015-1230-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 05/28/2015] [Indexed: 10/23/2022]
Abstract
PURPOSE An important issue in the deployment of braided stents, such as flow diverters, is the change in length, also known as foreshortening, underwent by the device when is released from the catheter into a blood vessel. The position of the distal end is controlled by the interventionist, but knowing a priori the position of the proximal end of the device is not trivial. In this work, we assess and validate a novel computer method to predict the length that a braided stent will adopt inside a silicon model of an anatomically accurate vessel. METHODS Three-dimensional rotational angiography images of aneurysmatic patients were used to generate surface models of the vessels (3D meshes) and then create accurate silicon models from them. A braided stent was deployed into each silicon model to measure its length. The same stents deployed on the silicon models were virtually deployed on the 3D meshes using the method being evaluated. RESULTS The method was applied to five stent placements on three different silicon models. The length adopted by the real braided device in the silicon models varies between 15 and 30% from the stent length specified by the manufacturer. The final length predicted by the method was within the estimated error of the measured real stent length. CONCLUSIONS The method provides, in a few seconds, the length of a braided stent deployed inside a vessel, showing an accurate estimation of the final length for the cases studied. This technique could provide useful information for planning the intervention and improve endovascular treatment of intracranial aneurysms in the future.
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Affiliation(s)
| | - Juan M Macho
- Hospital Clinic Provincial de Barcelona, Barcelona, Spain
| | - Jordi Blasco
- Hospital Clinic Provincial de Barcelona, Barcelona, Spain
| | - Luis San Roman
- Hospital Clinic Provincial de Barcelona, Barcelona, Spain
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