Flow Diverter Implantation Research Articles

Numerical simulation of individualized flow diversion cerebral aneurysms treatment

AbstractFlow diverter implantation has emerged as a highly effective treatment for cerebral aneurysms. However, the variability in patient‐specific vascular anatomy necessitates detailed pre‐operative planning to mitigate potential complications arising from standard, one‐size‐fits‐all devices. To address these challenges, robust predictive simulation tools are essential for optimizing flow diverter design and implantation strategies tailored to the unique characteristics of each patient's anatomy. This study focuses on developing an advanced numerical simulation tool for modeling the mechanical behavior of braided flow diverters during crimping and navigation through patient‐specific vasculature. Using isogeometric analysis (IGA) with NURBS‐based representations in LS‐Dyna, the intricate deformations of the flow diverter wires during catheter crimping are captured with high accuracy. The patient‐specific vessel geometries, derived from imaging data, are integrated into the model to account for variations in vascular structure, ensuring precise alignment and controlled navigation of the device. The navigation process relies on optimizing the central axis of the blood vessel to minimize torsional stress on the flow diverter, reducing the risk of device malfunction or failure during deployment. By incorporating patient‐specific information, such as vessel curvature and tortuosity, the simulation tool enables the prediction of potential issues, thus allowing for intervention planning that is tailored to individual anatomy. This patient‐specific approach enhances the safety and efficacy of flow diverter implantation and serves as a foundation for improved device design prior to prototype development.

Non-ischemic cerebral enhancing (NICE) lesions after flow diversion for intracranial aneurysms: a multicenter study

BackgroundNon-ischemic cerebral enhancing (NICE) lesions have been reported as a rare complication of various neuroendovascular procedures, but information on their incidence after flow diversion is scant. It is unclear if...

Safety and efficacy of coated flow diverters in the treatment of cerebral aneurysms during single antiplatelet therapy: A multicenter study.

This multicenter study evaluates the safety and efficacy of coated flow diverters (cFDs) for the treatment of cerebral aneurysms under single antiplatelet therapy (SAPT). This is a retrospective, observational study of 41 patients (median age: 58 years) with 41 aneurysms (median size: 7 mm, 29 [71%] saccular, 9 [22%] ruptured) treated with cFDs at four neurovascular centers between 2020 and 2023. Scheduled cases received continuous SAPT starting seven days before the procedure. Emergency cases were treated with tirofiban followed by SAPT loading. The safety endpoint was ischemic complications occurring during the procedure and within four months of clinical follow-up. The Pipeline Vantage or Flex Shield was used in 26 (63%) procedures, the FRED X in 12 (29%), the p48/64 Hydrophilic Polymer Coating in 2 (5%), and the Derivo Embolization Device 2heal in 1 (2%). Single antiplatelet therapy consisted of prasugrel in 27 (66%) patients, ticagrelor in 9 (22%), and ASA in 5 (12%). There were 2 (5%) early ischemic complications (one minor stroke and one transient ischemic attack). There were no late ischemic complications in the four-month follow-up of 35 patients. The six dropouts included four nontreatment-related deaths after subarachnoid hemorrhage and two patients with a poor outcome after subarachnoid hemorrhage. Complete and favorable occlusion rates (median: 7 months) were 75% (27/36) and 89% (32/36), respectively. Coated flow diverter implantation in the setting of SAPT was safe and effective and warrants confirmation in a prospective comparative trial.

Endovascular Management of Basilar Artery Aneurysms: A Consecutive Series of 124 Patients

There is currently no established criterion for determining when interventional treatment is necessary and what strategy is appropriate for basilar artery (BA) aneurysms. Through this study, we aimed to propose an algorithm that can effectively determine the optimal endovascular treatment (EVT) option for BA aneurysms. We enrolled patients with BA aneurysms from June 2016 to December 2022 and performed procedures based on the algorithm. The analysis included demographic, clinical, and aneurysmal characteristics, procedural details, complications, angiographic outcomes, and clinical outcomes. This study included 124 patients (mean age 55.0 years) with a BA aneurysm who underwent EVT. Of these, 21 aneurysms were treated in the setting of subarachnoid hemorrhage (SAH). The majority of aneurysms were located at the basilar apex (74), followed by the basilar trunk (30) and vertebrobasilar junction (20). Coiling was used in 18.5% of cases, while stent-assisted coiling embolization was chosen for 58.9%. Overlapping stents were used in 12.9%, flow diverter (FD) implantation in 3.2%, Y/T stent techniques in 4.8%, and stent adjunctive coiling with unilateral vertebral artery (VA) occlusion in only 1.6%. Procedure-related complications occurred in 15 patients (12.1%). Patients had a modified Rankin Scale(mRS) score of 0.74±1.62; 98 (86.7%) had good prognosis with mRS scores ranging from 0 to 2 at the last follow-up. DSA was performed on 105 (84.7%) patients revealing that 101 (81.5%) achieved complete or near-complete occlusion. The endovascular treatment criteria for BA aneurysms depended on the multi-characteristics was safe and effective. However, further evidence is needed from large cohort studies.

Comprehensive Analysis of Post-Pipeline Endothelialization and Remodeling.

Successful post-flow-diverter endoluminal reconstruction is widely believed to require endothelial overgrowth of the aneurysmal inflow zone. However, endothelialization/neointimal overgrowth is a complex process, over which we currently have very limited influence. Less emphasized is vascular remodeling of the target arterial segment, the dynamic response of the vessel to flow-diverter implantation. This process is distinct from flow modifications in covered branches. It appears that basic angiographic methods allow simple and useful observations. The purpose of this article was to quantitatively evaluate observable postimplantation changes in target vessels following deployment of Pipeline endoluminal constructs. One hundred consecutive adults with unruptured, previously untreated, nondissecting aneurysms treated with the Pipeline Embolization Device with Shield Technology and the availability of follow-up conventional angiography were studied with 2D DSA imaging. Target vessel size; Pipeline Embolization Device diameter; endothelial thickness; and various demographic, antiplatelet, and device-related parameters were recorded and analyzed. The thickness of neointimal overgrowth (mean, 0.3 [SD, 0.1] mm; range, 0.1-0.7 mm) is inversely correlated with age and is independent of vessel size, smoking status, sex, and degree of platelet inhibition. The decrease in lumen diameter caused by neointimal overgrowth, however, appears counteracted by outward remodeling (dilation) of the target arterial segment. This leads to an increase in the diameter with a corresponding decrease in length (foreshortening) of the implanted Pipeline Embolization Device. This physiologic remodeling process affects optimally implanted devices and is not a consequence of stretching, device migration, vasospasm, and so forth. A direct, linear, statistically significant relationship exists between the degree of observed outward remodeling and the diameter of the implanted Pipeline Embolization Device relative to the target vessel. Overall, remodeled arterial diameters were reduced by 15% (SD, 10%) relative to baseline and followed a normal distribution. Clinically relevant stenosis was not observed. Vessel healing involves both outward remodeling and neointimal overgrowth. Judicial oversizing could be useful in specific settings to counter the reduction in lumen diameter due to postimplant neointimal overgrowth; however, this overszing needs to be balanced against the decrease in metal coverage accompanying the use of oversized devices. Similar analysis for other devices is essential.

310 The Derivo 2 Heal Embolization Device in the Treatment of Ruptured and Unruptured Intracranial Aneurysms: A Retrospective Multicenter Analysis

INTRODUCTION: The Derivo 2 Flow diverter has been previously described for the treatment of intracranial aneurysms. To overcome the risk of in-stent thrombosis and thrombo-embolism as a well-known risk of intracranial flow diverter implantation, the device was modified by adding an antithrombogenic fibrin-heparin coating. The fibrin network aims at surface passivation, reduction of inflammatory reactions and building a scaffold for endothelial cells. The covalently bound heparin reduces the thrombogenicity by locally reducing platelet activation and inhibtion of the coagulation cascade. METHODS: We perform a retrospective multicenter, single-arm trial at seven neurovascular centers. Patients treated with the D2H for unruptured or ruptured intracranial aneurysms are included in the study. The primary endpoint is angiographic aneurysm occlusion at six months as assessed by the O’Kelly-Marotta (OKM) grading scale. Clinical outcome is evaluated after intervention and at six months with major morbidity defined as modified Rankin Scale scores (mRS) of 3-5. RESULTS: Between October 2021 and March 2023 56 patients with ruptured and unruptered intracranial aneurysms were treated with the D2H embolization device and included in our analysis. All patients were subjected to the regular antiplatelet pre- and post-treatment medication as per standard of care in the respective institutions with no deviations being reported. No differences in terms of technical device properties were observed. By the time of the conference, data evaluation will be completed and clinical as well as safety results including angiographic follow-up will be available. CONCLUSIONS: The Derivo 2 heal Flow Diverter is a promising antithrombogenic coated device for the treatment of ruptured and unruptured intracranial aneurysms. Early post-interventional and long-term results will provide further insight into the effect of antithrombogenicity and endothelial healing.

Computational Flow Diverter Implantation—A Comparative Study on Pre-Interventional Simulation and Post-Interventional Device Positioning for a Novel Blood Flow Modulator

Due to their effect on aneurysm hemodynamics, flow diverters (FD) have become a routine endovascular therapy for intracranial aneurysms. Since over- and undersizing affect the device’s hemodynamic abilities, selecting the correct device diameter and accurately simulating FD placement can improve patient-specific outcomes. The purpose of this study was to validate the accuracy of virtual flow diverter deployments in the novel Derivo® 2 device. We retrospectively analyzed blood flows in ten FD placements for which 3D DSA datasets were available pre- and post-intervention. All patients were treated with a second-generation FD Derivo® 2 (Acandis GmbH, Pforzheim, Germany) and post-interventional datasets were compared to virtual FD deployment at the implanted position for implanted stent length, stent diameters, and curvature analysis using ANKYRAS (Galgo Medical, Barcelona, Spain). Image-based blood flow simulations of pre- and post-interventional configurations were conducted. The mean length of implanted FD was 32.61 (±11.18 mm). Overall, ANKYRAS prediction was good with an average deviation of 8.4% (±5.8%) with a mean absolute difference in stent length of 3.13 mm. There was a difference of 0.24 mm in stent diameter amplitude toward ANKYRAS simulation. In vessels exhibiting a high degree of curvature, however, relevant differences between simulated and real-patient data were observed. The intrasaccular blood flow activity represented by the wall shear stress was qualitatively reduced in all cases. Inflow velocity decreased and the pulsatility over the cardiac cycle was weakened. Virtual stenting is an accurate tool for FD positioning, which may help facilitate flow FDs’ individualization and assess their hemodynamic impact. Challenges posed by complex vessel anatomy and high curvatures must be addressed.

Early clinical experience with the new generation Pipeline Vantage flow diverter in the treatment of unruptured saccular aneurysms using short-term dual antiplatelet therapy.

The Pipeline Vantage flow diverter with Shield technology (PV) used in this study is a 4th-generation flow diverter (FD) designed to reduce thrombogenicity, promote endothelialization of the implant and increase efficiency in achieving aneurysm closure. In this study, we report the aneurysm occlusion rate, complication rate and clinical outcome with short-term dual antiplatelet therapy (DAPT) in the treatment of unruptured intracranial saccular aneurysms using the PV. We retrospectively identified patients treated between September 2021 and January 2023 with the PV and subsequently underwent short-term DAPT for 3 months. Patient and aneurysm characteristics, peri- and post-procedural complications, clinical outcomes and the grade of aneurysm occlusion were documented. Thirty patients with 32 aneurysms were treated. Successful FD implantation was achieved in all cases (100%). No periprocedural complications were documented. The overall symptomatic complication rate was 10% and the neurologic, treatment-related symptomatic complication rate was 6.6%. Only one symptomatic complication (3.3%) was device-related. Permanent clinical deterioration occurred in 2/30 patients (6.6%), leading to deterioration of the mRS within the first 3 months after treatment. No mortality was documented. The rate of complete aneurysm occlusion after 3 months and after a mean imaging follow-up of 9.9 months was 65.6% and 75%, respectively. Implantation of the PV for the treatment of saccular intracranial aneurysms achieves a good aneurysm occlusion rate with a low rate of complications. In addition, the use of short-term DAPT after PV implantation appears to be safe.

Intracranial aneurysms treatment using new generation FRED X flow diverters with antithrombotic coating and preoperative PreSize Neurovascular software simulation: literature review and own clinical observations analysis

Objective: Evaluate the possibilities of treating giant intracranial aneurysms and complex anatomy aneurysms by implanting new generation of FRED X flow diverters (MicroVention, USA) with antithrombogenic surface subject to preoperative virtual modeling and sizing with PreSize Neurovascular software (Oxford Heartbeat Ltd, Great Britain). Materials and Methods. FRED X flow diverters with antithrombogenic surface were implanted in 7 patients with giant cerebral aneurysms and complex anatomy aneurysms in the Endovascular Center at Mechnikov Dnipropetrovsk Regional Clinical Hospital, Dnipro, within two months (May 2, 2023 to June 27, 2023). Our study group consisted of 4 (57.1%) female patients and 3 (42.9%) male patients (p=1.0). The average age was 50.4±13.7. 4 patients had single intracranial aneurysms and 3 patients had multiple aneurysms. 2 patients had 2 aneurysms and 1 patient had 4 aneurysms. 3 patients had a hemorrhagic clinical course of the disease (spontaneous subarachnoid hemorrhage in the history), 3 patients had asymptomatic aneurysms, and 1 patient had a pseudotumorous aneurysm. Results. All 7 patients underwent the ICA aneurysm(s) surgery. 3 patients had a flow diverter implanted at the level of multiple aneurysms (in 2 patients, 2 aneurysms; in 1 patient, 3 aneurysms). 2 patients, in addition to flow diverter implantation, underwent coil aneurysms embolization (using jailing technique). In all patients, the flow diverter was implanted under dual (ticagrelor and acetylsalicylic acid) antiplatelet therapy. 3 patients with a history of subarachnoid aneurysmal hemorrhage received a loading dose of dual antiplatelet therapy immediately before the flow diverter implantation. In one patient with a complex closed siphon shape, balloon angioplasty was required to optimize flow diverter opening to the arterial wall. In all other 6 patients, the flow diverters were opened in a controlled manner with a Push & Pull technique variant: Load/Tension Unsheath technique. Conclusions: In the endovascular treatment of giant and complex aneurysms, the use of new generation FRED X flow diverters (MicroVention, USA) with antithrombogenic coating subject to proper diverters sizing with PreSize Neurovascular software does not cause technical difficulties and is controlled.

Comparison of arterial wall integration of different flow diverters in rabbits: The CICAFLOW study

Background and purposeNew coated flow diverters (FDs) claim antithrombotic properties and increased arterial wall integration. The aim of this study is to compare in vivo endothelial coverage of coated and uncoated FD in the context of different antiplatelet regimens. MethodsDifferent FDs (Silk Vista – SV, Pipeline with Shield technology – PED shield and Surpass Evolve – SE) were implanted in the aorta of rabbits, all 3 in each animal with 3 different antiplatelet regimens: no antiplatelet therapy, aspirin alone, or aspirin and ticagrelor. Four weeks after FD implantation, angiography, flat-panel CT, and optical coherence tomography (OCT) were performed before harvesting the aorta. Extensive histopathology analyses were performed including environmental scanning electron microscopy (ESEM), multiphoton microscopy (MPM) and histological staining with qualitative and/or quantitative assessment of device coverage. ResultsAll 23 FDs that were implanted remained patent without hyperplasia. Qualitative stent coverage assessment revealed that there were no statistically significant differences between the FD groups (p = 0.19, p = 0.45, p = 0.40, and p = 0.84 for OCT, ESEM, MPM and histology, respectively). Quantitative neointimal measurement of histological sections also showed similar results in all 3 FD groups (p = 0.70). However, there were significant differences between the 3 groups of antiplatelet regimens (p = 0.07) with a higher rate in the no antiplatelet group (p = 0.05 versus aspirin alone and p = 0.03 versus aspirin and ticagrelor). ConclusionOur study provides evidence that FD integration into the arterial wall is similar with coated (PED shield) and uncoated devices (SV, SE), regardless of the antiplatelet regimen. FD integration with specific surface coverage should be promoted. Trial registrationAPAFIS #2022011215518538.

De novo expansion formation in the outer curvature of the internal carotid artery after flow diverter deployment for an infectious cavernous carotid aneurysm: illustrative case.

Infectious aneurysms very rarely occur in the cavernous carotid artery. Recently, treatment by flow diverter implantation with preservation of the parent artery has been the treatment of choice. A 64-year-old woman presented with stenosis at the C5 segment of the left internal carotid artery (ICA), followed by ocular symptoms within 2 weeks, with a de novo aneurysm in the left cavernous carotid artery and wall irregularity with stenosis from the C2 to C5 segments of the left ICA. Antimicrobial therapy was given for 6 weeks, and a Pipeline Flex Shield was implanted. Angiography 6 months after treatment showed complete obliteration of the infectious aneurysm and improvement of the stenosis. However, de novo expansions were formed in the outer curvature of C3 and C4 segments of the ICA where the Pipeline device had been deployed. Aneurysms that develop rapidly and show shape changes over time, accompanied by fever and inflammation, may be associated with an infection. Because of the fragility in the irregular wall of the parent vessel associated with infectious aneurysms, de novo expansion may form in the outer curvature of the parent vessel after flow diverter placement; thus, careful follow-up is necessary.

Bioresorbable Poly (L-Lactic Acid) Flow Diverter Versus Cobalt-Chromium Flow Diverter: In Vitro and In Vivo Analysis.

Permanent metallic flow diverter (FD) implantation for treatment of intracranial aneurysms requires antiplatelet therapy for an unclear duration and restricts postprocedural endovascular access. Bioresorbable FDs are being developed as a solution to these issues, but the biological reactions and phenomena induced by bioresorbable FDs have not been compared with those of metallic FDs. We have developed a bioresorbable poly (L-lactic acid) FD (PLLA-FD) and compared it with an FD composed of cobalt-chromium and platinum-tungsten (CoCr-FD). FD mechanical performance and in vitro degradation of the PLLA-FD were evaluated. For in vivo testing in a rabbit aneurysm model, FDs were implanted at the aneurysm site and the abdominal aorta in the PLLA-FD group (n=21) and CoCr-FD group (n=15). Aneurysm occlusion rate, branch patency, and thrombus formation within the FD were evaluated at 3, 6, and 12 months. Local inflammation and neointima structure were also evaluated. Mean strut, porosity, and pore density for the PLLA-FD were 41.7 μm, 60%, and 20 pores per mm2, respectively. The proportion of aneurysms exhibiting a neck remnant or complete occlusion did not significantly differ between the groups; however, the complete occlusion rate was significantly higher in the PLLA-FD group (48% versus 13%; P=0.0399). Branch occlusion and thrombus formation within the FD were not observed in either group. In the PLLA-FD group, CD68 immunoreactivity was significantly higher, but neointimal thickness decreased over time and did not significantly differ from that of the CoCr-FD at 12 months. Collagen fibers significantly predominated over elastic fibers in the neointima in the PLLA-FD group. The opposite was observed in the CoCr-FD group. The PLLA-FD was as effective as the CoCr-FD in this study and is feasible for aneurysm treatment. No morphological or pathological problems were observed with PLLA-FD over a 1-year period.

The incidence and predictors of in-stent stenosis after pipeline flow-diverter stenting for intracranial aneurysm treatment.

Data on in-stent stenosis (ISS) following the flow diverter (FD) implantation method are scarce and inconsistent. In the present study, we sought to determine the incidence of ISS and identify the factors that predict its severity via the use of ordinal logistic regression. A retrospective review of our center's electronic database was conducted to identify all patients with intracranial aneurysms (IAs) who received pipeline embolization device (PED) implantation between 2016 and 2020. Patient demographics, aneurysm characteristics, procedural information, and clinical and angiographic outcomes were reviewed. ISS was quantitatively assessed on angiographic follow-ups and graded as mild (<25%), moderate (25-50%), or severe (>50%). Ordinal logistic regression was conducted to determine the predictors of stenosis severity. A total of 240 patients with 252 aneurysms treated in 252 procedures were enrolled in this study. ISS has been detected in 135 (53.6%) lesions, with a mean follow-up time of 6.53 ± 3.26 months. The ISS was mild in 66 (48.9%) cases, moderate in 52 (38.5%) cases, and severe in 17 (12.6%) cases. All patients were asymptomatic, except for two of them with severe stenosis who presented with symptoms of acute cerebral thrombosis. Ordinal logistic regression identified that younger age and a longer procedure duration were independent predictors of a higher likelihood of ISS. ISS is a common angiographic finding after PED implantation for IAs and is presented as a largely benign course through long-term follow-up. Patients who were younger in age and had a longer procedure duration were found to be at a greater risk of developing ISS.

Abstract Number ‐ 140: Transcranial Doppler Emboli Monitoring for Stroke Prevention after Flow Diversion: A Single Center Experience

Introduction Following the favorable clinical and radiographical results of flow diversion, its use has continually expanded for the treatment of complex intracranial aneurysms. The high metal surface of flow diverters (FD) increases the risk of thromboembolic complications. Current emboli monitoring data after FD placement is limited. Transcranial doppler (TCD) offers a non‐invasive evaluation of microembolic signals and might be a valuable tool to prevent ischemic complications. We evaluated the rate of embolic signals and their management after FD implantation. Methods We performed a retrospective, single‐center evaluation of adult patients who underwent a FD procedure with the Pipeline Embolization Device (PED) for unruptured intracranial aneurysms between 2012 and 2016. Covariates included patient demographics, comorbidities, aneurysm characteristics, procedure characteristics, and post‐procedure TCD emboli monitoring (immediate and &gt;12 hours post‐operative). TCD emboli signals were classified as positive (&lt; 15 microembolic signals) and strongly positive (&gt;15 signals). The primary outcome was the rate of symptomatic stroke at 2 and 12 weeks in these patients. Results 105 patients with 132 aneurysms were analyzed. Mean age was 59.7 years, and 78% were females. Mean aneurysm size was 7.8 ± 6.4 mm. Most of them were located in the paraclinoid region (40%). Two PEDs were implanted in 12 (11%) cases and adjunctive coiling was performed in 15 (14%) cases. Microemboli were detected in 11.4% of cases (12/105 patients) after PED deployment. In 5/12 patients, the emboli resolved upon repeat testing with no intervention. In 6/12 patients, further heparinization, additional clopidogrel administration, or change in antiplatelet agents were needed. These treatments reduced the microembolic events. In 1 patient who was clopidogrel‐resistant and a ticagrelor super‐responder, mechanical thrombectomy was necessary due to acute in‐stent thrombosis. There were no symptomatic strokes at 2 and 12 weeks. Conclusions TCD emboli monitoring can be a powerful non‐invasive tool for the early identification and prevention of thromboembolic events after FD implantation. Early detection of microembolic signals offers the possibility to modify postoperative management, avoid silent emboli, and potentially avoid symptomatic strokes.

Clinical characteristics, endovascular choices, and surgical outcomes of intracranial vertebral artery dissecting aneurysms: a consecutive series of 196 patients.

The authors aimed to evaluate the clinical features, endovascular strategy selection, and outcomes of vertebral artery (VA) dissecting aneurysms (VADAs) near the origin of the posterior inferior cerebellar artery (PICA). Clinical data were obtained from 196 patients with 202 VADAs who had been surgically treated at the authors' hospital between 2005 and 2021. The patients' medical records, imaging data, and follow-up outcomes were retrospectively analyzed. All 196 patients (148 male, 48 female; mean age 53 years) underwent endovascular therapy for VADA. The most common chief complaints were headache (56.6%), dizziness (40.8%), and other occasional symptoms (18.4%). Twenty-six patients experienced posterior circulation ischemia, and 25 patients experienced subarachnoid hemorrhage (SAH). On DSA images, 37 aneurysms were found in the dominant VA, and 165 aneurysms were found on the nondominant side. Eighty-eight VADAs had stenosis. Regarding the VADA location, there were 59 distal, 51 proximal, 23 ventral, 64 PICA, and 5 obliteration types. Single-stent implantation (10.9%), overlapping stent implantation (23.8%), flow diverter (FD) implantation (11.9%), single stent-assisted coil (SAC) embolization (31.7%), overlapping SAC embolization (12.9%), parent artery occlusion (PAO) (8.4%), and FD-assisted coil embolization (0.5%) were chosen. The follow-up rate was 82.7%. The modified Rankin Scale (mRS) score was 0.5 ± 1.1. Ninety-six patients underwent DSA. The complete occlusion rates were 100%, 81.4%, 56.7%, and 76.5% in the PAO group, SAC reconstruction group, stent implantation group, and FD implantation group, respectively. Young patients showed a higher probability of SAH, and elderly patients showed a higher probability of posterior circulation infarction. The surgical plan selection should be based on the SAH history, VA dominant side, and PICA origin location.

Hyperperfusion Syndrome After Flow Diverter Implantation for an Aneurysm of the Internal Carotid: a case report

Hyperperfusion Syndrome After Flow Diverter Implantation for an Aneurysm of the Internal Carotid: a case report

Retreatment with a flow diverter for recurrent blood blister-like aneurysms after embolization: A single-center case series.

Background and purposeTreatment of blood blister-like aneurysms (BBAs) has been a significant challenge mainly due to their high recurrence rate even after stent-assisted coiling (SAC) embolization. This study aims to evaluate the safety and efficacy of treating recurrent BBAs after SAC with a flow diverter (FD).MethodsA retrospective series of patients with recurrent BBAs who underwent the retreatment with the FD from June 2018 to December 2021 was included to analyze perioperative safety and immediate postoperative and follow-up outcomes.ResultsThe study enrolled 13 patients with recurrent BBAs previously treated with SAC. Within previous stents, an FD was deployed for retreatment, including eight Tubridge FDs and five PEDs. The time interval between initial treatment and FD implantation was 14–90 days. A total of 11 cases were treated with a single FD alone; two cases were treated with further endovascular coiling embolization, followed by FD implantation. The angiographic follow-up (6–12 months) was available in 12 patients, and all 12 recurrent BBAs were completely occluded. No perioperative complication was detected, and no rebleeding was found during the clinical follow-up (6–36 months).ConclusionThe use of the FD to manage recurrent BBAs after SAC is technically feasible, safe, and effective. The key to the success of the procedure is to ensure that the FD stent is fully open and has good apposition with the previously implanted stent.

Investigation of surface endothelialization on nitinol: Effects of composite hydrogel coatings

BackgroundDue to high metal coverage and high mesh density，flow diverters (FD) are widely used for endovascular reconstruction of cerebrovascular disease. However, incomplete endothelialization, restenosis, and thrombosis hamper the long term clinical success. Thus, an effective coating to accelerate the endothelialization of the cerebrovascular FD raw materials and reduce the incidence of thrombosis and restenosis is needed. MethodsA novel composite hydrogel composed of matrigel and sodium alginate (SA) with different blending ratios, which was cross-linked with calcium chloride, was successfully prepared. The hydrophilicity of the coating surface was detected by measurement of the contact angle, and the surface morphology of the nitinol (NiTi) before and after modification was characterized by scanning electron microscopy (SEM). The elastic modulus was utilized to verify the mechanical properties and plasticity of the coating, and the release experiment was conducted to characterize the composite hydraulic coagulation. Additionally, biocompatibility was tested by in vitro cellular experiments. ResultsThe SEM observations showed that when the concentrations of matrigel and SA were 5 and 3 mg/ml, respectively, cross-linking with 40 mg/ml calcium chloride solution was resulted in formation of the uniform M/SA composite hydrogel coating. The contact angle of M/SA-NiTi was only (32.28 ± 1.55°) (P < 0.0001), indicating a strong hydrophilicity of M/SA-NiTi. The 48 h coating release rate is 61.5%. In addition, M/SA-NiTi exhibited to have better biocompatibility and plasticity than B-NiTi and M-NiTi. ConclusionsMatrigel/sodium alginate composite hydrogel coating has good biocompatibility and low thrombosis characteristics, and strong drug-carrying capacity, which is expected to accelerate the endothelialization after FD implantation. It has also a great potential application value in the surface modification of biological materials.

And don't forget your anti in-stent stenosis pill! Commentary on 'Factors associated with in-stent stenosis after cerebral aneurysm embolization using a Pipeline embolization device' by Flores-Milan et al.

In their INR study, Flores-Milan et al. present a retrospective single-centre study that aimed to investigate and determine some of the factors associated with in-stent stenosis (ISS) after intracranial aneurysm (IA) embolization using a commercially available flow diverter stent (FD). The retrospective analyses included ruptured and unruptured intracranial aneurysms treated with standalone flow diverter stent implantation or initial coil obliteration with the FD device placed subsequently two weeks after initial treatment. The article's methodology was carefully tailored to demystify the unknown pathophysiological mechanism behind the entity of interest called in-stent stenosis. Study outcomes also included angiographic evaluation of aneurysm occlusion thrombotic and hemorrhagic events. The authors reported excellent technical and clinical results altogether. The achieved angiographic occlusion rates resonate with the current obliteration results reported in the literature. Mortality and morbidity are congruent with previously published results and were 5.3% and 1.1%, respectively.

Predicting flow diverter sizing using the AneuGuideTM software: a validation study

BackgroundStent sizing remains a challenging task for flow diverter implantation because of stent foreshortening. In this study, we aimed to quantify the change in length after implantation and assess the...