Flow-diverting Stents Research Articles

Paraclinoid internal carotid artery aneurysm with delayed stent occlusion after deployment of a flow diverter stent involving the orifice of the anterior cerebral artery: illustrative case.

In-stent thrombotic occlusion is a serious ischemic complication that can also result in ischemia in the distal perfusion territory and the territory of side branches for the artery in which the flow diverter (FD) stent is deployed. A 49-year-old female with a large paraclinoid internal carotid artery (ICA) aneurysm was treated with an FD involving the orifice of the anterior cerebral artery (ACA). The antiplatelet dose was reduced because of an increased clopidogrel response postintervention. The patient developed aphasia 2 months later. Emergency magnetic resonance imaging and digital subtraction angiography of the brain indicated FD stent occlusion and a small infarct in the distal vascular territory of the ipsilateral ICA, but the anterior choroidal artery (AChoA) territory was preserved by collateral flow. Emergency superficial temporal artery to middle cerebral artery anastomosis was performed, and she was discharged without neurological deficit 2 weeks after the second operation. In-stent occlusion after FD deployment involving the orifice of the ACA can cause severe cerebral ischemia that requires an adequate antiplatelet effect and careful follow-up. The AChoA territory can be preserved by collateral blood flow even in cases of in-stent occlusion.

Giant ICA Cavernous Aneurysm with Coarctation of Aorta and Autoimmune Hemolytic Disease Posted for Flow Diverter Stenting

AbstractAnesthetic management of a case of intracranial aneurysm with coarctation of the aorta poses a formidable challenge to the anesthesiologist. The perioperative risks associated with such cases are rupture of an aneurysm, cardiac arrhythmias, stroke from cerebral insufficiency, intracerebral hemorrhage, myocardial ischemia, thromboembolic stroke, and aortic dissection. Endovascular stenting is preferred over surgical clipping of an aneurysm as flow diverter stenting has less morbidity and mortality compared to the latter, and the parent vessel can also be preserved. Despite the perioperative risks, successful stenting of an internal carotid artery aneurysm is beneficial in preventing impending aneurysm rupture and the progressive worsening of neurological symptoms. Therefore, it is imperative to understand the physiological basis behind the unforeseen complex hemodynamic fluctuations occurring during the procedure, as well as the anesthetic goals and complications encountered during the procedure. We describe and discuss the successful anesthetic management of a case of a giant internal carotid artery aneurysm with coarctation of the aorta and autoimmune hemolytic disease posted for flow diverter stenting.

Ghost twisting of the dual-layer flow-diverting stent.

The twisting phenomenon of the flow diverter stents rarely occurs, but it recently became relatively well-recognized. There have been few reports on single-layer flow diverters only. The Flow Redirection Endoluminal Device (FRED) (MicroVention, Tustin, California) has a unique design characterized by a braided dual-layer self-expanding stent. There have been no reports on the twisting phenomenon of FRED. This study reports two cases of acute in-stent blood flow disturbances after the deployment of FRED in a patient with intracranial aneurysms associated with "ghost twisting." In this phenomenon, the inner layer does not expand with the coning deformation, even though the outer layer is fully open. This was confirmed through high-resolution cone-beam computed tomography, but not conventional angiography. The two cases were successfully treated using balloon angioplasty and showed favorable outcomes. The structural issue of "ghost twisting" was a possible underlying factor for the ischemic complications associated with FRED deployment.

Device use trends in neuroendovascular procedures in the United States from 2015 to 2020.

Neuroendovascular therapies involve an everchanging landscape of new technologies. Understanding the real-world timeframe of adaptation of such technologies can provide further guidance on mechanisms that could be employed to shorten the duration necessary for the widespread use of proven therapies. In this study, we aim to investigate the trends in the use of neuroendovascular technologies, utilizing the sales of neuroendovascular devices, as a proxy for procedural volume. Utilizing a device sales data registry from the Decision Resources Group, a healthcare research and consulting company, we examined trends in the sales of devices utilized in cerebrovascular thrombectomy, cerebral aneurysm treatment, and carotid stenting from the same 407 reporting hospitals in the United States between January 1, 2015, and January 1, 2020. Device sales per year were plotted as both the total number of devices sold per year as well as the percent of total device sales when compared against at least one other device. The Cochran-Armitage test for trend was performed when comparing at least two devices to each other. Analyses were performed using RStudio Version 1.1.456 (https://rstudio.com). Between 2015 and 2020, there was a significant increase in the use of flow-diverting stents as well as nondiverting stents utilized for coil assistance. However, the total number of coils utilized over the years has declined. In terms of stroke therapy, between 2015 and 2020, there was a trend of increased use of both aspiration catheters as well as stent retrievers, which plateaued in 2020. The number of stents used for carotid procedures has also been gradually increasing over time. Our study demonstrates an increase in the use of flow-diverting stents, nondiverting stents, carotid stents, and reperfusion devices for acute ischemic stroke intervention between 2015 and 2020. Coil use for aneurysmal treatment has declined.

Comparison of pipeline embolization device, flow re-direction endoluminal device and surpass flow diverters in the treatment of intracerebral aneurysms.

The use of flow diversion for the treatment of intracranial aneurysms has gained broad acceptance. Three flow-diverting stents are approved by the Food and Drug Administration for use in the United States. We sought to compare the outcomes and safety profiles between the three devices at our institution. A retrospective review of aneurysms treated with pipeline embolization device (PED), flow re-direction endoluminal device (FRED), and SURPASS was performed for aneurysms treated between 2018 and 2022 at our institution. The study cohort consisted of 142 patients. Precisely, 86 aneurysms were treated with a pipeline, 33 aneurysms were treated with FRED, and 23 aneurysms were treated with SURPASS. The 1-year complete occlusion rates were 59.4%, 60%, and 65%, respectively (0.91). Linear regression models found that only adjunctive coiling predicted aneurysm occlusion at 6 months (p = 0.02), but this effect was lost at 1 year and beyond. There was no significant difference in acute thrombotic or acute hemorrhagic complications between the three cohorts. There was a higher rate of delayed hemorrhagic complications in the SURPASS cohort (10%) compared to the PED (1.3%) and FRED (0%) cohorts (p = 0.04). There was also a higher rate of in-stent stenosis in the SURPASS cohort (20%) compared to the PED (5%) and FRED (3.1%) cohorts (p < 0.01). Treatment with PED, FRED, and SURPASS all resulted in similar complete occlusion rates at 6 months and 1 year. SURPASS was associated with higher in-stent stenosis as well as delayed hemorrhagic complications. Additional future studies evaluating the newest generation of flow-diverting stents with long-term follow-up will be necessary to make any definitive conclusions.

Flow Diverter Stenting for Symptomatic Intracranial Internal Carotid Artery Aneurysms: Clinical Outcomes and Factors for Symptom Improvement.

Flow diverter (FD) stenting is expected to improve cranial nerve symptoms caused by aneurysms via the theoretical reduction of the mass effect by promoting spontaneous thrombosis through the flow diversion effect. However, the factors involved in symptom improvement after treatment remain unclear. This study was performed to identify factors for symptom improvement after FD stenting and the symptom improvement rate of each impaired cranial nerve. We retrospectively evaluated 33 patients who underwent FD stenting for symptomatic internal carotid artery aneurysms at our institution from January 2016 to June 2021. Twenty-three (69.7%) patients had resolved or improved symptoms after 1 year of treatment. The optic nerve was affected in 12 patients; the oculomotor nerve, in 16; the trigeminal nerve, in 2; and the abducens nerve, in 13. There was no statistically significant difference in the symptom improvement rate of each impaired cranial nerve. The patients were classified into the improved and nonimproved groups based on their symptoms after 1 year of treatment, and the factors related to the symptoms were analyzed. The time from onset to treatment was significantly shorter in the improved group than in the nonimproved group (197.1 and 800 days, respectively; p = 0.023). There were no significant differences in age, aneurysm diameter, adjunctive coil embolization, partial thrombosis, change in mass diameter on magnetic resonance imaging, or aneurysm occlusion rate on angiography between the two groups. These results suggest that early treatment after the onset of aneurysm-induced cranial neuropathies increases the likelihood of symptom improvement.

Comparative evaluation of brain perfusion with ASL and DSC MRI following intracranial vascular flow diverter stent replacement.

The objective of this study was to asses brain perfusion parameters and ischemic changes following treatment of aneurysm with flow diverters with two different perfusion MRI technique (Arterial spin labeling and DSC MRI), and to compare the results and effectiveness of these two methods. The prospective data was collected from patients with aneurysm who treated with flow diverters. MR examinations, including diffusion-weighted imaging (DWI), ASL, and DSC perfusion MRI, were conducted before and after treatment within the first week and at 6 months. Perfusion parameters of territory area and contralateral side were measured and analyzed by statistically. The relationships between ASL and DSC parameters were analyzed by using Sperman's correlation analysis. A total of 14 cases of aneurysms in 11 patients treated successfully with endovascular flow diverter stent placement. Pretreatment and post treatment (within first week and 6 months) MRI images were evaluated. Asymptomatic randomly distributed millimetric restricted diffusion foci were observed in 8 of all patients. There was no statistically difference between pre and post treatment perfusion parameters (p > 0.05). A statistically significant correlation was found between variable ASL CBF, and the variables of DSC CBF and TTP. Notwithstanding the fact that flow diverters change flow dynamics in aneurysm sac, there is no any perfusion abnormality in the territory area. Asymptomatic randomly distributed diffusion restricted foci in the both cerebral hemisphere can be observed. ASL and DSC MRI are effective for evaluation of brain perfusion.

Endovascular stenting techniques for blunt carotid injury.

While methods of endovascular carotid artery stenting have improved over time, concerns surrounding the safety and efficacy of stenting for blunt carotid injury (BCI) remain. This study aims to present our approach to carotid artery stenting (CAS) by incorporating new technologies such as flow-diverting stents and circuits. There is no robust evidence to support routine carotid artery stenting; however, there are several therapeutic options and approaches for treating BCI that currently require an individualized approach. Endovascular stenting and specific stent selection are largely dictated by the disease process the surgeon intends to treat. We will discuss patient selection, medical management, and the most common revascularization techniques, including transfemoral stenting, trans-carotid arterial revascularization using flow reversal, and stent-assisting coiling. It must be stressed that endovascular intervention is not an alternative to or preclusive of antithrombotic or anticoagulant therapy. In the setting of BCI, transfemoral CAS is most appropriate in patients who are symptomatic, have a rapidly progressing or large lesion, and do not have a soft thrombus present due to risk of embolism. Unlike transfemoral CAS, TCAR offers an elegant solution for embolic protection when patients have a soft thrombus present. In the case of a large pseudoaneurysm, we perform stent-assisted coiling. We practice selective endovascular intervention, stenting lesions that are flow-limiting or have large or rapidly expanding pseudoaneurysms, and only in patients for whom anticoagulation and antiplatelet agents are not contraindicated. As technology and investigation progress, the concerns regarding the safety and the role of endovascular intervention in the treatment of BCI will be more clearly defined.

Effect of Platelet Function Testing Guidance on Clinical Outcomes for Patients with Intracranial Aneurysms Undergoing Endovascular Treatment.

Platelet function testing has been proposed to better adjust individualized antiplatelet treatment for patients undergoing endovascular treatment for intracranial aneurysms. Its clinical significance needs to be comprehensively evaluated. Our aim was to evaluate the impact of platelet function testing-guided versus standard antiplatelet treatment in patients receiving endovascular treatment for intracranial aneurysms. PubMed, EMBASE, and the Cochrane Library of clinical trials were searched from inception until March 2023. Eleven studies comprising 6199 patients were included. ORs with 95% CIs were calculated using random effects models. The platelet function testing-guided group was associated with a decreased rate of symptomatic thromboembolic events (OR = 0.57; 95% CI, 0.42-0.76; I2 = 26%). No significant difference was found in asymptomatic thromboembolic events (OR = 1.07; 95% CI, 0.39-2.94; I2 = 48%), hemorrhagic events (OR = 0.71; 95% CI, 0.42-1.19; I2 = 34%), intracranial hemorrhagic events (OR = 0.61; 95% CI, 0.03-10.79; I2 = 62%), morbidity (OR = 0.53; 95% CI, 0.05-5.72; I2 = 86%), and mortality (OR = 1.96; 95% CI, 0.64-5.97; I2 = 0%) between the 2 groups. Subgroup analysis suggested that platelet function testing-guided therapy may contribute to fewer symptomatic thromboembolic events in patients who received stent-assisted coiling (OR = 0.43; 95% CI, 0.18-1.02; I2 = 43%) or a combination of stent-assisted and flow-diverter stent placement (OR = 0.61; 95% CI, 0.36-1.02; I2 = 0%) or who changed from clopidogrel to other thienopyridines (OR = 0.64; 95% CI, 0.40-1.02; I2 = 18%), though the difference did not reach statistical significance. Heterogeneous endovascular treatment methods and adjusted antiplatelet regimens were limitations. Platelet function testing-guided antiplatelet strategy significantly reduced the incidence of symptomatic thromboembolic events without any increase in the hemorrhagic events for patients undergoing endovascular treatment for intracranial aneurysms.

Comaneci stent-angioplasty for the optimization of inadequately deployed flow diverter stents.

In endovascular procedures, inadequate deployment of a flow diverter stent is a highly concerning technical complication that can lead to acute parent vessel occlusion and ischaemic events. This study aimed to assess the off-label use of the Comaneci device in managing technical difficulties associated with flow diversion. We conducted an analysis of all flow diverter procedures documented in our prospectively collected database. Our objective was to identify patients with inadequately deployed implants who underwent Comaneci stent-angioplasty. Both Comaneci 17 and Comaneci 21 devices were utilized to address and remediate technical complications related to stent deployment. We reviewed anatomical features, technical details, intraprocedural complications, as well as clinical and angiographic outcomes. Thirty-one Comaneci devices were employed to remediate 31 inadequately deployed flow diverter stents. Successful resolution of technical complications associated with flow diverter placement was achieved in all attempted cases. No clinically significant complications were attributed to the technique, and no mortality was observed during the study. Technical issues arising from flow diverter stent deployment are formidable complications. Familiarity with appropriate corrective manoeuvres is essential to achieve successful outcomes. The Comaneci device can be safely and effectively incorporated into the range of techniques used to rectify inadequately deployed stents.

Hemodynamic Investigation of the Flow Diverter Treatment of Intracranial Aneurysm

Flow diverter stents (FDS) are increasingly used for the treatment of complex intracranial aneurysms such as fusiform, giant, or wide-neck aneurysms. The primary goal of these devices is to reconstruct the diseased vascular segment by diverting blood flow from the aneurysm. The resulting intra-aneurysmal flow reduction promotes progressive aneurysm thrombosis and healing of the disease. In the present study, a numerical investigation was performed for modeling blood flow inside a patient-specific intracranial aneurysm virtually treated with FDS. The aim of the study is to investigate the effects of FDS placement prior to the actual endovascular treatment and to compare the effectiveness of devices differing in porosity. Numerical simulations were performed under pulsatile flow conditions, taking into account the non-Newtonian behavior of blood. Two possible post-operative conditions with virtual stent deployment were simulated. Hemodynamic parameters were calculated and compared between the pre-operative (no stent placement) and post-operative (virtual stent placement) aneurysm models. FDS placement significantly reduced intra-aneurysmal flow velocity and increased the Relative Residence Time (RRT) on the aneurysm, thus promoting thrombus formation within the dilatation and aneurysm occlusion. The results highlighted an increase in the effectiveness of FDS as its porosity increased. The proposed analysis provides pre-operative knowledge on the impact of FDS on intracranial hemodynamics, allowing the selection of the most effective treatment for the specific patient.

Numerical simulation of flow-diverting stent: comparison between branches in bifurcation brain aneurysm.

The usage of flow-diverting stents in the treatment of intracranial aneurysms is widespread due to their high success and low complication rates. However, their use is still not officially recommended for bifurcation aneurysms, as there is a risk of generating ischemic complications due to the reduced blood flow to the jailed branch. Many works utilize computational fluid dynamics (CFD) to study how hemodynamic variables respond to flow diverter placement, but few seem to use it to verify flow variation between branches of bifurcation aneurysms and to aid in the choice of the best ramification for device placement. This investigation was performed in the present work, by comparing wall shear stress (WSS) and flowrates for a patient-specific scenario of a middle cerebral artery (MCA) aneurysm, considering device placement on each branch. A secondary objective was to follow a methodology that provides fast results, envisioning application to daily medical practice. The device was simplified as a homogeneous porous medium, and extreme porosity values were simulated for comparison. Results suggest that stent placement on either branch is both safe and effective, significantly reducing WSS and flow into the aneurysm while maintaining flow to the different ramifications within acceptable thresholds.

Letter: Transradial Flow-Diverting Stent Placement Through an Arteria Lusoria: 2-Dimensional Operative Video.

To the Editor: We read with great interest the article “Transradial Flow-Diverting Stent Placement Through an Arteria Lusoria: 2-Dimensional Operative Video” by Hackett et al.1 The authors present a case of a patient with an arteria lusoria who received effective flow-diverting stent therapy for a large left internal carotid artery (ICA) aneurysm using a large bore guide catheter through right transradial access (TRA). Diagnostic angiography showed that the left ICA could be accessed through the right TRA. A 6F radial sheath was introduced into the right radial artery, and the sheath was then exchanged over a 0.035″ guidewire for an 8F 90-cm guide catheter (Infinity; Stryker Neurovascular). After navigating a 5F 130-cm Simmons catheter into the left common carotid artery through the arteria lusoria, the 8F guide catheter was delivered into the left ICA using the telescoping technique. The large left ICA-ophthalmic artery aneurysm was successfully treated with a pipeline embolization device (Medtronic). The importance of evaluating transradial diagnostic angiography to determine whether a catheter system can safely track into the target supra-aortic vessels is critical for successful transradial neurointervention in patients with arteria lusoria, and we wholeheartedly concur with the authors' conclusion on this point. Cannulation into the supra-aortic vessels through right TRA can be extremely challenging in patients with arteria lusoria because of unfavorable catheter trajectory.2 In addition, the right TRA can cause fatal arteria lusoria dissection.3 Therefore, transfemoral access is frequently employed as first-line access if neurointerventionalists encounter arteria lusoria.2 Previous study reported that left TRA is a technically feasible alternative in neurointerventions for patients with arteria lusoria.4 Nevertheless, a guide catheter may result in a failed TRA that necessitates a crossover to transfemoral access because of a failed cannulation, a kinked catheter, or an unstable system. We have used transradial access as the first-line access for neurointerventions.5-18 The first-line TRA using a 6F preshaped Simmons guiding sheath (outer diameter, 2.70 mm; inner diameter, 0.088″; usable length, 90 cm; 6F Axcelguide Stiff-J; Medikit) offers a large bore working channel and a high procedural success rate without catheter kinking or system instability even in patients with an unfavorable steep supra-aortic take-off.5-7,13 The 6F Simmons guiding sheath is fully engaged into the target common carotid artery with a pull-back maneuver (the pull-back technique) after reforming the Simmons curve within the ascending aorta. The Simmons curve can be reformed by anchoring the 6F Simmons guiding sheath to the descending aorta (the descending aorta anchoring technique) or contralateral subclavian artery (the subclavian artery anchoring technique) through the left TRA. Transradial carotid cannulation with the pull-back technique is technically simple and promising. As a result, left TRA with the 6F Simmons guiding sheath can be a beneficial treatment choice for performing anterior circulation procedures in patients with arteria lusoria. Finally, we would like to express our appreciation to the authors for their interesting article that advances the transradial neurointerventional method.

Usefulness of silent magnetic resonance angiography for intracranial aneurysms treated with a flow re-direction endoluminal device.

Flow re-direction endoluminal device (FRED) is a novel dual-layer flow-diverting stent to treat cerebral aneurysms with high obliteration rates, however, it induces inevitable metal-related artifacts. We compared silent magnetic resonance angiography (MRA), a new MRA method using ultra-short time of echo and arterial spin-labeling, with conventional time-of-flight (TOF)-MRA for imaging aneurysms treated using FRED. Between May 2020 and September 2022, 16 patients with unruptured internal carotid aneurysms treated using FRED simultaneously underwent silent MRA and TOF-MRA after treatment, with 36 follow-up sessions in total. Two observers independently graded the quality of intra-aneurysmal flow and stented parent arteries under both types of MRA from 1 (not visible) to 4 (nearly equal to digital subtraction angiography [DSA]), with reference to DSA images as a standard criterion. The mean scores for intra-aneurysmal flow and stented parent arteries were significantly better for silent MRA (3.93 ± 0.21 and 3.82 ± 0.32, respectively) than for TOF-MRA (2.08 ± 0.99 and 1.92 ± 0.79, respectively) (P < 0.01). Intermodality agreements for intra-aneurysmal flow and stented parent arteries were 0.87 and 0.90, respectively. Silent MRA is superior to TOF-MRA for assessing patients treated with FRED, with potential as an alternative imaging modality to DSA.

Silk + flow-diverter stent for the treatment of intracranial aneurysms associated with balloon angioplasty: A retrospective study.

The silk + flow-diverter stent is increasingly used to treat complex intracranial aneurysms including wide-neck and fusiform aneurysms. Balloon angioplasty has been used to better appose the flow diverter (FD) to the vessel wall and, thus, improve aneurysm occlusion rates and decrease periprocedural complications. Sparse data are available concerning the results of this technique. We report our experience with silk + FD associated with balloon angioplasty for the treatment of intracranial aneurysms. A retrospective study was conducted on all patients treated by the silk + FD. Clinical charts, procedural data, and angiographic results were reviewed and compared between those treated with balloon angioplasty. A multivariate analysis was conducted to identify predictors of complications, occlusion, and outcome. Between July 2014 and May 2016, we identified 209 patients with 223 intracranial aneurysms. There were 176 (84.2%) women and 33 (15.8%) men. The most common stent size used was 4.5 mm in 101 patients (46.1%), followed by 4 mm in 57 patients (26%). Univariate analysis observed that stent diameter was significantly related to aneurysm occlusion (P < 0.05). Patients with more than 1 aneurysm treated with silk + stent have a 9.07 times greater chance of having complications in the procedure than patients with only 01 aneurysm (OR = 9.07; P = 0.0008). Patients who had angioplasty without the use of a balloon have a 13.69-times-higher risk of complications (OR = 13.69; P = 0.0003). Older age, larger aneurysms, and the use of more than 1 FD device were predictors of recanalization. Endovascular treatment of intracranial aneurysms with the silk + FD associated with balloon angioplasty is a safe and effective therapeutic option. Balloon angioplasty in combination with FD lowers the risk of complications. Higher complication rates and worse outcomes are associated with older age and large aneurysms.

OUTCOME EVALUATION OF FLOW DIVERTER STENT PLACEMENT IN TREATMENT OF RUPTURED AND UNRUPTURED CEREBRAL ANEURYSMS

Background: Cerebral aneurysms affect about 5% of the population and are associated with high mortality rates and severe complications for families and society. Complex aneurysm types include giant aneurysms, wide - necked aneurysms, blister - like aneurysms, recurrent aneurysms, fusiform aneurysms, and multiple aneurysms, which are difficult to manage with conventional endovascular or surgical methods due to complications such as coil migration and high rates of re - rupture. The development of flow diverter stents has been a breakthrough in recent decades and has been demonstrated to be safe and effective in treating aneurysms. The aim of this study was to evaluate the outcomes of flow diverter stent placement in the treatment of ruptured and unruptured cerebral aneurysms. Methods: This was a descriptive prospective study that followed up on 23 patients diagnosed and treated for cerebral aneurysms with flow - diverter stent intervention at the Stroke Department of Hue Central Hospital from 6/2020 to 6/2022. The follow - up data after 6 months and 12 months were recorded. Results: There were 23 patients (9 males, 14 females) with 28 cerebral aneurysms, with a mean age of 51.7 ± 9.9 years. Aneurysms were predominantly located in the anterior circulation (85.7%) and 14.3% in the posterior circulation. The most common aneurysm type was fusiform (75%), followed by dissecting (17.9%) and blister - like (7.1%). Most aneurysms had wide necks, with a neck - to - dome ratio &lt; 1.5, accounting for 82.1%. Flow diverter stent placement was successfully performed in 91.3% of patients, with 27 stents used. Stents were properly positioned, well - expanded in 88.9%. The complication rate after intervention was 4.3%. Complete aneurysm occlusion rates at 6 to 12 months were 92.9% and 96.4%, respectively. The rate of mild in - stent stenosis without clinical symptoms was 4.3%. The good outcome rate (mRS 0 - 2) was 91.3%. Conclusion: Flow diverter stent is effective and safe with high rate of successful and low procedural complications in the treatment of complex cerebral aneurysms.

Acute cerebral thrombosis caused by flow diversion stent and resistance to ticagrelor - Case report

Acute cerebral thrombosis caused by flow diversion stent and resistance to ticagrelor - Case report

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.

Clinical and Radiological Outcomes of Vertebral Artery Dissecting Aneurysms Treated with Endovascular Treatments: A 12-year Single-Center Experience

We aimed to compare the clinical and radiological outcomes of vertebral artery dissecting aneurysms (VADAs) stratified using different endovascular treatment methods. We retrospectively reviewed 116 patients with VADAs treated at a single tertiary institute between September 2008 and December 2020. We analyzed and compared the clinical and radiological parameters according to different treatment methods. In total, 127 endovascular procedures were performed in 116 patients. We initially treated 46 patients with parent artery occlusion, nine with coil embolization without stent, 43 with single stent with or without coil, 16 with multiple stents with or without coils, and 13 with flow-diverting stent. At the last follow-up (mean 37.8 ± 30.9 months), the complete occlusion rate (85.7%) was higher in the multiple stent group than in the groups that received other reconstructive treatment methods. Moreover, the recurrence (0%) and retreatment (0%) rates were significantly lower in the multiple stent group (p<0.001). The coil embolization-only group showed the highest recurrence (n=5, 62.5%) and incomplete occlusion (n=1, 12.5%) rates. The single-stent group showed higher recurrence (n=9, 22.5%) and retreatment (n=3, 7%) rates. Multivariate logistic regression analyses showed that coil embolization without stent placement (OR=172.76, p=0.002, 95% confidence interval [CI] 6.83-4366.85) was significantly associated with recurrence. At the last follow-up (mean 42.1 ± 37.7 months), we achieved favorable clinical outcomes (mRS ≤ 2) in 106 of 127 patients. When treating VADAs, multiple stent placements may play a key role in achieving favorable long-term radiological outcomes.

Long-Term Outcomes of Ruptured Blood Blister-Like Aneurysms with Multiple (≥2) Overlapping Stents and Coiling: A Single-Center Experience

To evaluate the long-term feasibility of multiple overlapping stents (≥2) with or without coiling for treating blood blister-like aneurysms (BBAs). BBAs treated with stent-assisted coiling or stent-only therapy wasincluded. BBAs with atypical anatomical locations, other endovascular or surgical techniques performed, and delayed treatment (>48hours) were excluded. Medical records of patients and procedures were retrospectively reviewed. Seventeen patients with BBAs were identified, and 15 were treated with stent-assisted coiling and 2 with stent-only therapy. Triple overlapping stents were performed in seven patients, double stents in nine, and a single stent with coiling in 1. One patient experienced in-stent fibrin formation and received intra-arterial tirofiban. Complementary treatment was required in four patients. Three patients were initially treated with double (3/9) and 1 with triple stents (1/7). Three recurred in the acute period (≤6weeks) and 1 recurred 14months after treatment. Three of 17 patients with Hunt Hess grade 5 died early. Thirteen patients were available for long-term angiographic follow-up (13.8±8.9months). Final angiography showed complete aneurysm occlusion in all patients without in-stent stenosis or perforating vessel occlusion. Clinical follow-up data were available for all 14 surviving patients (66.8±40.9months). Eight patients had favorable outcomes, five had unfavorable outcomes, and 1 died of a subarachnoid hemorrhage-unrelated cause. Delayed infarct or hemorrhage was not documented. Even in the era of flow diverter stents, the use of multiple overlapping stents with or without coiling can be a feasible alternative for treating ruptured BBAs.