Safety and efficacy of coated flow diverters in the treatment of ruptured intracranial aneurysms: a retrospective multicenter study.

BACKGROUND: This multicenter study evaluated the safety and efficacy of coated flow diverters (cFDs) for the treatment of ruptured intracranial aneurysms. METHODS: Consecutive patients treated with different cFDs for ruptured aneurysms under tirofiban at eight neurovascular centers between 2016 and 2023 were retrospectively analyzed. The majority of patients were loaded with dual antiplatelet therapy after the treatment. Aneurysm occlusion was determined using the O'Kelly-Marotta (OKM) grading scale. Primary outcome measures were major procedural complications and aneurysmal rebleeding during hospitalization. RESULTS: The study included 60 aneurysms (posterior circulation: 28 (47%)) with a mean size of 5.8±4.7 mm. Aneurysm morphology was saccular in 28 (47%), blister-like in 12 (20%), dissecting in 13 (22%), and fusiform in 7 (12%). Technical success was 100% with a mean of 1.1 cFDs implanted per aneurysm. Adjunctive coiling was performed in 11 (18%) aneurysms. Immediate contrast retention was observed in 45 (75%) aneurysms. There was 1 (2%) major procedural complication (a major stroke, eventually leading to death) and no aneurysmal rebleeding. A good outcome (modified Rankin Scale 0-2) was achieved in 40 (67%) patients. At a mean follow-up of 6 months, 27/34 (79%) aneurysms were completely occluded (OKM D), 3/34 (9%) had an entry remnant (OKM C), and 4/34 (12%) had residual filling (OKM A or B). There was 1 (3%) severe in-stent stenosis during follow-up that was treated with balloon angioplasty. CONCLUSIONS: Treatment of ruptured aneurysms with cFDs was reasonably safe and efficient and thus represents a valid treatment option, especially for complex cases.

Prasugrel Single Antiplatelet Therapy versus Aspirin and Clopidogrel Dual Antiplatelet Therapy for Flow Diverter Treatment for Cerebral Aneurysms: A Retrospective Multicenter Study.

BACKGROUND AND PURPOSE: The optimal antiplatelet regimen after flow diverter treatment of cerebral aneurysms is still a matter of debate. A single antiplatelet therapy might be advantageous in determined clinical scenarios. This study evaluated the efficacy and safety of prasugrel single antiplatelet therapy versus aspirin and clopidogrel dual antiplatelet therapy. MATERIALS AND METHODS: We performed a post hoc analysis of 4 retrospective multicenter studies including ruptured and unruptured aneurysms treated with flow diversion using either prasugrel single antiplatelet therapy or dual antiplatelet therapy. Primary end points were the occurrence of any kind of procedure- or device-related thromboembolic complications and complete aneurysm occlusion at the latest radiologic follow-up (mean, 18 months). Dichotomized comparisons of outcomes were performed between single antiplatelet therapy and dual antiplatelet therapy. Additionally, the influence of various patient- and aneurysm-related variables on the occurrence of thromboembolic complications was investigated using multivariable backward logistic regression. RESULTS: A total of 222 patients with 251 aneurysms were included, 90 (40.5%) in the single antiplatelet therapy and 132 (59.5%) in the dual antiplatelet therapy group. The primary outcome-procedure- or device-related thromboembolic complications-occurred in 6 patients (6.6%) of the single antiplatelet therapy and in 12 patients (9.0%) of the dual antiplatelet therapy group (P = .62; OR, 0.712; 95% CI, 0.260-1.930). The primary treatment efficacy end point was reached in 82 patients (80.4%) of the single antiplatelet therapy and in 115 patients (78.2%) of the dual antiplatelet therapy group (P = .752; OR, 1.141; 95% CI, 0.599-2.101). Logistic regression showed that non-surface-modified flow diverters (P = .014) and fusiform aneurysm morphology (P = .004) significantly increased the probability of thromboembolic complications. CONCLUSIONS: Prasugrel single antiplatelet therapy after flow diverter treatment may be as safe and effective as dual antiplatelet therapy and could, therefore, be a valid alternative in selected patients. Further prospective comparative studies are required to validate our findings.

Long-term Follow-up After Aneurysm Treatment with the Flow Redirection Endoluminal Device (FRED) Flow Diverter.

INTRODUCTION: This study focuses on long-term outcomes after aneurysm treatment with either the Flow Re-Direction Endoluminal Device (FRED) or the FRED Jr. to investigate the durability of treatment effect and long-term complications. METHODS: This study is based on a retrospective analysis of a prospectively maintained patient data base. Patients treated with either FRED or FRED Jr. between 2013 and 2017 at our institution, and thus a possibility for ≥ 5 years of follow-up, were included. Aneurysm occlusion rates, recurrence rates, modified Rankin scale score shifts to baseline, and delayed complications were assessed. RESULTS: In this study 68 patients with 84 aneurysms had long-term follow-up with a mean duration of 57.3 months and 44 patients harboring 52 aneurysms had a follow-up ≥ 5 years with a mean follow-up period of 69.2 months. Complete occlusion was reached in 77.4% at 2 years and increased to 84.9% when the latest available imaging result was considered. Younger age and the absence of branch involvement were predictors for aneurysm occlusion in linear regression analysis. After the 2­year threshold, there were 3 reported symptomatic non-serious adverse events. Of these, one patient had a minor stroke, one a transitory ischemic attack and one had persistent mass effect symptoms due to a giant aneurysm, none of these resulted in subsequent neurological disability. CONCLUSION: This long-term follow-up study demonstrates that the FRED and FRED Jr. are safe and effective for the treatment of cerebral aneurysms in the long term, with high rates of complete occlusion and low rates of delayed adverse events.

Sclerotherapy of Venous Malformations Using Polidocanol: Effectiveness, Safety, and Predictors of Outcomes and Adverse Events.

PURPOSE: To assess the effectiveness, safety, and predictors of outcomes and adverse events for percutaneous sclerotherapy using polidocanol for the treatment of venous malformations (VMs). METHODS: A retrospective single-center analysis was performed, including patients with VMs who were treated with sclerotherapy using polidocanol between January 2011 and November 2021 at a tertiary center. Demographic characteristics, clinical data, and radiologic features were analyzed, and the influence of patient- and VM-related factors on the subjective clinical outcome and adverse events were investigated using a multivariate logistic regression analysis. RESULTS: In total, 167 patients who received 325 treatment sessions were included in this study. Overall symptom improvement was observed in 67.5%, stable symptoms were observed in 25.0%, and worsening was reported in 7.5% (clinical follow-up, 1.04 ± 1.67 years). The total adverse event rate was 10.2%, with an overall rate of 4.2% for permanent adverse events within the cohort. In multivariate analysis, the clinical outcome was worse in children (P = .01; 57.1% symptom improvement in children [age, <18 years] and 79.7% in adults), and adverse events were more frequently observed after the treatment of VMs located at the extremities (P < .01; 8.4% for VMs of the extremities and 1.2% for VMs in other locations). CONCLUSIONS: Sclerotherapy using polidocanol can be an effective treatment option for VMs with an acceptable safety profile. However, it can be less effective in children, and adverse events can be more frequently expected for VMs of the extremities.

Pressure cooker technique in cerebral AVMs and DAVFs: different treatment strategies.

BACKGROUND: The pressure cooker technique (PCT) was developed to enable safer and more extensive embolization of hypervascular lesions by simultaneously minimizing backflow of liquid embolic materials and thus reduce the risk of non-target embolization of adjacent healthy vessels. We report our experience in applying the PCT to cerebral arteriovenous malformations (AVMs) and dural arteriovenous fistulas (DAVFs) and additionally suggest our technical adjustments. METHODS: We retrospectively reviewed all patients suffering from AVMs or DAVFs that were treated with the PCT between 2018 and 2020 in two university hospitals. The endpoints of the study were clinical safety and the technical efficacy. The endpoints of the study were clinical safety and the technical efficacy. Clinical safety was the absence of death, major or minor symptomatic stroke, TIA and procedure-related intracranial bleeding (SAH) in the peri-procedural period until dismission. Good clinical outcome was defined as no deterioration of the modified Rankin Scale (mRS) score (comparing the pre- and post-procedural mRS evaluated by a trained neurologist at admission and dismission). The technical efficacy was considered as the complete embolization occlusion of the target vessels of the lesion documented on the final control angiogram. Long-term follow-up evaluation was not intended for this study as it was not available for all patients. RESULTS: Fifteen consecutive patients (6 women; mean age 55 y; range 20-82 y) with seven AVMs and eight DAVFs met the inclusion criteria. The primary clinical safety end point was obtained in all cases as no intraprocedural complications were encountered. All patients had a good clinical outcome with no difference between the pre- and post-mRS scores. The primary efficacy end point was reached in all cases. CONCLUSION: The PCT is a safe and effective technique in the treatment of cerebral AVMs and DAVFs. Adding an easy and fast step to the procedure, namely the injection of contrast media to test the complete obstruction by the plug, the risk of reflux seems to additionally be reduced.

Flow Diverting Stents in Cerebral Small Caliber Vessels (< 2 mm) for Aneurysm Treatment : A Three Center Retrospective Study.

PURPOSE: The off-label use of flow diverting stents (FDS) for treating cerebral aneurysms in small distal vessels is increasing in clinical practice with encouraging results; however, data directly addressing the parent vessel size are still scarce. Our aim was to evaluate the safety and efficacy of FDS placement in anterior and posterior circulation aneurysms with parent arteries ≤ 2 mm in a real-world representative setting. METHODS: We retrospectively reviewed patients treated with FDS at the three participating university hospitals between 2009 and 2021. The inclusion criteria were the placement of at least one FDS in a parent vessel with a maximum diameter of 2 mm or less. The primary clinical safety endpoint was the absence of death, major or minor symptomatic stroke, transient ischemic attack and procedure-related intracranial hemorrhage. Clinical outcome was assessed using the modified Rankin Scale (mRS) score at the follow-up visit at 1 year. The primary efficacy endpoint was defined as complete and near-complete occlusion at the 1­year follow-up. RESULTS: We identified 55 patients harboring 56 aneurysms. The primary clinical safety endpoint was obtained in 93% of cases. The hemorrhagic and thromboembolic complication rates were 4% and 9%, respectively. No patient died or had a relevant discrepancy (> 1 point) at the pre-mRS and post-mRS. The primary efficacy endpoint was reached in 80% of cases. CONCLUSION: The use of FDS in vessels < 2 mm is technically feasible with good aneurysm occlusion rates and an acceptable safety profile. Nevertheless, it is essential to be aware of the of the main complications associated when operating in small diameter vessels.

Comparison between second generation HydroSoft coils and bare platinum coils for the treatment of large intracranial aneurysms.

BACKGROUND: The development of HydroSoft coils (HSC) aims to reduce the high recurrence and retreatment rates observed in large brain aneurysms by improving primary brain aneurysm filling and thus occlusion efficacy. We compared clinical and angiographic effectiveness of bare platinum coils (BPC) versus second generation HSC for large intracranial aneurysms at our center. METHODS: We included 61 large aneurysms between 2015 and 2018, 29 embolized primarily using HSC and 32 treated with BPC. The aneurysm occlusion rates were assessed after 3 and 12 months with an MRI scan and at 6 moths with a control digital subtraction angiography (DSA) using the Raymond-Roy occlusion classification (RROC). Clinical outcomes were evaluated using the modified ranking scale (mRS). RESULTS: The observed immediate occlusion rate was slightly better in the BPC group, however, this group had a significant increase of progressive reperfusion at all imaging follow-up. Contrarily, the rate of complete occlusion increased significantly in the HSC group, starting from the 6 and 12-months follow-up. 7 aneurysms (11.4%) were re-treated (15.6% BPC and 6.9% HSC). The 6 and 12-months clinical data showed mRS score 0-1 in 96.7% of patients. CONCLUSIONS: In our single-center experience, the second generation HydroSoft coils were shown to be safe and effective for endovascular treatment of large intracranial aneurysms with encouraging clinical and angiographic results, also for ruptured aneurysms. Even if the validity is limited due to our small cohort size, HSC showed a significantly lower rate of recurrence at mid-term follow-up when compared to BPC.

Visibility of liquid embolic agents in fluoroscopy: a systematic in vitro study.

BACKGROUND: Endovascular embolization using liquid embolic agents (LEAs) is frequently applied for the treatment of intracranial vascular malformations. Appropriate visibility of LEAs during embolization is essential for visual control and to prevent complications. Since LEAs contain different radiopaque components of varying concentrations, our aim was the systematic assessment of the visibility of the most used LEAs in fluoroscopy. METHODS: A specifically designed in vitro model, resembling cerebral vessels, was embolized with Onyx 18, Squid 18, Squid 12, PHIL (precipitating hydrophobic injectable liquid) 25%, PHIL LV (low viscosity) and NBCA (n-butyl cyanoacrylate) mixed with iodized oil (n=3 for each LEA), as well as with contrast medium and saline, both serving as a reference. Fluoroscopic image acquisition was performed in accordance with clinical routine settings. Visibility was graded quantitatively (contrast to noise ratio, CNR) and qualitatively (five-point scale). RESULTS: Overall, all LEAs provided at least acceptable visibility in this in vitro model. Onyx and Squid as well as NBCA mixed with iodized oil were best visible at a comparable level and superior to the formulations of PHIL, which did not differ in quantitative and qualitative analyses (eg, Onyx 18 vs PHIL 25% along the 2.0 mm sector: mean CNR±SD: 3.02±0.42 vs 1.92±0.35; mean score±SD: 5.00±0.00 vs 3.75±0.45; p≤0.001, respectively). CONCLUSION: In this systematic in vitro study, relevant differences in the fluoroscopic visibility of LEAs in neurointerventional embolization procedures were demonstrated, while all investigated LEAs provided acceptable visibility in our in vitro model.

Acute Intraprocedural Thrombosis After Flow Diverter Stent Implantation: Risk Factors and Relevance of Standard Observation Time for Early Detection and Management.

PURPOSE: Acute intraprocedural thrombosis (AIT) is a severe complication of flow diverter stent (FDS) implantation for the treatment of intracranial aneurysms. Even though device-related thromboembolic complications are well known, there are no acknowledged risk factors nor defined surveillance protocols for their early detection. This study aimed to demonstrate that an angiographic active surveillance is effective to detect and treat AIT. Furthermore, we investigated risk factors for the occurrence of AIT. METHODS: A prospective institutional protocol consisting of a defined observation period of 30 min following FDS deployment was established to detect AIT. Overall incidence, as well as the efficacy and safety of AIT treatment were assessed. Moreover, radiological and clinical outcomes of patients with AIT were analyzed. The influence of various patient- and procedure-related factors on the occurrence of AIT was investigated using multivariable forward logistic regression. RESULTS: During active surveillance twelve cases of AIT were observed among a total of 161 procedures (incidence: 7.5%). The median time of first observation was 15.5 min (IQR 9.5) after FDS implantation. The early recognition of AIT ensured a prompt treatment with intravenous application of a glycoprotein IIb/IIIa inhibitor, which led to complete thrombus resolution in all cases without hemorrhagic complications. Patients with pre-existing arterial hypertension and side branches originating from the aneurysmal sac had a higher risk of AIT (respectively OR, 9.844; OR, 3.553). There were two cases of re-thrombosis in the short-term postoperative period, of whom one died. The remaining patients with AIT had a good clinical outcome. CONCLUSION: Active surveillance for 30 min after FDS implantation is an effective strategy for early detection and ensuing treatment of AIT and can thus prevent secondary sequalae. Hypertension and side branches originating from the aneurysmal sac may increase the risk of AIT.

Pre-surgical embolization of carotid body paragangliomas: advantages of direct percutaneous approach and transitory balloon-occlusion at the origin of the external carotid artery.

PURPOSE: Different embolization techniques and materials are available for the pre-operative embolization of carotid body paragangliomas. In this study, we report the first experience of the direct percutaneous puncture technique under fluoroscopic guidance using the low-viscosity formula of SQUID-12. The additional use of a transitory balloon-blockage at the origin of the external carotid artery aims to confer higher protection by limiting the risk of non-target embolization and subsequent neurological sequelae. MATERIALS AND METHODS: We retrospectively reviewed all cases of carotid body paragangliomas that have undergone pre-surgical embolization with a direct puncture technique and balloon-assistance at our institution between 2019 and 2020. The use of the liquid EVOH-based SQUID-12 as the sole embolic agent was the main inclusion criteria. RESULTS: A total of 9 patients with 9 carotid body paragangliomas were enrolled in this case series. The mean volume of the lesion was 309 mm3. The mean embolization-session time amounted to 88 min. The average number of needles inserted was 2, and the mean volume of SQUID-12 used per case was 23 ml. Successful total devascularization was obtained in all cases. No long-term sequelae due to the embolization procedure occurred. CONCLUSIONS: Pre-operative paraganglioma embolization with SQUID-12 using a direct puncture and balloon-assisted technique is a safe and efficient method with few complications.

Resorbable Purified Porcine Skin Gelatin Cross-Linked with Glutaraldehyde Spheres for Preoperative Embolization of Carotid Body Paraganglioma.

Chemodectomas are rare neuroendocrine tumors that typically arise at the carotid bifurcation and progressively englobe the internal and external carotid artery. Surgical asportation of the capsulated mass is the elective treatment. Pre-procedural embolization of this high vascular tumors is highly recommended because it has shown to improve surgical outcome by reducing both, mean blood loss and total operation time. Many different embolization techniques have been described in literature. In the here presented case we opted for an endovascular approach using resorbable purified porcine skin gelatin cross-linked with glutaraldehyde microspheres (Optisphere - MEDTRONIC) as an embolic agent. These turned out to be very safe and effective in improving surgical outcome by reducing operative blood loss and thus reducing treatment-related morbidity.

Branch vessel occlusion in aneurysm treatment with flow diverter stent.

Flow diverter placement for treatment of intracranial aneurysms gained growing consensus in the past years. A major concern among professionals is the side branch coverage which leads in some cases to vessel occlusion. However, the lost vessel patency only infrequently is accompanied by a new onset of neurological deficits secondary to ischaemic lesions. A retrospective analysis of all patients treated with flow diversion at our hospital was aimed to better understand this phenomenon in order to formulate a hypothesis about the causes. We concluded that vessel occlusion occurs due to a reduced blood pressure gradient in those vessels with a strong collateral or anastomotic vascularization that refurnishes the same distal vascular territories. Indeed, we detected no new brain infarction since blood flow was always guaranteed.

WEB as a combined support and embolization device in a giant partially thrombosed donut-shaped aneurysm.

BACKGROUND: Giant partially thrombosed aneurysms are challenging lesions for which treatment can be difficult due to their unfavourable anatomical configuration and abnormal flow conditions. CASE DESCRIPTION: The patient presented in this report suffered from a symptomatic giant partially thrombosed donut-shaped aneurysm of the left-sided supraophthalmic internal carotid artery. Due to the location and the size of the aneurysm, endovascular treatment was performed. Navigation of the microcatheter-microwire-system distal to the aneurysm for stent deployment was technically not possible due to limited support, caused by the large aneurysm. Therefore, a WEB device was placed in the distal leg of the donut-shaped aneurysm. Additionally to the occlusion of this part of the aneurysm, the WEB device enabled enough support to navigate the microcatheter-microwire-system distal to the aneurysm. After deployment of a flow-diverting stent, coiling of the aneurysm was performed. Follow-up angiography showed complete occlusion of the aneurysm. The patient suffered from severe headaches which were no longer present 6 months after treatment. CONCLUSIONS: The WEB intraaneurysmal flow diverter can be effectively used as combined support and embolization device for the treatment of complex aneurysms in selective cases where other catheterization and embolization strategies have failed.