A case report: new-onset nummular headache after stenting of the middle cerebral artery.

BACKGROUND: Nummular headache (NH) is categorized as a primary headache in the International Classification of Headache Disorders, Third edition (ICHD-3) diagnostic criteria, but there are secondary etiologies as well. We present a case of secondary NH that associated with vascular lesion. CASE PRESENTATION: We report on a 40-year-old man with a medical history of symptomatic intracranial arterial stenosis who developed a headache after percutaneous transluminal angioplasty and stenting because of Intracranial atherosclerotic stenosis(ICAS). This new-onset headache was a pinprick headache confined to the parietal part of the head and 5 cm in size. This headache most closely resembled the phenotype of a NH. And other causes of secondary headache were excluded. Thus, the diagnosis of NH was highly speculated. This patient represents a rare headache phenomenon after intracranial arterial stent placement. CONCLUSION: This is the first report of NH after stent placement treatment in a patient with ICAS.

Acute Stenting and Concomitant Tirofiban Administration for the Endovascular Treatment of Acute Ischemic Stroke Related to Intracranial Artery Dissections: A Single Center Experience and Systematic Review of the Literature.

BACKGROUND: Intracranial artery dissection is an uncommon cause of acute ischemic stroke. Although acute stenting of the dissected arterial segment is a therapeutic option, the associated antiplatelet regimen remains a matter of debate. OBJECTIVES: To evaluate the efficacy and safety of acute intracranial stenting together with concomitant intravenous administration of tirofiban and to perform a systematic review of the literature. MATERIALS AND METHODS: A single-center, retrospective study of the clinical and radiological records of all patients treated at our center by intracranial stenting in the setting of acute ischemic stroke between January 2010 and December 2020. A systematic review of the literature was conducted according to the PRISMA-P guidelines for relevant publications from January 1976 to December 2020 on intracranial artery dissection treated by stent. RESULTS: Seven patients with intracranial artery dissections underwent acute stenting with concomitant tirofiban during the study period. Mid-term follow-up showed parent artery patency in 6/7 cases (85.7%). The modified Rankin Score was ≤ 0-2 at 3 months in 5/7 cases (71.4%). The literature review identified 22 patients with intracranial artery dissection treated with acute stenting in association with different antithrombotic therapies. Complete revascularization was obtained in 86.3% of cases with a modified Rankin Score of ≤ 0-2 in 68% of patients at 3-month follow-up. CONCLUSIONS: Acute intracranial stenting together with intravenous tirofiban administration could be a therapeutic option in patients with intracranial artery dissection and a small ischemic core.

Use of intracranial stent as rescue therapy after mechanical thrombectomy failure-9-year experience in a comprehensive stroke centre.

PURPOSE: There is no established rescue treatment in patients with mechanical thrombectomy (MT) failure. Our aim is to analyse whether the use of an intracranial stent improves prognosis in these patients. METHODS: Retrospective analysis of a prospective cohort of patients with ischemic stroke due to middle cerebral artery occlusion (MCA) or distal intracranial carotid artery (ICA) occlusion, from September 2009 to April 2019 in our comprehensive stroke care centre. Patients with MT failure were identified and dichotomized into two groups according to whether or not an intracranial stent was implanted. We analysed clinical outcomes in both groups. RESULTS: There was MT failure in 60 patients (14%) of the 433 with large vessel occlusion in distal ICA and proximal MCA. A stent was placed in 20 of them (33.3%). Compared to patients without rescue stenting, they showed better rates of independence at 3 months (mRS ≤ 2) 45% vs 2.5% (p < 0.001) and lower mortality 15% vs 50% (p = 0.009), maintaining statistical significance after multivariate analysis, without a significant increase of the rate of symptomatic intracranial haemorrhage (p = 0.209). CONCLUSION: Placement of an intracranial stent as rescue therapy after MT failure was associated with better clinical outcome without significant increase in haemorrhagic complications. We believe that this procedure should be appraised in these patients.

Emerging Technologies in Flow Diverters and Stents for Cerebrovascular Diseases.

PURPOSE OF REVIEW: Stents and flow diverters have revolutionized the treatment of cerebrovascular disease. Guglielmi coils, flexible microcatheters, and first-generation intracranial stents, such as Neuroform (Stryker Neurovascular) and Enterprise stents (Codman/DePuy-Synthes), have paved the way for the development of the Pipeline Embolization Device (PED) (ev3/Covidien/Medtronic) and other endovascular approaches. RECENT FINDINGS: This review discusses the historical development of flow diverter technologies from the PED to similar devices, such as the Surpass stent (Stryker Neurovascular), the Flow-Redirection Endoluminal Device (FRED; MicroVention, Inc.), the SILK stent (Balt Extrusion), and the p64 Flow Modulation Device (Phenox). In addition, the potential use of drug-eluting stents and various bioresorbable scaffolds (e.g., poly-L-lactic acid, magnesium), new developments in stent material (e.g., thin-film nitinol), design (e.g., biocompatible polymers, embedded microcircuitry, flow models), and potential applications for flow diverters will be considered. Endovascular treatment of cerebrovascular disease is rapidly advancing via continued development of new technology.

Clipping in Awake Surgery as End-Stage in a Complex Internal Carotid Artery Aneurysm After Failure of Multimodal Endovascular and Extracranial-Intracranial Bypass Treatment.

BACKGROUND: Intracranial carotid artery aneurysm can be treated via microsurgical or endovascular techniques. The optimal planning is the result of the careful patient selection through clinical, anatomic, and angiographic analysis. CLINICAL PRESENTATION: We present a case of ruptured internal carotid artery (ICA) aneurysm that became a complex aneurysm after failure of multi-endovascular and surgery treatment. We describe complete trapping in awake craniotomy after failure of coiling, stenting, and bypassing. CONCLUSIONS: ICA aneurysms could become complex aneurysms following multi-treatment failure. Endovascular approaches to treat ICA aneurysms include coiling, stenting, flow diverter stenting, and stenting-assisted coiling technique. The role of surgery remains relevant. To avoid severe neurologic deficits, recurrence, and the need of retreatment, a multidisciplinary discussion with experienced endovascular and vascular neurosurgeons is mandatory in such complex cases.

Influence of different reconstruction parameters in the visualization of intracranial stents using C-arm flat panel CT angiography: experience in an animal model.

BACKGROUND: C-arm flat panel computed tomography angiography (CA-CTA) is a relatively new imaging modality. Consequently, knowledge about postprocessing parameters and their influence on image quality is still limited, especially for the visualization of implanted microstents. PURPOSE: To optimize reconstruction parameters by evaluating the influence of these different parameters for CA-CTA visualization of microstents in an animal model. MATERIAL AND METHODS: Eleven microstents were implanted within the left common carotid artery of 11 New Zealand white rabbits. Both CA-CTA, using intra-venous delivery of contrast material, and conventional digital subtraction angiography (DSA) was performed. CA-CTA datasets were reconstructed using three different image characteristics (normal, sharp, smooth). Two experienced neuroradiologists evaluated the image quality and performed measurements of inner and outer stent diameters as well as measurements of the lumen area. RESULTS: Stent deployment was performed successfully in all animals. Inter-observer correlation coefficient for all measurements was high (r = 0.87-0.92). Lumen area and inner stent diameter were significantly smaller in image characteristic "smooth" (P < 0.01) than in "sharp" and "normal". Outer stent diameter was larger in "smooth" than in "sharp" and "normal" (P < 0.01). Stent strut size was significantly wider using image characteristic "smooth". "Sharp" and "normal" compared best to DSA, with "sharp" providing the closest match to DSA measurements, with the trade-off of significantly more noise than in the "normal" reconstructions. CONCLUSION: The use of different image characteristics in the postprocessing of CA-CTA datasets has an influence on the visualization of implanted stents. Image characteristic "sharp" and "normal" compared best to DSA.

Clinical experience in intracranial stenting of Wingspan stent system under local anesthesia.

Objective: The use of endovascular treatments for symptomatic intracranial atherosclerosis disease (ICAD) remains contentious due to high periprocedural complications. Many centers resort to general anesthesia for airway protection and optimal periprocedural conditions; however, this approach lacks real-time monitoring of patients' neurological status during procedures. In this study, we employed intracranial stenting with the Wingspan system under local anesthesia to address this challenge. Methods: We conducted a retrospective study of 45 consecutive ICAD patients who underwent intracranial stenting with the Wingspan system at our hospital from August 2013 to May 2021. These stenting procedures were performed under local anesthesia in a hybrid operation room. Neurological assessments were conducted during the procedure. The patients with periprocedural complications were analyzed for the risk factors. Results: The study included 45 ICAD patients (median age 62 years; 35 male and 10 female individuals). Among them, 30 patients had anterior circulation ICAD, and 15 had posterior circulation ICAD. The periprocedural complication rate was 8.9% (4/45), with an overall mortality rate of 2.2% (1/45). Notably, no procedure-related perforation complications were found, and all ischemic complications occurred in the perforating bearing artery, specifically in patients with stents placed in the middle cerebral artery or basilar artery, while no complications were observed in the non-perforating bearing artery of the internal carotid artery and vertebral artery (p = 0.04). Conclusion: Our study demonstrates the safety and efficacy of the Wingspan stent system when performed on selected patients under local anesthesia. This approach seems to reduce procedural-related morbidity and be a safe intervention. In addition, it is crucial for surgeons to be aware that patients with perforator-bearing artery stenosis may be at a higher risk of complications.

Y Stent-Assisted Coiling Technique for Bifurcation Aneurysms Using Double Neuroform® Stent: a Large Restrospective Series.

BACKGROUND: Stent assisted coiling technique have shown to be an effective and safe endovascular strategy for wide neck bifurcation aneurysms in achieving greater packing, allowing the closure of the aneurysm and preserving the parent arteries, compared to simple coiling. MATERIAL AND METHODS: We conducted a retrospective analysis of 79 patients with cerebral aneurysms treated using 'Y'-configuration double Neuroform® stent-assisted coiling at our center from July 2009 to July 2022. RESULTS: Of the 79 patients, 76% (60/79) were incidental unruptured cerebral aneurysm and 24% were patients treated for aneurysm recanalization of a previous ruptured aneurysm (19/79). The most frequent locations were anterior communicating artery (AComA) 44.3% (35/79) and middle cerebral artery (MCA) 32.9% (26/79). We found a complete and almost complete aneurysm occlusion (Raymond-Roy occlusion classification (RROC) 1 and 2): in 100% (79/79) in the angiography after procedure, in 97.6% (42/43) at the first follow-up at 6-8 months and 100% (57/57) at the first 1-2 years of follow-up. No mortality related to treatment was detected. We registered 2.5% (2/79) major ipsilateral strokes, one due to acute in stent thrombosis (patient had a mRS: 0 in follow up at 90 days) and a spinal anterior artery occlusion (patient had a mRS: 3 in follow up at 90 days). CONCLUSION: The 'Y' stent-assisted coiling technique with double Neuroform® is a safe and effective technique for the treatment of wide-neck bifurcation aneurysms, with high rates of complete occlusion, preserving the permeability of the afferent and efferent arteries and low rate of complications.

Design of the Vitesse Intracranial Stent Study for Ischemic Therapy (VISSIT) trial in symptomatic intracranial stenosis.

BACKGROUND: Patients with high-grade symptomatic intracranial stenosis (≥ 70%) have an increased risk of recurrent stroke despite medical treatment with antiplatelet or anticoagulant therapy. Intracranial stenting has been proposed as a viable treatment option for this high-risk patient population; however, evaluation of this therapy in randomized multicenter trials is needed. In this article, we present the design and methods of the Vitesse Intracranial Stent Study for Ischemic Therapy (VISSIT) trial for symptomatic intracranial stenosis. METHODS: The VISSIT trial is a randomized control study designed to evaluate the safety, probable benefit, and effectiveness of the PHAROS Vitesse neurovascular balloon-expandable stent system plus medical therapy versus medical therapy alone in patients with cerebral or retinal ischemia due to neurovascular stenosis (≥ 70%) for preventing the primary composite end point: stroke in the same territory (distal to the target lesion) as the presenting event within 12 months of randomization or hard transient ischemic attack in the same territory (distal to the target lesion) as the presenting event from day 2 through month 12 postrandomization. RESULTS: Enrollment began in February 2009 and was halted in January 2012 with 112 subjects enrolled into the study. Clinical follow-up will continue for the planned period of 12 months postrandomization. CONCLUSIONS: The VISSIT trial may provide valuable insight into the use of balloon-expandable intracranial stent as a treatment option for high-risk patients. Lessons learned from this trial may better guide future clinical trial design on best patient selection, stenting techniques, and periprocedural management.

Resolute onyx stent more effective than wingspan stent at preventing procedural complications and long-term restenosis.

BACKGROUND AND PURPOSE: Angioplasty and stenting is a treatment option for patients with medically refractory symptomatic intracranial atherosclerotic disease (sICAD). Currently the Wingspan Stent System (WSS) is the only FDA approved device for this indication. We find the Resolute (R) Onyx Stent, a drug-eluting balloon mounted stent (DES), a better alternative to the WSS for treatment of sICAD. Herein, we present our findings comparing the two stents based on our single center experience. METHODS: A prospectively maintained neuro-endovascular databased was queried for patients between January 2013 to June 2021. Inclusion criteria for patients included sICAD with failed medical management, and intracranial stenting with either R-Onyx DES or WSS, including patients treated within 7 days of their last stroke. Primary outcomes were assessed via the occurrence of ischemic or hemorrhagic stroke or death within 72 h of the procedure. Secondary outcomes consisted of recurrent stroke or significant in-stent restenosis evaluated by a clinical or angiographic follow-up at 6 months. RESULTS: A total of 184 patients, average age 61.26 (SD = 12.53) (44% women), were eligible for analysis with 58 having R-onyx DES and 126 having WSS. Within 72 h, the primary outcome was observed in 1.7% (n = 1) of patients in the R-onyx DES group and 6.3% (n = 8) of patients in the WSS group (p = 0.089). Among 41 angiographic and clinical follow-ups in the R-onyx DES group, none had a recurrent stroke, while among 101 patients who had follow-up in the WSS group, 8.9% (n = 9) had a stroke (p = 0.024). At a 6-month angiographic follow-up, there was a significantly lower rate of symptomatic in-stent restenosis among the R-onyx DES group with 1.7% (n = 1) compared with 21.4% (n = 27) in the WSS group (p = 0.0003). CONCLUSION: R-onyx DES is more effective than WSS in treating sICAD with low rates of periprocedural complications and long-term strokes and symptomatic in-stent restenosis. Future prospective randomized multicenter trials are needed.

Ticagrelor versus clopidogrel after intracranial stent angioplasty: a real-world study.

Objective: It was unknown whether a regimen of aspirin plus ticagrelor (aspirin-ticagrelor) attenuates ischemic vascular events without increasing bleeding risk in patients who had undergone intracranial stenting compared with an aspirin plus clopidogrel (aspirin-clopidogrel) regimen. This article compares the efficacy and safety outcomes of the two double antibody regimens in patients undergoing intracranial stent and investigates whether aspirin-ticagrelor could be an alternative antiplatelet agent without increasing the risk of bleeding. Methods: We conducted a retrospective analysis of our database for patients who had undergone intracranial stenting. From January 2017 to May 2021, consecutive patients treated with endovascular stenting were identified and dichotomized by whether aspirin-ticagrelor or aspirin-clopidogrel were used. The outcomes were compared by propensity score matching. Results: A total of 340 patients treated with intracranial stent were included. Of all, 132 patients were matched. At 180 days, ischemic vascular events occurred in one patient (1.5%) in the aspirin-ticagrelor group and in six patients (9.1%) in the aspirin-clopidogrel group. Although the absolute incidence of ischemic vascular events [1.5% (1/66) vs. 9.1% (6/66), p = 0.125] was lower in the aspirin-ticagrelor group than in the aspirin-clopidogrel group, there were no statistical differences. There were no statistical differences in ischemic vascular events, ischemic stroke, or death up to 180 days between the two groups. In addition, the incidence of bleeding did not differ. No intracranial hemorrhage or mild bleeding occurred. No statistically significant difference was noted in restenosis and symptomatic restenosis at follow-up. Conclusion: In our study involving patients with acute ischemic stroke who had undergone intracranial stenting, aspirin-ticagrelor was not found to be superior to aspirin-clopidogrel in reducing the rate of ischemic vascular events. The risk of bleeding did not differ between the two groups. Aspirin-ticagrelor does not lower total restenosis and symptomatic restenosis risk at follow-up.

Use of the neuroform atlas for stenting of intracranial atherosclerotic disease: Clinical and angiographic outcomes.

BACKGROUND: Intracranial atherosclerotic disease (ICAD) is a potential cause of ischemic stroke. Treatment of ICAD can include intracranial stenting. There are specifically designed stents for this use-case; however, less is known about the off-label use of the Neuroform Atlas stent. In this study, we describe the outcomes of the Neuroform Atlas stent for treatment of ICAD. METHODS: Adult patients with symptomatic ICAD failing best medical treatment undergoing elective intracranial stenting using the Neuroform Atlas stent between November 2018 and March 2021 were included. Patient demographics, procedure-related details and clinical and imaging outcomes were analyzed. RESULTS: Eighteen patients met the inclusion criteria, with a mean follow-up duration of 9.6 ± 6.8 (standard deviation) months. There were two procedure-related mortalities (one massive intracranial hemorrhage and one groin site complication with sepsis). Fifteen patients were alive at the 6-month follow-up, all with satisfactory stent patency on follow-up imaging without any new ischemic events. Modified Rankin Scale at latest follow-up was 1.9 (interquartile range 5). CONCLUSION: In this single-center consecutive series, intracranial stenting with the Neuroform Atlas stent was a safe and effective treatment for symptomatic ICAD patients failing best medical management.

Cone-beam CT angiography to assess the microvascular anatomy of intracranial arterial dissections.

BACKGROUND: Intracranial artery dissection is a rare and generally under-recognized cause of ischaemic stroke or subarachnoid haemorrhage. OBJECTIVES: The aim of this study was to analyse the efficacy of cone-beam computed tomography angiography (CBCT-A) to detect arterial ultrastructural alterations in intracranial artery dissection. METHOD: This is an observational and retrospective case series. RESULTS: Between January 2018 and November 2020, four patients were admitted with an acute ischaemic stroke due to intracranial dissection studied with CBCT-A. In all cases, the CBCT-A documented vascular ultrastructural alterations related with the intracranial dissection. CONCLUSIONS: CBCT-A is an intraprocedural diagnostic technique that is useful for the diagnosis of intracranial dissections.

Comprehensive Risk Analysis of the Wingspan Stent in Relation to Target Vessels.

Objective: To facilitate understanding for the safe use of the Wingspan stent, a comprehensive literature analysis was conducted, and incidence rates of 30-day stroke or death before and after the Stenting versus Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial were compared. We also investigated the associations between 30-day stroke or death rate and four lesion vessels, the internal carotid artery (ICA), middle cerebral artery (MCA), basilar artery (BA), and vertebral artery (VA). Methods: We searched MEDLINE, Embase, Web of Science, and Cochrane Library databases. The incidence rates of 30-day stroke or death in pre- and post-SAMMPRIS were compared using forest plots and funnel plots. Results: Thirty studies (15 before and 15 after the SAMMPRIS) were identified, comprising 2071 patients. Post-SAMMPRIS studies showed lower incidence rates of 30-day stroke or death compared to the pre-SAMMPRIS studies (8.5% vs. 5.6%, p = 0.014). The odds ratio of 30-day stroke or death of the post-SAMMPRIS group compared to that of the pre-SAMMPRIS group was 0.64 (95% confidence interval: 0.45-0.92, p = 0.014). The average 30-day stroke or death rates of overall, pre-, and post-SAMMPIS studies were 1.1%, 1.1%, and 1.1% for ICA; 6.2%, 8.8%, and 5.3% for MCA; 0.9%, 6.0%, and 2.7% for VA; and 13.5%, 15.1%, and 12.5% for BA, respectively. The post-SAMMPRIS study group showed significantly lower event rates for the treatment of MCA and VA than the pre-SAMMPRIS group did (p = 0.003 and p = 0.006, respectively). The incidence rates of ischemic and hemorrhagic stroke were 3.5% and 2.0%, respectively. Conclusion: This systematic surveillance study indicated that the modification of the indications for use based on the results of the SAMMPRIS trial for the Wingspan stent was effective in reducing 30-day stroke or death.

Comparison of the Physical Characteristics of Support Stents for Cerebral Aneurysm Embolization.

Objective: There is a limited understanding of the characteristics of individual intracranial stents used for aneurysm treatment. We used an experimental model to evaluate the physical characteristics of support stents for aneurysm embolization. Methods: Enterprise 2 VRD 4.0 × 39 mm, Neuroform Atlas 4.5 × 21 mm, and LVIS 4.5 × 32 mm stents were: 1) observed under light microscopy and subjected to measurements of 2) circumferential radial force, 3) strut tension, 4) stent compression, and 5) conformability upon bending. Results: 1) Light microscopy showed a large structural difference between laser-cut (Enterprise 2 VRD, Neuroform Atlas) and braided (LVIS) stents. 2) Within the range of indicated blood vessel diameters, the radial force of Enterprise 2 VRD was higher than that of Neuroform Atlas. An extremely large force was required to decrease the LVIS diameter. 3) Neuroform Atlas easily deformed compared to Enterprise 2 VRD, while LVIS was extended with a smaller traction force than that required for Neuroform Atlas. 4) The compression strength was in the order of Enterprise 2 VRD >Neuroform Atlas >LVIS. 5) Enterprise 2 VRD showed a decreased cell area on the concave side, and Neuroform Atlas showed deformation with overlapping struts on the concave side. LVIS naturally adhered to the wall of the blood vessel model. Conclusion: Laser-cut and braided stents showed different physical characteristics that were visualized and shown as numerical data. These findings improve the understanding of the proper use of these stents in clinical applications.

A novel technique for stenting of intracranial stenosis using the Neuroform Atlas stent and Gateway balloon catheter.

Management of intracranial stenosis remains controversial. Stenting for intracranial stenosis has been associated with high complication and restenosis rates. Morbidity may be related to the intracranial microcatheter exchange that is required in stent placement after the angioplasty. We present a technique in which we deploy an Neuroform Atlas stent through the lumen of a Gateway balloon microcatheter in order to avoid intracranial microcatheter exchange and the associated morbidity. We discuss advantages and pitfalls of this novel technique.

Management of intracranial vertebral artery stenosis with ipsilateral vertebral artery hypoplasia and contralateral vertebral artery occlusion via type 2 proatlantal intersegmental artery.

BACKGROUND: Proatlantal intersegmental artery (PIA) is a rare primitive carotid-basilar anastomosis. PIA may accompany with ipsilateral or bilateral vertebral arteries (VAs) agenesis. Here, we presented the case with intracranial VA stenosis supplying via PIA and demonstrated how we evaluated and managed. METHODS: Dual antiplatelet therapy and adequate hydration were given for three weeks for intracranial atherosclerotic disease (ICAD). We arranged magnetic resonance (MR) vessel wall imaging to survey both intracranial VAs. Intracranial right VA stenosis supplying via PIA with ipsilateral VA hypoplasia and contralateral intracranial VA occlusion caused multiple posterior circulation infarcts. We performed angioplasty and intracranial stenting for ICAD at the right VA V4 segment via PIA. RESULTS: National Institute of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS) got improved at discharge and ten months. CONCLUSIONS: This case is the first report for ICAD management via PIA. A persistent type 2 PIA is essential for supplying posterior circulation.

Improvement of Hemifacial Spasm after Stent-assisted Coil Embolization for Ipsilateral Vertebral Artery Dissecting Aneurysm.

Microvascular decompression (MVD) is the gold standard in the treatment of hemifacial spasm (HFS), and endovascular surgery has been described as a treatment only for aneurysm-induced HFS in several previous cases. We describe symptomatic HFS caused by a normal vertebral artery (VA) trunk adjacent to the ipsilateral dissecting VA aneurysm completely cured after stent-assisted coil embolization. A 52-year-old man presented with a 2-month history of gradually worsening left HFS. Magnetic resonance imaging (MRI) and cerebral angiography revealed a dissecting VA aneurysm on the left side. Based on the findings from preoperative MRI, not the aneurysmal dome itself, but the VA trunk just distal to the aneurysmal dome was considered likely to be compressing the root exit zone (REZ) of the facial nerve. Stent-assisted coil embolization was conducted for the VA aneurysm, and the stent was deployed to cover the wide neck of the aneurysm and offending zone of the VA trunk simultaneously. HFS started to show improvement just after the procedure and complete disappearance within 1 year. HFS was completely resolved by stenting of the offending artery. Stents may show efficacy for "intra-arterial decompression" by reducing pulsatility against the REZ of the facial nerve due to the thickness and rigidity of the stent metal and delayed endothelialization.

The Geometry of Y-Stent Configurations Used for Wide-Necked Aneurysm Treatment: Analyzing Double-Barrel Stents In Vitro Using Flat-Panel Computed Tomography.

BACKGROUND: Stent-assisted coil embolization of wide-necked bifurcation aneurysms often employs a Y configuration stent. A similar stent configuration, termed kissing/double-barrel (KDB), is used often at the aortoiliac bifurcation. Studies of KDB stents in aortoiliac disease show that rates of thromboembolic complications vary with the cross-sectional geometry of the stent pair, a function of the radial crush resistive force of each stent. We assessed cross-sectional geometry of intracranial stent pairs in an in vitro model of the basilar artery using flat-panel computed tomography. METHODS: In a silicone model of a wide-necked basilar tip aneurysm, 6 simulated KDB stent deployment trials were performed using combinations of 5 stents (Enterprise 1, Enterprise 2, Neuroform Atlas, LVIS, LVIS Jr.). Flat-panel computed tomography reconstructions were used to assess cross-sectional stent geometry. Relative conformability, defined by ovalization and D-ratio, radial crush resistive force (predicted vs. actual), and radial mismatch fraction were compared by stent type (braided vs. laser-cut). RESULTS: Several distinct forms of cross-sectional stent geometry were observed. Braided stents had lower ovalization and D-ratio (P = 0.015) than laser-cut stents. The Neuroform Atlas/LVIS combination yielded the lowest radial mismatch fraction (19.7% vs. mean 44.3% ± 0.7%). Braided stents tended to have a deployed stent radius closer to the expected (nominal) diameter (i.e., higher relative crush resistive force) than laser-cut stents (measured vs. nominal diameter discrepancy +38.6% ± 21.1% vs. -10.7% ±16.1%, P = 0.14). CONCLUSIONS: In constant anatomy, cross-sectional geometry of the KDB stent configuration will vary depending on the design and structure of the stents employed.

The p64 Flow Diverter-Mid-term and Long-term Results from a Single Center.

BACKGROUND AND PURPOSE: The p64 is a flow modulation device designed to be used in endovascular treatment of intracranial aneurysms. There is limited data on the long-term effectiveness of the device. This study sought to determine the safety and long-term efficacy of this device. METHODS: A retrospective review of a prospectively maintained database was performed to identify all patients treated with a p64 between March 2015 and November 2018 at University Hospital St. Ivan Rilski. Anatomical features, intraprocedural complications, clinical, and angiographic outcomes were also taken into account and reviewed. RESULTS: A total of 72 patients with 72 aneurysms who met the inclusion criteria were identified. Device placement was successful in all patients. Follow-up angiographic imaging at 6 months showed complete occlusion (O'Kelly-Marotta scale [OKM] D) in 55 (76.3%) patients, subtotal aneurysmal filling (OKM B) in 10 (13.8%) patients, and neck remnant (OKM C) in 7 (9.7%) patients. Catheter angiography at 12 months was available for 70 patients (97.2%) and of these patients 91.4% of the aneurysms were completely occluded (OKM D) (64/72). Delayed angiography at 24 months was available for 68 patients (94.4%) and of these 98.5% (67/68) had completely occluded aneurysms. A 36-month angiography was available for 61 patients (84.4%) by which point all aneurysms had been completely occluded (100%). Permanent morbidity due to delayed aneurysmal rupture occurred in one patient (1.38%). The mortality rate was 0%. Self-limiting mild intimal hyperplasia was seen in 2 patients (2.72%). CONCLUSION: Treatment of intracranial aneurysms with a p64 flow modulation device is safe and effective with a high success rate and only infrequent complications.