Treatment of intracranial bifurcation aneurysms with "X" stent-assisted coiling: A case series and literature review.

PURPOSE: To clarify the safety and efficacy of "X" stent-assisted coiling (X-stenting) for the treatment of intracranial bifurcation aneurysms and to review the literature. METHODS: We retrospectively reported five consecutive patients with six intracranial bifurcation aneurysms who underwent X-stenting between June 2014 and June 2020. The clinical and angiographic results were analyzed. We also performed an extensive PubMed review of medical literature up to June 2021. RESULTS: Endovascular procedures were successfully applied to all six aneurysms. No procedure-related complications were noted. Follow-up angiograms were available for all patients and revealed occlusion in five aneurysms and improvement in one aneurysm. Clinical follow-up was performed for all patients, and the mRS score at follow-up was 0 in all patients. Thus, good outcomes were achieved in all patients, and no ischemic or hemorrhagic events were observed. CONCLUSIONS: X-stenting appears to be safe for treating intracranial bifurcation aneurysms and effective in immediate and short-term outcome. Further research is required with well-designed, prospective studies with large sample sizes.

Microcatheter movement in the aneurysm due to low-profile visualized intraluminal support deployment: An in vitro study.

BACKGROUND: When a microcatheter is in the aneurysm, it may move due to low-profile visualized intraluminal support (LVIS) deployment. This study was designed to determine this mechanism. METHODS: Six silicon aneurysm models were created by combining the aneurysm location (side wall or bifurcation) and the parent vessel configuration (straight, ipsilateral bending, or contralateral bending). After adjusting the microcatheter tip position in the aneurysm by pushing or pulling, an LVIS stent was deployed to cover the aneurysm neck, and the changes in the microcatheter tip position was measured. Pushing and pulling were performed 15 times each for each model, for a total of 180 experiments. RESULTS: In all experiments, the microcatheter tip moved with LVIS deployment. The total movement distance was 3.00±1.59 mm, which was significantly different between the push and pull groups (p = 0.049), between the three side-wall aneurysm models (p<0.0001), and between the three bifurcation aneurysm models (p<0.0001). Backward movement in the aneurysm occurred in 21% (37/180). The frequency of backward movement was significantly different between the side-wall and bifurcation aneurysm models (p = 0.0265) and between the push and pull groups (p<0.0001). The forward movement distance was significantly different between the side-wall (n = 78) and bifurcation (n = 65) aneurysm models (p<0.0001). CONCLUSIONS: The aneurysm location, the parent vessel configuration, and adjustment of the microcatheter tip position by pushing or pulling may affect the total movement distance and forward/backward movement of the microcatheter tip due to LVIS deployment.

Partially thrombosed giant basilar tip aneurysm that remarkably decreased in size after stent-assisted coiling associated with the disappearance of neovascularization.

Endovascular treatment for partially thrombosed giant basilar tip aneurysms has not been established because of its low cure rate and numerous associated comorbidities. Although some authors reported the growth mechanism of partially thrombosed aneurysm, there is no report for the process of its shrinkage after treatment. We describe a case of a partially thrombosed giant basilar tip aneurysm presenting with disturbance of consciousness because of a mass effect and brain edema. The patient underwent stent-assisted coiling using a low-profile visualized intraluminal support stent (Terumo). Although pre-operative magnetic resonance imaging (MRI) and angiography revealed prominent neovascularization of the inner aneurysmal layer, this vessel was absent on follow-up angiography 1 month after treatment. Repeat angiography demonstrated the gradual recanalization of the aneurysm. However, repeat MRI examinations showed remarkable shrinkage of the thrombosed aneurysm, and the complete disappearance of the thrombosed component was noted 6 months after treatment. The disappearance of neovascularization 1 month after the treatment may have contributed to the shrinkage of the thrombosed aneurysm. Stent-assisted coiling combined with alteration caused a hemodynamic change in this aneurysm, and the flow-diverting effect might have controlled this partially thrombosed giant aneurysm.

Factors related to microcatheter passage through the trans-cell approach using a low-profile visualized intraluminal support device: an in-vitro study.

BACKGROUND AND PURPOSE: The trans-cell approach using a low-profile visualized intraluminal support (LVIS) device is sometimes used for aneurysm coil embolization. However, factors related to microcatheter passage remain uninvestigated. We aimed to examine in-vitro factors related to microcatheter passage using the trans-cell approach with an LVIS. METHODS: Silicone vessel models (inner diameter, 4 mm) were created with different bend segments and a 4-mm hole assuming an aneurysm neck on the side of the greater curvature. The LVIS Blue (4.5 × 32 mm) was deployed at the bend segment, and passability on the trans-cell surface was evaluated by passing the microcatheter along the micro guidewire. A total of 800 passage experiments were performed using two types of microcatheter, ten types of silicone vessel, four cell widths, five cells with the same LVIS device, and two micro guidewire directions in the aneurysm. RESULTS: The Headway Duo microcatheter (35.5%, 142/400) tended to have better passability compared with the Headway 17 microcatheter (29.3%, 117/400) (p = 0.070). As the cell width and angle between the trans-cell surface and microcatheter direction increased, passability significantly increased (p = 0.027 and p < 0.001, respectively). There was no significant difference in passability when the micro guidewire was directed to the proximal side versus the distal side (p = 0.45). CONCLUSIONS: A large cell width and an obtuse angle between the trans-cell surface and microcatheter direction facilitated good passability. Although statistically marginal, microcatheters with small ledges and small tips had relatively good passability.

Stent anchor technique to reduce microcatheter loop for stent-assisted coiling of anterior communicating artery aneurysm.

Stent-assisted coiling offers a potential solution for coil embolization of broad-based aneurysms. Challenges associated with navigating a microcatheter beyond these aneurysms sometimes require looping the microcatheter within the aneurysm dome. Reducing microcatheter loops within domes can be difficult, and anchor techniques have been described, including balloon anchor, stent-retriever anchor, and stent anchor techniques. The authors present a patient requiring stent-assisted coiling of an anterior communicating artery aneurysm in whom a stent anchor technique was used to reduce a microcatheter loop within an aneurysm dome before coil embolization. Postembolization angiographic runs showed complete coil occlusion of the aneurysm with approximately 35% packing density.The video can be found here: https://youtu.be/zHR1ZOArUro.

Endovascular Treatment of Ruptured Tiny Intracranial Aneurysms with Low-Profile Visualized Intraluminal Support Device.

BACKGROUND: Ruptured tiny intracranial aneurysms (TIAs) have been challenging both for endovascular and neurosurgical interventions. Thus, we aimed to evaluate the safety and efficacy of low-profile visualized intraluminal support (LVIS) device in the treatment of ruptured TIAs (rTIAs). MATERIAL AND METHODS: Among 761 intracranial aneurysms which were treated either surgically or endovascularly, 32 rTIAs underwent stent-assisted coiling with LVIS device between 2014 and 2017. Patient data were reviewed retrospectively. Clinical and radiological outcomes were recorded at discharge and mid-term follow-up. RESULTS: Mean patient ages were 53 ± 14.5 years. Mean aneurysm size was 2.28 ± .53 mm (range, 1-2.9 mm) with a mean dome:neck ratio of 1.08 (range, .75-2.14). The LVIS stents were successfully implanted in all patients. Mean follow-up period was 9.3 ± 1.9 months (range, 6-15 months). Immediate angiographic evaluation demonstrated complete occlusion in 13 (40.6%) patients, while neck remnant and residual sac were observed in 12 (37.5%) and 7 (21.9%), respectively. All patients had moderate disability (mRS 2-3) at discharge. Number of aneurysms with complete occlusion significantly increased and 82.1% of the patients (23 of 28) demonstrated complete occlusion at follow-up (P = .0015). Among these, 27 had good outcome (mRS 0-1; 96.9%) with significant improvement compared to discharge (P = .0001). There was no recurrence or enlargement of the residual aneurysms. Additionally, there were no procedure-related complications except the one (3.6%) showing asymptomatic stenosis of the posterior cerebral artery in follow-up imagings. CONCLUSIONS: Stent-assisted coiling of rTIAs with LVIS device provides high rates of technical success and complete occlusion at mid-term follow-up with an excellent safety profile.

[Visualization of Four Intracranial Stents and In-stent Stenosis with Stenotic Models by 3D-TOF-MRA].

In recent years, various types of stents are deployed for the treatment of intracranial artery stenosis and aneurysms. Digital subtraction angiography has been considered to be the gold standard for the follow-up study. However, magnetic resonance angiography (MRA) is less invasive and the recent advances may contribute to the imaging of patients with intracranial stents. Then, a phantom study was carried out to evaluate the MR lumen visibility with these stents. Four stents [low-profile visualized intraluminal support (LVIS), Neuroform Atlas, Neuroform EZ, and Enterprise 2] were placed into plastic tubes with 3 mm inner diameter, and fixed in a container filled with agar. Time-of-flight MRA (TOF-MRA) was performed for these stents, and the signal intensities inside and outside the stents were measured on ImageJ software. Furthermore, 25%, 50%, and 75% stenosis models were created and passed through these stents to evaluate the diagnostic accuracy of in-stent stenosis. The signal intensity inside the LVIS stent was the highest among the four stents (P<0.001), and no significant difference was found between the signal intensities inside and outside the LVIS stent. The diagnostic accuracy with LVIS was also higher than that of Enterprise 2 (P<0.001). In conclusion, the visibility with LVIS indicates that TOF-MRA could be reliably utilized as a diagnostic tool for the detection of in-stent stenosis.

Update on flow diverters for the endovascular management of cerebral aneurysms.

Flow diversion has become a well-accepted option for the treatment of cerebral aneurysms. Given the significant treatment effect of flow diverters, numerous options have emerged since the initial Pipeline embolization device studies. In this review, the authors describe the available flow diverters, both endoluminal and intrasaccular, addressing nuances of device design and function and presenting data on complications and outcomes, where available. They also discuss possible future directions of flow diversion.

Flow diverter effect of LVIS stent on cerebral aneurysm hemodynamics: a comparison with Enterprise stents and the Pipeline device.

BACKGROUND: The aim of this study was to quantify the effect of the new Low-profile Visualized Intraluminal Support (LVIS®D) device and the difference of fluid diverting effect compared with the Pipeline device and the Enterprise stent using computational fluid dynamics (CFD). METHODS: In this research, we simulated three aneurysms constructed from 3D digital subtraction angiography (DSA). The Enterprise, LVIS and the Pipeline device were virtually conformed to fit into the vessel lumen and placed across the aneurysm orifice. Computational fluid dynamics analysis was performed to compare the hemodynamic differences such as WSS, Velocity and Pressure among these stents. RESULTS: Control referred to the unstented model, the percentage of hemodynamic changes were all compared to Control. A single LVIS stent caused more wall shear stress reduction than double Enterprise stents (39.96 vs. 30.51 %) and velocity (23.13 vs. 18.64 %). Significant reduction in wall shear stress (63.88 %) and velocity (46.05 %) was observed in the double-LVIS stents. A single Pipeline showed less reduction in WSS (51.08 %) and velocity (37.87 %) compared with double-LVIS stent. The double-Pipeline stents resulted in the most reduction in WSS (72.37 %) and velocity (54.26 %). Moreover, the pressure increased with minuscule extent after stenting, compared with the unstented model. CONCLUSIONS: This is the first study analyzing flow modifications associated with LVIS stents. We found that the LVIS stent has certain hemodynamic effects on cerebral aneurysms: a single LVIS stent caused more flow reductions than the double-Enterprise stent but less than a Pipeline device. Nevertheless, the double-LVIS stent resulted in a better flow diverting effect than a Pipeline device.

A clinical comparative study of dual LVIS devices and single flow diversion stenting for the treatment of unruptured V3-V4 vertebral artery dissection.

PURPOSE: This study aims to compare the efficacy and safety of using overlapping low-profile visualized intraluminal support (LVIS) devices and flow diversion (FD) for the treatment of unruptured vertebral artery dissection (VAD) in the V3-V4 segments. METHODS: The clinical and imaging data of 71 patients with unruptured VAD in the V3-V4 segments who underwent either dual LVIS stenting (d-LVIS group) or single FD stenting (FD group) at our center from September 2014 to December 2021 were retrospectively analyzed. RESULTS: Immediate postoperative angiography revealed no significant difference in the degree of occlusion between the two groups in treating vertebral artery dissecting aneurysms (with or without noncompact coiling). However, the d-LVIS group had significantly higher fluoroscopy exposure time and total radiation exposure dose compared to the FD group. During the perioperative period, two cases of pontine infarction and one case of acute thrombosis were encountered. One patient died from subarachnoid hemorrhage during the follow-up period. For dissecting the aneurysm, angiographic follow-up (8.56 ± 1.96 months) showed similar healing outcomes between the two groups (with or without noncompact coiling). However, seven patients (7/40, 17.5%) showed poor healing and one patient showed mild in-stent stenosis. For simple dissection, angiographic follow-up (8.78 ± 1.83 months) showed patent lumens in both groups, with all dissections healing well, and two patients having mild in-stent stenosis. CONCLUSION: Both methods could effectively treat unruptured VAD in V3-V4 segments. Nevertheless, simple FD implantation is relatively easier to perform and involves lower radiation exposure.

Low-Profile Visualized Intraluminal Support Device for Y-Stent-Assisted Coiling of Wide-Neck Intracranial Aneurysms: A Single-Center Experience.

BACKGROUND: The Low-Profile Visualized Intraluminal Support (LVIS) device has been frequently used as an intracranial stent for treating intracranial aneurysms. However, the feasibility and efficacy of LVIS devices in Y-stent-assisted coiling (Y-SAC) have remained contentious. This study aimed to evaluate long-term angiographic and clinical outcomes of Y-SAC using LVIS devices. METHODS: We retrospectively reviewed the clinical presentation and angiography data of patients treated with Y-SAC using LVIS stents. The vascular angle geometry between the parent and the 2 branch vessels, before and after stent deployment and after coiling, were analyzed. Based on the Raymond-Roy Occlusion Classification (RROC), aneurysm occlusion status was classified. Clinical outcomes were assessed using the modified Rankin Scale. RESULTS: Forty patients with 40 aneurysms were included in this study. Immediate postprocedural angiograms showed complete/near-complete occlusion (RROC 1 and 2) in 31 aneurysms (77.5%). The long-term follow-up angiographic studies were available in 32 patients and showed RROC class 1 and 2 in 93.8% of patients. Y-SAC with LVIS devices significantly decreased the angle between the bifurcation branches from 171.90° ± 48.0° (standard deviation) to 130.21° ± 46.3° (standard deviation) (P < 0.0001). Periprocedural complications occurred in 5 patients (12.5%) including 4 in-stent thromboses (10.5%). Thirty-six patients (90.0%) had favorable clinical outcomes at the final follow-up. Univariate analysis showed that World Federation of Neurological Societies grade 3-5, thickness of subarachnoid hemorrhage on head computed tomography, intraprocedural complications, and in-stent thrombosis were predictors of poor outcome. CONCLUSIONS: Y-SAC using the LVIS device for intracranial bifurcation aneurysms is a feasible and relatively safe procedure with favorable long-term angiographic and clinical outcomes.

Safety and Efficacy of LVIS Jr Stent-assisted Coiling of Intracranial Aneurysms in Small-diameter Parent Arteries : A Single-center Experience.

OBJECTIVE: To investigate the safety and efficacy of LVIS Jr stent-assisted coiling (SAC) of intracranial aneurysms (IAs) in small-diameter parent arteries and determine the factors influencing incomplete aneurysm occlusion. MATERIAL AND METHODS: Clinical and imaging data of 130 patients with IAs in small-diameter parent arteries that were treated with LVIS Jr SAC were retrospectively analyzed. Stent apposition was evaluated by high-resolution flat detector CT, and aneurysm embolization density was evaluated using 2D-DSA. Perioperative complications were recorded. Multivariate logistic regression analyses were performed to determine possible factors for incomplete aneurysm occlusion. RESULTS: In this study, 130 patients (60 and 70 patients with ruptured and unruptured aneurysms, respectively) were successfully treated with LVIS Jr SAC. Immediate digital subtraction angiography (DSA) showed that the aneurysm occlusion was Raymond-Roy class I, II, IIIa, and IIIb in 93 (71.5%), 24 (18.5%), 8 (6.2%), and 5 (3.8%) cases, respectively. There were three cases of acute in-stent thrombosis and two cases of severe vasospasm observed during the perioperative period. The 6­month follow-up angiograms indicated that complete aneurysm occlusion in 122 patients was 79.5% (97/122). Multivariate logistic regression analyses showed that an aneurysm size > 10.0 mm, parent artery mean diameter < 2.0 mm, and incomplete stent apposition at the aneurysm neck were possible risk factors for incomplete aneurysm occlusion. CONCLUSION: The LVIS Jr SAC is effective for managing IAs in small-diameter parent arteries. An aneurysm size > 10.0 mm, parent artery mean diameter < 2.0 mm, and incomplete stent apposition at the aneurysm neck are possible risk factors for incomplete aneurysm occlusion.

Long term safety and effectiveness of LVIS Jr for treatment of intracranial aneurysms- a Canadian Multicenter registry.

BACKGROUND: The Low-profile Visible Intraluminal Support device (LVIS Jr) has become a commonly used intracranial stent for the treatment of intracranial aneurysms. However long-term stability and effectiveness remains to be seen. The purpose of the study was to assess the long-term efficacy, safety and durability of LVIS Jr. in a retrospective multicenter registry. METHODS: Patients with saccular aneurysms treated at centers across Canada using LVIS Jr for intracranial aneurysms were included in this retrospective registry between the dates of January 2013 and April 2019. Self reported outcomes were collected and used to assess both perioperative and long term safety and effectiveness. Both univariate and multivariate analysis were performed. RESULTS: Total of 196 patients (132 Women; mean age of 57.6 years) underwent endovascular aneurysm treatment with at least 1 LVIS Jr. stent. Mean aneurysm dome size was 7.4 mm, and mean neck size of 4.3 mm. Mean clinical and imaging follow up were 950 and 899 days respectively. Class I/II was achieved in 85% on long term follow up. Periprocedural morbidity and mortality was 4.6% and 2% and additional delayed morbidity and mortality was 3% and 2.5%. Aneurysm size >10 mm was independent predictor of periprocedural complication (OR 2.59, p = 0.048) while an increased dome to neck ratio >1.5 was independent predictor of increased delayed complications (OR 3.99, p = 0.02). CONCLUSION: The LVIS Jr. intracranial stent is an effective device in the treatment of intracranial aneurysms. Satisfactory long term occlusion rates can be achieved safely with stent-assisted coil embolization.

Low-Profile Visualized Intraluminal Support Junior Flow-Diversion Properties Used for Stabilization of a Superior Cerebellar Artery Pseudoaneurysm.

BACKGROUND: Pseudoaneurysms of the posterior circulation pose a unique management challenge. The fragile nature of the pseudoaneurysm wall presents a high risk of rupture and demands treatment. Small vasculature, particularly distal in the posterior circulation, can preclude management with traditional flow diverters, where the alternative of vessel sacrifice is unacceptable. Small stents can have flow-diversion properties and can be used in these high-risk, difficult-to-access aneurysms. METHODS: We describe a 40-year-old woman presenting with a ruptured dissecting right superior cerebellar artery pseudoaneurysm after minor trauma. Given the aneurysm's small size and morphology, it was not amenable to coiling and parent vessel sacrifice was potentially morbid. The pseudoaneurysm was initially stabilized with a Low-Profile Visualized Intraluminal Support Junior (LVIS Jr.) stent due to its reported flow-diverting properties. RESULTS: At six-month follow-up the pseudoaneurysm was stable and the vasospasm had resolved. At this point, definitive treatment with a "FRED Jr." (Flow Re-Direction Endoluminal Device Junior) flow diverter was pursued. Complete obliteration of the pseudoaneurysm was seen at 12 months' follow-up after staged treatment. CONCLUSIONS: Due to the unique challenges associated with ruptured pseudoaneurysms located on small-caliber vessels, the options for definitive treatment are limited. The small size of the LVIS Jr. stent and its flow-diverting properties make it a practical treatment option in a difficult situation. This case report provides further support for the flow-diverting properties of the LVIS Jr. and its potential application in the treatment of ruptured pseudoaneurysms in small-caliber intracranial vessels.

Exploring communicative competence in autistic children who are minimally verbal: The Low Verbal Investigatory Survey for Autism (LVIS).

LAY ABSTRACT: Approximately one in three autistic children is unable to communicate with language; this state is often described as minimally verbal. Despite the tremendous clinical implications, we cannot predict whether a minimally verbal child is simply delayed (but will eventually develop spoken language) or will continue to struggle with verbal language, and might therefore benefit from learning an alternative form of communication. This is important for clinicians to know, to be able to choose the most helpful interventions, such as alternative forms of communication. In addition, the field lacks a standard definition of "minimally verbal." Even when we do agree on what the term means (e.g. fewer than 20 words), describing a child based on their lack of words does not tell us whether that child is communicating in other ways or how they are using those 20 words. To address these concerns, we developed the Low Verbal Investigatory Survey (LVIS), a one-page parent-report measure designed to help us characterize how minimally verbal autistic children are communicating. Parents of 147 children (aged 1-8 years) completed the LVIS. Here, we ask (1) whether the survey measures what it was designed to measure, that is, communicative ability in children without much spoken language, and (2) how the LVIS relates to cognitive and language ability, and symptoms of autism. Results suggest that this survey, which takes only 5 min to complete, is a good estimate of the child's communication skills. Furthermore, LVIS survey scores are correlated with other measures of language and cognitive abilities as well as autism symptomatology. The LVIS has the potential to save time and money in both clinical and research efforts to assess communication skills in minimally verbal autistic children.

Enterprise stents versus low-profile visualized intraluminal support stents for stent-assisted coiling of unruptured paraclinoid aneurysms.

BACKGROUND: The microsurgical treatment of paraclinoid aneurysms can be challenging due to the anatomical structures that surround them. OBJECTIVE: This study compared the clinical and angiographic outcomes of unruptured paraclinoid aneurysms treated with enterprise (EP) stents and low-profile visualized intraluminal support (LVIS) stents. METHODS: A retrospective analysis of the clinical and radiological data from 133 patients with 139 unruptured paraclinoid aneurysms, who received an EP or an LVIS stent between January 2017 and June 2021 at Taizhou People's Hospital, was performed. Immediate postoperative and follow-up angiographic results were analyzed retrospectively using the Raymond-Roy occlusion classification (RROC). Any complications following the procedure and the patients' clinical outcomes were noted. RESULTS: Enterprise stents were used for stent-assisted coiling in 64 patients with 68 aneurysms and LVIS stents were used in 69 patients with 71 aneurysms. Both groups exhibited an increase in the proportion of aneurysms meeting the criteria for RROC class I, but the LVIS group demonstrated a higher rate of aneurysms meeting the class I criteria compared with the EP group, both on immediate postoperative angiography (45.1% vs. 11.8%, p< 0.001) and on follow-up angiography (94.9% vs. 80.6%, p= 0.025). Procedure-related complications were experienced by 9.4% of patients in the EP group (one coil prolapse, two parent artery occlusions, and three thromboembolic events), and 8.7% of patients in the LVIS group (three stent-related thrombosis and three thromboembolic events). There were no statistically significant differences between the two groups in relation to perioperative complications (p= 0.746) or favorable clinical outcomes (p= 0.492). CONCLUSION: A greater proportion of aneurysms in the LVIS group met the criteria for RROC class I compared with the EP group. There is no significant difference in procedural complications or clinical outcomes between EP and LVIS stents. Although no aneurysm recurrence was observed during the short follow-up period, continued monitoring is required.

Utility of low-profile visualized intraluminal support (LVIS™) stent for treatment of acutely ruptured bifurcation aneurysms: A single-center study.

Objective: Stent-assisted coiling has been increasingly used in the treatment of intracranial aneurysms. However, its application in ruptured bifurcation aneurysms remains controversial and challenging. This study aimed to present the safety and feasibility of low-profile visualized intraluminal support (LVIS™, LVIS, and LVIS Jr.) stent for acutely ruptured bifurcation aneurysms. Methods: A total of 41 patients with acutely ruptured intracranial aneurysms arising at the bifurcation were treated with LVIS™ stent-assisted coiling in our hospital between January 2017 and December 2021. The clinical data and angiographic results of the patients were analyzed. Results: Among these patients, all stents were successfully implanted. According to the immediate angiographic results, 29 aneurysms (70.7%) were completely occluded. Intraoperative thrombosis and hemorrhage occurred in two and one cases, respectively. No post-operative thrombosis or rebleeding events were observed. The clinical follow-up of all patients revealed that 38 (92.7%) cases had favorable outcomes (modified Rankin scale: 0-2). The angiographic results available for the 36 patients during the follow-up period revealed complete occlusion was achieved in 30 patients (83.3%) and residual neck in six patients. Conclusion: The LVIS™ stent-assistant coiling is a safe and feasible option for acutely ruptured bifurcation aneurysms. Further studies with a prospective design, a larger sample size, and long-term follow-up are needed to validate these findings.

Clinical and Angiographic Outcomes of Endovascular Treatment for Acute Intracranial Vertebral Artery Dissecting Aneurysms Using Double-Overlapping Stents : Low-Profile Visualized Intraluminal Support within Enterprise Stents.

Objective: The use of reconstructive treatment with a double-overlapping stents has proven to be effective and safe in the current treatment of intracranial vertebral artery dissecting aneurysms (VADAs). We employed a combination of overlapping stents, using low-profile visualized intraluminal support (LVIS) within the Enterprise stent. This combination was chosen to minimize the outward bulging of the inner LVIS by overlapping it with the Enterprise stent while maintaining flow diversion and stability. This study aimed to evaluate the clinical and angiographic outcomes following the use of double-overlapping stents with LVIS within the Enterprise stent for the treatment of VADAs. Methods: From March 2016 to January 2022, total 28 patients with unruptured VADAs were treated with the double-overlapping stent technique using LVIS within an Enterprise stent in our institute. The Enterprise stent was deployed first, followed by the LVIS stent. Patient clinical and angiographic characteristics, procedural complications, and follow-up outcomes were retrospectively reviewed. Results: All 28 patients (18 males and 10 females) were successfully treated with double-overlapping stent deployment. There were no procedural complications or new neurological deficits in any patient. Of the 28 patients, four VADAs had posterior inferior cerebellar artery involvement. Procedure-related parent artery occlusion did not occur during the angiographic follow-up conducted 6 to 12 months after the procedure. Out of 28 patients, 24 showed complete healing, three had focal residual stenosis or dilatation with residual sac and only one had a residual dissecting flap with aneurysm. All patients, including the four patients, did not require any additional procedures. The postoperative modified Rankin Scale (mRS) scores were 0-1 for all patients. Conclusion: A double-overlapping stent, with a flow-diversion effect, is a safe and effective treatment for patients with VADAs. In particular, when using the LVIS stent within an Enterprise stent, it minimizes the bulging of the inner LVIS stent while maintaining flow diversion and stability. Therefore, both can be effectively utilized as overlapping stents.

Low-profile visualized intraluminal support-within-Enterprise overlapping-stent technique versus flow diversion in the treatment of intracranial vertebrobasilar trunk dissecting aneurysms.

Background: It is necessary to explore the safety and efficacy of various endovascular treatment techniques in the treatment of patients with intracranial vertebrobasilar trunk dissecting aneurysms (VBTDAs). This study sought to compare the clinical and angiographic outcomes of patients with intracranial VBTDAs following low-profile visualized intraluminal support (LVIS)-within-Enterprise overlapping-stent technique with those of flow diversion (FD). Methods: This was a retrospective, observational, cohort study. Between January 2014 and March 2022, 9,147 patients with intracranial aneurysms were screened, and 91 patients with 95 VBTDAs who underwent LVIS-within-Enterprise overlapping-stent assisted-coiling technique or FD were included in the analysis. The primary outcome was the complete occlusion rate at the last angiographic follow-up. The secondary outcomes included adequate aneurysm occlusion, in-stent stenosis/thrombosis, general neurological complications, neurological complications within 30 days after the procedure, the mortality rate, and unfavorable outcomes. Results: Among the 91 included patients, 55 were treated with LVIS-within-Enterprise overlapping-stent technique (the LE group) and 36 were treated with FD (the FD group). The angiography results at the median follow-up time of 8 months showed complete occlusion rates of 90.0% and 60.9% for the LE and FD groups, respectively, with an adjusted odds ratio of 5.79 (95% CI: 1.35-24.85; P=0.01). Adequate aneurysm occlusion (P=0.98), in-stent stenosis/thrombosis (P=0.46), general neurological complications (P=0.22), neurological complications within 30 days after the procedure (P=0.63), mortality rate (P=0.31), and unfavorable outcomes (P=0.07) at the last clinical follow-up did not differ significantly between the 2 groups. Conclusions: A significantly higher complete occlusion rate for VBTDAs was found following LVIS-within-Enterprise overlapping-stent technique as compared with FD. The 2 treatment modalities have comparable adequate occlusion rates and safety profiles.

Safety and efficacy of the Low-Profile Visualized Intraluminal Support stent in treating intracranial atherosclerotic stenosis.

PURPOSE: The performance of the Low-Profile Visualized Intraluminal Support (LVIS) stent deployed following balloon angioplasty is unknown in treating intracranial atherosclerotic stenosis, and this study was to investigate the safety and efficacy of the LVIS stent in treating intracranial atherosclerotic stenosis in the middle cerebral artery M1 segment. METHODS: Thirty-five patients were enrolled with 35 atherosclerotic stenoses at the M1 segment. The stenosis was about 75% in 16 patients, 80% in 15, and 90% in the rest four. The LVIS stent was used to treat these patients. RESULTS: The success rate of stenting was 97.1%. The stenting procedure was failed in one patient because of intraprocedural dissection of the stenotic (75%) segment, resulting in a 30-day periprocedural complication rate of 2.9% (1/35). Before stenting, the stenosis rate ranged 75%-90% (mean 78.9%±4.7%), and after stenting, the diameter of the stented segment was significantly (P<0.0001) increased to 1.5-3.4mm (mean 2.1±0.32mm) ranging 68.2%-100% (mean 94.0%±5.8%) of the normal arterial diameter, with the residual stenosis ranging 0-31.8% (median 4.8%, IQR 2.4%-7.3%). Follow-up was performed at 6-20 months (mean 8.5) after stenting. One patient (2.9%) had occlusion of the stented M1 segment with no symptoms, and two patients (5.7%) had slight asymptomatic instent stenosis (40%) at the M1 segment, with the instent restenosis and occlusion rate of 8.6% (3/35). CONCLUSION: The braided LVIS stent can be safely applied for treatment of intracranial atherosclerotic stenosis in the middle cerebral artery with good safety and efficacy immediately after stenting and at follow-up.