Flow diversion treatment of complex bifurcation aneurysms beyond the circle of Willis: complications, aneurysm sac occlusion, reabsorption, recurrence, and jailed branch modification at follow-up

Pipeline versus non-pipeline flow diverter treatment for M1 aneurysms: A systematic review and meta-analysis

BACKGROUND

The flow diversion treatment of aneurysms located distal to the Circle of Willis has recently increased in frequency. We conducted a systematic review and meta-analysis of the clinical and radiological outcomes of flow diverter (FD) embolization in treating M1 aneurysms.

METHODS

PubMed, Web of Science, Ovid Medline, Ovid Embase, and Scopus were searched up to May 2024 using the Nested Knowledge platform. We included studies assessing the long-term clinical and radiological outcomes for M1 aneurysms. Results of FDs classified as Pipeline Embolization Devices (PED) versus other types of FDs. Angiographic occlusion rates, ischemic and hemorrhagic complications, and favorable clinic outcomes were included. All data were analyzed using R software version 4.2.2.

RESULTS

Thirteen studies with 112 total patients (58 patients for PED and 54 patients for other FD devices) were included in our meta-analysis. The overall adequate (complete + near-complete) occlusion rates were 85.1%. The complete occlusion rate was higher with PED than with other FD devices (72.9% PED and 41.6% for non-PED FDs, respectively, p-value <.01). The ischemic complications were 9.9% and 9.0% for the PED and non-PED groups, respectively (p-value = .89). The overall modified Rankin Scale 0-2 was 100% for the non-PED and 97.1% for the PED group (p-value = .51). In-stent stenosis rate was 7.5% for PED devices compared to 2.6% in the non-PED group (p-value = .35).

CONCLUSIONS

This relatively small meta-analysis showed high rates of adequate and complete occlusion in FD treatment of M1 segment aneurysms, with favorable safety profiles. PEDs were associated with higher rates of complete aneurysm occlusion compared to other types of FDs.

Appraisal of the Flow Diversion Effect Provided by Braided Intracranial Stents

Objective: Comparison of the results of stent-assisted coiling (SAC) with braided stents (BS), flow diverters (FD), and laser-cut stents (LCS) to determine the relative flow-diverting capacity of BS (Leo baby and Accero). Methods: Saccular intracranial aneurysms treated by SAC and FD-assisted coiling were retrospectively evaluated. Aneurysm occlusion, as graded per Raymond-Roy score, was categorized as either recanalization/stable residual filling (Group A; lacking a flow diversion effect) or stable/progressive occlusion (Group B with a "flow diversion effect"). Factors predicting the flow diversion effect were evaluated. Results: Of the 194 aneurysms included, LCS, BS, and FD were used in 70 (36.1%), 86 (44.3%), and 38 (19.6%) aneurysms, respectively. Aneurysms treated by FD were larger, had wider necks, and were located on larger parent arteries (p < 0.01, 0.02, and <0.01, respectively). The mean imaging follow-up duration was 24.5 months. There were 29 (14.9%) aneurysms in Group A and 165 (85.1%) in Group B. Among a spectrum of variables, including sex, age, aneurysm size, neck width, parent artery diameter, follow-up duration, and stent type, the positive predictors for stable/progressive aneurysm occlusion were aneurysm size and placement of an FD or BS (p < 0.01 and p < 0.01, respectively, and were positive predictors over LCS: ORs 6.34 (95% CI: 1.62-24.76) and 3.11 (95% CI: 1.20-8.07), respectively) in multivariate analysis. Conclusions: The placement of BS was a predictor of flow diversion over laser-cut stents. However, the flow diversion effect was approximately half that of FDs, suggesting that BS may only be considered to have some (partial) flow diversion effects.

Safety and anatomical outcome analysis after flow diverter coverage of the anterior cerebral artery

OBJECTIVES

Few studies on ischemic complications and flow changes after a flow diverter covering the anterior cerebral artery. The purpose of the study was to explore the ischemic complications and anatomical alterations associated with the flow diverter after it covers the anterior cerebral artery.

MATERIALS AND METHODS

In this single-center study, patients treated with FD covering the anterior cerebral artery at the First Affiliated Hospital of Zhengzhou University were retrospectively collected. The primary endpoint was ischemic complications related to the anterior cerebral artery. Secondary endpoints were anatomical changes in the anterior cerebral artery postoperatively and at follow-up.

RESULTS

A total of 59 patients were included in this study. Four (6.8%) patients presented with ischemic stroke symptoms. Immediately after the procedure, complete occlusion of A1 and decreased blood flow was observed in 13 (22.0%) and 21 patients (35.6%), respectively. At follow-up, A1 artery was occluded in 34 patients (57.6%) and decreased blood flow was observed in 10 patients (16.9%). Symptoms of neurological deficits related to the anterior cerebral artery were not observed in all patients at follow-up.

CONCLUSION

Coverage of A1 is safe, with a low incidence of ischemic stroke, when using an FD to treat aneurysms. Risk of reduced perfusion of the anterior cerebral artery postoperatively even if the anterior communicating artery is open. In cases with A1 occlusion, the blood flow in the distal the anterior cerebral artery can be adequately compensated by opening the anterior communicating artery and good vascular anastomoses.

Endovascular treatment of direct carotid cavernous fistula resulting from rupture of intracavernous carotid aneurysm: A case report

BACKGROUND

Direct carotid cavernous fistulas (CCFs) are typically the result of a severe traumatic brain injury. High-flow arteriovenous shunts secondary to rupture of an intracavernous aneurysm, resulting in direct CCFs, are rare. The use of a pipeline embolization device in conjunction with coils and Onyx glue for treatment of direct high-flow CCF resulting from ruptured cavernous carotid artery aneurysm in a clinical setting is not well documented.

CASE SUMMARY

A 58-year-old woman presented to our department with symptoms of blepharoptosis and intracranial bruits for 1 wk. During physical examination, there was right eye exophthalmos and ocular motor palsy. The rest of the neurological examination was clear. Notably, the patient had no history of head injury. The patient was treated with a pipeline embolization device in the ipsilateral internal carotid artery across the fistula. Coils and Onyx were placed through the femoral venous route, followed by placement of the pipeline embolization device with assistance from a balloon-coiling technique. No intraoperative or perioperative complications occurred. Preoperative symptoms of bulbar hyperemia and bruits subsided immediately after the operation.

CONCLUSION

Pipeline embolization device in conjunction with coiling and Onyx may be a safe and effective approach for direct CCFs.

Pipeline embolization of complex, wide-necked middle cerebral artery bifurcation aneurysms: A single-center experience

PURPOSE

To evaluate the performance of Pipeline Embolization Device (PED) in complex, wide-necked middle cerebral artery (MCA) bifurcation aneurysms.

METHODS

We performed a retrospective review of patients treated with PED for complex, wide-necked MCA bifurcation aneurysms between August 2016 and March 2021. In addition to demographic data, we collected aneurysmal neck width, dome-to-neck ratio, complications, and clinical and angiographic follow-up. The embolization degree of aneurysms was evaluated by O'Kelly-Marotta (OKM) grading scale, and the prognosis was assessed with the modified Rankin Scale (mRS).

RESULTS

From August 2016 to March 2021, a total of 46 patients with 49 MCA bifurcation aneurysms in our center were enrolled, of whom all received PEDs successfully. The O'Kelly-Marotta (OKM) grading showed that post-procedure 15 patients (32.6%) were grade C, another 8 patients (17.4%) were grade D. Aneurysms with small remnant or complete occlusion were 50%, symptomatic ischemic events occurred in 3 (6.5%), and bleeding events in 1 (2.2%). 41 patients underwent a 6-month angiography follow-up, in which 7 patients (17.1%) remained OKM grade C and 30 patients (73.2%) achieved OKM grade D. Complete occlusion and small remnant aneurysms were up to 90.3%. 40 (97.6%) patients' mRS scores were 0, and 1 (2.4%) patient was 2. No new bleeding and ischemic events occurred during the 6-month.

CONCLUSIONS

The Pipeline Embolization Device provides a safe and effective treatment alternative for complex, wide-necked MCA aneurysms. A larger number with longer-term follow-up data is needed for further verification.

In vitro flow diversion effect of the ReSolv stent with the shelf technique in a bifurcation aneurysm model

BACKGROUND

Flow-diverting stents are not currently indicated for the treatment of bifurcation aneurysms, and some case series have demonstrated low occlusion rates, possibly due to a lack in neck coverage. The ReSolv stent is a unique hybrid metal/polymer stent that can be deployed with the shelf technique in order to improve neck coverage.

METHODS

A Pipeline, unshelfed ReSolv, and shelfed ReSolv stent were deployed in the left-sided branch of an idealized bifurcation aneurysm model. After determining stent porosity, high-speed digital subtraction angiography runs were acquired under pulsatile flow conditions. Time-density curves were created using two region of interest (ROI) paradigms (total aneurysm and left/right), and four parameters were extracted to characterize flow diversion performance.

RESULTS

The shelfed ReSolv stent demonstrated better aneurysm outflow alterations compared to the Pipeline and unshelfed ReSolv stent when using the total aneurysm as the ROI. On the left side of the aneurysm, there was no significant difference between the shelfed ReSolv stent and the Pipeline. On the right side of the aneurysm, however, the shelfed ReSolv stent had a significantly better contrast washout profile than the unshelfed ReSolv stent and the Pipeline stent.

CONCLUSIONS

The ReSolv stent with the shelf technique demonstrates the potential to improve flow diversion outcomes for bifurcation aneurysms. Further in vivo testing will help to determine whether the additional neck coverage leads to better neointimal scaffolding and long-term aneurysm occlusion.

Safety and efficacy of the flow diverter device for treating middle cerebral artery aneurysms of the proximal (M1) segment related to the lenticulostriate arteries: A single-center experience

BACKGROUND

Experience using flow diverter devices (FDDs) to treat proximal (M1) middle cerebral artery aneurysms associated with the lenticulostriate artery (M1A-LA) remains limited. This study aimed to examine the efficacy and safety of an FDD to manage M1A-LA.

METHOD

Patients with M1A-LA who received FDD treatment at a single center were included in the analysis. Data on the baseline characteristics, postoperative conditions, and follow-up results of the participants were recorded and analyzed. The aneurysms were categorized into three subtypes based on morphology and location. Aneurysms confined to the M1 segment were categorized as subtype A. Those extending to the M2 segment were classified as subtype B. Aneurysms designated as subtype C were confined to the M1 segment but with another independent aneurysm in the distal artery and the presence of healthy vessels between the two. Subgroup analyses were conducted on these subtypes and aneurysm sizes. To assess the consistency of follow-up results, Cronbach's kappa/alpha was used to calculate inter-rater variability. Somers's D coefficient was used to assess the correlation between each subgroup and the imaging outcomes; Fisher's exact test was used to compare the variability among the subgroups.

RESULT

The cohort comprised 11 patients. Their Modified Rankin Scale scores between the perioperative and follow-up periods did not differ. During the follow-up period, four patients had completely occluded aneurysms, and five patients had partial occlusions. The remaining patients did not present with changes in their aneurysms. The kappa coefficient was 0.864 (p < 0.001). M1A-LA was divided into subtypes A, B, and C. Subtype A (defined as an aneurysm completely located in the M1 segment) had a higher complete occlusion rate than that of subtypes B and C, Somers's D R/C correlation coefficient was 0.553, with a 95% confidence interval of 0.1229-0.9823 (p = 0.009). The radiographic follow-up findings were not significantly correlated with the size of the aneurysm (p = 0.121) or the use of coiling (p = 0.903). No significant differences in subtypes (p = 0.264), aneurysm size (p = 0.657), or coiling use (p > 0.999) were observed.

CONCLUSION

FDDs were safe and possibly effective against M1A-LA. However, they were not as effective as for intracranial aneurysms in other locations. FDDs are a satisfactory treatment option for M1A-LA, particularly for subtype A aneurysms.

Flow-diverter stents in intracranial aneurysm treatment: impact on covered cerebral artery branches

OBJECTIVE

Flow diverter stents (FDSs) have attracted interest for intracranial aneurysm (IA) treatment; however, occlusion of side branches and related complications have been reported. This study aimed to investigate the effects of FDSs in IA management when different branches of intracranial arteries are covered.

MATERIALS AND METHODS

A cross-sectional study was conducted using PUBMED, Embase, Web of Science, and Cochrane databases to include randomized or nonrandomized comparative-designed studies from January 2000 to August 2022 which reported outcomes of occlusion/narrowing of branches after IA treatment using FDSs. The PRISMA guidelines were used for our report. A random-effects meta-analysis was conducted to pool the outcomes, which included incidence rates of occlusion/narrowing of FDS-covered branches, branch occlusion-related symptoms, obliteration of IAs, and ideal clinical outcomes (modified Rankin Scale score ≤2).

RESULTS

The authors identified 57 studies involving 3789 patients with IA managed by FDSs covering different branches. During the median imaging follow-up at 12 months, the IA obliteration rate was satisfactory (>70%) when covering the ophthalmic artery (OA), posterior communicating artery (PComA), anterior choroidal artery (AChoA) or anterior cerebral artery (ACA), but not the middle cerebral artery-M2 segment (MCA-M2; 69.5%; 95% CI: 60.8-77.5%) and posterior inferior cerebellar artery (PICA; 59.1%, 13/22). The overall ideal clinical outcome was observed in 97.4% of patients (95% CI: 95.5-98.9%). Higher rates of occlusion/narrowing of branches were identified when FDSs covered the ACA (66.6%; 95% CI: 45.1-85.3%), PComA (44.3%; 95% CI: 34.2-54.6%), or MCA-M2 (39.2%; 95% CI: 24.5-54.7%); the risks were lower when covering the OA (11.8%; 95% CI: 8.8-15.1%), PICA (6.8%; 95% CI: 1.5-14.5%), and AchoA (0.5%; 95% CI: 0.0-2.9%). The risk of branch occlusion-related complications was low (incidence rate <5%) for each of the six evaluated branches.

CONCLUSIONS

Acceptable outcomes were identified following treatment of IAs when FDSs were placed across each of the six studied cerebral arteries. Treatment decisions regarding FDS placement across branch arteries should be made with the risk of complications from branch occlusion in mind.

Safety and Efficacy of Flow Diverters for Treatment of Unruptured Anterior Communicating Artery Aneurysms: Retrospective Multicenter Study

BACKGROUND

The anterior communicating artery (AComm) region is the most common site of intracranial aneurysms, with increased rupture risk compared with other locations. Overall, flow diverters present as a safe and efficacious treatment for intracranial aneurysms, but there is paucity of data for their use in the treatment of unruptured AComm aneurysms. We present the largest multicentric analysis evaluating the outcomes of flow diverters in AComm aneurysm treatment.

METHODS

Databases from 10 centers were retrospectively reviewed for unruptured AComm aneurysms treated with flow diverters. Demographics, clinical presentation, radiographic characteristics, procedural complications, and outcomes were assessed.

RESULTS

A total of 144 patients harboring 147 AComm aneurysms were treated between January 2012 and December 2021. Seventy-four were women (51.4%) and median age was 60 (IQR 50-67) years. All were unruptured AComm aneurysms. Half of the cohort had similar anterior cerebral artery sizes (51.4%). The most common morphology was saccular (94.6%), with a branch involvement in 32.7% of cases. Median vessel diameter was 2.4 mm, and the Pipeline Flex was the most prevalent device (32.7%). Median follow-up time was 17 months, with complete occlusion in 86.4% at the last follow-up. Functional independence (modified Rankin Scale score 0-2) was reported in 95.1%. Intraprocedural complications occurred in 5.6%, and postoperative complications were noted in 9.7% of cases. Combined major complication and mortality rate was 2.1%.

CONCLUSIONS

Our study suggests that flow diverters are a useful treatment for AComm aneurysms. Mid-term results indicated favorable aneurysm occlusion with a good safety profile. Additional prospective studies with longer follow-up periods and independent adjudication are warranted to better assess these results.

Flow diversion for the treatment of intracranial bifurcation aneurysms: a systematic review and meta-analysis

BACKGROUND

Flow diversion (FD: flow diversion, flow diverter) is an endovascular treatment for many intracranial aneurysm types; however, limited reports have explored the use of FDs in bifurcation aneurysm management. We analyzed the safety and efficacy of FD for the management of intracranial bifurcation aneurysms.

METHODS

A systematic review identified original research articles that used FD for treating intracranial bifurcation aneurysms. Articles with >4 patients that reported outcomes on the use of FDs for the management of bifurcation aneurysms along the anterior communicating artery (AComA), internal carotid artery terminus (ICAt), basilar apex (BA), or middle cerebral artery bifurcation (MCAb) were included. Meta-analysis was performed using a random effects model.

RESULTS

19 studies were included with 522 patients harboring 534 bifurcation aneurysms (mean size 9 mm, 78% unruptured). Complete aneurysmal occlusion rate was 68% (95% CI 58.7% to 76.1%, I2=67%) at mean angiographic follow-up of 16 months. Subgroup analysis of FD as a standalone treatment estimated a complete occlusion rate of 69% (95% CI 50% to 83%, I2=38%). The total complication rate was 22% (95% CI 16.7% to 28.6%, I2=51%), largely due to an ischemic complication rate of 16% (95% CI 10.8% to 21.9%, I2=55%). The etiologies of ischemic complications were largely due to jailed artery hypoperfusion (47%) and in-stent thrombosis (38%). 7% of patients suffered permanent symptomatic complications (95% CI 4.5% to 9.8%, I2=6%).

CONCLUSION

FD treatment of bifurcation aneurysms has a modest efficacy and relatively unfavorable safety profile. Proceduralists may consider reserving FD as a treatment option if no other surgical or endovascular therapy is deemed feasible.

Two year follow-up of distal unruptured intracranial aneurysms treated with a surface modified flow diverter under prasugrel monotherapy

BACKGROUND

A new generation of modified surface flow diverters (FDs) and monotherapy using new antiplatelets may reduce both ischemic and hemorrhagic complications during the treatment of intracranial aneurysms. Previous preliminary safety analysis of distal unruptured intracranial aneurysms treated with the FD p48 MW HPC (phenox-Wallaby, Bochum, Germany) under antiplatelet monotherapy with prasugrel showed promising results. However, the long term outcomes of distal intracranial aneurysms treated with FDs under antiplatelet monotherapy are not known.

METHODS

This was a single center, prospective, pivotal, open single arm study. The primary (safety) endpoint was absence of any new neurological deficits after treatment until the 24 month follow-up. The primary (efficacy) endpoint was the incidence of complete aneurysm occlusion 24 months after treatment. The secondary (efficacy) endpoints were any incidence of aneurysm dome reduction 24 months after treatment.

RESULTS

21 patients harboring 27 distal aneurysms of the anterior circulation were included. No patient had neurologic deficits in the time from treatment to the 24 month follow-up. Complete aneurysm occlusion occurred in 20 (74%) of 27 aneurysms at the 24 month follow-up. Four aneurysms (14.8%) had dome reduction, and three aneurysms (11.1%) remained unchanged.

CONCLUSIONS

In this pilot trial, treatment of distal unruptured intracranial aneurysms with an FD under monotherapy with prasugrel, followed by monotherapy with aspirin, appeared to be safe and effective. Randomized studies with long term follow-up are needed to confirm these results.

Comparison of Solitaire and Neuroform Stenting for Coiling of Intracranial Bifurcation Aneurysms

PURPOSE

To compare the technical performance and outcomes of Solitaire and Neuroform stents for treatment of intracranial bifurcation aneurysms (IBAs).

METHODS

IBAs treated by stent-assisted coiling using a Solitaire or Neuroform stent between October 2010 and December 2019 were retrospectively evaluated. Patient demographics, aneurysm information, treatment technique, periprocedural and device-related complications, parent artery angle change, along with initial and follow-up angiographic results were analyzed.

RESULTS

One hundred twenty-one patients with 121 IBAs treated with Solitaire (n = 101) or Neuroform (n = 20) stent-assisted coiling were included. Aneurysm size, thrombotic and hemorrhagic complication rate, initial occlusion rate and in-stent stenosis between the two cohorts were not significantly different. Aneurysm location was significantly different between the two groups (p = 0.032). Jailing technique rate for coiling was significantly higher in the Solitaire than the Neuroform group (70.3% vs. 35.0%, p < 0.01). Follow-up DSA demonstrated a significantly lower recurrence rate for the Solitaire cohort (2.9% vs. 22.2%, p = 0.016). Parent artery angle changes, immediately post-operative and on follow-up were significantly greater in the Solitaire stent group (p < 0.05).

CONCLUSIONS

For intracranial bifurcation aneurysms, Solitaire stent-assisted coiling achieved a significantly lower recurrence rate and induced more favorable parent artery angular remodeling than Neuroform stenting.

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.

Intrasaccular flow disruption for brain aneurysms: a systematic review of long-term outcomes

OBJECTIVE

The long-term safety and efficacy of intrasaccular flow disruption (IFD) for the treatment of brain aneurysms remain unclear. With accumulating experience and increasing use of IFD devices, recent studies have provided additional data regarding their outcomes. This review summarizes the long-term outcomes of IFD-treated brain aneurysms.

METHODS

A systematic literature review was performed on May 23, 2021, in PubMed, Web of Science, and Ovid MEDLINE for aneurysm treatment outcomes with IFD devices. Procedural details, including use of adjunctive devices and complications, were collected. The quality of studies was assessed using the Downs and Black checklist. Angiographic outcomes were classified as complete occlusion, residual neck, and residual aneurysm. Other outcomes included need for retreatment, permanent neurological deficit, and mortality. Pooled analyses were performed.

RESULTS

The final analysis comprised 1217 patients with 1249 aneurysms from 22 studies. The mean aneurysm diameter and neck width were 6.9 and 4.5 mm, respectively, and 27.6% of aneurysms were ruptured. The complete occlusion rates at 12 months and final follow-up (pooled mean duration 15.7 months) were 50.1% and 58.2%, respectively. Adjunctive devices were used in 6.4% of cases. The rates of hemorrhage, symptomatic infarction, permanent neurological deficit, and mortality were 1.2%, 2.8%, 1.0%, and 2.6%, respectively.

CONCLUSIONS

IFD is a very safe treatment for appropriately selected brain aneurysms with low complication and neurological deterioration rates. However, complete occlusion is achieved in only half of IFD-treated aneurysms at 1 year with a modest increase beyond this time point. As the majority of the studies were single arm, the pooled data are subject to selection and reporting biases. Future device developments, increased operator experience, and direct comparisons with alternative endovascular strategies and surgical clipping may clarify the role of IFD in aneurysm management.

Intrasaccular neck-bridging: A technical note on Nautilus-assisted coiling of wide-necked cerebral aneurysms. Feasibility study, immediate and early angiographic results

PURPOSE

Various adjunctive devices have been reported to be helpful during the endovascular coiling of complex, wide-necked cerebral aneurysms. This study aimed to describe the utilization of a recently introduced intrasaccular neck-bridging implant specifically designed to facilitate coil embolization.

METHODS

We retrospectively reviewed eight consecutive patients who underwent treatment for intracranial aneurysms with the Nautilus intrasaccular bridging system between February 2022 to May 2022. We evaluated the angiographic appearances of treated aneurysms at the end of the procedure and early follow-up, the clinical status and complications.

RESULTS

Eight patients with eight cerebral aneurysms (3 men and 5 women, mean age 52.8 years (range 39-66) were analyzed. Five of the treated aneurysms were managed in an acute case scenario. There were no technical difficulties while executing the technique. No other procedural adverse events were documented. Immediate complete occlusion of the aneurysm was seen in 6 patients, neck remnant in 1 and stable aneurysm reperfusion in one case. Early radiological follow-up was available in five patients, and the observed occlusion rates were - RR class I in all radiologically screened aneurysms.

CONCLUSION

Nautilus-assisted coil embolization represents a rapid and safe solution for complex cerebral aneurysms. In our opinion this device symbolizes a significant step forward in treating intracranial aneurysms. We believe that the technique's actual value consists of the fact that the device is fully compatible with the modern low-profile microcatheter technology and does not involve the need for antiplatelet medications.

Hemodynamic Effects of Stent-Induced Straightening of Parent Artery vs. Stent Struts for Intracranial Bifurcation Aneurysms

Objective

This study aims to compare the hemodynamic impact of stent-mesh and stent-induced straightening of the parent artery in intracranial bifurcation aneurysms using finite element method simulation.

Material and Methods

Three intracranial bifurcation aneurysms treated with different stent-assisted coil embolization were evaluated. Simulation using the finite element method was conducted for Solitaire, LVIS and Neuroform stents. Four models of each stent were established, including a pre-treatment baseline, stenting without parent artery straightening (presented as stent-mesh effect), no-stent with parent artery reconstruction (to reveal the straightening impact), and stenting with straightening (categorized as Models I–IV respectively). Hemodynamic characteristics of the four models for each stent were compared.

Results

In the Neuroform stent, compared with the pre-treatment model (100%), the mean WSS decreased to 82.3, 71.4, and 57.0% in Models II-IV, velocity to 88.3, 74.4, and 62.8%, and high flow volume (HFV, >0.3 m/s) to 77.7, 44.0, and 19.1%. For the LVIS stent, the mean WSS changed to 105.0, 40.2, and 39.8% in Models II to IV; velocity to 91.2, 58.1, and 52.5%, and HFV to 92.0, 56.1, and 43.9%. For the Solitaire stent, compared with the pre-treatment model (100%), the mean WSS of Models II-IV changed altered by 105.7, 42.6, and 39.4%, sac-averaged velocity changed to 111.3, 46.6, and 42.8%, and HFV 115.6, 15.1, and 13.6%.

Conclusion

The hemodynamic effect of straightening the parent artery of intracranial bifurcation aneurysms by stenting was noticeably improved over stent mesh diversion in all three stents tested. Therefore stent-induced remodeling of the parent artery appears to be the best method of decreasing recurrence in intracranial bifurcation aneurysms.

Safety and Long-Term Efficacy Outcomes for Endovascular Treatment of Wide-Neck Bifurcation Aneurysms of the Middle Cerebral Artery: Insights From the SMART Registry

Introduction

Wide-necked middle cerebral artery bifurcation aneurysms pose specific challenges to endovascular management. Surgical clipping remains the standard treatment approach for these aneurysms in many centers. While recent data suggests the endovascular treatment may be comparable, a prospective datapoint has been lacking.

Materials and Methods

The Penumbra SMART registry, a prospective, multi-center, single-arm outcomes registry of Penumbra coil-treated aneurysms, was queried for endovascularly treated MCA bifurcation aneurysms with wide necks (dome:neck ratio <2 or neck >4 mm). Safety and efficacy outcomes were summarized for ruptured and unruptured aneurysms, including rupture, complication rate, and 1-year occlusion outcomes.

Results

Seventy-two aneurysms across 31 sites were enrolled. Of these, a total of 15 presented as ruptured aneurysms. Serious adverse events were reported in 21 (29.2%) of patients, with 8 (11.1%) attributed to the device/procedure. Immediately postoperatively, 75.0% of cases achieved “adequate” Raymond Roy Class I (40.3%) or II (34.7%) occlusion outcomes. Of the 72 patients treated, 60 (83.3%) underwent follow-up angiography at 1 year, and among these, 95.0% had 1-year occlusion outcomes of Raymond Roy Class I (71.7%) or II (23.3%). A total of 6 aneurysms (10.0%) were required or were planned for retreatment at the last follow-up.

Conclusion

This study represents the most significant prospective sample of endovascularly treated wide-neck MCA bifurcation aneurysms conducted to date. It supports the safety and efficacy of endovascular treatment of these aneurysms.

Staged Hybrid Techniques With Straightforward Bypass Surgery Followed by Flow Diverter Deployment for Complex Recurrent Middle Cerebral Artery Aneurysms

Background

Recurrent complex middle cerebral artery (MCA) aneurysms after combined clipping and endovascular surgery are challenging, and if conventional techniques are adapted, advanced surgical, endovascular, and a combination of both techniques are often required. For such complex aneurysms, safe and effective straightforward techniques for all neurovascular surgeons are warranted. We describe the details of staged hybrid techniques with straightforward bypass surgery followed by flow diverter deployment in a patient with complex MCA aneurysm.

Illustrative Case

A 69-year-old woman presented with left recurrent large MCA aneurysm enlargement 25 years after direct surgery and coil embolization for ruptured aneurysm. The recurrent MCA aneurysm had large and complex morphology and was adhering to the brain tissues. Therefore, it was unsuitable to treat such aneurysm with conventional surgical and endovascular techniques with a high risk of morbidity. We performed (1) M2 ligation following superficial temporal artery-M2 bypass and (2) flow diverter deployment assisted with coil packing in two sessions. Three months after the second session, the aneurysm was completely occluded with endothelialization of the neck. Angiographic findings revealed no recurrence 12 months after the treatment.

Conclusions

Staged hybrid techniques with straightforward bypass surgery followed by flow diverter deployment may be a safe and effective treatment for complex recurrent MCA aneurysms.

Pipeline embolization of proximal middle cerebral artery aneurysms: A multicenter cohort study

BACKGROUND AND PURPOSE

Flow diversion of aneurysms located in the M1 segment and middle cerebral artery bifurcation with Pipeline embolization device is sometimes performed, but further study is needed to support its regular use in aneurysm treatment. Here, we report measures of safety and efficacy for Pipeline embolization in the proximal middle cerebral artery in a multi-center cohort.

MATERIALS AND METHODS

Clinical and angiographic data of eligible patients were retrospectively obtained from participating centers and assessed for key clinical and angiographic outcomes. Additional details were extracted for patients with complications.

RESULTS

In our multi-center cohort, complete aneurysm occlusion was achieved in 71% (17/24) of treated aneurysms. There were no deaths or disabling strokes, but non-disabling ischemic strokes occurred in 8% (2/24) of patients. For aneurysms in the M1 segment, complete aneurysm occlusion was observed in 75% (12/16) of aneurysms, aneurysm volume reduction was observed in 100% (16/16) of aneurysms, and non-disabling ischemic strokes occurred in 13% (2/16) of patients. For aneurysms at the middle cerebral artery bifurcation, complete aneurysm occlusion was observed in 63% (5/8) of aneurysms, aneurysm volume reduction occurred in 88% (7/8) of aneurysms, and ischemic or hemorrhagic complications occurred in 0% (0/8) of patients.

CONCLUSION

Pipeline embolization of cerebral aneurysms in the M1 segment and middle cerebral artery bifurcation demonstrated a 71% rate of complete aneurysm occlusion. There were no deaths or disabling strokes, but there was an 8% rate of non-disabling ischemic strokes.

Unruptured Aneurysmal Shrinkage of the Distal Posterior Inferior Cerebellar Artery Following Stent Jailing of the Arterial Orifice: A Case Report

A 57-year-old woman who presented with a sudden severe headache and subsequently diagnosed with a subarachnoid hemorrhage was referred to our hospital. CTA revealed a large irregularly shaped dissecting aneurysm of the right vertebral artery (VA) and a small round distal aneurysm of the right posterior inferior cerebellar artery (PICA), which originated just proximal to the VA aneurysm. We diagnosed the VA aneurysm as a ruptured aneurysm and performed endovascular treatment the day the patient was hospitalized. Because the left VA was aplastic, stent-assisted coiling was performed to preserve the blood flow of the right VA, following the administration of antiplatelets and heparin. The proximal part of the laser-cut closed-cell stent jailed the orifice of the right PICA. The postoperative course was uneventful, and she was discharged from the hospital 3 weeks later without any neurological deficits. The follow-up VA angiogram revealed complete disappearance of the distal PICA aneurysm 17 months after stent jailing. Flow reduction by stent jailing of the arterial orifice is considered to be the main mechanism of aneurysmal shrinkage. Jailing of the orifice of the cerebral artery using even a low-metal-coverage stent may cause arterial flow reduction, which may shrink a distal aneurysm.

Indirect Flow Diversion for Off-Centered Bifurcation Aneurysms and Distant Small-Vessel Aneurysms, a Retrospective Proof of Concept Study From Five Neurovascular Centers

Background: Treatment of cerebral aneurysms using hemodynamic implants such as endosaccular flow disruptors and endoluminal flow diverters has gained significant momentum during recent years. The intended target zone of those devices is the immediate interface between aneurysm and parent vessel. The therapeutic success is based on the reduction of aneurysmal perfusion and the subsequent formation of a neointima along the surface of the implant. However, a subset of aneurysms-off-centered bifurcation aneurysms involving the origin of efferent branches and aneurysms arising from peripheral segments of small cerebral vessels-oftentimes cannot be treated via coiling or implanting a hemodynamic implant at the neck level for technical reasons. In those cases, indirect flow diversion-a flow diverter deployed in the main artery proximal to the parent vessel of the aneurysm-can be a viable treatment strategy, but clinical evidence is lacking in this regard. Materials and Methods: Five neurovascular centers contributed to this retrospective analysis of patients who were treated with indirect flow diversion. Clinical data, aneurysm characteristics, anti-platelet medication, and follow-up results, including procedural and post-procedural complications, were recorded. Results: Seventeen patients (mean age: 60.5 years, range: 35-77 years) with 17 target aneurysms (vertebrobasilar: n = 9) were treated with indirect flow diversion. The average distance between the flow-diverting stent and the aneurysm was 1.65 mm (range: 0.4-2.4 mm). In 15/17 patients (88.2%), perfusion of the aneurysm was reduced immediately after implantation. Follow-ups were available for 12 cases. Delayed opacification (OKM A3: 11.8%), reduction in size (OKM B1-3: 29.4%) and occlusion (D1: 47.1%) were observable at the latest investigation. Clinically relevant procedural complications and adverse events in the early phase and in the late subacute phase were not observed in any case. Conclusion: Our preliminary data suggest that indirect flow diversion is a safe, feasible, and effective approach to off-centered bifurcation aneurysms and distant small-vessel aneurysms. However, validation with larger studies, including long-term outcomes and optimized imaging, is warranted.

Flow diversion for aneurysms beyond the circle of Willis: A preliminary experience

OBJECTIVE

To evaluate the safety and efficacy of flow diversion (FDs) for the aneurysms beyond the circle of Willis.

METHODS AND MATERIALS

We retrospectively reviewed the prospectively maintained database in our center and enrolled patients with aneurysms beyond the circle of Willis (defined as at or distal to the M1, A2, and P2 segments) that were treated with FDs.

RESULTS

Between July 2017 to December 2020, 28 patients with 28 aneurysms met the inclusion criteria and were included in this study, with a median age of 50 years old (IQR, 36-63 years). Thirty FDs, including 5 Pipelines and 25 Tubridge FDs, were deployed. Perioperative complications were noticed in 2 patients (7.1%), while asymptomatic adverse events occurred in another three patients (10.7%). Delayed complications occurred in 3.6% of patients (1/28). All patients received clinical follow-up, with the mortality and long-term morbidity of 0 and 3.6% (1/28), respectively. Angiographic follow-up data were available for 26 patients (92.9%) with an interval of 10 ± 7 months (ranged 2-26 months). Sixteen patients (61.5%) showed complete or nearly complete occlusion of aneurysms (OKM grading scale D and C); 6 cases (23.1%) were revealed incomplete occlusion (OKM grading scale B), and 4 cases (15.4%) remained unchanged (OKM grading scale A). The existence of the perforators derived from aneurysms was associated with a lower occlusion rate (p = 0.032).

CONCLUSION

Flow diversion is reliable in the treatment of distal aneurysms with a high technical success rate and low permanent disability rate. The presence of side branches derived from aneurysms was associated with a lower aneurysm occlusion rate.

Microsurgical Clipping of Intracranial Aneurysms in the Endovascular Era

The treatment of intracranial aneurysms (IA) began in the late 19th century. Some degree of controversy has always surrounded the best treatment modality for IA. Cushing and Dandy debated about cervical carotid ligation as the only surgical alternative before the introduction of microsurgical clipping. In the early 21st century, the debate has centered on surgical versus^ endovascular techniques. With the advent of newer endovascular techniques and devices, there has been a dramatic shift in treatment paradigms toward endovascular intervention that is preferred by both physicians and patients. However, there will always be a need for microsurgical cerebrovascular expertise since some aneurysms cannot or should not be embolized. This creates a difficult conundrum as only the most complex of aneurysms will require open surgery, but the lack of volume and training will be a challenge in teaching and maintaining the surgical expertise required to safely treat them. The purpose of this review is to discuss the history of IA treatment and critically evaluate the current state of the art of IA treatment, with a specific focus on the necessary role microsurgical clipping continues to play in the current treatment landscape.

Endoluminal flow diverting stents for middle cerebral artery bifurcation aneurysms: multicenter cohort

BACKGROUND

Data regarding the safety and efficacy of flow diverting stents (FDS) in the treatment of middle cerebral artery (MCA) bifurcation aneurysms are scarce and limited to small single center series, with particular concern for increased risk of ischemic complications with jailing one of the M2 branches.

METHODS

Prospectively-maintained databases at six North American and European centers were queried for patients harboring MCA bifurcation aneurysms undergoing treatment with FDS (2011-2018). The pertinent clinical and radiographic data were collected and analyzed.

RESULTS

87 patients (median age 60 years, 69% females) harboring 87 aneurysms were included. The majority of aneurysms were unruptured (79%); 75.9% were saccular with a median maximal diameter of 8.5 mm. Radiographic imaging follow-up was available in 88.5% of cases at a median of 16.3 months post-treatment, showing complete occlusion in 59% and near complete occlusion (90-99%) in 18% of aneurysms. The overall rate of ischemic and hemorrhagic complications was 8% and 1.1%, respectively. Symptomatic and permanent complications were encountered in 5.7% and 2.3% of patients respectively, with retreatment pursued in 2.3% of patients. Jailed branch occlusion was detected in 11.5% of cases, with clinical sequelae in 2.3%. Last follow-up modified Rankin Scale of 0-2 was noted in 96.8% of patients. On multivariate analysis, male sex was the only independent predictor of aneurysmal persistence at last follow-up imaging (p=0.019).

CONCLUSION

FDS treatment for MCA bifurcation aneurysms is feasible, with comparable safety and efficacy profiles to other available endovascular options when utilized in carefully selected aneurysms. Jailing of M2 branches was not associated with a higher risk of post-procedural ischemic complications.

Endovascular Treatment of Intracranial Aneurysms in Small Peripheral Vessel Segments-Efficacy and Intermediate Follow-Up Results of Flow Diversion With the Silk Vista Baby Low-Profile Flow Diverter

Background and Purpose: Low-profile flow diverter stents (FDS) quite recently amended peripheral segments as targets for hemodynamic aneurysm treatment; however, reports on outcomes, especially later than 3 months, are scarce. This study therefore reports our experience with the novel silk vista baby (SVB) FDS and respective outcomes after 8 and 11 months with special respect to specific adverse events.

Materials and Methods: Forty-four patients (mean age, 53 years) harboring 47 aneurysms treated with the SVB between June 2018 and December 2019 were included in our study. Clinical, procedural, and angiographic data were collected. Follow-ups were performed on average after 3, 8, and 11 months, respectively. Treatment effect was assessed using the O'Kelly Marotta (OKM) grading system.

Results: Overall, angiographic follow-ups were available for 41 patients/45 aneurysms. Occlusion or significant reduction in aneurysmal perfusion (OKM: D1, B1–B3 and A2–A3) was observed in 98% of all aneurysms after 8 months. Only 2% of the treated aneurysms remained morphologically unaltered and without an apparent change in perfusion (OKM A1). Adverse events in the early post-interventional course occurred in seven patients; out of them, mRS-relevant morbidity at 90 days related to FDS treatment was observable in two patients. One death occurred in the context of severe SAH related to an acutely ruptured dissecting aneurysm of the vertebral artery.

Conclusion: The SVB achieves sufficient occlusion rates of intracranial aneurysms originating from peripheral segments, which are comparable to prior established conventional FDS with acceptably low complication rates. However, alteration of a hemodynamic equilibrium in distal localizations requires special attention to prevent ischemic events.

Treatment of distal unruptured intracranial aneurysms using a surface-modified flow diverter under prasugrel monotherapy: a pilot safety trial

BACKGROUND

Flow diverters (FDs) are effective in the treatment of carotid aneurysms. Compared with carotid aneurysms, the treatment of distal intracranial aneurysms with FDs has been associated with a relatively high incidence of complications. Low thrombogenic modified-surface FDs may reduce ischemic complications and allow for the use of a single antiplatelet medication. The aim of this study was to assess the safety and efficacy of the p48 MW HPC Flow Modulation Device (Phenox GmbH, Bochum, Germany) to treat distal intracranial aneurysms used in combination with prasugrel monotherapy.

METHODS

This was a single-center, prospective, pivotal, open, single-arm study. Patients were included in this study from December 2019 to September 2020. The primary endpoints were the incidence of any neurologic deficit after treatment until 1 month of follow-up, defined as National Institutes of Health Stroke Scale (NIHSS) ≥1, and the incidence of acute ischemic lesions in magnetic resonance imagin (MRI) images 48 hours after treatment. The secondary endpoint was the rate of complete occlusion of the aneurysms at the 1-month follow-up.

RESULTS

Twenty-one patients harboring 27 distal aneurysms of the anterior circulation were included. Mean age was 57.8 (SD 9.7) years, and 16 patients were female (80%). No patient had neurologic symptoms at the 1-month follow-up. Four patients (20%) had asymptomatic acute brain ischemic lesions on MRI. Complete aneurysm occlusion occurred in 9/27 (33.3%) aneurysms at the 1-month follow-up.

CONCLUSION

In this pilot safety trial, treatment of distal intracranial aneurysms with p48 MW HPC under monotherapy with prasugrel appeared to be safe.

Aspirin monotherapy in the treatment of distal intracranial aneurysms with a surface modified flow diverter: a pilot study

BACKGROUND

Flow diverters (FDs) result in high occlusion rates of aneurysms located distally to the carotid artery. However, the complications reported are not negligible. New modified surface FDs have low thrombogenic properties that may reduce ischemic complications related to the treatment. In addition, a modified surface FD may allow for the use of a single antiplatelet medication to reduce hemorrhagic risk during the procedure. The aim of this study was to assess the safety and efficacy of the p48 MW HPC (phenox, Bochum, Germany) to treat distal intracranial aneurysms under the use of aspirin monotherapy.

METHODS

The primary endpoint was the incidence of any neurologic deficit after treatment after 6 months of follow-up. The secondary endpoint was the rate of the complete occlusion of the aneurysms at the 6-month follow-up. Enrollment of 20 patients was planned, but after inclusion of seven patients the study was stopped due to safety issues.

RESULTS

Seven patients with eight aneurysms were included. Among the seven patients, three (42.8%) had ischemic complications on the second day after FD deployment. Two patients experienced complete recovery at discharge (National Institutes of Health Stroke Scale (NIHSS) score=0), while one patient maintained mild dysarthria at discharge (NIHSS score=1) which improved after 6 months (NIHSS score=0). All three patients had no new symptoms during the 6-month follow-up. Complete aneurysm occlusion occurred in six (75%) of the eight aneurysms at the 6-month follow-up.

CONCLUSIONS

Antiplatelet monotherapy with aspirin for the treatment of distal intracranial aneurysms with this modified surface FD resulted in a significant incidence of ischemic complications after treatment.

Surface-modified flow diverter p48-MW-HPC: Preliminary clinical experience in 28 patients treated in two centers

BACKGROUND AND PURPOSE

Flow diversion is increasingly used for endovascular treatment of distal intracranial aneurysms and has led to the development of small diameter flow diverters such as p48-MW (phenox, Bochum, Germany). Use of flow diverters is limited, however, as patients require dual antiplatelet treatment to avoid thromboembolic complications. Hydrophilic Polymer Coating was developed to reduce platelet aggregation on the p48-MW (p48-MW-HPC). This study reports preliminary experience with p48-MW-HPC in aneurysm treatment in two centers.

MATERIALS AND METHODS

Patients with ruptured, unruptured, and recanalized aneurysms treated with p48-MW-HPC were prospectively included and retrospectively analyzed for safety and efficacy. Safety was evaluated by analyzing intra- and postoperative complications as well as thromboembolic events depicted by DWI in the 72 h post-procedure. Efficacy was evaluated at 6 months based on aneurysm occlusion.

RESULTS

From April 2019 to May 2020, 28 patients aged 25-82 years with 29 aneurysms were treated. Two thromboembolic events (7.1%) were reported with good clinical outcome. Final morbidity and mortality were both 0.0%. Post-operative DWI-MRI was depicting lesions in 70.0% of patients. Short-term (6 months) anatomical results were complete aneurysm occlusion in 87.0% of aneurysms, neck remnant in 8.7%, and aneurysm remnant in 4.3%.

CONCLUSION

This preliminary clinical evaluation conducted in a relatively small sample size shows high feasibility (100.0%) of p48-MW-HPC aneurysm treatment, without morbidity or mortality, and high efficacy (complete occlusion in 90.0%). Additional larger comparative studies are needed to confirm these results and optimize perioperative antiplatelet treatment.

Expanding Indications for Flow Diverters: Distal Aneurysms, Bifurcation Aneurysms, Small Aneurysms, Previously Coiled Aneurysms and Clipped Aneurysms, and Carotid Cavernous Fistulas

Flow diverter devices have gained wide acceptance for the treatment of unruptured intracranial aneurysms. Most studies are based on the treatment of large aneurysms harboring on the carotid syphon. However, during the last years the “off-label” use of these stents has widely grown up even if not supported by randomized studies. This review examines the relevant literature concerning “off-label” indications for flow diverter devices, such as for distal aneurysms, bifurcation aneurysms, small aneurysms, recurrent aneurysms, and direct carotid cavernous fistulas.

Longitudinal Monitoring of Flow-Diverting Stent Tissue Coverage After Implant in a Bifurcation Model Using Neurovascular High-Frequency Optical Coherence Tomography

BACKGROUND

Tissue growth over covered branches is a leading cause of delayed thrombotic complications after flow-diverter stenting (FDS). Due to insufficient resolution, no imaging modality is clinically available to monitor this phenomenon.

OBJECTIVE

To evaluate high-frequency optical coherence tomography (HF-OCT), a novel intravascular imaging modality designed for the cerebrovascular anatomy with a resolution approaching 10 microns, to monitor tissue growth over FDS in an arterial bifurcation model.

METHODS

FDS were deployed in a rabbit model (n = 6), covering the aortic bifurcation. The animals were divided in different groups, receiving dual antiplatelet therapy (DAPT) (n = 4), aspirin only (n = 1), and no treatment (n = 1). HF-OCT data were obtained in vivo at 3 different time points in each animal. For each cross-sectional image, metal and tissue coverage of the jailed ostium was quantified. Scanning electron microscopy images of harvested arteries were subsequently obtained.

RESULTS

Good quality HF-OCT data sets were successfully acquired at implant and follow-up. A median value of 41 (range 21-55) cross-sectional images were analyzed per ostium for each time point. Between 0 and 30 d after implant, HF-OCT analysis showed a significantly higher ostium coverage when DAPT was not given. After 30 d, similar growth rates were found in the DAPT and in the aspirin group. At 60 d, a coverage of 90% was reached in all groups.

CONCLUSION

HF-OCT enables an accurate visualization of tissue growth over time on FDS struts. The use of FDS in bifurcation locations may induce a drastic reduction of the jailed-branch ostium area.

Effects of two different glycoprotein platelet IIb/IIIa inhibitors and the clinical endpoints in patients with intracranial Pipeline flow diverter implant

Objective

To compare the antiplatelet effect and major adverse cerebrovascular events of Pipeline for intracranial aneurysms using glycoprotein IIb/IIIa antagonists (GPI) eptifibatide and tirofiban.

Methods

Retrospective analysis of relevant data of patients using GPIs combined with oral antiplatelet therapy in Nanfang Hospital of Southern Medical University from December 2017 to December 2019. The study was approved by the ethics Committee of Nanfang Hospital of Southern Medical University. According to the random use of GPIs drugs, they were assigned to the eptifibatide group and tirofiban group. Basic data, platelet inhibition rates at baseline, 24h and 72h after administration, short-term major adverse cerebrovascular events, and bleeding complications were compared between the two groups.

Results

A total of 47 patients were included in this study, including 24 patients in eptifibatide group and 23 patients in tirofiban group. There was no significant difference in average age (53.75 vs. 53.91 years) and body mass index (BMI) (24.39 vs. 22.73 ​kg/m2) between eptifibatide group and tirofiban group. There was no significant difference in coagulation factor function (R), fibrinogen function (K), fibrinolysis function (EPL), comprehensive coagulation index (Cl), arachidonic acid pathway inhibition rate (AA%) and adenosine diphosphate inhibition rate (ADP%). However, the baseline level of residual platelet function MA (ADP) in eptifibatide group was significantly higher than that in tirofiban group (50.79 vs. 35.29 ​mm, P ​= ​0.0026). There was a statistical difference in the platelet aggregation function MA (65.38 vs. 62.54 ​mm, p ​= ​0.0442), the rate of spontaneous hemorrhagic stroke (4.3% vs. 0%) and the rate of asymptomatic minor bleeding (26.08% vs. 4.1%) in the two groups (P ​< ​0.05).

Conclusion

Both eptifibatide and tirofiban can effectively inhibit platelets, but the effect of etifeptide is better than that of tirofiban in preventing intracranial microhemorrhage and asymptomatic cerebral infarction.

Advances in endovascular aneurysm management: flow modulation techniques with braided mesh devices

Flow diverters and flow disruption technology, alongside nuanced endovascular techniques, have ushered in a new era of treating cerebral aneurysms. Here, we provide an overview of the latest flow modulation devices and highlight their clinical applications and outcomes.

Complex cerebral aneurysms: intra-luminal reconstruction using Pipeline flow-diverting stent and the obliteration mechanism

OBJECTIVES

Patients with complex cerebral aneurysms can now be treated intravascularly with the help of flow-diverting stents. The primary purpose of this article is to document the clinical and angiographic outcomes in 80 patients who were treated with the Pipeline flow-diverting stent (PFS; Medtronic, Dublin, Ireland) and the obliteration mechanism was discussed.

PATIENTS AND METHODS

Between October 2015 and October 2019, 80 patients with 90 complex (undefined neck, large/giant, blood blister-like, and recurrent side-wall) cerebral aneurysms treated with the PFS were retrospectively reviewed. Forty-five patients were women and 35 were men, with a mean age of 52 years. Large or giant aneurysms were defined as 10 mm or larger and small aneurysms were defined as less than 10 mm at the largest diameter measured on angiogram.

RESULTS

Forty-one aneurysms (45.6%) were large or giant, 41 (45.6%) were small, four (4.4%) were recurrent side-wall aneurysms and four (4.4%) were blood blister-like aneurysms. In total, 87 PFSs were placed in 80 patients with 90 aneurysms. In six patients, coexisting proximal stenosis of parent artery was also covered with PFS without balloon angioplasty. Adjunct coils were placed in 31 aneurysms (34%). One patient died of intracerebral hematoma after thrombolysis. There was one intrastent occlusion at six-month follow-up without any symptoms. The morbidity and the mortality rate is 0% and 1.3% (95% confidence interval (CI), 0%-3.7%). Control angiography was available in 74 (92.5%) patients with 83 aneurysms, and the aneurysm occlusion rate was 98.8% (95% CI, 96.5%-100%) in 6 to 12 months.

CONCLUSION

For wide-necked saccular, large/giant, blood blister-like aneurysms and recurrent side-wall aneurysms, PFS is a valid and safe treatment option.

Preliminary in vitro angiographic comparison of the flow diversion behavior of Evolve and Pipeline devices

Background and purpose

Flow diverters are increasingly used to treat a broad category of cerebral aneurysms. We conducted an in vitro study to angiographically compare the flow diversion effect of Surpass Evolve from Stryker Neurovascular with the Pipeline Shield Embolization Device from Medtronic Neurovascular.

Methods

Three copies each of three carotid aneurysm geometries were manufactured from silicone. Evolve and Pipeline flow diverters were deployed in one copy of each geometry; the third copy was used as Control. High-speed angiography was acquired under pulsatile flow in each replica, contrast concentration-time curves within the aneurysms were recorded, and the curves were quantified with six parameters. The parameters were statistically evaluated to compare the flow diversion effect of both devices.

Results

The Evolve showed greater flow diversion trends in almost all intra-geometry comparisons than the Pipeline. When aggregated over the three geometries, the Evolve was statistically significantly better than the Pipeline in four of the six parameters, and about the same or better (not statistically significant) than the Pipeline in the other two parameters.

Conclusions

The Evolve device demonstrated greater in vitro flow diversion effects than Pipeline. Comparative efficacy of the devices will need to be adjudicated based on clinical outcomes.

Preliminary Experience with Cangrelor for Endovascular Treatment of Challenging Intracranial Aneurysms

BACKGROUND AND PURPOSE

Cangrelor is a P2Y12 inhibitor that presents the advantage of having a short half-life. Its use may be helpful in the management of antiplatelet therapy for patients with intracranial aneurysms treated by stent-assisted coiling or flow-diverter stents. The purpose of this study was to report early experiences in using cangrelor for such indications.

MATERIAL AND METHODS

From October 2017 to November 2018, 7 consecutive patients (5 females, 2 males, mean age = 56 years) were managed with cangrelor as antiplatelet therapy, combined with aspirin, for stent-assisted coiling embolization and flow-diverter embolization of challenging intracranial aneurysms. Anti-aggregation protocols, including cangrelor, were systematically recorded. Treatment-related complications (minor/major hemorrhagic complications, ischemic complications) as well as clinical and angiographic outcomes (evaluated at 8.7 ± 4.2 and 8.75 ± 10 months, respectively) were retrospectively analyzed.

RESULTS

Of the aneurysms 71.4% (5 out of 7) were ruptured and treated in the acute phase. In one case cangrelor was used as an alternative to clopidogrel in an asymptomatic hemorrhagic complication after stent-assisted coiling for better control of a possible worsening of the intracranial bleeding. Of the patients, 1 (14%) with a complex ruptured MCA aneurysm treated with a flow-diverter stent experienced a severe intracranial hemorrhage, which occurred after switching the cangrelor to ticagrelor and eventually led to death. No hemorrhagic complications under cangrelor were recorded for the six remaining patients. No mRS worsening was observed at discharge, except for the patient who died and six out of the seven patients had a mRS ≤2 at follow-up.

CONCLUSION

Cangrelor is a new antiplatelet therapy with a P2Y12 inhibiting effect, with a rapid onset and offset of action, owing to its short half-life. This cases series presents a pilot experience with promising results in terms of antiplatelet management for challenging intracranial aneurysms treated by stent assisted coiling or flow-diverter stents.