Treatment Of Intracranial Bifurcation Aneurysms Research Articles

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

BackgroundFlow 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...

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

PurposeTo clarify the safety and efficacy of “X” stent-assisted coiling (X-stenting) for the treatment of intracranial bifurcation aneurysms and to review the literature. MethodsWe 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. ResultsEndovascular 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. ConclusionsX-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.

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

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

The Safety and Effectiveness of the Contour Neurovascular System (Contour) for the Treatment of Bifurcation Aneurysms: The CERUS Study.

The Contour is a novel intra-aneurysmal flow disrupting device to treat intracranial aneurysms. To evaluate the safety and effectiveness of the Contour device for treatment of nonruptured intracranial bifurcation aneurysms through a prospective, multicenter, single-arm study. Thirty-four patients were enrolled. Primary end points were successful occlusion at 6 mo for efficacy and any major stroke or nonaccidental death up to 30 d or major disabling stroke within 6 mo for safety. Secondary end points were occlusion at 12 mo, retreatment rate, procedure time, and procedure-related/device-related adverse events. Procedural and follow-up imaging was reviewed by an independent core laboratory. Adverse events were reviewed and adjudicated by a clinical events committee. In total, 32 of 34 aneurysms were successfully implanted and, 2 of 34 in the intention-to-treat (ITT) group did not receive the Contour and were excluded from follow-up after 30 d. In addition, 2 of 32 were lost to angiographic follow-up and regarded as treatment failure. The primary safety end point was met in 2 patients in the ITT group. In the perprotocol (PP) group, complete occlusion was seen in 14 of 32 (44%) at 6 mo and 22 of 32 (69%) at 12 mo. Adequate occlusion (Raymond-Roy [RR] 1 and 2) was reached in 84% at a last available follow-up. One patient from the ITT group and 1 from the PP group received additional treatment during follow-up. The Contour seems to be both safe and effective in the treatment of intracranial bifurcation aneurysms.

Particle Image Velocimetry Measurements of the Flow-Diverting Effects of a New Generation of the eCLIPs Implant for the Treatment of Intracranial Bifurcation Aneurysms

Flow diverters (FDs) for the endovascular treatment of intracranial aneurysms are effective for sidewall aneurysms, but their use at a bifurcation is problematic because FDs only partially cover the aneurysm neck and impede flow into a daughter branch; they are thus not employed routinely in this anatomy. eCLIPs was developed as a non-tubular implant to completely cover the neck of an aneurysm and serve as a coil retention device necessary for the adequate treatment of wide-neck bifurcation aneurysms. eCLIPs has shown some flow diversion effects in bifurcation anatomy but not equal to those exhibited by clinically accepted flow diverters in sidewall anatomy. A new generation of eCLIPs implant, the eCLIPs bifurcation flow diverter (eBFD), with higher metal coverage, was developed to achieve a similar flow diversion as a Pipeline Embolization Device (PED), a prototypical FD. Particle image velocimetry was used to capture the fluid dynamics and velocity reduction within silicone aneurysm replicas. A circulatory mimicking loop was developed to circulate the flow through the silicone models. All generations of eCLIPs implants had some flow-diverting effect, with increasing metal coverage density of the implant proportionately increasing the flow diversion effect. The eBFD, with a metal density of 35%, showed greater flow diversion than PED, with 30% metal density, for bifurcation anatomy. The eBFD showed similar reduction of flow in a bifurcation anatomy to PED in a sidewall, both sufficient to permit early thrombosis of the aneurysm. Thus, the eBFD can potentially provide sufficient flow diversion for the treatment of bifurcation aneurysms to avoid adjunctive coiling.

The Hemodynamic Effect of Flow Diverter Treatment of Intracranial Bifurcation Aneurysms

Flow diverter (FD) is a novel technique used for intracranial aneurysms, but the hemodynamic changes caused by FD implantation in bifurcation aneurysms (BAs) are still undefined. Computational fluid dynamics (CFD) were applied to analyze the hemodynamic parameters in a patient-specific basilar artery tip aneurysmal model, which include blood flow velocity, wall shear stress (WSS), aneurysmal wall pressure and branch vessel flow rate. The porous media model was used to simulate three different FD implantation strategies: single FD in a larger branch, single FD in a smaller branch and Y-shaped FD into bilateral branches. The flow velocity inside the aneurysmal sac was decreased by 70.99%, 76.13%, and 69.30% in strategies 1, 2 and 3, respectively. The mean WSS was decreased by 71.9% in Strategy 1, 73.9% in Strategy 2 and 76.1% in Strategy 3. The aneurismal wall pressure was dropped by 8.2% and 7.9% in Strategies 2 and 3, while the pressure was increased by 14.2% in Strategy 1. The velocity of the two small covered branches was dropped by 99.3% and 99.1% in Strategy 1, 10.3% and 7.5% in Strategy 2, and 15.2% and 6.3% in Strategy 3. The porous media model was considered feasible to simulate the implantation strategies of FD in BAs. The reduction velocity and WSS were observed in all FD implantation strategies, indicating the effectiveness of FD treatment in BAs. The blood flow of small covered branch vessels was decreased after FD implantation, suggesting potential risk of occlusion.

Letter to the Editor Regarding “PulseRider-Assisted Coil Embolization for Treatment of Intracranial Bifurcation Aneurysms: A Single-Center Case Series with 24-Month Follow-up”

Letter to the Editor Regarding “PulseRider-Assisted Coil Embolization for Treatment of Intracranial Bifurcation Aneurysms: A Single-Center Case Series with 24-Month Follow-up”

PulseRider-Assisted Coil Embolization for Treatment of Intracranial Bifurcation Aneurysms: A Single-Center Case Series with 24-Month Follow-up

Although endovascular coiling of unruptured aneurysms is widely accepted, the endovascular treatment of wide-neck bifurcation aneurysms remains one of the most challenging morphologies. Our purpose was to describe our experience with 24-month follow-up for the treatment of unruptured intracranial bifurcation aneurysms using the PulseRider (Cerenovus, New Brunswick, NJ). This study is a single-center, single-arm registry performed under institutional review board control to evaluate efficacy and safety of the PulseRider. Patients with bifurcation aneurysms were identified and enrolled prospectively. Angiography immediately after treatment and at 6 months, and magnetic resonance imaging and magnetic resonance angiography at 12- and 24-month follow-up were retrospectively analyzed. A modified Rankin score was obtained prior to procedure, at discharge, and at 6-, 12- and 24-month follow-up visits. Eight patients with a mean age of 66 years were treated with the PulseRider. All patients had bifurcation aneurysms (2 anterior communicating, 2 carotid terminus, and 4 basilar apex). The aneurysm diameters ranged from 4.6 to 13.6 mm (mean 7.4 mm) with dome/neck ratio ranging from 1.4 to 2.2 (mean 1.6). In all cases, the PulseRider was successfully deployed. Complete occlusion was demonstrated at 6-month follow-up on 6 of 8 (75%), near complete occlusion in 1 of 8 (12.5%), and residual aneurysm in 1 of 8 (12.5%) patients. There was no change or recurrence on magnetic resonance angiography, nor clinical complication after the procedure through 24-month follow-up. Our experience with 24-month follow-up demonstrated favorable efficacy in the treatment of intracranial wide-neck bifurcation aneurysms using the PulseRider.

The Role of Hemodynamics in Intracranial Bifurcation Arteries after Aneurysm Treatment with Flow-Diverter Stents.

Treatment of intracranial bifurcation aneurysms with flow-diverter stents can lead to caliber changes of the distal vessels in a subacute phase. This study aims to evaluate whether local anatomy and flow disruption induced by flow-diverter stents are associated with vessel caliber changes in intracranial bifurcations. Radiologic images and demographic data were acquired for 25 patients with bifurcation aneurysms treated with flow-diverter stents. Whisker plots and Mann-Whitney rank sum tests were used to evaluate if anatomic data and caliber changes could be linked. Symmetry/asymmetry were defined as diameter ratio 1 = symmetric and diameter ratio <1 = asymmetric. Computational fluid dynamics was performed on idealized and patient-specific anatomies to evaluate flow changes induced by flow-diverter stents in the jailed vessel. Statistical analysis identified a marked correspondence between asymmetric bifurcation and caliber change. Symmetry ratios were lower for cases showing narrowing or subacute occlusion (medium daughter vessel diameter ratio = 0.59) compared with cases with posttreatment caliber conservation (medium daughter vessel diameter ratio = 0.95). Computational fluid dynamics analysis in idealized and patient-specific anatomies showed that wall shear stress in the jailed vessel was more affected when flow-diverter stents were deployed in asymmetric bifurcations (diameter ratio <0.65) and less affected when deployed in symmetric anatomies (diameter ratio ∼1.00). Anatomic data analysis showed statistically significant correspondence between caliber changes and bifurcation asymmetry characterized by diameter ratio <0.7 (P < .001). Similarly, computational fluid dynamics results showed the highest impact on hemodynamics when flow-diverter stents are deployed in asymmetric bifurcations (diameter ratio <0.65) with noticeable changes on wall sheer stress fields. Further research and clinical validation are necessary to identify all elements involved in vessel caliber changes after flow-diverter stent procedures.

PulseRider-assisted treatment of wide-necked intracranial bifurcation aneurysms: safety and feasibility study.

OBJECTIVE The goal of this study was to assess the safety and feasibility of PulseRider, a novel endovascular stent, in the treatment of intracranial bifurcation aneurysms with wide necks. The authors present the initial results of the first 10 cases in which the PulseRider device was used. METHODS Patients whose aneurysms were intended to be treated with the PulseRider device at 2 institutions in the United Kingdom were identified prospectively. Patient demographics, procedural details, immediate neurological and clinical status, and immediate angiographic outcomes and 6-month clinical and imaging follow-up were recorded prospectively. RESULTS At the end of the procedure, all 10 patients showed complete aneurysm occlusion (Raymond Class 1). There were no significant intraprocedural complications except for an occurrence of thromboembolism without clinical sequelae. There was no occurrence of aneurysm rupture or vessel dissection. At 6-month follow-up, 7 and 3 patients had modified Rankin Scale scores of 0 and 1, respectively. All 10 patients had stable aneurysm occlusion (Raymond Class 1) and daughter vessel intraluminal patency on 6-month follow-up catheter angiography. CONCLUSIONS The authors' early experience with the PulseRider device demonstrates that it is a safe and effective adjunct in the treatment of bifurcation aneurysms with wide necks arising at the middle cerebral artery bifurcation, anterior cerebral artery, basilar apex, and carotid terminus. It works by providing a scaffold at the neck of the bifurcation aneurysm, enabling neck remodeling and coil support while maintaining parent vessel intraluminal patency. Early clinical and radiological follow-up showed good functional outcome and stable occlusion rates, respectively. Further data are needed to assess medium- and long-term outcomes with PulseRider.