Single-Center Experience With the Bare p48MW Low-Profile Flow Diverter and Its Hydrophilically Covered Version for Treatment of Bifurcation Aneurysms in Distal Segments of the Anterior and Posterior Circulation

Review: Flow Diversion for the Treatment of Middle Cerebral Artery Aneurysms

The invention of flow diverting stents (FDS) is a novel milestone in the field of endovascular aneurysm therapy, promoting physiological healing of the vessel segment contrary to prior deconstructive treatment strategies, such as coiling. The effects of FDS are based on changes in flow patterns, segmental wall stabilization, and the growth of a neointima. Although flow diversion is already well established for cerebral aneurysms in proximal segments, peripheral locations remain challenging. Especially the middle cerebral artery (MCA) with its predominance of non-collateralized perforators and functional end arteries that supply the eloquent areas of the brain is of major concern.The literature was reviewed for flow diversion of the MCA and antiplatelet therapy.Resulting from the special anatomical characteristics of the MCA, FDS implantation in this territory is completely different from the proximal vessel segments. Still, flow diversion represents an effective endovascular strategy, especially in otherwise non-accessible or sufficiently treatable lesions. However, the risk of ischemic adverse events might be increased. Special attention to the individual decision regarding device selection, antiplatelet regimen, and exact definition of the proximal and distal landing zone considering the jailed side branches is essential for a good angiographic and clinical outcome. · MCA aneurysms can be sufficiently treated by FDS.. · The anatomic and hemodynamic characteristics of the MCA result in an increased risk of thromboembolism.. · Individual device selection and antiplatelet regimen are essential for treatment success.. · Schüngel M, Wohlgemuth WA, Elolf E et al. Review: Flow Diversion for the Treatment of Middle Cerebral Artery Aneurysms. Fortschr Röntgenstr 2024; DOI 10.1055/a-2343-0046.

Phenox HPC and Phenox flow modulation devices for the endovascular treatment of intracranial aneurysms: a systematic review and meta-analysis

BACKGROUND

Surface-modified flow diverters are increasingly used in clinical settings. However, their safety profiles and additional benefits over non-coated devices still need to be explored. In this meta-analysis, we aimed to investigate and compare the clinical outcomes of the uncoated Phenox and coated Phenox HPC flow diverters.

METHODS

A systematic literature review was performed using PubMed, Scopus, Embase, and Web of Science databases. Collected data were pooled and corresponding 95% confidence intervals (CI) were calculated. Outcomes of interest included aneurysm occlusion (>6 months) and complication rates. Additionally, the safety outcomes of prophylactic single (SAPT) and dual antiplatelet treatment (DAPT) approaches were compared for patients treated with coated Phenox HPC flow diverters.

RESULTS

We included 17 studies with 1238 patients. The overall complete occlusion rates were 80% (95% CI 74.01% to 86.56%) for Phenox HPC and 71.3% (95% CI 59.71% to 85.20%) for non-coated Phenox flow diverters (p=0.24). Ischemic complication rates were 7.3% (95% CI 4.6% to 11.39%) with the Phenox HPC and 5.3% (95% CI 4.07% to 6.91%) with the Phenox (p=0.24). For patients treated with Phenox HPC, the SAPT (5.5%; 95% CI 2.83% to 10.85%) and DAPT (7.1%; 95% CI 1.23% to 41.45%) approaches resulted in comparable ischemic complication rates (p=0.79). The DAPT group (4.8%; 95% CI 1.46% to 16.24%) had higher hemorrhagic complication rates than the SAPT group (1.7%; 95% CI 0.52% to 6.09%), but the difference was not statistically significant for patients treated with Phenox HPC (p=0.25).

CONCLUSIONS

Our findings indicate that Phenox HPC is equally as safe and effective as non-coated Phenox devices. Additionally, our results suggest that prasugrel monotherapy might effectively prevent ischemic complications in patients treated with Phenox HPC flow diverters.

Flow Diverters with Surface Modification in Patients with Intracranial Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND

Flow diverters with surface modification (FDSM) are increasingly being used in the treatment of intracranial aneurysms (ANs). We aimed to evaluate the effectiveness and safety across different devices and antiplatelet therapies using a systematic review and meta-analysis.

METHODS

A systematic review was performed to identify original studies of ≥10 patients with intracranial ANs treated with FDSM from database inception through August 2023. Primary effectiveness outcome was the rate of complete AN occlusion at follow-up ≥6 months. Safety outcomes included ischemic stroke, hemorrhage, and in-stent thrombosis, and were stratified by FDSM devices and antiplatelet therapies. Certainty of evidence was evaluated following the Grading of Recommendations, Assessment, Development, and Evaluations approach.

RESULTS

Twenty-seven studies were included, yielding 2161 patients with 2373 ANs. A total of 70.5% of the ANs were located on the internal carotid artery (ICA). Total 10.3% were acutely ruptured. The complete AN occlusion rate was 72.3% at follow-up ≥6 months. Sensitivity analysis in the ICA AN cohort yielded comparable occlusion rates between Pipeline Flex Embolization Device-Shield (80.4%) and Phenox-hydrophilic polymer-coated (77.5%, P = 0.54), but a lower 66.2% rate for Flow Redirection Endoluminal Device-X (P = 0.02). The rate of in-stent thrombosis and stenosis tended to be higher in Phenox-hydrophilic polymer-coated (3.4%) and Flow Redirection Endoluminal Device-X (4.3%) versus Pipeline Flex Embolization Device-Shield (0.8%, P = 0.05).

CONCLUSIONS

FDSM were safe with satisfactory effectiveness for intracranial ANs. More specific investigations are warranted to explore their performance in ANs beyond the ICA and optimal antiplatelet therapy.

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.

Distal Flow Diversion with Anti-Thrombotically Coated and Bare Metal Low-Profile Flow Diverters—A Comparison

Background and purpose: The establishment of low-profile flow diverting stents (FDS), for example, the Silk Vista Baby (SVB) and the p48MW, facilitated endovascular treatment of peripheral cerebral aneurysms. This study therefore aims to compare the performance and outcomes of the SVB with those of the p48MW HPC, with a special focus on hemodynamic aspects of peripheral segments and bifurcations. Materials and methods: The study cohort comprises 108 patients, who were either treated with the SVB or the p48MW HPC between June 2018 and April 2021. Results: Sixty patients received a SVB and forty-eight patients a p48MW HPC. The SVB was used predominantly in the AcomA-complex, and the p48MW HPC in the MCA bifurcation. Immediately after implantation, significant hemodynamic downgrading (OKM A2-A3, B1-B3, C3) was achieved in 60% in the SVB group vs. 75.1% in the p48MW HPC group. At the second follow-up, after an average of 8.8 and 10.9 months, respectively, OKM D1 was observed in 64.4% of the SVB group vs. 27.3% in the p48MW HPC group. Only 1.7% vs. 6.8% of the aneurysms remained morphologically unaltered (OKM A1). Adverse events with persisting neurologic sequalae at last follow-up were largely comparable in both groups (5.0% vs. 4.2%). Conclusion: Immediately after implantation, the p48MW HPC had a more profound hemodynamic impact than the SVB; however, early complete occlusions were achieved in a greater proportion of lesions after implantation of the uncoated SVB.

Endovascular treatment of challenging aneurysms with FRED Jr flow diverter stents: a single-center experience

PURPOSE

To analyze clinical safety and efficacy of flow re-direction endoluminal device (FRED) Jr flow diverter for treatment of unruptured, ruptured, or recanalyzed aneurysms.

MATERIALS AND METHODS

Between October 2019 and February 2022, 25 patients with 31 aneurysms treated with FRED Jr were included in the study. Clinical and radiological records, procedural details, and follow-up outcomes were retrospectively evaluated. Eighteen (72%) patients were female. Median age was 48.8 (age range 9-85). Mean follow-up was 21 months (6-28 months). Location of the aneurysms were as follows; 13 in middle cerebral artery (MCA), 7 in anterior cerebral artery (ACA), 4 in posterior cerebral artery (PCA), 3 in true posterior communicating artery (PCom), 2 in anterior communicating artery (ACom), 1 in superior cerebellar artery (SCA), 1 in true ophthalmic artery. Five patients (20%) presented with acute subarachnoid hemorrhage (aSAH).

RESULTS

In all procedures, FRED Jr was successfully deployed. Three true Pcom aneurysms and a true ophthalmic aneurysm were treated with FRED Jr. Three patients with two adjacent aneurysms were treated with a single FRED Jr. In two (8%) patients in-stent thrombosis occurred intraoperatively, they were treated with iv tirofiban and thrombectomy without any sequelae. Post-discharge 2 weeks later, intraparenchymal hemorrhage occurred in a patient. He was treated with surgical drainage, the clinical course was modified Rankin score (mRS) 2. Digital subtraction angiography (DSA) was performed on 16 (64%) patients with 21 (67%) aneurysms. Near complete-complete occlusion (O'Kelly-Morata grading scale (OKM C-D) was documented in 15/16 (93.7%) patients, 20/21 (95.2%) aneurysms. In nine (36%) patients, no residual filling was observed in the magnetic resonance angiography (MRA). Good clinical outcome (mRS 0-1) was achieved in 24/25 (96%) of patients.

CONCLUSION

Endovascular treatment of small cerebral aneurysms with FRED Jr is safe and effective even in complex and challenging morphologies allowing high rates of aneurysm occlusion with low periprocedural complications. Our cohort, consisting of a rate 20% acute ruptured aneurysms, is the major additive data to the published literature.

Endovascular treatment of intracranial vertebral artery unruptured dissecting aneurysms: Comparison of flow diversion and stent-assisted coiling or stenting alone

Purpose

To investigate the effect and safety of flow diverters in the treatment of unruptured dissecting intracranial aneurysms of the vertebral artery in comparison with stent-assisted coiling or stenting alone.

Materials and methods

Patients with unruptured dissecting intracranial aneurysms of the vertebral artery treated with the flow diverter, stent-assisted coiling, or stenting alone were retrospectively enrolled. The clinical data were analyzed and compared.

Results

Twenty-five patients were enrolled in the flow diversion group and 42 patients in the stenting group. Twenty-six flow diverters were deployed in the flow diversion group. Immediate angiography revealed contrast agent retention within the aneurysm cavity in all patients. In the stenting group, 48 stents were deployed, and immediate angiographic outcome showed O'Kelly-Marotta (OKM) grade D in 18 (42.9%) aneurysms, grade C in 16 (38.1%), and grade B in 8 (19.0%). Periprocedural ischemic complications of thrombosis occurred in two (4.8%) patients and were treated with thrombolysis. In the flow diversion group, 19 (76%) patients underwent angiographic follow-up 3–46 (median 24) months after the procedure, with the OKM grade D in 11 (57.9%) patients, C in two (10.5%), and B in six (31.6%). The aneurysm recurrence rate was zero, and all diverters remained patent. Asymptomatic instent stenosis occurred in two (10.5%) patients. In seven of the ten patients with mild or moderate parent artery stenosis before the procedure who experienced angiographic follow-up, the stenosis was improved in five (71.4%) patients. In the stenting group, angiographic follow-up was carried out in 33 (78.6%) patients 6–58 months (median 34) after the procedure, with OKM grade D in 22 (66.7%) patients, grade C in five (15.2%), grade B in three (9.1%), and aneurysm recurrence (grade B, with increased contrast agent into the aneurysm cavity) in three (9.1%). Five (16.7%) patients experienced asymptomatic instent stenosis, and six of the 12 patients (50%) with parent artery stenosis were improved.

Conclusion

Flow diverters with or without selective adjunctive coiling for the treatment of unruptured dissecting intracranial aneurysms of the vertebral artery may be safe and effective with good occlusion effects not inferior to those of stent-assisted coiling and stenting alone even though the long-term effect still warrants confirmation.

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.

First Experience of Three Neurovascular Centers With the p64MW-HPC, a Low-Profile Flow Diverter Designed for Proximal Cerebral Vessels With Antithrombotic Coating

Background: In the last decade, flow diversion (FD) has been established as hemodynamic treatment for cerebral aneurysms arising from proximal and distal cerebral arteries. However, two significant limitations remain—the need for 0.027” microcatheters required for delivery of most flow diverting stents (FDS), and long-term dual anti-platelet therapy (DAPT) in order to prevent FDS-associated thromboembolism, at the cost of increasing the risk for hemorrhage. This study reports the experience of three neurovascular centers with the p64MW-HPC, a FDS with anti-thrombotic coating that is implantable via a 0.021” microcatheter.

Materials and methods: Three neurovascular centers contributed to this retrospective analysis of patients that had been treated with the p64MW-HPC between March 2020 and March 2021. Clinical data, aneurysm characteristics, and follow-up results, including procedural and post-procedural complications, were recorded. The hemodynamic effect was assessed using the O'Kelly–Marotta Scale (OKM).

Results: Thirty-two patients (22 female, mean age 57.1 years) with 33 aneurysms (27 anterior circulation and six posterior circulation) were successfully treated with the p64MW-HPC. In 30/32 patients (93.75%), aneurysmal perfusion was significantly reduced immediately post implantation. Follow-up imaging was available for 23 aneurysms. Delayed aneurysm perfusion (OKM A3: 8.7%), reduction in aneurysm size (OKM B1-3: 26.1%), or sufficient separation from the parent vessel (OKM C1-3 and D1: 65.2%) was demonstrated at the last available follow-up after a mean of 5.9 months. In two cases, device thrombosis after early discontinuation of DAPT occurred. One delayed rupture caused a caroticocavernous fistula. The complications were treated sufficiently and all patients recovered without permanent significant morbidity.

Conclusion: Treatment with the p64MW-HPC is safe and feasible and achieves good early aneurysm occlusion rates in the proximal intracranial circulation, which are comparable to those of well-established FDS. Sudden interruption of DAPT in the early post-interventional phase can cause in-stent thrombosis despite the HPC surface modification. Deliverability via the 0.021” microcatheter facilitates treatment in challenging vascular anatomies.

Early clinical experience with the p48MW HPC and p64MW HPC flow diverters in the anterior circulation aneurysm using single anti-platelet treatment

Background

The p64MW HPC and p48MW HPC flow diverters have reduced thrombogenicity due to hydrophilic coating. The purpose of this study was to evaluate its safety and efficacy in Mongolian patients under single antiplatelet therapy (SAPT) with prasugrel.

Materials and methods

We performed a retrospective review of patients enrolled into our prospectively maintained database to identify all patients treated with either the p48MW HPC or p64MW HPC under SAPT. We recorded baseline demographics, aneurysm size and location, procedural complications, angiographic and clinical results.

Results

24 patients, (female = 21, 87.5%), age 48.2 ± 11.6 years (range 25–63) underwent treatment of 30 aneurysms with either p64MW HPC or p48MW HPC. All aneurysms were saccular with dome width 8.2 ± 6.5 (range 1.6–26.0 mm) and dome height 7.6 ± 6.7 (range 1.6–30.0 mm). None of the aneurysms were previously treated. The average PRU was 54.6 ± 31.2 (range 1–127) on pre-operative VerifyNow testing. Angiographic follow-up was available for 13 patients (17 aneurysms), 183 ± 36 days post-procedure, at which point 64.7% of aneurysms (n = 11/17) were completely occluded and 11.8% (n = 2/17) had only neck remnants resulting in 76.5% of aneurysms being adequately occluded A single intra-operative complication (4.2%) occurred however all patients were mRS ≤1 at last follow-up. There were two post-operative complications neither of which resulted in permanent neurological morbidity. There were no instances of post-operative aneurysmal rupture or delayed parenchymal haemorrhage. The overall mortality was 0%.

Conclusion

The efficacy and safety of p64MW HPC coated devices under SAPT is similar to uncoated flow diverters that require DAPT.

Flow Diversion for Reconstruction of Intradural Vertebral Artery Dissecting Aneurysms Causing Subarachnoid Hemorrhage-A Retrospective Study From Four Neurovascular Centers

Objective: Dissecting aneurysms (DAs) of the vertebrobasilar territory manifesting with subarachnoid hemorrhage (SAH) are associated with significant morbi-mortality, especially in the case of re-hemorrhage. Sufficient reconstruction of the affected vessel is paramount, in particular, if a dominant vertebral artery (VA) is impacted. Reconstructive options include stent-assisted coiling and flow diversion (FD). The latter is technically less challenging and does not require catheterization of the fragile aneurysm. Our study aims to report a multicentric experience with FD for reconstruction of DA in acute SAH.

Materials and Methods: This retrospective study investigated 31 patients (age: 30–78 years, mean 55.5 years) who had suffered from SAH due to a DA of the dominant VA. The patients were treated between 2010 and 2020 in one of the following German neurovascular centers: University Hospital Leipzig, Katharinenhospital Stuttgart, BG Hospital Bergmannstrost Halle/Saale, and Heinrich-Braun-Klinikum Zwickau. Clinical history, imaging, implanted devices, and outcomes were reviewed for the study.

Results: Reconstruction with flow-diverting stents was performed in all cases. The p64 was implanted in 14 patients; one of them required an additional balloon-expandable stent to reconstruct severe stenosis in the target segment. One case demanded additional liquid embolization after procedural rupture, and in one case, p64 was combined with a PED. Further 13 patients were treated exclusively with the PED. The p48MW-HPC was used in two patients, one in combination with two additional Silk Vista Baby (SVB). Moreover, one patient was treated with a single SVB, one with a SILK+. Six patients died [Glasgow Outcome Scale (GOS) 1]. Causes of death were periprocedural re-hemorrhage, thrombotic occlusion of the main pulmonary artery, and delayed parenchymal hemorrhage. The remaining three patients died in the acute–subacute phase related to the severity of the initial hemorrhage and associated comorbidities. One patient became apallic (GOS 2), whereas two patients had severe disability (GOS 3) and four had moderate disability (GOS 4). Eighteen patients showed a complete recovery (GOS 5).

Conclusion: Reconstruction of VA-DA in acute SAH with flow-diverting stents is a promising approach. However, the severity of the condition is reflected by high overall morbi-mortality, even despite technically successful endovascular treatment.

The p48 flow diverter: First clinical results in 25 aneurysms in three centers

BACKGROUND

The novel low-profile p48 flow diverter has been designed to treat aneurysms on small vessels of 1.75-3mm. We report our first clinical experiences.

METHODS

Between March 2018-January 2020, 22 patients with 25 aneurysms were treated with the p48 in 3 centers. One patient had 3 aneurysms covered by one p48 and one patient had 2 aneurysms. There were 5 men, 17 women, with a mean age of 55 years (median 59, range 29-73 years).

RESULTS

In 25 aneurysms, 24 p48 flow diverters were placed. In 1 patient additional coils were placed in the aneurysm. Procedural vessel rupture by the micro guidewire occurred in 2 patients and vessel rupture during p48 balloon dilatation occurred in 1 patient. Overall, the permanent morbidity rate was 13.6% (3 of 22, 95%CI 3.9-34.2%) and mortality was 4.5% (1 of 22, 95%CI <0.01-23.5%). Most complications were procedure-related and not device-specific. Of 22 patients with 25 aneurysms treated with p48, 18 patients with 20 aneurysms had angiographic follow-up after 5-18 months. Of 19 aneurysms, 10 were occluded and 7 showed a remnant. Two aneurysms were open after 6 months. Three aneurysms were still not occluded after 12, 14, and 18 months and these 3 were retreated. Retreatment rate was 16% (3 of 19) and the adequate occlusion rate was 90% (17 of 19).

CONCLUSIONS

Treatment of aneurysms in small-caliber vessels with the p48 is feasible and effective but is not without complications. More data is needed to establish indications, safety, and efficacy more accurately.

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.