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

Background and Purpose: Flow diversion has profoundly changed the way aneurysms are treated. However, it conventionally requires dual antiplatelet medication and has yet been considered off-label use in the posterior circulation or within peripheral vessels of the anterior circulation. Here, we report our experience with the p48MW/p48MW hydrophilic coating (HPC) in the anterior and posterior circulation. This novel low-profile flow diverter is specifically designed for treatment of small peripheral vessels, and the p48MW HPC has an anti-thrombotic polymer coating, which allows application of a single antiplatelet function medication in conditions that expectably require further surgery. Materials and Methods: Thirty-two patients were prospectively included. Twenty-six treatments were performed with one flow diverter, four required two overlapping flow diverters, one case demanded three overlapping flow diverters, and in one case, extensive dissecting aneurysm telescoping with eight flow diverters was necessary. Twenty-two complex bifurcation aneurysms were treated. Three months’ follow-up was available for 14 patients. Results: Deployment was uneventful in all cases. In four cases, undersizing was unavoidable and resulted in significant shortening of the flow diverter, which demanded implantation of further flow diverters to sufficiently treat the target aneurysm. Three flow diverters required balloon angioplasty for optimal wall approximation. All parent vessels remained patent. Available 3-month follow-up studies showed decreased influx or delayed washout in all aneurysms; none was occluded completely. There were no device-related clinical complications. Conclusions: Implantation of the p48MW/p48MW HPC is safe and effective for treatment of distally located cerebral aneurysms. Considering the reported rates of ischemic complications associated with flow diversion of complex bifurcation aneurysms, the p48MW/p48MW HPC potentially provides increased safety for complex bifurcation aneurysms in the anterior and posterior circulation

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

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

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

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

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

Background and Purpose: Flow diversion has profoundly changed the way aneurysms are treated. However, it conventionally requires dual antiplatelet medication and has yet been considered off-label use in the posterior circulation or within peripheral vessels of the anterior circulation. Here, we report our experience with the p48MW/p48MW hydrophilic coating (HPC) in the anterior and posterior circulation. This novel low-profile flow diverter is specifically designed for treatment of small peripheral vessels, and the p48MW HPC has an anti-thrombotic polymer coating, which allows application of a single antiplatelet function medication in conditions that expectably require further surgery. Materials and Methods: Thirty-two patients were prospectively included. Twenty-six treatments were performed with one flow diverter, four required two overlapping flow diverters, one case demanded three overlapping flow diverters, and in one case, extensive dissecting aneurysm telescoping with eight flow diverters was necessary. Twenty-two complex bifurcation aneurysms were treated. Three months’ follow-up was available for 14 patients. Results: Deployment was uneventful in all cases. In four cases, undersizing was unavoidable and resulted in significant shortening of the flow diverter, which demanded implantation of further flow diverters to sufficiently treat the target aneurysm. Three flow diverters required balloon angioplasty for optimal wall approximation. All parent vessels remained patent. Available 3-month follow-up studies showed decreased influx or delayed washout in all aneurysms; none was occluded completely. There were no device-related clinical complications. Conclusions: Implantation of the p48MW/p48MW HPC is safe and effective for treatment of distally located cerebral aneurysms. Considering the reported rates of ischemic complications associated with flow diversion of complex bifurcation aneurysms, the p48MW/p48MW HPC potentially provides increased safety for complex bifurcation aneurysms in the anterior and posterior circulation

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

Background and Purpose: Flow diversion has profoundly changed the way aneurysms are treated. However, it conventionally requires dual antiplatelet medication and has yet been considered off-label use in the posterior circulation or within peripheral vessels of the anterior circulation. Here, we report our experience with the p48MW/p48MW hydrophilic coating (HPC) in the anterior and posterior circulation. This novel low-profile flow diverter is specifically designed for treatment of small peripheral vessels, and the p48MW HPC has an anti-thrombotic polymer coating, which allows application of a single antiplatelet function medication in conditions that expectably require further surgery. Materials and Methods: Thirty-two patients were prospectively included. Twenty-six treatments were performed with one flow diverter, four required two overlapping flow diverters, one case demanded three overlapping flow diverters, and in one case, extensive dissecting aneurysm telescoping with eight flow diverters was necessary. Twenty-two complex bifurcation aneurysms were treated. Three months’ follow-up was available for 14 patients. Results: Deployment was uneventful in all cases. In four cases, undersizing was unavoidable and resulted in significant shortening of the flow diverter, which demanded implantation of further flow diverters to sufficiently treat the target aneurysm. Three flow diverters required balloon angioplasty for optimal wall approximation. All parent vessels remained patent. Available 3-month follow-up studies showed decreased influx or delayed washout in all aneurysms; none was occluded completely. There were no device-related clinical complications. Conclusions: Implantation of the p48MW/p48MW HPC is safe and effective for treatment of distally located cerebral aneurysms. Considering the reported rates of ischemic complications associated with flow diversion of complex bifurcation aneurysms, the p48MW/p48MW HPC potentially provides increased safety for complex bifurcation aneurysms in the anterior and posterior circulation

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

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

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