AUTHOR=Winters Helge , Schüngel Marie-Sophie , Scherlach Cordula , Mucha Dirk , Thalwitzer Jörg , Härtig Wolfgang , Donitza Aneta , Bailis Nikolaos , Maybaum Jens , Hoffmann Karl Titus , Quäschling Ulf , Schob Stefan 

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

JOURNAL=Frontiers in Neurology

VOLUME=Volume 12 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2021.724705

DOI=10.3389/fneur.2021.724705

ISSN=1664-2295

ABSTRACT=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 who were treated with the p64MW-HPC between 03/2020 and 03/2021. 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
32 patients (22 female, mean age 57.1y) with 33 aneurysms (27 anterior circulation, 6 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%) were demonstrated at the last available follow-up after a mean of 5.9 months. In 2 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.