On Flow Diversion: The Changing Landscape of Intracerebral Aneurysm Management

Abstract

Uptake of flow-diverting technology is rapidly outpacing the availability of clinical evidence. Most current usage is off-label, and the endovascular community is nearer the beginning than the end of the learning curve, given the number of devices in development. A comprehensive overview of technical specifications alongside key outcome data is essential both for clinical decision-making and to direct further investigations. Most-studied has been the Pipeline Embolization Device, which has undergone a transition to the Pipeline Flex for which outcome data are sparse or heterogeneous. Alternative endoluminal devices do not appear to be outperforming the Pipeline Embolization Device to date, though prospective studies and long-term data mostly are lacking, and between-study comparisons must be treated with caution. Nominal technical specifications may be unrelated to in situ performance, emphasizing the importance of correct radiologic sizing and device placement. Devices designed specifically for bifurcation aneurysms also lack long-term outcome data or have only recently become available for clinical use. There are no major studies directly comparing a flow-diverting device with standard coiling or microsurgical clipping. Data on flow-diverting stents are too limited in terms of long-term outcomes to reliably inform clinical decision-making. The best available evidence supports using a single endoluminal device for most indications. Recommendations on the suitability and choice of a device for bifurcation or ruptured aneurysms or for anatomically complex lesions cannot be made on the basis of current evidence. The appropriateness of flow-diverting treatment must be decided on a case-by-case basis, considering experience and the relative risks against standard approaches or observation. ABBREVIATION: MCR ϭ metal coverage ratio T he Pipeline Embolization Device (PED; Covidien, Irvine, California) was approved by the FDA in 2011 and by the European Medicines Agency (EMA) in 2008 for the treatment of large or giant, wide-neck intracranial aneurysms of the internal carotid artery from the petrous to the superior hypophyseal segments. 1 Currently, this is the only device approved in the United States. In Europe, there are additional options, including the PED,

Aneurysm characteristics, coil packing, and post-coiling hemodynamics affect long-term treatment outcome

“…Therefore, IAs with wide necks are likely to be more prevalent in the ruptured subcohort. On the other hand, unruptured IAs with wide necks are typically treated with adjunctive stents or FDs, but these treatment cases were excluded in our study 30. Consequently, IAs in our unruptured subcohort may not have as wide necks, but still might have large sizes.…”

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

“…Currently, a number of second-generation FDSs have been made available for endovascular surgeons (15). However, a significant drawback of treatment with most FDSs is the requirement of large microcatheters (0.027-0.033 in.)…”

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

“…Flow diverters have been used successfully to treat patients with aneurysms for more than a decade 5–7. The success of flow diversion in larger aneurysms has led to an expanded indication to treat small and medium-sized, side wall aneurysms 8–12. Since the SILK (Balt Extrusion, France) and Pipeline (Covidien/Medtronic, USA) devices received CE Mark a decade or more ago, multiple devices have subsequently been developed and commercialized in the EU, including Surpass Streamline (Stryker Neurovascular, USA), FRED (Microvention/Terumo, USA), p64 (phenox, Germany), Derivo (Acandis, Germany), Bravo (Cerenovus, USA), and Tubridge (Microport, China).…”