Small Pipes: Preliminary Experience with 3-mm or Smaller Pipeline Flow-Diverting Stents for Aneurysm Repair prior to Regulatory Approval

Abstract

SUMMARY:Flow diversion has become an established treatment option for challenging intracranial aneurysms. The use of small devices of Յ3-mm diameter remains unapproved by major regulatory bodies. A retrospective review of patients treated with Pipeline Embolization Devices of Յ3-mm diameter at 3 Canadian institutions was conducted. Clinical and radiologic follow-up data were collected and reported. Twelve cases were treated with Ն1 Pipeline Embolization Device of Յ3-mm diameter, including 2 with adjunctive coiling, with a median follow-up of 18 months (range, 4 -42 months). One patient experienced a posttreatment minor complication (8%) due to an embolic infarct. No posttreatment hemorrhage or delayed complications such as in-stent stenosis/thrombosis were observed. Radiologic occlusion was seen in 9/12 cases (75%) and near-occlusion in 2/12 cases (17%). Intracranial aneurysm treatment with small-diameter flow-diverting stents provided safe and effective aneurysm closure in this small selected sample. These devices should be further studied and considered for regulatory approval.

Endovascular flow diversion for treatment of anterior communicating artery region cerebral aneurysms: a single-center cohort of 50 cases

“…Martin and colleagues hypothesized that thrombosis and in-stent stenosis may be more likely in small distal vessels where a 1–2 mm reduction in arterial caliber is a greater impediment to laminar flow, but observed neither complication in their series of 12 patients at Canadian institutions treated with the PED for aneurysms arising from vessels <3 mm in diameter 29. In our series, one patient developed stent thrombosis intra-procedurally, which resolved completely with abciximab administration.…”

Multicenter Experience with FRED Jr Flow Re-Direction Endoluminal Device for Intracranial Aneurysms in Small Arteries

“…While conventional microsurgical clipping or coiling with possible ballooning or stent placement remains the treatment of choice, few studies in the past have investigated the use of flow diverters in small vessels. [11][12][13][14][15][16] This new generation of intracranial flow diverters dedicated to vessels of Յ3 mm may provide a promising alternative for the safe and effective treatment of these challenging aneurysms. In this series, all treated aneurysms were completely covered by the flow diverter at postprocedural follow-up.…”

“…These findings are comparable with those in previous studies that focused on distal-circulation aneurysms treated with various intracranial flow diverters (in most cases the Pipeline Embolization Device), with up to 17.6% transient neurologic deficits, up to 10.7% permanent neurologic deficits, and no mortality. [11][12][13][14][15][16]…”

“…10 However, clinical experience with such potential complications has rarely been reported. [11][12][13][14][15][16] Here, we report on our multicenter experience of the FRED Jr flow diverter endovascular treatment of aneurysms in small cerebral vessels and present the feasibility, safety, and effectiveness of this treatment.…”

Endovascular treatment of PICA aneurysms with a Low-profile Visualized Intraluminal Support (LVIS Jr) device

“…The sole presence of the stent struts within a dilated vessel segment like a fusiform aneurysm serves as a scaffold for endothelial growth (case 2, figure 2). Flow diversion has been successfully used in PICA reconstruction with a small 2×15 mm Silk device (Balt, France) and a ≤3 mm Pipeline Embolic Device (Covidien, USA) 13 14. However, access to small and distal vessels is likely to be more difficult because flow diverters are delivered in a large and relatively stiff 0.027-inch microcatheter and tortuosity or sharp corners can pose serious challenges.…”