Very late ischemic complications in flow-diverter stents: a retrospective analysis of a single-center series

Abstract

OBJECTIVE The authors evaluate the rate and discuss the pathomechanisms of very late (≥ 4-month) ischemic complications after flow-diverter stent (FDS) placement for intracranial aneurysms. METHODS The authors retrospectively reviewed the clinical data of the patients treated at Pitié-Salpêtrière Hospital between January 2010 and September 2014, who underwent FDS placement for intracranial aneurysm. The patients received dual-antiplatelet therapy (clopidogrel and aspirin) 5 days before and 3-6 months after the procedure and then aspirin alone for 6-9 months. An ischemic complication was defined as a sudden focal neurological deficit documented on diffusion-weighted images. RESULTS Eighty-six consecutive patients were included. Three (3.5%) patients treated with the Pipeline embolization device experienced a delayed acute ischemic stroke (2 cases of perforator/side-wall branch infarction and 1 case of thromboembolic stroke) with an average delay of 384 days (4 months, 20 months, and 13 months, respectively). The aneurysm locations were the left superior cerebellar artery, the right anterior choroid artery, and the left internal carotid artery (paraclinoid segment), respectively. The complications occurred after the patients had completed the antiaggregation protocol, except for Patient 1, who was receiving aspirin alone because of a spontaneous hematoma. At the acute phase, no in-stent thromboses were found on digital subtraction angiography. In Patient 2, the treated anterior choroid artery was occluded 20 months after the procedure. In Patient 3, a focal stenosis (approximately 40%) of the distal aspect of the FDS, probably caused by intimal hyperplasia, was seen. CONCLUSIONS Very late ischemic complications after FDS treatment were observed in 3.5% of the cases in the authors' series, some of which occurred as late as more than 1 year after placement.

Tourniquet parent artery occlusion after flow diversion

“…In our series, one patient (case 1) had PED occlusion after discontinuation of clopidogrel 6 months after the procedure. Despite all three cases of occlusion being asymptomatic, rigorous adherence to antiplatelet therapy is still strongly encouraged to prevent acute and delayed thromboembolic events that would cause clinical sequelae 15. We continue to follow PRU and P2Y12 assays, despite somewhat conflicting expert opinion over their use.…”

Phosphorylcholine surface modified flow diverter associated with reduced intimal hyperplasia

“…Neointimal hyperplasia (NIH) is frequently depicted during the imaging follow-up of flow diverter treatment,1 and may lead to delayed ischemic strokes 2. Phosphorylcholine surface modified flow diverters (Pipeline Flex with Shield Technology, sPED) were recently developed and demonstrated reduced thrombogenicity both in vitro3 and vivo 4.…”

Republished: Delayed ischemic stroke due to stent marker band occlusion after stent-assisted coiling

“…In terms of the effects of intracranial stents, a stent strut can have a considerable influence on the flow in the affected perforating vessels near the treated cerebral aneurysms 6 7. When using a flow diverter stent with high surface coverage and low porosity, delayed ischemic stroke may occur due to perforating ischemia 7. Perforating vessels covered by conventional intracranial stent struts are usually patent; however, a marker band is larger than a stent strut and can be a risk factor for decreased flow in the same way as a flow diverter stent; ischemic stroke could be induced when the marker band is covered with a small perforating artery.…”