RT Journal Article
SR Electronic
T1 Aneurysm Rupture Following Treatment with Flow-Diverting Stents: Computational Hemodynamics Analysis of Treatment
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 27
OP 33
DO 10.3174/ajnr.A2398
VO 32
IS 1
A1 J.R. Cebral
A1 F. Mut
A1 M. Raschi
A1 E. Scrivano
A1 R. Ceratto
A1 P. Lylyk
A1 C.M. Putman
YR 2011
UL http://www.ajnr.org/content/32/1/27.abstract
AB BACKGROUND AND PURPOSE: Flow-diverting approaches to intracranial aneurysm treatment had many promising early results, but recent apparently successful treatments have been complicated by later aneurysm hemorrhage. We analyzed 7 cases of aneurysms treated with flow diversion to explore the possible rupture mechanisms. MATERIALS AND METHODS: CFD analysis of pre- and posttreatment conditions was performed on 3 giant aneurysms that ruptured after treatment and 4 successfully treated aneurysms. Pre- and posttreatment hemodynamics were compared including WSS, relative blood flows, vascular resistances, and pressures, to identify the effects of flow-diverter placements. RESULTS: Expected reductions in aneurysm velocity and WSS were obtained, indicating effective flow diversion from the sac into the parent artery, consistent with periprocedural observations. In each case with postaneurysm rupture, the result of flow diversion led to an increase in pressure within the aneurysm. This pressure increase is related to larger effective resistance in the parent artery from placement of the devices and, in 2 cases, the reduction of a preaneurysm stenosis. CONCLUSIONS: Flow-diversion devices can cause intra-aneurysmal pressure increases, which can potentially lead to rupture, especially for giant aneurysms. This relates both to changes in the parent artery configuration, such as reduction of a proximal stenosis, and to the flow diversion into higher resistance parent artery pathways combined with cerebral autoregulation, leading to higher pressure gradients. These may be important effects that should be considered when planning interventions. Potentially dangerous cases could be identified with angiography and/or patient-specific CFD models. CFDcomputational fluid dynamicsΔPpressure drop3DRA3D rotational angiographyICAinternal carotid artery,PAparent arteryPEDPipeline Embolization DevicePTApercutaneous transarterial angioplastyPostafterPrebeforePipressure at the model inletPopressure at the model outletPssystemic pressureQflow rateRacombined resistance of the aneurysm and the parent artery segment at the aneurysm locationRddistal resistanceRpproximal resistanceWSSwall shear stress