PT  - JOURNAL ARTICLE
AU  - J.R. Cebral
AU  - F. Mut
AU  - M. Raschi
AU  - E. Scrivano
AU  - R. Ceratto
AU  - P. Lylyk
AU  - C.M. Putman
TI  - Aneurysm Rupture Following Treatment with Flow-Diverting Stents: Computational Hemodynamics Analysis of Treatment
AID  - 10.3174/ajnr.A2398
DP  - 2011 Jan 01
TA  - American Journal of Neuroradiology
PG  - 27--33
VI  - 32
IP  - 1
4099  - http://www.ajnr.org/content/32/1/27.short
4100  - http://www.ajnr.org/content/32/1/27.full
SO  - Am. J. Neuroradiol.2011 Jan 01; 32
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