Effect of flow diverter stent malposition on intracranial aneurysm hemodynamics-An experimental framework using stereoscopic particle image velocimetry.

Roloff, Christoph; Berg, Philipp

doi:10.1371/journal.pone.0264688

by Christoph Roloff, Philipp Berg

Abstract:

BACKGROUND: Flow-diverting stents are increasingly used for the minimally-invasive treatment of intracranial aneurysms. However, a correct positioning of such devices can be challenging due to varying vessel diameters as well as the complex anatomy of the neurovasculature. As a consequence, unsuccessful treatment outcomes are increasingly reported requiring an improvement of the understanding of stent-induced flow modification. METHODS: To evaluate the effect of different degrees of flow diverter stent malposition on intra-aneurysmal hemodynamic changes, a controlled hemodynamic configuration was created using an idealized intracranial aneurysms model. Afterwards, four different treatment scenarios were reproduced comprising of 1) the ideal treatment, 2) an insufficient wall apposition in the region of the ostium, 3) a distorted device migrating into the aneurysm sac and 4) an inaccurately deployed stent due to wrong release location. For the assessment of the individual flow modifications, high-resolution stereoscopic particle image velocimetry (PIV) measurements were carried out. RESULTS: The analysis of the precise in-vitro PIV measurements reveals that in all cases a considerable reduction of the cycle-averaged and peak-systolic velocity was obtained. Compared to the untreated aneurysm configuration, the flow reduction ranged from 63\% (scenario 4) up to 89\% (scenario 3). The ideal treatment reached a reduction of 78\%, which is known to be sufficient for a successful therapy. However, inaccurate device positioning leads to increased oscillating flow towards the lateral directions reducing the chances of sufficient thrombus formation. CONCLUSIONS: High-resolution in-vitro PIV measurements enable an accurate quantification of the treatment efficacy for flow-diverting devices. Furthermore, insufficient treatment outcomes can be reproduces allowing for an assessment of intra-aneurysmal hemodynamic changes.

Reference:

Effect of flow diverter stent malposition on intracranial aneurysm hemodynamics-An experimental framework using stereoscopic particle image velocimetry. (Christoph Roloff, Philipp Berg), In PloS one, volume 17, 2022.

Bibtex Entry:

@article{roloff_effect_2022,
	title = {Effect of flow diverter stent malposition on intracranial aneurysm  hemodynamics-{An} experimental framework using stereoscopic particle image  velocimetry.},
	volume = {17},
	issn = {1932-6203 1932-6203},
	doi = {10.1371/journal.pone.0264688},
	abstract = {BACKGROUND: Flow-diverting stents are increasingly used for the  minimally-invasive treatment of intracranial aneurysms. However, a correct  positioning of such devices can be challenging due to varying vessel diameters as  well as the complex anatomy of the neurovasculature. As a consequence,  unsuccessful treatment outcomes are increasingly reported requiring an  improvement of the understanding of stent-induced flow modification. METHODS: To  evaluate the effect of different degrees of flow diverter stent malposition on  intra-aneurysmal hemodynamic changes, a controlled hemodynamic configuration was  created using an idealized intracranial aneurysms model. Afterwards, four  different treatment scenarios were reproduced comprising of 1) the ideal  treatment, 2) an insufficient wall apposition in the region of the ostium, 3) a  distorted device migrating into the aneurysm sac and 4) an inaccurately deployed  stent due to wrong release location. For the assessment of the individual flow  modifications, high-resolution stereoscopic particle image velocimetry (PIV)  measurements were carried out. RESULTS: The analysis of the precise in-vitro PIV  measurements reveals that in all cases a considerable reduction of the  cycle-averaged and peak-systolic velocity was obtained. Compared to the untreated  aneurysm configuration, the flow reduction ranged from 63\% (scenario 4) up to 89\%  (scenario 3). The ideal treatment reached a reduction of 78\%, which is known to  be sufficient for a successful therapy. However, inaccurate device positioning  leads to increased oscillating flow towards the lateral directions reducing the  chances of sufficient thrombus formation. CONCLUSIONS: High-resolution in-vitro  PIV measurements enable an accurate quantification of the treatment efficacy for  flow-diverting devices. Furthermore, insufficient treatment outcomes can be  reproduces allowing for an assessment of intra-aneurysmal hemodynamic changes.},
	language = {eng},
	number = {3},
	journal = {PloS one},
	author = {Roloff, Christoph and Berg, Philipp},
	year = {2022},
	pmid = {35235597},
	pmcid = {PMC8890739},
	keywords = {*Intracranial Aneurysm/therapy, hemodynamics, Humans, Rheology, Stents, Treatment Outcome},
	pages = {e0264688}
}