Enhanced aneurysmal flow diversion using a dynamic push-pull technique: an experimental and modeling study.
OBJECTIVE
Neurovascular flow diverters are flexible, braided stent-meshes for intracranial aneurysm treatment. We applied the dynamic push-pull technique to manipulate the flow-diverter mesh density at the aneurysm orifice to maximize flow diversion. This study investigated the hemodynamic impact of the dynamic push-pull technique on patient-specific aneurysms by using the developed high-fidelity virtual-stenting computational modeling technique combined with computational fluid dynamics.


METHODS
We deployed 2 Pipeline Embolization Devices into 2 identical sidewall anterior cerebral artery aneurysm phantoms by using the dynamic push-pull technique with different delivery-wire advancements. We then numerically simulated these deployment processes and validated the simulated mesh geometry. Computational fluid dynamics analysis was performed to evaluate detailed hemodynamic changes by deployed flow diverters in the sidewall aneurysm and a fusiform basilar trunk aneurysm (deployments implemented previously). Images of manipulated flow diverter mesh from sample clinical cases were also evaluated.


RESULTS
The flow diverters deployed in silico accurately replicated in vitro geometries. Increased delivery wire advancement (21 versus 11 mm) by using a dynamic push-pull technique produced a higher mesh compaction at the aneurysm orifice (50% metal coverage versus 36%), which led to more effective aneurysmal inflow reduction (62% versus 50% in the sidewall aneurysm; 57% versus 36% in the fusiform aneurysm). The dynamic push-pull technique also caused relatively lower metal coverage along the parent vessel due to elongation of the flow diverter. High and low mesh compactions were also achieved for 2 real patients by using the dynamic push-pull technique.


CONCLUSIONS
The described dynamic push-pull technique increases metal coverage of pure braided flow diverters over the aneurysm orifice, thereby enhancing the intended flow diversion, while reducing metal coverage along the parent vessel to prevent flow reduction in nearby perforators.
From the Toshiba Stroke and Vascular Research Center (D.M., J.X., A.H.S., H.M.) Departments of Mechanical and Aerospace Engineering (D.M., J.X., H.M.).
D
D
Ma
From the Toshiba Stroke and Vascular Research Center (D.M., J.X., A.H.S., H.M.) Departments of Mechanical and Aerospace Engineering (D.M., J.X., H.M.) Neurosurgery (J.X., S.K.N., A.H.S., H.M.).
J
J
Xiang
Department of Neurosurgery (H.C.), Upstate Medical University, The State University of New York, Syracuse, New York.
H
H
Choi
Department of Surgery (T.M.D.), The University of Arizona; Tucson, Arizona.
T M
TM
Dumont
Neurosurgery (J.X., S.K.N., A.H.S., H.M.).
S K
SK
Natarajan
From the Toshiba Stroke and Vascular Research Center (D.M., J.X., A.H.S., H.M.) Neurosurgery (J.X., S.K.N., A.H.S., H.M.) Radiology (A.H.S.), University at Buffalo, The State University of New York, Buffalo, New York.
A H
AH
Siddiqui
From the Toshiba Stroke and Vascular Research Center (D.M., J.X., A.H.S., H.M.) Departments of Mechanical and Aerospace Engineering (D.M., J.X., H.M.) Neurosurgery (J.X., S.K.N., A.H.S., H.M.) huimeng@buffalo.edu.
H
H
Meng
D000328:Adult; D003198:Computer Simulation; D004621:Embolization, Therapeutic / Q000379:methods*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D057446:Hydrodynamics; D002532:Intracranial Aneurysm / Q000628:therapy*; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D015607:Stents; D014656:Vascular Surgical Procedures / Q000379:methods*