Hemodynamic Effect of Flow Diverter and Coils in Treatment of Large and Giant Intracranial Aneurysms

World Neurosurg. 2016 May;89:199-207. doi: 10.1016/j.wneu.2016.01.079. Epub 2016 Feb 4.

Abstract

Background: This study aimed to investigate the hemodynamic changes induced by a flow diverter (FD) and coils in the treatment of internal carotid artery aneurysms, as well as to evaluate the effect of this treatment by using angiographic follow-up data.

Methods: Six large and giant aneurysms were treated by the Tubridge FD and loose packing coils between June 2013 and May 2015. Patient-specific models were constructed and analyzed using a computational fluid dynamics (CFD) method. The virtual FD deployment method was used to implant the Tubridge stent into a 3-dimensional digital subtraction angiographic image of the aneurysms, and the coils were simulated by a porous medium model.

Results: Tubridge FD alone can significantly reduce the intra-aneurysmal flow velocity (0.17 ± 0.05 m/s-0.11 ± 0.06 m/s, P < 0.001) and wall shear stress (WSS, 1.39 ± 0.29 Pa-0.77 ± 0.34 Pa, P = 0.001) and increase the low wall shear area (LSA, 6.38% ± 1.49%-34.60% ± 28.90%, P = 0.047). Coils, as a supplementary measure, further reduced the velocity (0.11 ± 0.06 m/s-0.08 ± 0.05 m/s, P = 0.03) and WSS (0.77 ± 0.34 Pa-0.47 ± 0.35 Pa, P = 0.04) and increased the LSA (34.60% ± 28.90%-63.33% ± 34.82%, P = 0.044). Aneurysm with sustained strong inflow after treatment (case 3, 25% reduction in velocity, 12% reduction in WSS, and 16% increment in LSA) showed partial patency, whereas others with a weaker inflow jet (mean 56% reduction in velocity, 74% reduction in WSS, and 1081% increment in LSA) showed complete occlusion at follow-up.

Conclusions: On the basis of using the CFD method, adjunctive coiling with the Tubridge FD placement may significantly reduce intra-aneurysmal flow velocity and WSS, promoting thrombosis formation and occlusion of aneurysms.

Keywords: Aneurysm; Coil; Computational fluid dynamics; Flow diverter; Hemodynamics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Angiography, Digital Subtraction
  • Blood Vessel Prosthesis*
  • Carotid Artery Diseases / diagnostic imaging
  • Carotid Artery Diseases / physiopathology
  • Carotid Artery Diseases / surgery*
  • Carotid Artery, Internal / diagnostic imaging
  • Carotid Artery, Internal / physiopathology
  • Carotid Artery, Internal / surgery*
  • Cerebral Angiography
  • Cerebral Revascularization* / instrumentation
  • Cerebral Revascularization* / methods
  • Cerebrovascular Circulation
  • Female
  • Follow-Up Studies
  • Hemodynamics*
  • Humans
  • Hydrodynamics
  • Imaging, Three-Dimensional
  • Intracranial Aneurysm / diagnostic imaging
  • Intracranial Aneurysm / physiopathology
  • Intracranial Aneurysm / surgery*
  • Male
  • Middle Aged
  • Patient-Specific Modeling
  • Stents
  • Stress, Mechanical
  • Treatment Outcome