Computational fluid dynamics for predicting the growth of small unruptured cerebral aneurysms

Masanori Tsuji; Fujimaro Ishida; Ryuta Yasuda; Takenori Sato; Kazuhiro Furukawa; Yoichi Miura; Yasuyuki Umeda; Naoki Toma; Hidenori Suzuki

doi:10.3171/2023.5.JNS222752

Computational fluid dynamics for predicting the growth of small unruptured cerebral aneurysms

J Neurosurg. 2023 Jun 30;140(1):138-143. doi: 10.3171/2023.5.JNS222752. Print 2024 Jan 1.

Authors

Masanori Tsuji¹, Fujimaro Ishida², Ryuta Yasuda¹, Takenori Sato¹, Kazuhiro Furukawa³, Yoichi Miura¹, Yasuyuki Umeda⁴, Naoki Toma¹, Hidenori Suzuki¹

Affiliations

¹ 1Department of Neurosurgery, Mie University Graduate School of Medicine, Tsu, Mie, Japan.
² 2Department of Neurosurgery, Mie Chuo Medical Center, National Hospital Organization, Tsu, Mie, Japan.
³ 3Hisai Neurosurgical Clinic, Tsu, Mie, Japan; and.
⁴ 4Department of Neurosurgery, Mie Prefectural General Medical Center, Yokkaichi, Mie, Japan.

PMID: 37410657
DOI: 10.3171/2023.5.JNS222752

Abstract

Objective: Larger cerebral aneurysms are more likely to enlarge, but even small aneurysms can grow. The aim of this study was to investigate the hemodynamic characteristics regarding the growth of small aneurysms using computational fluid dynamics (CFD).

Methods: The authors analyzed 185 patients with 215 unruptured cerebral aneurysms with a maximum diameter of 3-5 mm, registered in a multicenter prospective observational study of unruptured aneurysms (Systematic Multicenter Study of Unruptured Cerebral Aneurysms Based on Rheological Technique at Mie) from January 2013 to February 2022. Based on findings on repeated images, aneurysms were divided into a stable group (182 aneurysms) and a growth group (33 aneurysms). The authors developed the high shear concentration ratio (HSCR), in which high wall shear stress (HWSS) was defined as a value of 110% of the time-averaged wall shear stress of the dome. High shear area (HSA) was defined as the area with values above HWSS, and the ratio of the HSA to the surface area of the dome was defined as the HSA ratio (HSAR). They also created the flow concentration ratio (FCR) to measure the concentration of the inflow jet. Multivariate logistic regression analysis was performed to determine morphological variables and hemodynamic parameters that independently characterized the risk of growth.

Results: The growth group had a significantly higher projection ratio (0.74 vs 0.67, p = 0.04) and volume-to-ostium area ratio (1.72 vs 1.44, p = 0.02). Regarding the hemodynamic parameters, the growth group had significantly higher HSCR (6.39 vs 4.98, p < 0.001), lower HSAR (0.28 vs 0.33, p < 0.001), and lower FCR (0.61 vs 0.67, p = 0.005). In multivariate analyses, higher HSCR was significantly associated with growth (OR 0.81, 95% CI 7.06 e-1 to 9.36 e-1; p = 0.004).

Conclusions: HSCR may be a useful hemodynamic parameter to predict the growth of small unruptured cerebral aneurysms.

Keywords: computational fluid dynamics; high shear area ratio; small unruptured cerebral aneurysms; vascular disorders.

Publication types

Observational Study
Multicenter Study

MeSH terms

Aneurysm, Ruptured* / complications
Hemodynamics
Humans
Hydrodynamics
Intracranial Aneurysm* / complications
Intracranial Aneurysm* / diagnostic imaging
Stress, Mechanical