Shear stress, vascular remodeling and neointimal formation

Area of Science:

• Cardiovascular Research
• Biomedical Engineering
• Medical Imaging

Background:

• Shear stress is a known factor in atherosclerosis.
• Its specific role in restenosis remains less understood.
• Restenosis, the re-narrowing of blood vessels after procedures like angioplasty, poses a significant clinical challenge.

Purpose of the Study:

• To introduce and validate a novel in vivo technique for measuring shear stress in blood vessels.
• To investigate the relationship between local shear stress and vascular remodeling in restenosis.
• To assess the potential of manipulating shear stress to prevent or reduce restenosis.

Main Methods:

• Development of a novel in vivo technique combining 3D reconstruction of blood vessels (using 3D intravascular ultrasound or fused angiography and IVUS) with computational fluid dynamics (CFD).
• Application of the technique to analyze shear stress distribution in relation to vessel wall morphology.
• Evaluation of a newly developed flow divider designed to locally increase shear stress.

Main Results:

• The combined 3D imaging and CFD technique successfully relates local shear stress to vessel wall morphology.
• Shear stress was demonstrated to play a predictive role in neointimal formation following in-stent restenosis and vascular remodeling after balloon angioplasty.
• Local increase of shear stress using the novel flow divider reduced in-stent neointimal formation by 50%.

Conclusions:

• The novel 3D imaging and CFD technique provides valuable insights into the role of shear stress in restenosis.
• Shear stress is a critical factor in predicting and potentially mitigating neointimal hyperplasia and vascular remodeling.
• Targeting shear stress through interventions like the developed flow divider shows significant therapeutic potential for reducing restenosis.