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A simulation of vessel-clamp interaction: transient closure dynamics.
Henry Y Chen1, Jose A Navia, Ghassan S Kassab
1Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA. hychen@purdue.edu
Annals of Biomedical Engineering
|June 25, 2009
Summary
This study simulated aortic cross-clamping in cardiac surgery, revealing that clamp design significantly impacts vessel stress. A plate clamp design proved superior in reducing both solid and fluid stresses, minimizing potential tissue injury.
Area of Science:
- Biomedical Engineering
- Cardiovascular Mechanics
- Surgical Simulation
Background:
- Aortic cross-clamping is a standard procedure in cardiac surgery.
- Understanding the mechanical stresses induced by clamping is crucial for patient safety and surgical technique optimization.
Purpose of the Study:
- To simulate aortic cross-clamping using computational modeling.
- To elucidate the perturbations in solid and fluid mechanics within the aorta during clamping.
- To compare the effects of different clamp geometries on stress distribution.
Main Methods:
- Development of Computer Assisted Design (CAD) and Finite Element Analysis (FEA) models of the aorta and surgical clamps.
- Simulation of a non-linear anisotropic vessel wall and Newtonian pulsatile fluid flow.
- Modeling of clamp application for total aortic occlusion within approximately 1 second.
- Evaluation of cylindrical and rectangular (plate) clamp geometries.
Main Results:
- High jet speeds and flow reversal were observed during the clamping process.
- Clamp design and vessel wall anisotropy influenced wall shear stress (WSS) and solid stresses.
- Maximum wall stresses increased significantly (170% for plate, 220% for cylindrical clamps).
- The plate clamp design demonstrated superior reduction in both solid and fluid shear stresses compared to the cylindrical clamp.
- Vibrations and WSS oscillations occurred before complete occlusion.
Conclusions:
- The study provides insights into tissue injury mechanisms during aortic cross-clamping.
- Computational modeling is valuable for analyzing surgical interventions.
- The plate clamp design is recommended for minimizing mechanical stresses, potentially reducing surgical complications and improving clamp design.
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