Assisting vascular access surgery planning for hemodialysis by using MR, image segmentation techniques, and computer...

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Computational Fluid Dynamics

Background:

• Surgical creation of vascular access for hemodialysis in renal patients has high complication rates (30-50%).
• Image-based computational modeling offers potential for enhanced preoperative hemodynamic analysis and outcome prediction.
• Personalized computer models are needed to improve surgical planning for vascular access.

Purpose of the Study:

• To investigate the preoperative personalization of a computational model using magnetic resonance (MR) imaging.
• To evaluate the accuracy of MR-personalized models in mimicking patient-specific hemodynamics.
• To assess the potential of this approach for improving surgical planning in hemodialysis access creation.

Main Methods:

• Acquired MR-angiography and MR-flow data from eight patients and eight volunteers.
• Utilized a segmentation algorithm to extract blood vessels for model input.
• Incorporated Windkessel elements to represent peripheral vascular beds.
• Employed Monte Carlo-based calibration to estimate non-measurable parameters.
• Compared predicted flow waveforms with MR-flow measurements for validation.

Main Results:

• Vascular segmentation was achieved in an average of <5 minutes per subject.
• Monte Carlo-calibrated simulations showed a 9% deviation for volunteers and 10% for patients between measured and simulated flow waveforms.
• The developed method accurately reproduced the preoperative hemodynamic state.
• The model allows interactive exploration of hemodynamics throughout the vascular tree.

Conclusions:

• Preoperative personalization of computational models using MR imaging is feasible and accurate.
• This approach effectively mimics patient-specific hemodynamics, providing valuable information for surgical planning.
• Integration of imaging measurements into modeling enhances preoperative decision-making for vascular access surgery.
• The method has the potential to improve surgical outcomes and reduce complications in hemodialysis patients.