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

Abstract

The surgical creation of a vascular access, used for hemodialysis treatment of renal patients, has considerable complication rates (30-50 %). Image-based computational modeling might assist the surgeon in planning by enhanced analysis of preoperative hemodynamics, and in the future might serve as platform for outcome prediction. The objective of this study is to investigate preoperative personalization of the computer model using magnetic resonance (MR). MR-angiography and MR-flow data were obtained for eight patients and eight volunteers. Blood vessels were extracted for model input by a segmentation algorithm. Windkessel elements were added at the ends to represent the peripheral beds. Monte Carlo-based calibration was used to estimate the most influential non-measurable parameters. The predicted flow waveforms were compared with the MR-flow measurements for framework evaluation. The vasculature of all subjects were segmented in on average <5 min. The Monte Carlo-calibrated simulations showed a deviation between measured and simulated flow waveforms of 9 and 10 % for volunteers and patients, respectively. The presented method accurately mimics the preoperative hemodynamic state. Furthermore, the surgeon can interactively explore the hemodynamics at any vascular tree position. This integration of measurements in a modeling approach can provide the surgeon with additional information for preoperative planning.

Vascular Access: Inukshuk

“…Currently, 2 predictive models that use ultrasonographic findings and non-gadolinium contrast-enhanced magnetic resonance angiography provide anticipated vascular access blood flow rates before vascular access surgery is attempted. 34,35 Such predictive models offer the way forward in conjunction with excellent clinical judgment that considers the individual clinical and functional characteristics, life circumstances, and preferences of patients.…”

Novel Therapeutic Paradigms to Treat Hemodialysis Access Dysfunction

“…Following-up on the work of Bode, a more recent study uses non contrast enhanced magnetic resonance angiography (NCE-MRA) to provide arterial characteristics and semi quantitative venous characteristics [8]. This study from Netherlands aimed to assess the effect of geometric input on prediction of blood flow in vascular access using a generic circulation model with individualization limited to arm geometry (arterial diameters by NCE-MRA and venous parameters by US) and arterial flow using duplex ultrasound.…”

Morphological and hemodynamical alterations in brachial artery and cephalic vein. An image‐based study for preoperative assessment for vascular access creation

“…It has been shown that the patient-based preoperative geometric and hemodynamic characteristics of the circulatory system with the use of computational fluid dynamics (CFD) can assist the physician during the treatment planning. 15,16 In this paper, we initiate a study to ascertain the homeostatic shear level of the brachial artery (BA) and cephalic vein (CV). These vessels are commonly utilised and manipulated to some degree to form a fistula in the upper arm.…”