Digital archive of theses discussed at the University of Pisa


Thesis etd-06212016-175846

Thesis type
Tesi di specializzazione (5 anni)
Thesis title
Computational modeling for surgical planning of arteriovenous fistula for hemodialysis: the AVF.sim system
Course of study
relatore Prof.ssa Egidi, Maria Francesca
  • doppler-ultrasound vascular mapping
  • arteriovenous fistula
  • computational model
  • hemodialysis vascular access
Graduation session start date
The native arteriovenous fistula (AVF) represents the vascular access (VA) of first choice for hemodialysis (HD) patients. Despite guidelines recommend pre-operative clinical and ultrasound criteria for the planning of AVF creation, the placement of a functioning AVF for haemodialysis is a difficult clinical task. Use of computational models to predict the AVF outcome could provide an efficient tool to assist the surgeon in selecting the optimal AVF location and configuration. Caroli et al. have recently reported interesting data that were collected in the context of the European ARCH project. They provided preliminary evidence about accuracy and reliability of the patient-specific computational model to predict the blood flow volume (BFV) distribution in the arm vasculature during VA maturation.
In order to evaluate the power of prediction and the acceptance in the clinical routine of this patient-specific computational model, Bozzetto M. and Remuzzi A. designed a multicentre prospective observational study involving six Italian clinical centers. In our centre, thirty-two patients with newly created AVF were enrolled. We placed two upper arm (brachiocephalic) and thirty lower arm (radiocephalic) AVF. All AVF had a side-to-end configuration.
We enjoyed the use of the model in the pre-operative AVF planning and it did not cause a further clinical workload. Despite the small sample size of data, predicted brachial artery blood flow volume at six weeks after surgery had a high significant linear correlation with measured values (in average 690±194 ml/min vs 704±186 ml/min, R=0.8, p<0.0001). Only few patients presented a discrepancy between predicted and measured brachial artery blood flow volume results.
In conclusion, this clinical observational study confirmed the accuracy of AVF blood flow volume predictions and showed that the system is easy to use and well accepted in the clinical setting. The AVF.SIM system can support the surgeon to plan more efficient AVF, with the reduction of no maturation events and the risk for heart failure and steal syndrome related to high blood flow volume AVF.