Advanced Ultrasound Applications for Predicting AVF Outcomes

This is an observational prospective pilot study of patients with end-stage renal disease (ESRD), who will be referred for AVF procedure. Duration: 21 Months The research team will collect data from the patients after they have signed the informed consent form. Data collection will take place before, during and after arteriovenous fistula (AVF) surgery. At 0 week, the patient will be interviewed to obtain clinical information. Also, blood pressure and body mass index will be checked and recorded. Next, pre-operative AVF assessment ultrasound measurements will be performed to assess flow, pulsatility and vessel diameter. Advanced ultrasound applications(2D strain speckle tracking and 2D Shear wave elastography) will be applied to assess arterial stiffness as additional measurement tools. These are quantitative measures of vessel stiffness. It takes less than five minutes to obtain these measurements from the imaged vessel. During AVF surgery, the endothelial function will be assessed intraoperatively by testing the ability of the endothelium to dilate, flow mediation dilation (FMD). Leftover vessel specimens will be collected for histopathological analysis purpose. At 6 week, post-AVF ultrasound assessment will be conducted to assess the maturation of AVF by measuring ultrasound parameters of blood flow, pulsatility and vessel diameter. Arterial stiffness parameters will be measured as well. Blood pressure and BMI will be assessed and recorded. Study data will be entered into a study database which will consist of a password encrypted stored on a password-protected computer in the vascular lab at Hammersmith Hospital. Only the study researchers will know the study database password. Data analysis will be performed after the enrolment of 20, 40 and 75 patients.