Interventional Nephrology and Dialysis: The Role of Sonography in the Planning of Arteriovenous Fistulas for Hemodialysis

Abstract

Patients presenting for initial access evaluation in contemporary practice are less likely to have arteries and veins suitable for native fistula (AVF) formation in the classic location. Physical examination of the upper extremity alone may be inadequate for selection of arteries and veins that will mature into a functioning AF. The purpose of this paper is to determine how duplex ultrasonography can be used as an effective modality for the preoperative evaluation of vessels before construction of arteriovenous fistula for hemodialysis. The author have used duplex ultrasound (DU) to assess upper-extremity vasculature for planning of dialysis access procedures. Criteria for selection of arteries and veins and a detailed description of DU examination protocol are reviewed. Routine use of upper-extremity DU has identified many patients with veins that are suitable for use and determined arteries with optimal arterial inflow for successful AFV creation.

Color Doppler ultrasound and arteriovenous fistulas for hemodialysis

“…Alternatively, he/she may be seated in front of the operator with the forearm resting on a stand. Most examiners prefer the supine position because it simplifies the assessment of the vascular structures of the arm (subclavicular axillary region) and is more comfortable for the patient [13,14]. The examination should be carried out in a comfortably warm room, and the gel should also be warmed to avoid triggering vasoconstriction of the structures being examined [13,14].…”

“…Most examiners prefer the supine position because it simplifies the assessment of the vascular structures of the arm (subclavicular axillary region) and is more comfortable for the patient [13,14]. The examination should be carried out in a comfortably warm room, and the gel should also be warmed to avoid triggering vasoconstriction of the structures being examined [13,14]. Ideally, the arterial and venous districts should be evaluated consecutively, with transverse and/or longitudinal scans of the arteries (from the root of the arm towards the hand) and veins (from the periphery towards the thorax).…”

“…The internal diameter of an artery can be measured on either longitudinal and transverse scans [14], but the former allows visualization of the intimal layers of the superficial and deep vessel walls, thereby facilitating more precise measurement of the intima-intima distance (i.e., the internal diameter of the vessel) [9]. To verify the precision of these measurements, sonographically measured vessel diameters have been compared with measurements obtained directly during surgery, and the correlation between the two proved to be good [17].…”

Fistula First Initiative

“…The criteria on which a vessel is suitable for AVF creation by duplex ultrasound are not established. Many variables should be considered (89,92,93), and using minimal vessel diameter as a sole criterion should be avoided. Doing so may preclude the use of veins that would have been acceptable by clinical examination (24,94).…”

Hemodialysis Vascular Access Dysfunction

“…These cells then could produce an array of mediators that hopefully would mimic the two main functions of endothelial cells (promote vascular dilation and inhibit neointimal hyperplasia). At a practical level, however, numerous clinical studies have been able to demonstrate a significant improvement in the maturation of AVF through an aggressive preoperative ultrasound evaluation of arterial and venous diameters (112)(113)(114). Malovrh et al (113), for example, demonstrated an immediate patency rate of 92% in patients with a preoperative internal diameter of Ͼ1.5 mm in the feeding artery as compared with a maturation rate of 45% in patients with an internal diameter of Ͻ1.5 mm.…”