While DSA allows for assessing vascular stenoses, most investigators tend towards an antegrade puncture at the distal aspect of the efferent vein for diagnostic fistulography. This necessitates retrograde opacification of the juxta- anastomotic segments to illustrate a possible stenosis. In identifying a stenosis in the proximal inflow segments during DSA, the interventionalist has to achieve retrograde sheath access to facilitate treatment, increasing procedure time [17]. Wasinrat et al [17] reported that DSA posed a limitation in facilitating stenosis detection on 2- D projections in the coronal view. Similarly, Heye et al [18] demonstrated an underestimation of stenoses on DSA when compared to multidetector CT (MDCT) angiography, where a stenosis was viewed in transverse and sagittal planes of planar reconstruction. It should be noted that the European Best Practice Guidelines Expert Group on Hemodialysis recommends against performing diagnostic fistulography without the intention to intervene on significant findings which may be causing the access dysfunction [19]. Diagnostic fistulography is useful for suspected dialysis access dysfunction if there is an intention to perform endovascular intervention on significant findings or if it is needed to support surgical planning [7]. US Duplex Doppler Hemodialysis Access Area of Interest US performed in B-mode and duplex Doppler US settings have sensitivity and specificity comparable to diagnostic fistulography for hemodynamically significant stenoses within the dialysis vascular access circuit. A study by Vardza Raju et al [25] examined the accuracy of the assessment of AVG and AVF using duplex US in comparison to noted findings on angiography in patients with failing vascular accesses in 51 accesses (35 AVF, 16 AVG). They reported that duplex Doppler US had 95.5% sensitivity and 57.1% specificity for stenoses >50% when using a ratio of peak systolic velocities.
Dialysis Fistula Malfunction. While DSA allows for assessing vascular stenoses, most investigators tend towards an antegrade puncture at the distal aspect of the efferent vein for diagnostic fistulography. This necessitates retrograde opacification of the juxta- anastomotic segments to illustrate a possible stenosis. In identifying a stenosis in the proximal inflow segments during DSA, the interventionalist has to achieve retrograde sheath access to facilitate treatment, increasing procedure time [17]. Wasinrat et al [17] reported that DSA posed a limitation in facilitating stenosis detection on 2- D projections in the coronal view. Similarly, Heye et al [18] demonstrated an underestimation of stenoses on DSA when compared to multidetector CT (MDCT) angiography, where a stenosis was viewed in transverse and sagittal planes of planar reconstruction. It should be noted that the European Best Practice Guidelines Expert Group on Hemodialysis recommends against performing diagnostic fistulography without the intention to intervene on significant findings which may be causing the access dysfunction [19]. Diagnostic fistulography is useful for suspected dialysis access dysfunction if there is an intention to perform endovascular intervention on significant findings or if it is needed to support surgical planning [7]. US Duplex Doppler Hemodialysis Access Area of Interest US performed in B-mode and duplex Doppler US settings have sensitivity and specificity comparable to diagnostic fistulography for hemodynamically significant stenoses within the dialysis vascular access circuit. A study by Vardza Raju et al [25] examined the accuracy of the assessment of AVG and AVF using duplex US in comparison to noted findings on angiography in patients with failing vascular accesses in 51 accesses (35 AVF, 16 AVG). They reported that duplex Doppler US had 95.5% sensitivity and 57.1% specificity for stenoses >50% when using a ratio of peak systolic velocities.