Doppler analysis of hemodialysis grafts: resistive index as a predictor of stenosis.

Abstract

A series of six hemodialysis vascular access patients was evaluated with duplex Doppler sonography and angiography to identify Doppler sonographic parameters that are predictors of venous outflow stenosis. This preliminary series indicates that no venous outflow stenosis was present angiographically when the resistive index gradient across the venous anastomosis is less than or equal to zero and a significant venous outflow stenosis (50 to 100%) was present when the resistive index gradient is 0.15 or greater (P = 0.002, r = 0.963). Doppler acquisition of resistive index gradients across regions of venous outflow is a promising, noninvasive means of rapid radiologic evaluation of hemodialysis graft patients, especially when the need for angiography is equivocal.

Interlocking Stents for Improving Stent Fixation at Graft–Venous Anastomosis

“…Pressure measurement in the venous limb of the dialysis circuit is a simple method of monitoring that has proven to be accurate in detecting venous stenoses [2,3]. Other monitoring methods have been suggested including monitoring the level of urea recirculation fraction, color and duplex sonography to evaluate flow rates [4], and MRI, which was recently demonstrated to be a new method for measuring blood flow [5].…”

Απεικονιστική διερεύνηση των επιπλοκών των αρτηριοφλεβωδών αναστομώσεων σε χρόνια αιμοκαθερούμενους ασθενείς με τη μέθοδο της έγχρωμης υπερηχογραφίας ροής (Color Doppler Flow Imaging). Συσχέτιση με αγγειογραφικά και χειρουργικά ευρύματα

“…Οι συχνότητες (f) των υπερήχων που χρησιμοποιούνται κυμαίνονται συνήθως από 3 μέχρι 10 εκατομμύρια κύκλους το δευτερόλεπτο (Hz). Το εύρος αυτών των συχνοτήτων τείνει καθημερινά να αυξάνεται (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Αξίζει να σημειωθεί ότι το κατώφλι ακοής στον άνθρωπο είναι 20.000 Hz.…”