Lucile Mercadal a , Emmanuel Challier b , Philippe Cluzel b , Abdelaziz Hamani a , Hacène Boulechfar a , Zhora Boukhalfa a , Hassane Izzedine a , Nader Bassilios a , Benoît Barrou c , Gilbert Deray a , Thierry Petitclerc a
30 January 2002
Background/Aim: The measurement of the vascular access blood flow rate (Q<sub>a</sub>) in chronic hemodialyzed patients was proposed to predict access thrombosis. We have recently presented a new method based on the measurements of ionic dialysance at normal and reversed positions of the blood lines. We evaluate the reliability of the measurement of Q<sub>a</sub> by this method in detecting significant access stenoses. Methods: Twenty-five patients on chronic hemodialysis and having a vascular access cannulated with two needles were studied. The Q<sub>a</sub> was evaluated by the Diascan<sup>®</sup> ionic dialysance (Q<sub>a-id</sub>) method and by the ultrasound dilution technique (Q<sub>a-us</sub>; Transonic<sup>®</sup>) during the same dialysis session. The measurements were available for 23 patients. In addition, the patients had ultrasonography of their fistula followed by angiography, if a stenosis was detected. Results: Q<sub>a-id</sub> and Q<sub>a-us</sub> were not significantly different, showing a difference in Q<sub>a</sub> at 32 ± 469 ml/min. Q<sub>a-id</sub> was significantly different between patients with or without stenosis (508 ± 241 vs. 1,125 ± 652 ml/min, p < 0.05). Among patients with a Q<sub>a</sub> <500 ml/min by Q<sub>a-id</sub>, 5 had a stenosis detected by ultrasonography (sensitivity 83%), and 3 had no stenosis (false-positive rate 18%). Of these 3 patients, 2 had a thrombotic event at 1 and 3 months, suggesting that a more sensitive detection of stenosis for this range of Q<sub>a</sub> is needed and that a Q<sub>a</sub> <500 ml/min has a higher power to predict thromboses than a stenosis by ultrasonography. Conclusions: The measurement of the access flow rate by the Q<sub>a-id</sub> method has a clinical relevance to the detection of vascular access stenosis. An intervention program based on the Q<sub>a-id</sub> has to be evaluated.