Duplex Scanning–Derived Access Volume Flow: Novel Predictor of Success Following Endovascular Repair of Failing or Nonmaturing Arteriovenous Fistulae for Hemodialysis

Abstract

The objective of this study was to evaluate the feasibility of duplex scanning-derived access volume flow (DAVQ) to predict the success or failure of arteriovenous fistulae (AVF) after interventions. Eighty-eight DAVQ measurements were available for 60 AVF in 59 patients. In 25 cases, physical examination findings or inadequate dialysis suggested failing (11) or nonmaturing (14) AVF. Outflow stenoses (1-4; mean 1.2 +/- 0.8) were confirmed by contrast fistulograms in 23 cases (17 peripheral; 6 central). These 23 cases underwent successful endovascular repair (17 balloon angioplasty; 6 stents) and had pre- and postintervention DAVQ measurements within 2 weeks of the procedure. Each was measured three times in a nontortuous venous segment with laminar flow, and mean values were used for comparison. The overall mean DAVQ for 65 functioning AVF was 1,199 +/- 485 mL/min, whereas it was 652 +/- 438 mL/min (range 150-1,840 mL/min) for the remaining 23 failing or nonmaturing cases (p < .0001). Postintervention, the latter values changed to 867 +/- 517 mL/min (range 257-2,020 mL/min), with a p < .13. Of these, 11 were still nonfunctional after endovascular procedures and had a mean DAVQ of 404 +/- 111 mL/min (range 257-652 mL/min). The remaining 12 cases had a mean DAVQ of 1,280 +/- 382 mL/min (range 762-2,020 mL/min) and were functional and usable for at least 6 months of follow-up (p < .0001). It is interesting to note that none of the AVF cases with postintervention DAVQ < 700 mL/min became functional and usable, whereas all cases with a higher DAVQ underwent successful hemodialysis treatments. This early experience suggests that DAVQ can be used to predict the success or failure of an AVF following endovascular procedures. To our knowledge, this is the first such report.

Vascular access surveillance: an ongoing controversy

“…As currently practiced, the 'access surveillance strategy' uses costly radiology resources and requires significant patient time and inconvenience. 76,79 We need to be able to define and target high risk populations for surveillance, find a validated test to predict those who will succeed or fail after an intervention, 80,81 and determine which interventions will facilitate increased access patency without harm. Targeting measurements to the newest accesses, which are most likely to fail, 50 appears to be a logical step.…”

Duplex Guided Dialysis Access Interventions can be Performed Safely in the Office Setting: Techniques and Early Results

“…Duplex derived access volume flow (DAVQ) has been reported by Ascher to be a good predictor of clinical success following endovascular repair of failing or immature access. 29 He found that DAVQ for functioning AAVA's averaged 1199 mL/min. The DAVQ in AAVA's that underwent intervention and went on to become functional for dialysis for at least 6 months was at least 867 mL/min.…”

“…Clinical criteria included the inability to achieve prescribed dialysis flow rates and difficulty with cannulation. Other indications included pulsatility (29), low access flow (28), decreased flow (23), infiltration (13), aneurysmal degeneration (11), bleeding (9), pseudoaneurysmal degeneration (6), elevated venous pressures (5), difficult cannulation (3), pain (3), ulceration (1), decreased clearance (1), swelling (1) and decreased arterial pressures (1). More than one indication for intervention was often present in an individual patient.…”

Dialysis Access: Percutaneous Endovascular Interventions under Sonographic Guidance Alone

“…Estimates of VFs were based on the mean of at least two congruent measurements in a non-tortuous segment of the brachial artery or in the prosthesis. All interventions were performed with a linear 12 MHz probe (Affiniti 70, Philips Medical Systems) [7]. The interventions were performed in a simple examination room in our outpatient clinic by an experimented angiologist assisted by one vascular nurse.…”