Bedside Screening for Fistula Stenosis Should Be Tailored to the Site of the Arteriovenous Anastomosis

Abstract

SummaryBackground and objectives Given different sites of stenosis and access blood flow rates (Qa), the criteria for diagnosing fistula stenosis might vary according to anastomotic site. To test this, we analyzed the database of a prospective blinded study seeking an optimal bedside screening program for fistula stenosis.Design, setting, participants, & measurements Several methods used during dialysis (physical examination [PE], dynamic and derived static venous pressure [VAPR], dialysis blood pump flow/arterial pressure ratio, and Qa measurement) to diagnose angiographically-proven Ͼ50% stenosis were assessed in an unselected population of hemodialysis patients with mature fistulae (43 at the wrist [distal fistulae], 76 at midforearm or the elbow [proximal fistulae]).Results Prevalence of inflow stenosis was uninfluenced by anastomotic site, whereas outflow stenoses were more prevalent in proximal fistulae. The best test for inflow stenosis was Qa Ͻ650 ml/min in distal fistulae and a combination of a positive PE and Qa Ͻ900 ml/m in proximal fistulae. In proximal fistulae, PE and VAPR Ͼ0.5 were both equally highly diagnostic of outflow stenosis. Tailoring choice of test to site of the anastomosis may also contain the screening-associated workload, by reducing the need to perform PE and measure VAPR, compared with a screening approach regardless of the access location. ConclusionsOur study shows that an effective bedside screening program with Ն85% accuracy for fistula stenosis can be tailored to the site of the anastomosis, Qa being the tool of choice for the wrist, and PE alone or combined with Qa and VAPR measurements for more proximally-located accesses.

Observational Study of Surveillance Based on the Combination of Online Dialysance and Thermodilution Methods in Hemodialysis Patients with Arteriovenous Fistulas

“…Lowrie et al [8] recommend monitoring the dialysis dose with a Kt of at least 40 liters in women and 45 liters in men or individually tailoring the dose according to the body surface area [9]. Assessment of vascular access function should always include an accurate physical examination [10,11,12]. …”

Efficacy of Percutaneous Transluminal Angioplasty on Dysfunctional Fistulae Because of Inflow Stenosis

“…We did not perform any access Qa monitoring at the time, before or after angioplasty, and the referral method for this study was based solely on clinical criteria; even so we achieved reasonable results, emphasizing the importance of clinical monitoring of hemodialysis accesses. Other surveillance techniques are associated with earlier detection of stenotic lesions, particularly when dysfunction comes from inflow lesions; however physical examination remains an invaluable monitoring method (25). sites along the drainage vein (9,19).…”

“…Venous problems have been regarded as the principal culprits for access dysfunction for a long time, with much less importance given to inflow problems which had an incidence of 0% to 4% (12). Although, in the last few years, inflow stenoses have been shown to be present in approximately 25% to 50% of the dysfunctional access (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26). Both radiocephalic and brachiocephalic fistulas commonly fail because of lesions located within the perianastomotic region; however, more proximal stenoses can also occur in both cases, especially in the case of brachiocephalic fistulas (cephalic arch stenosis) (27).…”

Radio‐cephalic fistula recovered with drainage to forearm basilic vein

“…3 However, some RC-AVF may cause dysfunction problems difficult to solve, raising great challenges to vascular surgeons. Monitoring and surveillance programs in dialysis units have shown improvement in access patency and a decrease in hospital admissions caused by access dysfunction.…”