Background The
vascular access guidelines recommend that arteriovenous fistulas (AVFs)
with access dysfunction and an access blood flow
(Qa) <300–500 mL/min be referred for stenosis
imaging and treatment. Significant (>50%) stenosis, however, may be
detected
in a well-functioning AVF with a Qa > 500
mL/min, too, but whether it is worth correcting or not remains to be
seen.
Methods In October
2006, we began an open randomized controlled trial enrolling patients
with an AVF with subclinical stenosis and
Qa > 500 mL/min, to see how elective stenosis
repair [treatment group (TX)] influenced access failure (thrombosis or
impending
thrombosis requiring access revision), or loss
and the related cost compared with stenosis correction according to the
guidelines,
i.e. after the onset of access dysfunction or a
Qa < 400 mL/min [control group (C)]. An interim analysis was
performed in
July 2012, by which time the trial had enrolled
58 patients (30 C and 28 TX).
Results TX led to a
relative risk of 0.47 [95% confidence interval (CI): 0.17–1.15] for
access failure (P = 0.090), 0.37 [95% CI:
0.12–0.97] for thrombosis (P = 0.033) and 0.36
[95% CI: 0.09–0.99] for access loss (P = 0.041). In the setting of our
study
(in which all surgery was performed as in
patient procedure) no significant differences in costs emerged between
the two strategies.
The mean incremental cost-effectiveness ratio
for TX was €282 or €321 to avoid one episode of thrombosis or access
loss, respectively.
Conclusions Our
interim analysis showed that elective repair of subclinical stenosis in
AVFs with Qa > 500 mL/min cost-effectively reduces
the risk of thrombosis and access loss in
comparison with the approach of the Kidney Disease Outcomes Quality
Initiative (KDOQI)
guidelines, raising the question of whether the
currently recommended criteria for assessing and treating stenosis
should
be reconsidered.
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