Clinical Trial Details
— Status: Recruiting
Administrative data
NCT number |
NCT06262659 |
Other study ID # |
2023-142 |
Secondary ID |
|
Status |
Recruiting |
Phase |
|
First received |
|
Last updated |
|
Start date |
March 8, 2024 |
Est. completion date |
September 10, 2024 |
Study information
Verified date |
March 2024 |
Source |
Hitit University |
Contact |
Kudret Atakan Tekin |
Phone |
+905424912184 |
Email |
dr.kudretatakantekin[@]gmail.com |
Is FDA regulated |
No |
Health authority |
|
Study type |
Observational
|
Clinical Trial Summary
Arteriovenous fistulas (AVF) are considered essential and the primary vascular access for
end-stage renal disease patients to receive hemodialysis (HD) treatment. The maturation
failure rate of AVFs is approximately 23%. The aim of our study is to compare intraoperative
fistula flow and measurements of vascular structures' diameters with postoperative fistula
maturation, following the completion of the fistula operation, to reveal the relationship
between them. Providing insights into the need for intraoperative intervention and/or
postoperative fistula management based on these measurements is intended to contribute to the
literature by offering predictions and perspectives.
Description:
Arteriovenous fistulas (AVF) are generally acknowledged as the 'gold standard' for
hemodialysis (HD) access in end-stage renal disease patients. While they exhibit the most
successful performance, their lifespan is longer compared to other access types, and the
infection and hospitalization rates are lower. However, it is known that many newly created
fistulas do not mature to a level that provides sufficient HD access. There is no universal
definition for a matured AVF, and the method adopted in the updated National Kidney
Foundation's Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) guidelines is widely
used. KDOQI has defined the "6s rule" to describe maturation (a flow rate of 600 ml/min, an
AVF located within 6 millimeters from the skin surface to facilitate successful and
repeatable cannulation by HD staff, and finally, a minimum diameter of 6 millimeters). A
matured AVF should be continuously cannulated and allow a minimum blood flow of 300-400 ml
per minute. Various patient factors, including Diabetes Mellitus (DM), female gender, and
age, have been suggested to be associated with poor AVF maturation. However, these factors
are less important when preoperative ultrasound mapping of the relevant arterial and venous
region shows vessels of sufficient size. Preoperative ultrasound venous mapping has been
proven to significantly assist in deciding on an AVF with a higher chance of successful
maturation. Surgical or endovascular intervention is frequently required for AVFs that do not
mature or to facilitate maturation. Even after successful AVF maturation, interventions are
often needed to maintain long-term patency in hemodialysis. The maturation of AVF typically
takes between 6 to 8 weeks. Previous studies have evaluated postoperative ultrasound criteria
to assess AVF maturation and determine the need for interventions that would promote
maturation. These studies reported high predictive values for AVF maturation using
postoperative blood flow thresholds of 420-800 ml/min or diameters of 3.6-5.4 mm. However,
the generalizability of these studies is limited due to the relatively small number of
patients, the prevalence of radiocephalic AVFs, and variable definitions of AVF maturation.
While published studies have focused on the value of postoperative AVF ultrasound
measurements in predicting maturation, none have assessed the predictive value for
determining primary patency (the time until the first intervention when the AVF achieves
independent maturation). Venous diameter maturity is an independent determinant, and a venous
diameter less than 2.5 mm is often associated with non-maturation, especially if the vein
cannot expand after tourniquet application; a preoperative ultrasound measurement of a vein
≥4 mm is expected to result in successful maturation. A series of 158 patients reported that
venous diameter was the main independent determinant of functional maturation, and it was the
only independent variable. NKF-KDOQI guidelines suggest allowing a fistula to mature for at
least one month before cannulation. Cannulating within 14 days after AVF creation reduces
long-term fistula survival and increases the risk of subsequent fistula failure by 2.1 times
compared to fistulas cannulated after 14 days. Fistulas cannulated between 15 and 28 days
showed no significant difference in non-maturation rates compared to those cannulated after
43 to 84 days. Ultrasound is a non-invasive imaging technology that can significantly
contribute to understanding vascular anatomy in the context of dialysis access. Depth
measurements and flow volume detections in arterial flow, in particular, can guide
interventions. Postoperative ultrasound is commonly used to assess AVF maturation for
hemodialysis.