Optimal Timing of Percutaneous Intervention in Non-maturing Dialysis Fistulas

Study Overview
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Brief Summary
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Arteriovenous fistulas (AVFs) are the preferred type of vascular access for dialysis, but many of them fail to mature. The optimal timing of intervention to salvage immature AVFs is unknown.The study proposes a randomized clinical trial comparing the clinical and economic impact of early vs late angioplasty in non-maturing AVFs. The study proposes a RCT to test the hypothesis that, as compared to early angioplasty of non-maturing AVFs, late angioplasty results in a lower proportion of AVFs being used at 6 months, but a greater long-term AVF patency , lower requirement of subsequent interventions to maintain AVF patency for dialysis, and lower overall cost of access maintenance.

Detailed Description
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The optimal timing of intervention in non-maturing AVFs remains controversial, and can only be definitively addressed by a randomized clinical trial (RCT) comparing early (6 weeks) vs late (3 months) angioplasty of non-maturing AVFs. The investigators will perform a single-center, prospective RCT. The investigators will recruit 112 patients who initiated hemodialysis with a CVC, then had a new AVF created after commencing dialysis, and then had a 6-week postoperative ultrasound that revealed an immature AVF (diameter < 4 mm diameter or blood flow < 500 ml/min). These patients will be randomized to one of two groups: an early intervention group that will undergo a routine PTA at 6 weeks after AVF creation, or a late intervention group in which early PTA will be avoided and subsequently be performed only if the 3-month ultrasound indicates persistent AVF immaturity. These patients will be followed for 2 years.

Official Title
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Optimal Timing of Percutaneous Intervention in Non-maturing Dialysis Fistulas

Conditions
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Immature Arteriovenous Fistula

Intervention / Treatment
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* Procedure: early Angioplasty
* Procedure: late Angioplasty


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with End stage renal disease (ESRD). Patients on hemodialysis. Patients using central venous catheter (CVC). Patients who had a new AVF created after commencing dialysis. Patients who had immature fistula ( 6-week postoperative ultrasound that revealed an immature AVF (diameter < 4 mm diameter or blood flow < 500 ml/min). Exclusion Criteria: • Children with Age below 18

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: early angioplasty<br>Patients who initiated hemodialysis with a CVC, then had a new AVF created after commencing dialysis, and then had a 6-week postoperative ultrasound that revealed an immature AVF (diameter < 4 mm diameter or blood flow < 500 ml/min). These patients who an early angioplasty intervention group that will undergo a routine Angioplasty at 6 weeks after AVF creation | Procedure: early Angioplasty<br>* Angioplasty is a minimally invasive, endovascular procedure to widen narrowed or obstructed arteries or veins. A deflated balloon attached to a catheter (a balloon catheter) is passed over a guide-wire into the narrowed vessel and then inflated to a fixed size. The balloon forces expansion of the blood vessel and the surrounding muscular wall, allowing an improved blood flow. This is part of standard of care for immature arteriovenous fistulas. Early means pt will get the procedure at 6 weeks from time of initiation of AVFs<br>* Other names: Early PTA;|
| Experimental: late Angioplasty<br>Patients who initiated hemodialysis with a CVC, then had a new AVF created after commencing dialysis, and then had a 6-week postoperative ultrasound that revealed an immature AVF (diameter < 4 mm diameter or blood flow < 500 ml/min). These patients who a late angioplasty intervention group in which early Angioplasty will be avoided and subsequently be performed only if the 3-month ultrasound indicates persistent AVF immaturity | Procedure: late Angioplasty<br>* Angioplasty is a minimally invasive, endovascular procedure to widen narrowed or obstructed arteries or veins. A deflated balloon attached to a catheter (a balloon catheter) is passed over a guide-wire into the narrowed vessel and then inflated to a fixed size. The balloon forces expansion of the blood vessel and the surrounding muscular wall, allowing an improved blood flow. This is part of standard of care for immature arteriovenous fistulas. Late means the angioplasty is done at 3 months from time of AVF creation if still immature at that time.<br>* Other names: Late PTA;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fistula Maturity | Ultrasound of the fistula: Mature fistula Criteria: Blood flow of at least 500 ml/min and Minimum diameter of 4 mm | baseline- 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fistula survival | Ultrasound of the fistula: Blood flow of at least 500 ml/min and Minimum diameter of 4 mm | baseline-2 years | 
| Fistula adequacy | Fistula is used for hemodilaysis and provide adequate clearance which is measured by: Kt/V: 1.4 where K: clearance [m3/s], t: time [m3/s], V:volume of distribution [m3] | Baseline- 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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immature AVF, percutaneous intervention