Volume Flow-guided Angioplasty of Dysfunctional Dialysis Access

Study Overview
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Brief Summary
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This is a pilot study investigating a new concept of intra-procedural percutaneous duplex ultrasound (DUS) volume flow-guided balloon angioplasty for the quantification and optimization of endovascular treatment outcomes of dysfunctional autologous arteriovenous fistulae (AVF).

Detailed Description
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This is a prospective, single-center, single-arm clinical trial introducing a new functional index of clinical success of endovascular treatment and investigating the feasibility of volume flow-guided balloon angioplasty of dysfunctional AVF assessed with intraprocedural percutaneous DUS. The study will include consecutive patients undergoing fluoroscopically-guided percutaneous balloon angioplasty due to dysfunctional AVF in the investigator's center. Exclusion criteria will be: (i) not available volume flow values at the time of AVF maturation, (ii) patients with arteriovenous synthetic grafts. Patients' demographical data, dialysis access history, and procedural details will be recorded. Intraprocedural volume flow measurements will be obtained just prior to the procedure and after each balloon dilation. Volume flow measurements will be correlated with digital subtraction angiography quantitative vessel analysis (QVA) performed by an independent investigator blinded to the volume flow analysis outcomes. Follow up DUS imaging including volume-flow assessment will be set at 24h, 6, and 12 months after the index procedure, while fistulograms with QVA analysis will be performed at 6 and 12 months. All DUS measurements will be performed using the same imaging protocol and the same operator. The study's primary endpoints will be (i) the quantification of angioplasty outcome using sequential DUS volume flow analysis following each balloon catheter dilation and (ii) to assess the correlation between volume flow and clinical success defined as high-quality dialysis for a period of at least one month. Secondary endpoints will be (i) re-intervention-free interval defined as the time interval between endovascular treatment and reintervention due to dysfunction recurrence of the treated AVF and (ii) correlation between volume flow and QVA measurements.

Official Title
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VOLume Flow-guided Angioplasty of Dysfunctional Autologous Arteriovenous Fistula. The VOLA Pilot Study

Conditions
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Dialysis Access Malfunction

Intervention / Treatment
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* Diagnostic Test: Volume flow guided angioplasty


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Consecutive patients undergoing fluoroscopically-guided percutaneous balloon angioplasty due to dysfunctional AVF Signed consent form Agree to the imaging protocol Exclusion Criteria: not available volume flow values at the time of AVF maturation patients with arteriovenous synthetic grafts.

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: Diagnostic
Intervention Model: Single Group Assignment
Interventional Model Description: The study will include consecutive patients undergoing fluoroscopically-guided percutaneous balloon angioplasty due to dysfunctional AVF. Intraprocedural volume flow measurements will be obtained just prior to the procedure and after each balloon dilation. Volume flow measurements will be correlated with digital subtraction angiography quantitative vessel analysis (QVA) performed by an independent investigator blinded to the volume flow analysis outcomes. Follow up DUS imaging including volume-flow assessment will be set at 24h, 6, and 12 months, while fistulograms with QVA analysis will be performed at 6 and 12 months.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Volume flow group<br>Consecutive patients undergoing sequential volume flow measurements using percutaneous DUS | Diagnostic Test: Volume flow guided angioplasty<br>* Volume flow measurements using DUS will be obtained at the end of each balloon dilation, at 24 hours, 6 months, and one year after index procedure.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quantification of angioplasty outcome | The quantification of angioplasty outcomes will be performed using sequential DUS volume flow analysis | At the end of the procedure | 
| Duplex Ultrasound volume flow values achieved following angioplasty and clinical success | The investigators will use ROC analysis to define a cut off value of volume flow increase (ml per minute) at the end of the procedure to predict clinical success. | 1 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Re-intervention-free interval | The time interval between endovascular treatment and reintervention due to dysfunction recurrence of the treated AVF | 6 months | 
| Comparison of Duplex Ultrasound volume flow values with digital subtraction angiography QVA measurements. | To assess wheather a significant volume flow decrease of >50% measured by Duplex ultrasound indicates an analougously significant late lumen loss (mm) of the target lesion measured with QVA analysis of digital subtracted venography | 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Percutaneous transluminal angioplasty, Volume-flow measurment, Autologous arteriovenous fistula, Dialysis access