Endothelial Function and Arterio-Venous Fistula Maturation

Study Overview
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Brief Summary
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An arterio-venous fistula is a surgical procedure that supports access for people undergoing hemodialysis (HD) for End Stage Renal Disease (ESRD). This observational pilot study seeks to better understand the factors that contribute to the successful maturation of an arterio-venous fistula. A primary aim of this study is to see if endothelial function (the biochemical events initiated by cells lining the arteries) is associated with successful maturation. Other aims include determining if pro-inflammatory markers in the blood or evidence of gene expression are associated with successful maturation.

Detailed Description
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Current practice guidelines stipulate that 65% of all prevalent ESRD patients should receive HD through some sort of arterio-venous fistula (AVF). An AVF is a subcutaneous, permanent vascular access created surgically by connecting a vein with an artery and is the preferred mode of access due to lower rates of infection or thrombosis compared to prosthetic grafts or tunneled lines. An AVF is mature if it can sustain high quality HD. However, rates of primary failure (the inability of an AVF to sustain HD) are high, ranging from 40-70%. Traditional coronary risk factors such as hypertension, hypercholesterolemia, and diabetes mellitus, have limited ability to allow surgeons to predict which AVFs will mature. One possible explanation involves vascular remodeling, the structural changes which occur in a blood vessel in response to hemodynamic stimuli. The endothelial, lying at the interface of the vessel wall and flowing blood, is a biosensor, responding to changes in blood flow and pressure. It initiates a complex biological response including cellular proliferation and migration, matrix degradation, and cellular apoptosis. This longitudinal, observational study hypothesizes that endothelial function is a critical modulator of AVF maturation. Specifically, that patients with inflammation will have impaired endothelial function and demonstrate less significant remodeling than others.

Official Title
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Endothelial Function and Arterio-Venous Fistula Maturation

Conditions
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Chronic Kidney Disease

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Chronic Kidney Disease classification Stage IV or V Adequate quality cephalic or basilic vein based on pre-operative assessment Able to provide written informed consent Able to travel to the SFVA Medical Center or UCSF Medical Center for follow-up examination Exclusion Criteria: Age >90 or < 18 years Diagnosed hypercoaguble state Recent surgery or other major illness or infection within 6 weeks Use of immunosuppresive medication History or organ transplantation Pregnancy or plans to become pregnant Estimated life expectancy is less than 1 year

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Chronic Kidney Disease<br>Individuals with Chronic Kidney Disease stages IV or V anticipating the need for hemodialysis access through an arterio-venous fistula. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maturation of Arteriovenous Fistula | Maturation is defined by either: Less than three months have elapsed since AVF creation and cannulation of the fistual with two 17 gauge needles and delivery of a minimum of 400 ml/min for the duration of dialysis Greater than three months have elapsed since AVF creation and the individual has not yet initiated hemodialysis and the vein diameter is 4 mm and the volumetric flow rate is 400 ml/min. | 90 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Primary Patency | Primary patency of the AV fistula | 90 days | 
| Secondary Patency | Secondary patency of the AV fistula | 90 days | 
| Stenosis of AV fistula | Moderate or severe stenosos of AV fistual as detected by duplex ultrasound or fistulagram | 90 days | 
| Venous remodeling | Venous remodeling at 3 months | 90 days | 
| Arterial remodeling | Arterial remodeling at 3 months | 90 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Chronic Kidney Disease, CKD, ESRD, AV Fistula, Arterio-venous fistula, hemodialysis