Vein Histology in Arteriovenous Fistulas and Its Effect on Fistula Surgery Success

Study Overview
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Brief Summary
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Patients whose kidneys have failed need to receive dialysis treatment, most commonly with a dialysis machine. In order to be connected to the machine an operation is often performed to join an artery to a vein in the arm. This forms what is known as an arteriovenous fistula. The fistula causes an increase in the flow of blood through the vein and the vein reacts to this by becoming bigger and thicker, making it easier to connect the patient to the machine. The success rate for the operation is relatively low and only approximately 65 from every 100 operations is still working after a year. It is thought that one factor that may cause problems with the fistula is the ability of the vein to stretch in response to increased blood flow. Previous research has shown that veins in kidney failure patients look different to those of people whose kidneys are working when viewed under a microscope. The investigators aim to study the structure of the vein that is used in making fistulas with a microscope and also to test it in an engineering laboratory to see how much it will stretch. The investigators hope that gaining information about the structure of the vein and its ability to stretch will help determine what it is about the vein that affects how well it works as part of a fistula. This information may help surgeons select the best possible vein in a given patient to give the best chance of a working fistula in the future.

Official Title
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A Cohort Study of the Histopathological Changes Evident in Vein Wall at the Time of Arteriovenous Dialysis Access Fistulas and the Effects of Such Changes on Biomechanical Compliance and Patient's Clinical Outcomes in a University Teaching Hospital.

Conditions
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Renal Replacement Therapy, Arteriovenous Fistula

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients referred to vascular consultants for AV fistula formation for haemodialysis access. Ability to give informed written consent Aged over 18 at time of referral Exclusion Criteria: Veins identified on preoperative ultrasound scanning to be of a calibre too small to allow sufficient material to be obtained for biomechanical testing (<3mm diameter). Inability to give informed written consent Aged under 18 at time of referral Inability to attend follow-up appointments

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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Observed cohort<br>All patients recruited. Observed for clinical outcomes | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Primary failure of access - Immediate/early thrombosis or failure to mature. | Failure to mature or thrombosis of fistula | within 30 days of formation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duplex findings of evidence of stenosis and correlation to compliance or histological findings |  | 6 months | 
| Correlation between biomechanical compliance and histological measures of pre existing venous pathology |  | 6 months | 
| Correlation between biomechanical compliance testing and clinical outcomes |  | 6 months | 
| Assisted primary and secondary patency rates at 3 and 6 months post fistula formation |  | 6 months | 
| Functional primary patency |  | 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Histology, Compliance, Dialysis, Arteriovenous access fistula, vein