Arteriovenous GraftVAVASCNCT04796558
Validation of Arterio Venous Access Stage (AVAS) Classification
An observational study of Arteriovenous Graft and Arteriovenous Fistula, run by Vascular surgery, University hospital Královské Vinohrady, Prague at 1 site in Czechia.
Trial summary
VAVASC trial is an observational multicentre study. The aim of this trial is to validate AVAS (arteriovenous vascular access stage) classification. The classification is used for determining which type of access is the most suitable for the patient on the basis of the patient´s vascular anatomy The methodology of this… Read more about this study
- Who is it for?
- Ages 16 years and older
- Conditions the study is for
- Arteriovenous Graft, Arteriovenous Fistula, Dialysis Access Malfunction
- What is being tested?
- AVAS Classification
- How many people
- 800 participants
- Where
- 1 siteCzechia
- Study dates
- 1 Apr 2021to 31 Dec 2024
- How long will I take part?
- 3 Years
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 16 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: - patients with kidney insufficiency who are indicated for creation of arterio venouss access for dialysis
Who may be able to join
- patients indicated for creation of arterio venous access for dialysis
Who cannot join
- patients who disagree to participate in the study
Trial locations and contacts
1 site in 1 country.
Czechia1 site
Vascular surgery, University hospital Královské Vinohrady
Prague, 10034
About this study
Official title: Validation of Arterio Venous Access Stage Classification by Using Machine Learning in Prediction of Vascular Access Creation and Uninterrupted Use of the Vascular Access for Dialysis
VAVASC trial is an observational multicentre study. The aim of this trial is to validate AVAS (arteriovenous vascular access stage) classification. The classification is used for determining which type of access is the most suitable for the patient on the basis of the patient´s vascular anatomy
The methodology of this trial is to apply AVAS classification on patients who are indicated for creation of vascular access for hemodialysis. Data on these patients (vascular anatomy status, AVAS type, and predicted type of arterio venous access, demographic data etc.) will be than statistically analysed. Patients will then undergo creation of the selected arteriovenous access. They will be observed in terms of the access functionality. The follow up will be 1 to 3 years. The second aim of this study is to evaluate the relationship between AVAS classification and uninterrupted use of the created arterio venous access.
Read the detailed description
Ultrasound of upper limb vessels as a part of preoperative assessment of patients referred for arteriovenous access placement has been recommended repeatedly in several studies and guidelines. Each patient needing arterio-venous access (AVA) is unique and has different possibilities for fistula creation that depend on many factors as well the anatomical condition of inflow arteries and outflow veins, the so-called 'arteriovenous access map'. In 2020 we created, published and retrospectively evaluated the inter-rater reliability of the AVAS classification, which is a simplified way of sharing the information about suitability for access creation depending on vascular anatomy (doi: 10.1093/ckj/sfaa189).
However, before routine use of the AVAS classification system in clinical practise it requires prospective validation and comparison with other clinical factors. Finally, whether the AVAS classification can be used for the prediction of vascular access function as defined by uninterrupted use of vascular access for dialysis without need for any access intervention/procedures (SONG-HD, doi: 10.1053/j.ajkd.2017.12.003) remains to be tested.
This project has two main parts:
- Validation of AVAS classification with and without combination with other factors using a predictive statistical model .
- Validation of AVAS classification in terms of prediction of uninterrupted use of successfully created vascular access for dialysis.
The data will be collected prospectively. Both parts of the project will be taking place simultaneously.
Data will be collected prospectively (Belfast City Hospital, UK, University hospital Královské Vinohrady Prague CZ). Other centres around the world will be asked for cooperation (announcement will be posted via Twitter, ResearchGate, LinkedIn, Facebook and Kidney Academy) in January 2021. The data collected will be the parameters of the vessels on the upper limb, in order to be able to evaluate AVAS (VAVASC FORM). Along with anatomical dispositions of the patients, other parameters will be collected.
Obligatory parameters (parameters A):
Side of the arm (Left / Right) Dominant hand (Left / Right) Allen's test (Positive / Negative) (A negative Allen's test is demonstration of a complete palmar arch and intact collateral blood flow to the hand) Sex(M / F) Age, Height, Weight, BMI, Diabetes (Yes / No) Central venous line previous or current (Yes / No) Side of the central venous line if place (Left / Right)
Non-obligatory parameters (parameters B):
Smoking history (Yes / No) Hypertension (Yes / No) Heart failure (Yes / No) Ischemic heart disease (Yes / No) Cancer (previous or current) (Yes / No)
In order to evaluate uninterrupted use of the vascular access for dialysis (part 2 of the study), we will follow the patients and do a time to event analysis of the arteriovenous accesses for one year after creation or up until the first intervention for maintaining patency has been performed. If the patient dies during follow up the date of death should be recorded. The data for this part will be collected prospectively (Belfast City Hospital, UK, University hospital Královské Vinohrady Prague, CZ and other centres).
Predictive models will be used for validation of AVAS classification. The data will be registered via electronic database and analysed by Waldauf, P. and O'Neill, S.
- Conditions
- Arteriovenous Graft, Arteriovenous Fistula, Dialysis Access Malfunction, Kidney Failure, Dialysis Related Complication
- Being tested
- AVAS Classification
- Keywords
- Arterio venous access, Dialysis, AVAS, Predictive modelling, Machine learning, VAVASC, Multicentre, Observational, Prospective
- Medical subject headings
- Arteriovenous Fistula, Renal Insufficiency
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AVAS ClassificationOther
Validation of AVAS classification
What is being measured
The primary outcome is the main question the study is designed to answer.
Arterio Venous Access Stage (AVAS) evaluation
What type of the Arterio Venous Access Stage (AVAS classification) the patient has based on his/her vascular anatomy of upper limbs
Measured: Baseline - recruiting (Year 1) - physical examination, data collection and evaluation of Arterio Venous Access Stage (AVAS)
Arterio Venous Access type predicted
What type of the Arterio Venous Access is predicted based on AVAS and other clinical factors
Measured: Baseline - recruiting (Year 1) - physical examination, data collection and evaluation of Arterio Venous Access Stage (AVAS) and predicting a type of arterio venous access
Final Arterio Venous Access
What type of the arterio venous access was eventually created (in corelation with AVAS evaluation and the predicted arteriovenous access type)
Measured: Follow up (up to 1-2 years) what type of arterio venous access was eventually created
Functionality of the arterio venous access
Uninterrupted use of the created arterio venous access
Measured: Year 2-3 - follow up, collection the data about the functionality (uninterrupted use) of the arterio venous access and evaluation of the relation between AVAS and the functionality of the arterio venous access
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Mar 2021
- Study start1 Apr 2021
- Primary completion31 Dec 2024 (estimated)
- Study completion31 Dec 2024 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Arteriovenous GraftStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 800 participants (estimated)
- Target duration
- 3 Years
Sponsor and investigators
- Lead sponsor
- Vascular surgery, University hospital Královské Vinohrady, Prague
- Sponsor type
- University, hospital or other
- Collaborators
- Belfast Health and Social Care Trust
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04796558
- Sponsor's protocol ID
- 532021
- Acronym
- VAVASC
- Status last verified
- Mar 2024
- First submitted
- 5 Mar 2021
- Last updated
- 29 Mar 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Lawrie K, Waldauf P, Balaz P, Bortel R, Lacerda R, Aitken E, Letachowicz K, D'Oria M, Di Maso V, Stasko P, Gomes A, Fontainhas J, Pekar M, Srdelic A; VAVASC Study Group; O'Neill S. Machine learning validation of the AVAS classification compared to ultrasound mapping in a multicentre study. Sci Rep. 2025 Jan 20;15(1):2538. doi: 10.1038/s41598-025-86456-3.
PubMed 39833325Katerina L, Stephen O, Petr W, Peter B. VAVASC study: Clinical trial protocol. J Vasc Access. 2023 Jul;24(4):792-797. doi: 10.1177/11297298211042677. Epub 2021 Sep 2.
PubMed 34472988
Study at a glance
From the registry record, last updated by the sponsor on 29 Mar 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Validation of Arterio Venous Access Stage Classification by Using Machine Learning in Prediction of Vascular Access Creation and Uninterrupted Use of the Vascular Access for Dialysis
- ClinicalTrials.gov ID
- NCT04796558
- Acronym / sponsor ID
- VAVASC / 532021
- Conditions
- Arteriovenous Graft, Arteriovenous Fistula, Dialysis Access Malfunction, Kidney Failure, Dialysis Related Complication
- Keywords
- Arterio venous access, Dialysis, AVAS, Predictive modelling, Machine learning, VAVASC, Multicentre, Observational
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 800 participants (estimated)
- Lead sponsor
- Vascular surgery, University hospital Královské Vinohrady, PragueUniversity, hospital or other
- Collaborators
- Belfast Health and Social Care Trust
- Study start
- 1 Apr 2021 (actual)
- Primary completion
- 31 Dec 2024 (estimated)
- Study completion
- 31 Dec 2024 (estimated)
- First posted
- 15 Mar 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
VAVASC trial is an observational multicentre study. The aim of this trial is to validate AVAS (arteriovenous vascular access stage) classification. The classification is used for determining which type of access is the most suitable for the patient on the basis of the patient´s vascular anatomy
The methodology of this trial is to apply AVAS classification on patients who are indicated for creation of vascular access for hemodialysis. Data on these patients (vascular anatomy status, AVAS type, and predicted type of arterio venous access, demographic data etc.) will be than statistically analysed. Patients will then undergo creation of the selected arteriovenous access. They will be observed in terms of the access functionality. The follow up will be 1 to 3 years. The second aim of this study is to evaluate the relationship between AVAS classification and uninterrupted use of the created arterio venous access.
Detailed description
Ultrasound of upper limb vessels as a part of preoperative assessment of patients referred for arteriovenous access placement has been recommended repeatedly in several studies and guidelines. Each patient needing arterio-venous access (AVA) is unique and has different possibilities for fistula creation that depend on many factors as well the anatomical condition of inflow arteries and outflow veins, the so-called 'arteriovenous access map'. In 2020 we created, published and retrospectively evaluated the inter-rater reliability of the AVAS classification, which is a simplified way of sharing the information about suitability for access creation depending on vascular anatomy (doi: 10.1093/ckj/sfaa189).
However, before routine use of the AVAS classification system in clinical practise it requires prospective validation and comparison with other clinical factors. Finally, whether the AVAS classification can be used for the prediction of vascular access function as defined by uninterrupted use of vascular access for dialysis without need for any access intervention/procedures (SONG-HD, doi: 10.1053/j.ajkd.2017.12.003) remains to be tested.
This project has two main parts:
- Validation of AVAS classification with and without combination with other factors using a predictive statistical model .
- Validation of AVAS classification in terms of prediction of uninterrupted use of successfully created vascular access for dialysis.
The data will be collected prospectively. Both parts of the project will be taking place simultaneously.
Data will be collected prospectively (Belfast City Hospital, UK, University hospital Královské Vinohrady Prague CZ). Other centres around the world will be asked for cooperation (announcement will be posted via Twitter, ResearchGate, LinkedIn, Facebook and Kidney Academy) in January 2021. The data collected will be the parameters of the vessels on the upper limb, in order to be able to evaluate AVAS (VAVASC FORM). Along with anatomical dispositions of the patients, other parameters will be collected.
Obligatory parameters (parameters A):
Side of the arm (Left / Right) Dominant hand (Left / Right) Allen's test (Positive / Negative) (A negative Allen's test is demonstration of a complete palmar arch and intact collateral blood flow to the hand) Sex(M / F) Age, Height, Weight, BMI, Diabetes (Yes / No) Central venous line previous or current (Yes / No) Side of the central venous line if place (Left / Right)
Non-obligatory parameters (parameters B):
Smoking history (Yes / No) Hypertension (Yes / No) Heart failure (Yes / No) Ischemic heart disease (Yes / No) Cancer (previous or current) (Yes / No)
In order to evaluate uninterrupted use of the vascular access for dialysis (part 2 of the study), we will follow the patients and do a time to event analysis of the arteriovenous accesses for one year after creation or up until the first intervention for maintaining patency has been performed. If the patient dies during follow up the date of death should be recorded. The data for this part will be collected prospectively (Belfast City Hospital, UK, University hospital Královské Vinohrady Prague, CZ and other centres).
Predictive models will be used for validation of AVAS classification. The data will be registered via electronic database and analysed by Waldauf, P. and O'Neill, S.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 3 Years
Who may qualify
- Ages
- 16 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- - patients with kidney insufficiency who are indicated for creation of arterio venouss access for dialysis
Key inclusion criteria (1 listed)
- patients indicated for creation of arterio venous access for dialysis
Key exclusion criteria (1 listed)
- patients who disagree to participate in the study
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| AVAS ClassificationValidation of AVAS classification | Other | – |
Primary outcome
Arterio Venous Access Stage (AVAS) evaluation
Time frame: Baseline - recruiting (Year 1) - physical examination, data collection and evaluation of Arterio Venous Access Stage (AVAS)
What type of the Arterio Venous Access Stage (AVAS classification) the patient has based on his/her vascular anatomy of upper limbs
Arterio Venous Access type predicted
Time frame: Baseline - recruiting (Year 1) - physical examination, data collection and evaluation of Arterio Venous Access Stage (AVAS) and predicting a type of arterio venous access
What type of the Arterio Venous Access is predicted based on AVAS and other clinical factors
Final Arterio Venous Access
Time frame: Follow up (up to 1-2 years) what type of arterio venous access was eventually created
What type of the arterio venous access was eventually created (in corelation with AVAS evaluation and the predicted arteriovenous access type)
Functionality of the arterio venous access
Time frame: Year 2-3 - follow up, collection the data about the functionality (uninterrupted use) of the arterio venous access and evaluation of the relation between AVAS and the functionality of the arterio venous access
Uninterrupted use of the created arterio venous access
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Mar 2024.
- Derived from this study: PubMed 39833325Lawrie K, Waldauf P, Balaz P, Bortel R, Lacerda R, Aitken E, Letachowicz K, D'Oria M, Di Maso V, Stasko P, Gomes A, Fontainhas J, Pekar M, Srdelic A; VAVASC Study Group; O'Neill S. Machine learning validation of the AVAS classification compared to ultrasound mapping in a multicentre study. Sci Rep. 2025 Jan 20;15(1):2538. doi: 10.1038/s41598-025-86456-3.
- Derived from this study: PubMed 34472988Katerina L, Stephen O, Petr W, Peter B. VAVASC study: Clinical trial protocol. J Vasc Access. 2023 Jul;24(4):792-797. doi: 10.1177/11297298211042677. Epub 2021 Sep 2.
- Related InfoLink provided by the sponsor.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Arteriovenous Graft and Arteriovenous Fistula, run by Vascular surgery, University hospital Královské Vinohrady, Prague at 1 site in Czechia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 29 Mar 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Czechia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Arterio Venous Access Stage (AVAS) evaluation (time frame: Baseline - recruiting (Year 1) - physical examination, data collection and evaluation of Arterio Venous Access Stage (AVAS)). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04796558, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Mar 2024.