End Stage Renal Disease (ESRD)NCT06771973
Ultrasound Prediction of Successful Balloon Assisted AVF Maturation
An observational study of End Stage Renal Disease (ESRD) and Chronic Kidney Disease Requiring Hemodialysis, run by Guy's and St Thomas' NHS Foundation Trust.
Trial summary
An arteriovenous fistula (AVF) is created to allow for cleaning of the blood in patients with severe kidney disease. An artery and a vein are surgically connected, typically in the arm. This connection changes how the blood flows through the vessels, creating much higher flow in the arm vein than before the operation. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- End Stage Renal Disease (ESRD), Chronic Kidney Disease Requiring Hemodialysis
- How many people
- 40 participants
- Where
- No sites listed yet
- Study dates
- 13 Jan 2025to 1 Apr 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adults with ESRD with immature AVFs requiring balloon assisted maturation procedures will be recruited from renal access clinics in a hospital setting
Who may be able to join
- Adult patients (>18 years of age) referred for BAM procedure due to immature native AVF
- AVFs with radio-cephalic or brachio-cephalic configuration
- AVF suitable for endovascular BAM procedure
- Patient is able to provide informed consent
- Patient is willing and able to comply with the study-related procedures
Who cannot join
- Brachio-basilic AVFs requiring transposition and superficialisation procedures during maturation phase
- Patients with arterio-venous grafts (AVGs) for vascular access
- Previous BAM procedures performed to facilitate maturation
- AVF unsuitable for BAM procedure or BAM procedure not performed
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: A Prospective Cohort Study Analysing Prediction of Successful Arteriovenous Fistula (AVF) Maturation Post Balloon Assisted Fistuloplasty With Duplex Ultrasound and Inflammatory Biomarkers
An arteriovenous fistula (AVF) is created to allow for cleaning of the blood in patients with severe kidney disease. An artery and a vein are surgically connected, typically in the arm. This connection changes how the blood flows through the vessels, creating much higher flow in the arm vein than before the operation. Higher blood flow enables blood flow to be cleaned externally with a machine replacing the function of the kidneys. This process is known as dialysis. However, a period known as maturation is required before an AVF can be used in this way. During this time, the vessels grow in size and blood flow continues to increase. In some cases this does not happen and a procedure is required to help the AVF to mature.
AVFs not likely to mature may undergo a procedure, known as balloon assisted maturation (BAM), in which a balloon on the end of a catheter is inserted into the AVF vein and inflated. This is typically needed if an AVF is not likely to develop in a way that can be used for dialysis. Blood cleaning, or haemodialysis, is vital in patients with end stage renal disease, or kidney failure. Blood flow measurement using ultrasound, and routine blood test results, may help us predict which AVFs will respond better to BAM. Ultrasound can be used in the clinic setting and can provide the consultants responsible for the patients ongoing management with information that can enable decisions to be made at an early opportunity, and allowing the participants to be involved in future management decisions. This study aims to identify features of the blood flow following the BAM procedure that might be used to predict if the AVF will successfully mature.
Read the detailed description
The study will be a prospective, longitudinal cohort study assessing maturation success following BAM procedures in immature AVFs. The primary outcome measure is successful AVF maturation at time of routine clinic appointment at 6 weeks post BAM procedure. Successful maturation is defined using a hybrid radiographic and clinical approach, namely a volume flow rate of ≥600ml/min, fistula vein diameter of ≥6mm combined with suitability for haemodialysis use as determined by clinician review. Failure to meet either criteria will be defined as failure to mature.
The primary objectives of the study will be met by comparing preoperative, postoperative and 6 week DUS values with maturation outcome. By comparing values obtained at these timepoints the investigators aim to identify factors predictive of maturation failure post BAM procedure. Neutrophil, platelet and lymphocyte values will be obtained from routine blood tests preoperatively and 2 week (+/- 1 week), and used to calculate both the neutrophil-lymphocyte (NLR) and platelet-lymphocyte ratios (PLR). Both ratios provide an indication of inflammatory status and will be compared with successful maturation post BAM procedure.
DUS scans will be performed pre- and post-BAM procedure in interventional radiology. Follow-up DUS scan will be performed when the participant is attending their 6 week routine clinical follow-up outpatient appointment. All scans will be performed by highly experienced clinical scientists using a single Philips Epiq 7 DUS scanner and L12-3 linear array transducer in accordance with a specified study scan protocol. A study preset will be used to standardise ultrasound settings. The DUS scan protocol will assess arterial inflow, arterio-venous anastomosis and venous outflow. Scan protocol and required measurements is the same for all DUS scans performed.
Arterial Inflow Peak systolic velocity (PSV), end diastolic velocity (EDV) and time averaged mean velocity (TAMV) will be measured in the brachial artery at each scan timepoint. TAMV will be measured across three cardiac cycles and combined with internal luminal diameter to calculate volume flow rate (Qa). Three measurements will be taken 10cm cranial to the antecubital fossa with a mean calculated. Sample volume gate for PSV measurements will be standardised at 1mm. Sample volume gate will be expanded to encompass the full vessel lumen for TAMV. TAMV sample volume gate will be recorded and remain consistent for subsequent scans for the same participant. Resistive (RI) and pulsatility indices (PI) will be calculated from the PSV and EDV values. All DUS-derived measurements will be recorded as absolute values and percentage change across DUS scans.
Access Anastomosis Anatomical location of the artery-vein anastomotic site will be recorded. PSV and EDV will be measured 5cm proximal to the anastomosis. Juxta-anastomotic PSV and EDV will also be measured. Stenoses present at the anastomosis will be graded using a ratio between PSV in the stenotic segment and the reference value 5cm proximally. Severity of stenoses will be recorded as a percentage. Minimal lumen diameter (MLD), defined as the narrowest luminal segment at the anastomosis will be recorded. Diameter of the arterial segment 2cm cranial to the anastomosis will be compared with the MLD to calculate the artery/fistula vein diameter ratio (A/V ratio).
Venous Outflow Venous outflow diameter and TAMV will be measured 10cm cranial to the arterial anastomosis, with venous Qa measured in the same way as for the brachial artery. Stenotic venous segments will be graded in the same way as the arterial inflow. Treatment of lesions as part of the BAM procedure will be noted from operative notes, and the treated lesions subsequently assessed. Residual stenosis, the presence of intimal hyperplasia and vein diameter will be measured at treatment site.
Neutrophil, lymphocyte and plasma values will be obtained from routine full blood count (FBC) results in the patient's electronic records. Neutrophil, lymphocyte and plasma values will be used to calculate neutrophil-to-lymphocyte (NLR) and plasma-to-lymphocyte ratios (PLR). Blood tests will be performed in accordance with standard of care. Patient age, sex, relevant medical history, current medication, and AVF configuration will be obtained from electronic patient records.
- Keywords
- arteriovenous fistula, AVF, CKD, ESRD
- Medical subject headings
- Kidney Failure, Chronic, Arteriovenous Fistula
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Immature AVF (requiring BAM) | Cohort to undergo BAM procedure. No additional interventions required. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Successful AVF maturation at time of routine clinic appointment at 6 weeks post BAM procedure
Hybrid radiographic and clinical approach, namely a volume flow rate of ≥600ml/min, fistula vein diameter of ≥6mm combined with suitability for haemodialysis use as determined by clinician review. Failure to meet either criteria will be defined as failure to mature.
Measured: 6 weeks post BAM
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Jan 2025
- Study start13 Jan 2025 (estimated)
- Primary completion1 Mar 2026 (estimated)
- Study completion1 Apr 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for End Stage Renal Disease (ESRD)Studies of the same condition, open and under way.
- More trials run by Guy's and St Thomas' NHS Foundation TrustThe sponsor's other registered studies.
- 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
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Guy's and St Thomas' NHS Foundation Trust
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06771973
- Sponsor's protocol ID
- 24/YH/0247
- Status last verified
- Jan 2025
- First submitted
- 8 Jan 2025
- Last updated
- 15 Jan 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Jan 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Prospective Cohort Study Analysing Prediction of Successful Arteriovenous Fistula (AVF) Maturation Post Balloon Assisted Fistuloplasty With Duplex Ultrasound and Inflammatory Biomarkers
- ClinicalTrials.gov ID
- NCT06771973
- Acronym / sponsor ID
- 24/YH/0247
- Keywords
- arteriovenous fistula, AVF, CKD, ESRD
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Guy's and St Thomas' NHS Foundation TrustUniversity, hospital or other
- Study start
- 13 Jan 2025 (estimated)
- Primary completion
- 1 Mar 2026 (estimated)
- Study completion
- 1 Apr 2026 (estimated)
- First posted
- 13 Jan 2025 (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.
An arteriovenous fistula (AVF) is created to allow for cleaning of the blood in patients with severe kidney disease. An artery and a vein are surgically connected, typically in the arm. This connection changes how the blood flows through the vessels, creating much higher flow in the arm vein than before the operation. Higher blood flow enables blood flow to be cleaned externally with a machine replacing the function of the kidneys. This process is known as dialysis. However, a period known as maturation is required before an AVF can be used in this way. During this time, the vessels grow in size and blood flow continues to increase. In some cases this does not happen and a procedure is required to help the AVF to mature.
AVFs not likely to mature may undergo a procedure, known as balloon assisted maturation (BAM), in which a balloon on the end of a catheter is inserted into the AVF vein and inflated. This is typically needed if an AVF is not likely to develop in a way that can be used for dialysis. Blood cleaning, or haemodialysis, is vital in patients with end stage renal disease, or kidney failure. Blood flow measurement using ultrasound, and routine blood test results, may help us predict which AVFs will respond better to BAM. Ultrasound can be used in the clinic setting and can provide the consultants responsible for the patients ongoing management with information that can enable decisions to be made at an early opportunity, and allowing the participants to be involved in future management decisions. This study aims to identify features of the blood flow following the BAM procedure that might be used to predict if the AVF will successfully mature.
Detailed description
The study will be a prospective, longitudinal cohort study assessing maturation success following BAM procedures in immature AVFs. The primary outcome measure is successful AVF maturation at time of routine clinic appointment at 6 weeks post BAM procedure. Successful maturation is defined using a hybrid radiographic and clinical approach, namely a volume flow rate of ≥600ml/min, fistula vein diameter of ≥6mm combined with suitability for haemodialysis use as determined by clinician review. Failure to meet either criteria will be defined as failure to mature.
The primary objectives of the study will be met by comparing preoperative, postoperative and 6 week DUS values with maturation outcome. By comparing values obtained at these timepoints the investigators aim to identify factors predictive of maturation failure post BAM procedure. Neutrophil, platelet and lymphocyte values will be obtained from routine blood tests preoperatively and 2 week (+/- 1 week), and used to calculate both the neutrophil-lymphocyte (NLR) and platelet-lymphocyte ratios (PLR). Both ratios provide an indication of inflammatory status and will be compared with successful maturation post BAM procedure.
DUS scans will be performed pre- and post-BAM procedure in interventional radiology. Follow-up DUS scan will be performed when the participant is attending their 6 week routine clinical follow-up outpatient appointment. All scans will be performed by highly experienced clinical scientists using a single Philips Epiq 7 DUS scanner and L12-3 linear array transducer in accordance with a specified study scan protocol. A study preset will be used to standardise ultrasound settings. The DUS scan protocol will assess arterial inflow, arterio-venous anastomosis and venous outflow. Scan protocol and required measurements is the same for all DUS scans performed.
Arterial Inflow Peak systolic velocity (PSV), end diastolic velocity (EDV) and time averaged mean velocity (TAMV) will be measured in the brachial artery at each scan timepoint. TAMV will be measured across three cardiac cycles and combined with internal luminal diameter to calculate volume flow rate (Qa). Three measurements will be taken 10cm cranial to the antecubital fossa with a mean calculated. Sample volume gate for PSV measurements will be standardised at 1mm. Sample volume gate will be expanded to encompass the full vessel lumen for TAMV. TAMV sample volume gate will be recorded and remain consistent for subsequent scans for the same participant. Resistive (RI) and pulsatility indices (PI) will be calculated from the PSV and EDV values. All DUS-derived measurements will be recorded as absolute values and percentage change across DUS scans.
Access Anastomosis Anatomical location of the artery-vein anastomotic site will be recorded. PSV and EDV will be measured 5cm proximal to the anastomosis. Juxta-anastomotic PSV and EDV will also be measured. Stenoses present at the anastomosis will be graded using a ratio between PSV in the stenotic segment and the reference value 5cm proximally. Severity of stenoses will be recorded as a percentage. Minimal lumen diameter (MLD), defined as the narrowest luminal segment at the anastomosis will be recorded. Diameter of the arterial segment 2cm cranial to the anastomosis will be compared with the MLD to calculate the artery/fistula vein diameter ratio (A/V ratio).
Venous Outflow Venous outflow diameter and TAMV will be measured 10cm cranial to the arterial anastomosis, with venous Qa measured in the same way as for the brachial artery. Stenotic venous segments will be graded in the same way as the arterial inflow. Treatment of lesions as part of the BAM procedure will be noted from operative notes, and the treated lesions subsequently assessed. Residual stenosis, the presence of intimal hyperplasia and vein diameter will be measured at treatment site.
Neutrophil, lymphocyte and plasma values will be obtained from routine full blood count (FBC) results in the patient's electronic records. Neutrophil, lymphocyte and plasma values will be used to calculate neutrophil-to-lymphocyte (NLR) and plasma-to-lymphocyte ratios (PLR). Blood tests will be performed in accordance with standard of care. Patient age, sex, relevant medical history, current medication, and AVF configuration will be obtained from electronic patient records.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Immature AVF (requiring BAM) | – | –Cohort to undergo BAM procedure. No additional interventions required. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adults with ESRD with immature AVFs requiring balloon assisted maturation procedures will be recruited from renal access clinics in a hospital setting
Key inclusion criteria (5 listed)
- Adult patients (>18 years of age) referred for BAM procedure due to immature native AVF
- AVFs with radio-cephalic or brachio-cephalic configuration
- AVF suitable for endovascular BAM procedure
- Patient is able to provide informed consent
- Patient is willing and able to comply with the study-related procedures
Key exclusion criteria (4 listed)
- Brachio-basilic AVFs requiring transposition and superficialisation procedures during maturation phase
- Patients with arterio-venous grafts (AVGs) for vascular access
- Previous BAM procedures performed to facilitate maturation
- AVF unsuitable for BAM procedure or BAM procedure not performed
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Successful AVF maturation at time of routine clinic appointment at 6 weeks post BAM procedure
Time frame: 6 weeks post BAM
Hybrid radiographic and clinical approach, namely a volume flow rate of ≥600ml/min, fistula vein diameter of ≥6mm combined with suitability for haemodialysis use as determined by clinician review. Failure to meet either criteria will be defined as failure to mature.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Jan 2025.
- 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.
Questions about this trial
What is this clinical trial studying?
An observational study of End Stage Renal Disease (ESRD) and Chronic Kidney Disease Requiring Hemodialysis, run by Guy's and St Thomas' NHS Foundation Trust.
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 5 inclusion and 4 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: opening soon, as of the sponsor's last update on 15 Jan 2025. Status can change between updates, so confirm with the study contact before making plans.
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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Luke H Smith, MSc (+442071886778, luke.smith1@gstt.nhs.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Successful AVF maturation at time of routine clinic appointment at 6 weeks post BAM procedure (time frame: 6 weeks post BAM). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 15 Jan 2025.