Prospective Feasibility Study Evaluating EchoMark LP Placement and EchoSure Measurements for Subjects Requiring Arteriovenous Fistulae
Phase: NA
Conditions: Kidney Diseases, Arteriovenous Fistula
Sponsor: Sonavex, Inc.

 
 
 
 
 
Prospective Feasibility Study Evaluating EchoMark LP 
Placement and EchoSure Measurements for Subjects 
Requiring Arteriovenous Fistulae  
 
 
 
 
Protocol Number: IDE-F1-2021 
National Clinical Trial (NCT) Identified Number: NCT04896476 
IDE Number: G210264 
Principal Investigator: 
 
 
 
 
 
Protocol 
Version 9.0 
 
July 27, 2023 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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Table of Contents 
STATEMENT OF COMPLIANCE .......................................................................................................5 
1. 
ABBREVIATIONS ...........................................................................................................................6 
2. 
PROTOCOL SUMMARY ................................................................................................................7 
3. 
INTRODUCTION ......................................................................................................................... 15 
3.1. 
Device Description ............................................................................................................................. 15 
3.2 
Product Development ....................................................................................................................... 17 
3.3 
Intended Use ....................................................................................................................................... 17 
3.4 
Indications for Use ............................................................................................................................ 17 
3.5 
Preliminary Investigations .............................................................................................................. 17 
3.6 
Prior Studies ....................................................................................................................................... 23 
4. 
OBJECTIVES AND ENDPOINTS ............................................................................................ 25 
4.1 
Objectives ............................................................................................................................................ 25 
4.2 
Study Endpoints ................................................................................................................................. 25 
4.2.1 
Primary Safety Endpoints ............................................................................................................................................... 25 
4.2.2 
Primary Feasibility (Technical Success): .................................................................................................................. 25 
4.2.3 
Observational Assessments ............................................................................................................................................ 25 
5. 
STUDY DESIGN ........................................................................................................................... 27 
5.1 
Overall Design .................................................................................................................................... 27 
5.2 
Blinding ................................................................................................................................................ 28 
5.3 
End of Study ....................................................................................................................................... 28 
6. 
STUDY POPULATION ................................................................................................................ 28 
6.1 
Clinical Sites........................................................................................................................................ 28 
6.2 
Determination of Study Eligibility ................................................................................................ 28 
6.3 
Inclusion Criteria ............................................................................................................................... 28 
6.4 
Exclusion Criteria .............................................................................................................................. 29 
6.5 
Strategies for Recruitment and Retention ................................................................................... 29 
6.6 
Screen Failures ................................................................................................................................... 29 
7. 
STUDY INTERVENTION ........................................................................................................... 30 
7.1 
EchoSure Scan Requirements ........................................................................................................ 30 
7.2 
Duplex Scan Requirements ............................................................................................................. 30 
7.3 
Pre-Procedure Requirements ......................................................................................................... 31 
7.4 
Study Procedure................................................................................................................................. 31 
7.5 
Post-Procedure Through Discharge .............................................................................................. 31 
7.6 
Pre-Maturation Follow-up at 15, 30, 60, 90, 120, 150 Days ..................................................... 31 

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7.7 
Post-Maturation Follow-up at 150 Days if Radiographic Mature ......................................... 32 
7.8 
180 Day and 12 Month (+ 15 Days) Follow-up ........................................................................... 33 
7.9 
15 Month, 18 Month, and 24 Month (+ 15 Days) Follow-up ................................................... 33 
7.10 
Fistula Outside of the EchoMark................................................................................................... 34 
7.11 
Fistula Failure .................................................................................................................................... 35 
7.12 
EchoMark Explantation .................................................................................................................. 35 
8. 
RISK AND BENEFIT ASSESSMENT ..................................................................................... 35 
9. 
ADVERSE EVENTS ..................................................................................................................... 36 
9.1 
Serious Adverse Event ...................................................................................................................... 36 
9.2 
Unanticipated Adverse Device Effects (UADE) ......................................................................... 36 
9.3 
Severity of an Adverse Event .......................................................................................................... 37 
9.4 
Relationship to the Study Intervention ........................................................................................ 37 
9.5 
Event Assessment and Follow-Up .................................................................................................. 37 
10. 
STUDY DISCONTINUATION AND WITHDRAWAL ..................................................... 38 
10.1. 
Discontinuation and Closure ........................................................................................................... 38 
10.2. 
Withdrawal ......................................................................................................................................... 39 
10.3. 
Lost to Follow-Up .............................................................................................................................. 39 
11. 
STATISTICAL ANALYSIS ..................................................................................................... 40 
11.1. 
Sample Size Considerations ............................................................................................................ 40 
11.2. 
Data Analysis Plan ............................................................................................................................ 40 
11.2.1 
General Principles ........................................................................................................................ 40 
11.2.2 
Subject Disposition ....................................................................................................................... 40 
11.2.3 
Study Conduct ............................................................................................................................... 41 
11.2.4 
Analysis Samples ........................................................................................................................... 41 
11.2.5 
Analysis of Population Demographics, Baseline and Procedural Characteristics ........ 41 
11.2.6 
Analysis of Primary Safety Endpoint ...................................................................................... 41 
11.2.7 
Analysis of Primary Feasibility (Technical Success) ............................................................ 41 
11.2.8 
Analysis of Observational Endpoints ....................................................................................... 41 
11.2.8.1 
Comparison of EchoSure volume flow, diameter and depth to Duplex values: ................. 41 
11.2.8.2 
Time to Radiographic Maturation .............................................................................................. 42 
11.2.8.3 
Time to Clinical Maturation ........................................................................................................ 43 
11.2.8.4 
Radiographic Maturation Success Rate .................................................................................... 43 
11.2.8.5 
Clinical Maturation Success Rate ............................................................................................... 43 
11.2.8.6 
6-Month Patency Rate ................................................................................................................... 43 

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11.2.8.7 
12-Month Patency Rate ................................................................................................................ 44 
11.2.8.8 
30-day occurrence of Interventions or Hospitalizations ......................................................... 44 
11.2.8.9 
Occurrence of Events: ................................................................................................................... 44 
11.2.8.10 
Composite of new major device related adverse events (MAEs) at 12 months .............. 45 
11.2.9 
Interim Analysis ............................................................................................................................ 45 
11.2.10 
Handling of Missing Data ........................................................................................................... 45 
12. 
REGULATORY, ETHICAL, AND OVERSIGHT CONSIDERATIONS ....................... 45 
12.1. 
Informed Consent Process ............................................................................................................... 45 
12.2. 
Confidentiality and Privacy ............................................................................................................ 46 
12.3. 
Study Device Use and Instruction .................................................................................................. 46 
12.3.1 
Preparation ..................................................................................................................................... 47 
12.3.2 
Implantation ................................................................................................................................... 47 
12.3.3 
Post-Procedure .............................................................................................................................. 47 
12.4. 
Device Accountability ....................................................................................................................... 48 
12.5. 
Future use of Data ............................................................................................................................. 48 
12.6. 
Key Roles and Study Governance ................................................................................................. 48 
12.7. 
Safety Oversight ................................................................................................................................. 48 
12.8. 
Duplex Quality Assessment ............................................................................................................. 49 
12.9. 
Clinical Monitoring ........................................................................................................................... 49 
12.10. 
Quality Assurance and Quality Control .................................................................................. 50 
12.11. 
Data Handling and Record Keeping ........................................................................................ 51 
12.12. 
Protocol Deviations ....................................................................................................................... 51 
12.13. 
Coverage of Subject Expenses ................................................................................................... 52 
12.14. 
Publication and Data Sharing .................................................................................................... 52 
12.15. 
Conflicts of Interest ...................................................................................................................... 52 
13. 
REFERENCES .......................................................................................................................... 53 
 
Figures 
Figure 1 Photo of EchoMark (left), EchoMark LP (center) and a Quarter (right). ....................... 15 
Figure 2. Photo of EchoMark placed under fistula. ...................................................................... 15 
Figure 3. Closeup Photo of EchoSure and EchoSure Probe (left). Photo of full EchoSure system 
on roll stand (right). ...................................................................................................................... 16 
 

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STATEMENT OF COMPLIANCE 
The Sonavex feasibility clinical trial will be conducted in accordance with International 
Conference on Harmonization Good Clinical Practice (ICH GCP), and applicable United States 
Code of Federal Regulations (CFR). The Principal Investigator will assure no deviations or 
changes to the protocol take place without prior agreement from Sonavex, the sponsor, and 
documented approval from the Institutional Review Board (IRB), except where necessary to 
eliminate an immediate hazard(s) to the trial participants. All personnel involved in the conduct 
of this study have completed Human Subjects Protection and ICH GCP Training. 
The protocol, informed consent form(s), and all participant materials will be submitted to the 
IRB for review and approval.  Approval of both the protocol and the consent form must be 
obtained prior to participant enrollment.  Amendments to the protocol will require review and 
approval by the IRB before any changes are implemented to the study.  All changes to the 
consent form will be IRB approved; a determination will be made regarding whether a new 
consent needs to be obtained from participants who have previously provided consent. 
 
 

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1. ABBREVIATIONS 
Abbreviation 
Definition 
AE 
Adverse Event 
CEC 
Clinical Events Committee 
CFR 
Case Report Form 
CKD 
Chronic Kidney Disease 
CPU 
Central Processing Unit 
DSMB 
Data Safety Monitoring Board 
ESRD 
End-Stage Renal Disease 
FDA 
Food and Drug Administration 
GLP 
Good Laboratory Practices 
GMP 
Good Manufacturing Practices 
ICH 
International Conference on Harmonization 
ICH GCP 
International Conference on Harmonization Good Clinical 
Practice 
IRB 
Institutional Review Board 
PHI 
Personal Health Information 
PI 
Principal Investigator 
QC 
Quality Control 
RVT 
Registered Vascular Technologist 
SAE 
Serious Adverse Event 
SOC 
Standard of Care 

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Abbreviation 
Definition 
SOP 
Standard Operating Practices 
UADE 
Unanticipated Adverse Device Effect 
US 
United States 
2. PROTOCOL SUMMARY 
STUDY TITLE 
Prospective Feasibility Study Evaluating EchoMark LP Placement and 
EchoSure Measurements for Subjects Requiring Arteriovenous Fistulae. 
INVESTIGATIONAL 
DEVICE 
EchoMark LP is a bioresorbable implant used as ultrasound marker for 
marking an arteriovenous fistula.  
The EchoSure System for AVF is a diagnostic ultrasound system. 
EchoSure and its transducer are intended for use in clinical examinations 
of arteriovenous fistulae and other blood vessels that are marked with an 
EchoMark LP implant.  
As a system, EchoMark and the EchoSure System for AVF provides 
measurements and information about blood flow, including volumetric 
flow rate, diameter, and depth, for assessing upper arm arteriovenous 
fistulae throughout the maturation period. 
OBJECTIVES 
To evaluate the feasibility and safety of the EchoMark LP and the 
EchoSure diagnostic ultrasound system for assessing AV fistula blood 
flow, diameter and depth. 
STUDY DESIGN 
Prospective, multi-center, single-arm, non-blinded feasibility clinical trial 
SUBJECT 
POPULATIONS 
Subjects undergoing new upper arm autologous arteriovenous fistula 
creation who require hemodialysis  
NUMBER OF 
SUBJECTS 
Up to 20 subjects will be enrolled for up to 365 days. Each site can enroll 
up to 3 “roll-in” subjects. Roll-in subjects will be consecutive and must 

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be identified as roll-in subjects prior to the EchoMark LP implantation 
and will not count toward the total enrollment of 20 subjects. 
NUMBER OF 
CLINICAL SITES 
Up to 6 sites within in the United States will be evaluated, qualified, and 
selected for participation. 
PROCEDURE AND 
FOLLOW-UP: 
All subjects that receive an EchoMark LP will be evaluated at the 
following time-points: 
• 15 days (+/- 7 days) 
• 30 days (+/- 7 days) 
• 60 days (+/- 15 days) 
• 90 days (+/- 15 days) 
• 120 days (+/- 15 days) 
• 150 days (+/- 15 days) 
• 180 days (6 month) (+/- 15 days) 
• 12 Month (1 Year) (+/- 15 days) 
• 15 Months (+ /- 15 days) 
• 18 Months (+/- 15 days) 
• 24 Months (+/- 15 days) 
 
Except for the 180 day (6 month), 12 month (1 year), 15 Month, 18 
Month, and 24 Months visits, each visit will include a physical exam, 
Duplex scan, EchoSure scan, and assessment for adverse events. The 
monthly EchoSure scans will be suspended after the 120-day (4 month) 
visit or once radiographic maturation is achieved, whichever is longer, 
but clinical follow-up and Duplex will continue per the above schedule.  
 
The 180-day (6-month) and 12 month (1 year)visits will include a 
physical examination, Duplex scan for patency, and an assessment for 
adverse events.  
 
The 15 Month, 18 Month, and 24 Month visits will include capture of 
medical history since the last visit, a duplex scan, information on any 
fluid collection observed on the Duplex scan, and an assessment for any 
adverse events.   
 
EchoSure scans will be completed by study personnel who do not have 
prior ultrasound training and are representative of non-expert users.  
 
Subjects that are consented but do not receive the EchoMark LP will be 
considered a screen failure, and can be replaced. 
PRIMARY 
ENDPOINT 
The primary safety and feasibility endpoints are as follows: 
Primary Safety:  

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Composite of new major device related adverse events (MAEs) at 30 
days post EchoMark LP implantation, as adjudicated by the Clinical 
Events Committee (CEC), including: 
• Device or procedure-related death 
• Device related infection 
• Device related interventions 
• Device related hospitalizations 
• Fistula failure  
• Fistula rupture  
• Aneurysm  
 
After the close of the final 90-day visit window, all evaluable subjects 
will be summarized and expansion to a pivotal trial will be requested 
under a new IDE. 
 
Primary Feasibility (Technical Success): 
Rate of Technical Success defined as the successful implantation of the 
EchoMark LP implant and the ability to determine blood flow, diameter 
and depth measurements using the EchoSure diagnostic ultrasound 
system. Technical success will be assessed from baseline to 4 months.  
OBSERVATIONAL 
ASSESSMENTS 
The following observational analyses will be performed and/or 
summarized: 
• Comparison of EchoSure and duplex measurements of flow, 
diameter, and depth. Only duplex images that pass a quality 
control check by an independent RVT will be included in the 
assessment.  
• Comparison of EchoSure depth measurements to Independent 
Reviewer measured depth results. 
• Time to radiographic maturation is defined as the number of days 
from baseline procedure to date of radiographic maturation (date 
of ultrasound imaging, as adjudicated by the CEC). Radiographic 
maturation is defined as a fistula with volume flow of 500mL/min 
and 5mm diameter. 
• Time to clinical maturation defined as the number of days from 
baseline procedure to date of clinical maturation. Clinical 
maturation is defined as 75% of dialysis sessions with successful 
2 needle cannulation. Date of clinical maturation is defined as 
first date of the 4-week window when clinical maturation is 
achieved.  
• Radiographic maturation success rate defined as the percentage of 
subjects that achieve radiographic maturation (as determined by 
the physician and adjudicated by the CEC) by end of study. 

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Radiographic maturation is defined as a fistula with 500mL/min 
and 5mm diameter. 
• Clinical maturation success rate is defined as the percentage of 
subjects that achieve clinical maturation by end of study. Date of 
clinical maturation is defined as first date of the 4-week window 
when clinical maturation is achieved. 
• 6-month patency rate as defined by the status (yes/no) of an 
arteriovenous dialysis access with detectable blood flow through 
and beyond the anastomosis shown by either an imaging modality 
or physical examination (presence of a palpable thrill or audible 
bruit along some point of the arteriovenous dialysis access beyond 
the arteriovenous anastomosis). 
• 12-month patency rate as defined by the status (yes/no) of an 
arteriovenous dialysis access with detectable blood flow through 
and beyond the anastomosis shown by either an imaging modality 
or physical examination (presence of a palpable thrill or audible 
bruit along some point of the arteriovenous dialysis access beyond 
the arteriovenous anastomosis). 
• Occurrence of events occurring within 30 days of implantation 
that require reinterventions (open or endovascular), 
hospitalizations, or prolongation of existing hospitalization. 
• Occurrence of reported reduction of blood flow of blood flow that 
prevents the ability to cannulate or requires further assessment 
and/or intervention from baseline procedure to 12 months. 
• Occurrence of reported inability to cannulate fistula beginning 
once the fistula is deemed radiographically and clinically mature 
to 12 months. 
• Occurrence of the development of steal syndrome from baseline 
to 12 months.  
• Occurrence of bleeding requiring surgical intervention (including 
PRBC transfusion) from baseline to 12 months. 
• Occurrence of infiltration requiring procedural intervention from 
baseline to 12 months. 
• Occurrence of hematoma requiring procedural intervention from 
baseline to 12 months. 
• Occurrence of the inability to use the EchoSure component of the 
system, from baseline to 4 months, due to: 
o Migration of the EchoMark device 
o Early resorption of the EchoMark device as defined as 
breakdown of the EchoMark shape prior to 4 months from 
index procedure.  
• Occurrence of pain related to the study devices from baseline to 
12 months. 
• Occurrence of infection (not limited to infection requiring implant 
explantation) from baseline to 12 months. 

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• Occurrence of infection confirmed by either implant explantation 
or purulent fluid on pathologic assessment during incision and 
drainage beginning at baseline to 12 months. 
• Composite of new major device related adverse events (MAEs) at 
12 months post EchoMark LP implantation, as adjudicated by the 
Clinical Events Committee (CEC). The proportion of subjects 
with device success and free from device- and/or procedure-
related SAEs (per CEC adjudication) at 12 months. The 
summaries for each individual safety data point will also be 
provided, including: 
o Device or procedure-related death 
o Device related infection 
o Device related interventions 
o Device related hospitalizations 
o Fistula failure  
o Fistula rupture  
o Aneurysm 
OVERSIGHT 
A Data Safety Monitoring Board (DSMB) will be employed to provide 
safety oversight. A Clinical Events Committee (CEC) will be employed 
to provide adjudication of endpoints. An Independent RVT will be 
employed to adjudicate and perform a quality check of Duplex imaging. 
The Independent RVT will not review any measurements from the 
EchoSure system.  
INCLUSION 
CRITERIA 
1. Males or non-pregnant, non-breastfeeding females ≥ 18 years of 
age but < 85 years of age at the time of informed consent 
2. Subject is able and willing to provide written informed consent 
prior to receiving any non-standard of care, protocol specific 
procedures 
3. Subject is willing and capable of complying with all required 
follow-up visits 
4. Subject and/or Care Team agree that the distance and 
transportation resources from the subject’s home to the clinic are 
reasonable for study participation and compliance 
5. Subject has an estimated life expectancy > 18 months 
6. Subject is ambulatory (cane or walker are acceptable) 
7. Subjects presenting for upper arm autologous arteriovenous 
fistula creation  
8. Vein diameter > 2.5 mm at the antecubital fossa via imaging 
9. Artery diameter > 3 mm via imaging 
10. Subject is not participating in another investigational clinical trial 
that has not met its primary endpoint. Participation in a post-
market registry is acceptable. 

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EXCLUSION 
CRITERIA 
1. Subject is receiving a forearm fistula. 
2. Subject has history of Steal Syndrome 
3. Subject who is immunocompromised or immunosuppressed 
4. Subject has had three previous failed AV fistulae for hemodialysis 
access 
5. Subjects expecting to undergo major surgery within 60 days from 
the EchoMark LP implantation.  
6. Known or suspected active infection on the day of the index 
procedure. 
7. Subjects who had infection(s) in the 30-day window prior to 
EchoMark placement to reduce the likelihood of partially treated 
infections that can seed the device and fistula. 
8. Subjects with diagnosed bleeding disorder, thrombocytopenia 
(platelet count <50,000), hypercoagulability, and history of 
recurrent deep vein thrombosis not related to AV access. 
9. Subjects with active malignancy. 
10. Subjects with a history of poor compliance with the dialysis 
protocol. 
11. Subjects with a known or suspected allergy to any of the device 
materials. 
12. Subjects with an existing fistula or graft. 
13. Subjects who are pregnant, plan to become pregnant, or are 
breastfeeding. 

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External 
EchoMark 
Measurements 
 
 
X 
X 
X 
X 
X 
X 
X 
X 
X 
 
 
 
Duplex Scans 
X 
 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
EchoSure 
Scans* 
 
 
X 
X 
X 
X 
X 
X 
X 
  
 
 
 
 
Cannulation 
Log, including 
attempts 
 
 
 
X 
X 
X 
X 
X 
X 
X 
X 
 
 
 
AE Monitoring 
 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
End of Study 
 
 
 
 
 
 
 
 
 
 
 
 
 
X 
 
 
** Note: The monthly EchoSure scans will be suspended after the 120 day (4 month) visit or once radiographic maturation is achieved, whichever is longer.  
Patients will continue to be followed monthly with physical examination, Duplex, and AE monitoring until the 180-day timepoint. If radiographic maturation is 
never achieved, patients will be followed until either the fistula is abandoned, or the patient reaches the 180-day timepoint. The 180-day timepoint is meant to 
assess patency via Duplex and is meant for AE monitoring. 

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• Time to radiographic maturation is defined as the number of days from baseline 
procedure to date of radiographic maturation (date of ultrasound imaging, as 
adjudicated by the CEC). Radiographic maturation is defined as a fistula with 
volume flow of 500mL/min and 5mm diameter. 
• Time to clinical maturation defined as the number of days from baseline 
procedure to date of clinical maturation. Clinical maturation is defined as 75% 
of dialysis sessions with successful 2 needle cannulation for 4 weeks. Date of 
clinical maturation is defined as first date of the 4-week window when clinical 
maturation is achieved.  
• Radiographic maturation success rate defined as the percentage of subjects that 
achieve radiographic maturation (as determined by the physician and 
adjudicated by the CEC) by end of study. Radiographic maturation is defined as 
a fistula with volume flow of 500mL/min and 5mm diameter. 
• Clinical maturation success rate is defined as the percentage of subjects that 
achieve clinical maturation by end of study. Date of clinical maturation is 
defined as first date of the 4-week window when clinical maturation is achieved.  
• 6-month patency rate as defined by the status (yes/no) of an arteriovenous 
dialysis access with detectable blood flow through and beyond the anastomosis 
shown by either an imaging modality or physical examination (presence of a 
palpable thrill or audible bruit along some point of the arteriovenous dialysis 
access beyond the arteriovenous anastomosis). 8 
• 12-month patency rate as defined by the status (yes/no) of an arteriovenous 
dialysis access with detectable blood flow through and beyond the anastomosis 
shown by either an imaging modality or physical examination (presence of a 
palpable thrill or audible bruit along some point of the arteriovenous dialysis 
access beyond the arteriovenous anastomosis). 
• Occurrence of events occurring within 30 days of implantation that require 
reinterventions (open or endovascular), hospitalizations, or prolongation of 
existing hospitalization. 
• Occurrence of reported reduction of blood flow that prevents the ability to 
cannulate or requires further assessment and/or intervention from baseline 
procedure to 12 months.  
• Occurrence of the reported inability to cannulate fistula beginning once the 
fistula is deemed radiographically and clinically mature to 12 months. 
• Occurrence of the development of steal syndrome from baseline to 12 months. 
• Occurrence of bleeding requiring surgical intervention (including PRBC 
transfusion) from baseline to 12 months. 
• Occurrence of infiltration requiring procedural intervention from baseline to 12 
months. 

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• Occurrence of hematoma requiring procedural intervention from baseline to 12 
months. 
• Occurrence of the inability to use the EchoSure component of the system, from 
baseline to 4 months, due to: 
o Migration of the EchoMark device 
o Early resorption of the EchoMark device as defined as breakdown of the 
EchoMark shape prior to 4 months from index procedure.  
 EchoMark will continue to be monitored throughout the duration 
of the study.  
• Occurrence of pain associated with the study devices from baseline to 12 
months. 
• Occurrence of infection (not limited to infection requiring implant explantation) 
from baseline to 12 months.  
• Occurrence of infection confirmed by either implant explantation or purulent 
fluid on pathologic assessment during incision and drainage from baseline to 12 
months.  
• Composite of new major device related adverse events (MAEs) at 12 months 
post EchoMark LP implantation, as adjudicated by the Clinical Events 
Committee (CEC). The proportion of subjects with device success and free from 
device- and/or procedure-related SAEs (per CEC adjudication) at 12 months. 
The summaries for each individual safety data point will also be provided, 
including: 
o Device or procedure-related death 
o Device related infection 
o Device related interventions 
o Device related hospitalizations 
o Fistula failure  
o Fistula rupture  
o Aneurysm 
 
5. STUDY DESIGN 
5.1 Overall Design 
This is a prospective, multi-center, single-arm, non-blinded clinical trial designed to evaluate 
the feasibility and safety of the Sonavex EchoMark and the EchoSure in subjects undergoing 
new upper arm autologous arteriovenous fistula creation who require hemodialysis. The trial 
will enroll up to 20 subjects in up to 6 clinical sites in the United States. Each site can enroll 
up to 3 “roll-in” subjects. Roll-in subjects will be consecutive, must be identified as roll-in 
subjects prior to the EchoMark implantation, and will not count toward the total enrollment 
of 20 subjects. 

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5.2 Blinding 
The data from EchoSure will not be used in clinical care. The study investigators will be 
blinded to EchoSure results and comparison of EchoSure measurements to Duplex 
measurements until the end of the study. 
5.3 End of Study 
All enrolled subjects will exit the study when all study related activities and visits are 
completed, but no later than 24 months.  
6. STUDY POPULATION 
6.1 Clinical Sites 
It is important to select the appropriate clinical sites for this trial. Investigators should be 
credible and experienced, and the sites should experience a high enough volume of subjects 
undergoing upper arm autologous arteriovenous fistula creation for hemodialysis. 
It is estimated that up to 6 clinical sites including hospitals and surgical centers in the United 
States will enroll in this trial. All follow up visits included in this study where the EchoSure 
device is used will be conducted at the vascular surgeon’s office/clinic. 
6.2 Determination of Study Eligibility 
All subjects will be required to sign the Institutional Review Board–approved informed 
consent form for the study. 
Upon satisfying inclusion and exclusion criteria, a clinical history and signing the informed 
consent form, a subject will be eligible for enrollment in the trial. 
6.3 Inclusion Criteria 
Subjects will be included if all the following inclusion criteria apply: 
1. Males or non-pregnant, non-breastfeeding females ≥ 18 years of age but < 85 years of age 
at the time of informed consent 
2. Subject is able and willing to provide written informed consent prior to receiving any 
non-standard of care, protocol specific procedures 
3. Subject is willing and capable of complying with all required follow-up visits 
4. Subject and/or Care Team agree that the distance and transportation resources from the 
subject’s home to the clinic are reasonable for study participation and compliance 
5. Subject has an estimated life expectancy > 18 months 
6. Subject is ambulatory (cane or walker are acceptable) 
7. Subjects presenting for upper arm autologous arteriovenous fistula creation  
8. Vein diameter > 2.5 mm at the antecubital fossa via imaging 
9. Artery diameter > 3 mm via imaging 

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10. Subject is not participating in another investigational clinical trial that has not met its 
primary endpoint. Participation in a post-market registry is acceptable. 
6.4 Exclusion Criteria 
Subjects will be excluded if any of the following exclusion criteria apply: 
1. Subjects receiving a forearm fistula.  
2. Subject has history of Steal Syndrome. 
3. Subject who is immunocompromised or immunosuppressed.  
4. Subject has had three previous failed AV fistulae for hemodialysis access 
5. Subjects expecting to undergo major surgery within 60 days from the EchoMark 
implantation.  
6. Known or suspected active infection on the day of the index procedure. 
7. Subjects who had infection(s) in the 30-day window prior to EchoMark placement to 
reduce the likelihood of partially treated infections that can seed the device and fistula 
8. Subjects with diagnosed bleeding disorder, thrombocytopenia (platelet count <50,000), 
hypercoagulability, and history of recurrent deep vein thrombosis not related to AV 
access 
9. Subjects with active malignancy 
10. Subjects with a history of poor compliance with the dialysis protocol 
11. Subjects with a known or suspected allergy to any of the device materials 
12. Subjects with an existing fistula or graft 
13. Subjects who are pregnant, plan to become pregnant, or are breastfeeding.  
6.5 Strategies for Recruitment and Retention 
The clinical research personnel will screen and attempt to enroll subjects in clinical settings 
scheduled for an upper arm autologous arteriovenous fistula creation who meet the study 
criteria. Qualified research personnel will be responsible for obtaining informed consent. The 
prospective participants will be informed the study is solely voluntary and that they can 
choose to not enroll or exit the study at any time without consequence to the quality of their 
care or services provided. Prospective participants will be provided with adequate time to 
make an informed decision and will be invited to ask questions.  
6.6 Screen Failures 
Screen failures are defined as subjects who consent to participate in the clinical trial but 
never have the EchoMark implanted. A minimum set of screen failure information is required 
including demographics, screen failure details, and eligibility criteria. Screen failures can be 
replaced.  
 
 

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7. STUDY INTERVENTION 
7.1 EchoSure Scan Requirements 
The EchoSure scans will be conducted at the vascular surgeon’s (investigator’s) office/clinic 
by a member of their staff that does not have formal ultrasound training and has been 
designated and trained as study personnel. Appropriate staff members to conduct the 
EchoSure scans include the study research coordinator(s), nurses, nursing assistants, or 
medical technicians. Prior to starting study activities, each site will designate at least one 
staff member without previous ultrasound training to conduct the EchoSure scans. These 
designated EchoSure users will be trained on the use of the EchoSure system and how to fill 
out the EchoSure case report form, including the blinding of the investigator, during Site 
Initiation Visits. The designated EchoSure users will be included in the study delegation log 
of authority and a copy their CV/resume will be included in the site’s study regulatory 
binder. No other study personnel will operate the EchoSure system. 
 
The follow-up EchoSure scans will be conducted by the designated EchoSure user without 
the investigator and without the sonographer/RVT conducting the Duplex exam in the room, 
either during the routine work-up prior to the surgeon seeing the patient or after. The 
EchoSure results for flow, and vessel depth and diameter are shown as numerical values on 
the screen of the EchoSure device. After each scan, the EchoSure user will transcribe these 
values onto the case report form. The EchoSure data will not be included elsewhere in the 
patient’s medical record. The CRF data will be entered in to an EchoSure master data 
spreadsheet by a data manager. This master data spreadsheet will not be available to 
investigators. While historical EchoSure scans and data are stored on the EchoSure system, 
the system requires a username and password to login. Only designated EchoSure users will 
be given login credentials. The investigator’s will not be provided with login credentials, so 
they will not be able to log in to the system to conduct EchoSure scans or view any of the 
EchoSure measurement data. 
7.2 Duplex Scan Requirements 
The Duplex exams will be conducted by certified sonographers or registered vascular 
technologists (RVT), or physicians experienced in vascular ultrasound exams who have been 
trained on the study’s Duplex data collection protocol (defined in Section 7.4, pg 36 – 39, of 
the Investigator’s Brochure). All study personnel will be instructed during training that the 
sonographer/RVT must not be in the room during the EchoSure scans. During the Duplex 
exam, the sonographer/RVT will fill out the Duplex Follow-Up CRF which includes 
transcribing the numerical values for flow and vessel depth and diameter that result from the 
Duplex exam. The saved Duplex data (specific images with caliper measurements and 
calculations as outlined in the study Duplex protocol) and the CRF will be sent to an 
Independent RVT for quality checks. An Independent RVT will verify the quality of Duplex 
images and measurements following defined specifications and key-in verified numerical 
values for flow and vessel depth and diameter into a Duplex master data spreadsheet. This 
master data spreadsheet will not be available to the investigators. 
 
 

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7.3 Pre-Procedure Requirements 
Once informed consent is obtained the subject is enrolled in the study. The subject will 
undergo the following procedures: 
• Demographics 
• Vital Signs 
• Medical History to include the most recent Kt/V, CBC, Serum Chemistry, Calcium, 
Phosphorous, Magnesium, Total Protein, Albumin, PTH 
• Relevant medications 
• Duplex scan to assess the blood flow, depth and diameter of the target vessels.  
• Duplex scan to assess the Brachial Artery for flow and diameter.  
• Blood culture to confirm absence of bacteremia. 
 
7.4 Study Procedure  
All subjects will undergo a physician exam prior to their arteriovenous fistula creation per the 
institution’s standard of care. After the fistula creation is completed, but prior to closure, the 
EchoMark will be implanted under the outflow vein and secured in place using 3-0 or 4-0 
Prolene or equivalent non-resorbable sutures. The EchoMark is to be secured a minimum of 
3 cm away from the anastomosis. Procedure details and outcomes will be collected, 
including: 
• Inflow Artery Diameter 
• Outflow Vein Diameter 
• Length of vessel from anastomosis to the closest edge of the EchoMark 
• Adverse Events 
• Procedure Success 
 
7.5 Post-Procedure Through Discharge 
Subjects will be followed through discharge. The subject will be evaluated for flow by 
physical exam to include assessment of palpable thrill and audible bruit and will be 
monitored for adverse events. The subject will undergo a duplex scan, capturing the flow 
rate, diameter, and depth when feasible. Additionally, an external measurement of each 
EchoMark corner location will be completed. The EchoMark will be located with palpitation 
and each corner will be measured independently to the antecubital fossa.   
7.6 Pre-Maturation Follow-up at 15, 30, 60, 90, 120, 150 Days 
Subjects will have follow-up visits at 15 (+/- 7 days), 30 (+/- 7 days), 60 (+/- 15 days), 90 
(+/- 15 days), 120 (+/- 15 days), and 150 (+/- 15 days) days from the baseline procedure, 
including a physical exam, duplex imaging, EchoSure scan, external EchoMark 
measurement, medical history, and adverse event monitoring. The EchoSure scans will be 
suspended after the 120 day (4 month) visit or once radiographic maturation is achieved, 

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whichever is longer. Radiographic maturation is defined as 500mL/min and a 5 mm 
diameter. The monthly clinical follow-up and duplex imaging will continue per the follow-up 
schedule. The physical exam will include assessing the fistula for bruit and thrill. The 
medical history will include all interventions, cannulation history including any attempts, and 
the most recent Kt/V, CBC, Serum Chemistry, Calcium, Phosphorous, Magnesium, Total 
Protein, Albumin, PTH. EchoSure scans will be completed by study personnel who do not 
have prior ultrasound training, are representative of non-expert users, and have been 
delegated on the delegation of authority log. Duplex and EchoSure scans will include: 
• A total of three (3) EchoSure scans performed at the site of the EchoMark. 
Volume flow, diameter, and depth data to be recorded. 
• A total of three (3) limited DUS scans performed at the site of the 
EchoMark. DUS will be performed in transverse Bmode and longitudinal 
view. Volume flow, diameter, depth, and distance from scan area to 
anastomosis will be recorded. 
• A total of three (3) limited DUS scans performed at the cannulation zone 
in transverse Bmode and longitudinal view. Volume flow, diameter, and 
depth, will be recorded. 
• The 9 Duplex images will be de-identified and undergo quality control 
checks performed by an Independent RVT.  
• A duplex exam of the fistula from the EchoMark location and beyond to 
assess for the presence of stenotic lesions. If a lesion is present, capture 
and save an image showing a longitudinal view of the fistula segment with 
the stenosis, note the location of the stenosis in relation to the anastomosis 
and EchoMark, and track the stenosis as an adverse event. 
• A duplex scan of the brachial artery to assess flow and diameter, capture a 
PW image showing the flow and diameter measurements.  
 
7.7 Post-Maturation Follow-up at 150 Days if Radiographic Mature 
The EchoSure scans will be suspended after the 120 day (4 month) visit or once radiographic 
maturation is achieved, whichever is longer. Radiographic maturation is defined as fistula 
diameter ≥ 5mm, fistula flow ≥ 500 mL/min. If radiographic maturation has been achieved 
before the 150-day follow-up visit, the subject will not switch to the Post Maturation follow-
up schedule until the 150 Day visit when the EchoSure scans are suspended. Post-Maturation 
follow-up visits will include a physical exam, medical history review, Duplex scan, external 
EchoMark measurement, and adverse event monitoring. The physical exam will include 
assessing the fistula for bruit and thrill. The medical history will include all interventions, 
cannulation attempts, and the most recent Kt/V, CBC, Serum Chemistry, Calcium, 
Phosphorous, Magnesium, Total Protein, Albumin, PTH, Duplex scans will include: 
• Assessment of patency (flow/no flow adjudicated by the CEC) 

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• Limited DUS scan performed at the site of EchoMark to determine 
EchoMark visibility including: 
o 1 BMode, transverse view of EchoMark at center 
o 1 BMode, transverse view of EchoMark at distal edge 
o 1 BMode, Transverse view of EchoMark at proximal edge 
o 1 BMode, Longitudinal view centered over vessel showing full 
length of EchoMark 
• A duplex exam of the fistula from the EchoMark location and beyond to 
assess for the presence of stenotic lesions. If a lesion is present, capture 
and save an image showing a longitudinal view of the fistula segment with 
the stenosis, note the location of the stenosis in relation to the anastomosis 
and EchoMark, and track the stenosis as an adverse event. 
• A duplex scan of the brachial artery to assess flow and diameter, capture a 
PW image showing the flow and diameter measurements.  
 
7.8 180 Day and 12 Month (+ 15 Days) Follow-up  
All subjects will have follow-up visit at 180 days and 12 months after baseline procedure. 
Follow-up visits will include a physical exam, medical history review, Duplex scan, external 
EchoMark measurement, and adverse event monitoring. The physical exam will include 
assessing the fistula for bruit and thrill. The medical history will include all interventions, 
cannulation attempts, and the most recent Kt/V, CBC, Serum Chemistry, Calcium, 
Phosphorous, Magnesium, Total Protein, Albumin, PTH, Duplex scans will include: 
• Assessment of patency (flow/no flow adjudicated by the CEC) 
• Limited DUS scan performed at the site of EchoMark to determine 
EchoMark visibility including: 
o 1 BMode, transverse view of EchoMark at center 
o 1 BMode, transverse view of EchoMark at distal edge 
o 1 BMode, Transverse view of EchoMark at proximal edge 
o 1 BMode, Longitudinal view centered over vessel showing full 
length of EchoMark. 
• A duplex exam of the fistula from the EchoMark location and beyond to 
assess for the presence of stenotic lesions or a fluid collection. If a lesion 
is present, capture and save an image showing a longitudinal view of the 
fistula segment with the stenosis, note the location of the stenosis in 
relation to the anastomosis and EchoMark, and track the stenosis as an 
adverse event. If a fluid collection is present, capture and save an image 
noting the location from the anastomosis and the size and volume.  
• A duplex scan of the brachial artery to assess flow and diameter, capture a 
PW image showing the flow and diameter measurements.  
7.9 15 Month, 18 Month, and 24 Month (+ 15 Days) Follow-up 

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All subjects who are willing to reconsent to longer-term follow-up will have a follow-up visit 
at 15 months, 18 months, and 24 months after baseline procedure. Follow-up visits will 
include a captures of medical history since the last visit, Duplex scan, and adverse event 
monitoring. The Duplex scans will include: 
• Limited DUS scan performed at the site of EchoMark to determine 
EchoMark visibility including: 
o 1 BMode, transverse view of EchoMark at center 
o 1 BMode, transverse view of EchoMark at distal edge 
o 1 BMode, Transverse view of EchoMark at proximal edge 
o 1 BMode, Longitudinal view centered over vessel showing full 
length of EchoMark 
• A duplex exam of the fistula from the EchoMark location and beyond to 
assess for the presence of a fluid collection. If a fluid collection is present, 
capture and save an image noting the location from the anastomosis and 
the size and volume. 
 
7.10 Fistula Outside of the EchoMark 
If the subject’s fistula is deemed to be outside of the EchoMark, an adverse event form will 
be completed and adjudicated by the CEC. The subject will remain in the study. The 
EchoSure scans will be suspended. The subject will complete the follow-up schedule as 
scheduled. Each follow-up visits will include a physical exam, medical history review, 
Duplex scan, external EchoMark measurement, and adverse event monitoring. The physical 
exam will include assessing the fistula for bruit and thrill. The medical history will include 
all interventions, cannulation attempts, and the most recent Kt/V, CBC, Serum Chemistry, 
Calcium, Phosphorous, Magnesium, Total Protein, Albumin, PTH, Duplex scans will 
include: 
• Depth, Diameter and Volume Flow at/near the EchoMark   
• Assessment of patency (flow/no flow adjudicated by the CEC) 
• Limited DUS scan performed at the site of EchoMark to determine 
EchoMark visibility including: 
o 1 BMode, transverse view of EchoMark at center 
o 1 BMode, transverse view of EchoMark at distal edge 
o 1 BMode, Transverse view of EchoMark at proximal edge 
o 1 BMode, Longitudinal view centered over vessel showing full 
length of EchoMark 
• A duplex exam of the fistula from the EchoMark location and beyond to 
assess for the presence of stenotic lesions. If a lesion is present, capture 
and save an image showing a longitudinal view of the fistula segment with 
the stenosis, note the location of the stenosis in relation to the anastomosis 
and EchoMark, and track the stenosis as an adverse event. 
• A duplex scan of the brachial artery to assess flow and diameter, capture a 
PW image showing the flow and diameter measurements. 

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The subject will follow the same 180-day and 12-month visit follow-up visit as described in 
Section 7.8 7.8 
180 Day and 12 Month (+ 15 Days) Follow-up 
 
7.11 Fistula Failure 
If the subject’s fistula is deemed a failure and abandoned by the investigator, a fistula failure 
case report form will be completed recording the reasoning for the failure. The subject will 
remain in the study and receive monthly telephone calls to monitor for adverse events and 
physical assessments of the EchoMark at all standard of care visits. The subject will 
complete the 180-day and 12 months visit as scheduled to undergo a physical exam, medical 
history review, adverse event monitoring, and duplex examination of the EchoMark and exit 
the study.  
7.12 EchoMark Explantation 
If the EchoMark is removed, the subject will be followed until the event is resolved. A case 
report form will be completed to track the reasoning, procedure details, and outcomes. The 
subject will be monitored with the institution’s standard of care, including physical exam and 
possibly ultrasound. The event will be tracked until the symptoms are resolved and the 
subject will exit the study.  
8. RISK AND BENEFIT ASSESSMENT 
The study involves the creation of an arteriovenous fistula, therefore the risks of participating 
in this research include the risks inherently associated with a standard AV fistula creation 
which may include bruising, numbness, tingling and/or coolness in the extremity, 
thrombosis, stenosis, failure to mature, additional interventions, venous hypertension, 
swelling, irritation or pain, bleeding/hemorrhage, hematoma, seroma, wound problem, fever, 
steal syndrome, ischemia, embolism, infection, increased risk of congestive heart failure, 
nerve damage, vessel damage, pseudoaneurysm, compartment syndrome, heart problems 
such as arrhythmias, burns, problems due to sedation or anesthesia, sepsis, allergic reaction, 
or death. 
With the implantation of any foreign material such as a radiologic marker (EchoMark), there 
is risk of allergic reaction, infection, inflammation, migration, or extrusion. Given the 
biocompatibility data collected by the company and the extensive prior use of the material in 
medicine, the probability of such risk is low. The safety of the device for general use has 
already been evaluated by the FDA during the clearance process for EchoMark and there has 
been a prior multicenter study in AV fistula patients that has shown maturation success rates 
that were in line with recent literature. There is also a possibility that the fistula may slide out 
of the EchoMark, which may prevent the EchoSure device from measuring the flow, 
diameter and depth accurately. When the EchoMark implant is secured properly the 
likelihood of this risk is low and standard of care methods for assessing the fistula are still 
available making the severity low. There is risk that the ultrasound scan may create mild 
discomfort for the subject on the wound site. The likelihood and severity of this risk is low. 

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Prior experience in the AV population captured adverse events including infection and 
seroma. All subjects are to be closely monitored for signs of an infection or seroma. If the 
subject begins to exhibit signs of infection, inflammation or extrusion, a clinical decision will 
be made by the team if the risk from the implantable device requires removal of the device. 
In these cases, the implantable device will be removed, and the subject will be monitored 
with the institution’s standard of care, including physical exam and possibly ultrasound. The 
event will be tracked until the symptoms are resolved.  
There is potential risk of loss of subject confidentiality in the event of a data breach. 
Protections are in place to minimize the risk. No protected health information (PHI), such as 
subject names, medical record numbers, or other identifying information which could be 
linked to a subject will be stored in the database. A subject ID number will be assigned to 
medical record information stored in the database. Information linking the subject ID to 
subject PHI will be store separately in a secure location, accessible to study personnel only.  
Participation in the clinical study does not provide any guarantee of benefit to the subject. 
However, the study follows existing Standard of Care with additional touchpoints. The study 
involves at least monthly post-op visits with the physician, providing the ability to detect any 
issues that may arise from the study and can then be addressed in a timely fashion. Second, 
subjects will receive additional care above and beyond the Standard of Care, including extra 
physical examinations and ultrasound assessments.   
9. ADVERSE EVENTS 
Adverse event means any untoward medical occurrence associated with the use of an 
intervention in humans, whether or not considered intervention-related (21 CFR 312.32 (a)). 
9.1 Serious Adverse Event 
An adverse event (AE) or suspected adverse reaction is considered "serious" if, in the view of 
either the investigator or sponsor, it results in any of the following outcomes: death, a life-
threatening adverse event, in subject hospitalization or prolongation of existing 
hospitalization, a persistent or significant incapacity or substantial disruption of the ability to 
conduct normal life functions, or a congenital anomaly/birth defect. Important medical events 
that may not result in death, be life-threatening, or require hospitalization may be considered 
serious when, based upon appropriate medical judgment, they may jeopardize the participant 
and may require medical or surgical intervention to prevent one of the outcomes listed in this 
definition.  
9.2 Unanticipated Adverse Device Effects (UADE)  
A UADE is considered “any serious adverse effect on health or safety or any life-threatening 
problem or death caused by, or associated with, a device, if that effect, problem, or death was 
not previously identified in nature, severity, or degree of incidence in the investigational plan 
or application (including a supplementary plan or application), or any other unanticipated 

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serious problem associated with a device that relates to the rights, safety, or welfare of 
subjects.” 
9.3 Severity of an Adverse Event 
For adverse events (AEs) the following guidelines will be used to describe severity.  
• Mild – Events require minimal or no treatment and do not interfere with the 
participant’s daily activities.  
• Moderate – Events result in a low level of inconvenience or concern with the 
therapeutic measures. Moderate events may cause some interference with 
functioning. 
• Severe – Events interrupt a participant’s usual daily activity and may require 
systemic drug therapy or other treatment. Severe events are usually potentially 
life-threatening or incapacitating. 
 
9.4 Relationship to the Study Intervention 
All adverse events (AEs) must have their relationship to study intervention assessed by the 
clinician who examines and evaluates the participant based on temporal relationship and 
his/her clinical judgment. The degree of certainty about causality will be graded using the 
categories below. In a clinical trial, the study product must always be suspect.  
• Related – The AE is known to occur with the study intervention, there is a reasonable 
possibility that the study intervention caused the AE, or there is a temporal 
relationship between the study intervention and event. Reasonable possibility means 
that there is evidence to suggest a causal relationship between the study intervention 
and the AE. 
• Possibly Related - There is some evidence to suggest a causal relationship (e.g., the 
event occurred within a reasonable time after administration of the study device). 
However, other factors may have contributed to the event (e.g., the participant’s 
clinical condition, other concomitant events). Although an AE may rate only as 
“possibly related” soon after discovery, it can be flagged as requiring more 
information and later be upgraded to “Related.” 
• Not Related – There is not a reasonable possibility that the administration of the study 
intervention caused the event, there is no temporal relationship between the study 
intervention and event onset, or an alternate etiology has been established. 
 
9.5 Event Assessment and Follow-Up 
The occurrence of an adverse event (AE) or serious adverse event (SAE) may come to the 
attention of study personnel during study visits and interviews of a study participant 
presenting for medical care, or upon review by a study monitor. 

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All AEs including local and systemic reactions not meeting the criteria for SAEs will be 
captured on the appropriate case report form (CRF). Information to be collected includes 
event description, time of onset, clinician’s assessment of severity, relationship to study 
product, and time of resolution/stabilization of the event. All AEs occurring while on study 
must be documented appropriately regardless of relationship. All AEs will be followed to 
adequate resolution.  
Any medical condition that is present at the time that the participant is screened will be 
considered as baseline and not reported as an AE. However, if the study participant’s 
condition deteriorates at any time during the study, it will be recorded as an AE.  
Changes in the severity of an AE will be documented to allow an assessment of the duration 
of the event at each level of severity to be performed. AEs characterized as intermittent 
require documentation of onset and duration of each episode. 
Investigators will record all reportable events with start dates occurring any time after 
informed consent is obtained until 7 (for non-serious AEs) or 30 days (for SAEs) after the 
last day of study participation.  At study visits, the investigator will inquire about the 
occurrence of AE/SAEs since the last visit.  Events will be followed for outcome information 
until resolution or stabilization. 
The Investigator is to report all SAEs to the study sponsor within 24 hours of first recognition 
of the event. Additionally, any device malfunctions, failures, and/or explants are to be 
reported to the sponsor within 24 hours of first recognition of the event.  
The study investigator shall complete an Unanticipated Adverse Device Effect Form and 
submit to the study sponsor and to the reviewing Institutional Review Board (IRB) as soon 
as possible, but in no event later than 10 working days after the investigator first learns of the 
effect.  The study sponsor is responsible for conducting an evaluation of an unanticipated 
adverse device effect and shall report the results of such evaluation to the Food and Drug 
Administration (FDA) and to all reviewing IRBs and participating investigators within 10 
working days after the sponsor first receives notice of the effect. Thereafter, the sponsor 
shall submit such additional reports concerning the effect as FDA requests. 
 
10. STUDY DISCONTINUATION AND WITHDRAWALDiscontinuation and 
Closure 
This study may be temporarily suspended or prematurely terminated if there is sufficient 
reasonable cause.  Written notification, documenting the reason for study suspension or 
termination, will be provided by the suspending or terminating party to study participants, 
investigators, sponsor and regulatory authorities.  If the study is prematurely terminated or 
suspended, the Principal Investigator (PI) will promptly inform study participants, the 
Institutional Review Board (IRB), and sponsor and will provide the reasoning for the 

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termination or suspension.  Study participants will be contacted, as applicable, and be 
informed of changes. 
Circumstances that may warrant termination or suspension include, but are not limited to: 
• Determination of unexpected, significant, or unacceptable risk to participants 
• Demonstration of efficacy that would warrant stopping 
• Insufficient compliance to protocol requirements 
• Data that are not sufficiently complete and/or evaluable 
• Determination that the primary endpoint has been met 
• Determination of futility 
Study may resume once concerns about safety, protocol compliance, and data quality are 
addressed, and satisfy the sponsor, IRB and/or Food and Drug Administration (FDA). 
The DSMB will meet at least every three months to assess the safety and efficacy data of the 
study. The DSMB will operate under the rules of an approved charter and each meeting must 
include a recommendation to continue or to terminate the study and whether the DSMB has 
any concerns about participant safety. Additionally, an emergency meeting of the DSMB 
may be called at any time by the DSMB chairperson should questions of patient safety arise. 
10.2.  Withdrawal 
Participants are free to withdraw from participation in the study at any time upon request. 
An investigator may discontinue or withdraw a participant from the study for the following 
reasons pregnancy, significant study intervention non-compliance, clinical adverse event 
(AE), laboratory abnormality, or other medical condition or situations such that continued 
participation in the study would not be in the best interest of the participant. 
 
The reason for participant discontinuation or withdrawal from the study will be recorded on 
the Case Report Forms (CRFs). Subjects who sign the informed consent form and are 
randomized but do not receive the study intervention may be replaced.  Subjects who sign the 
informed consent form, and are randomized and receive the study intervention, and 
subsequently withdraw, or are withdrawn or discontinued from the study, and will not be 
replaced. 
10.3.  Lost to Follow-Up 
A participant will be considered lost to follow-up if he or she fails to return for scheduled 
visits and is unable to be contacted by the study site staff. The following actions must be 
taken if a participant fails to return to the clinic for a required study visit: 
1. The site will attempt to contact the participant and reschedule the missed visit and 
counsel the participant on the importance of maintaining the assigned visit and 
ascertain if the participant wishes to and/or should continue in the study. 
2. Before a participant is deemed lost to follow-up, the investigator or designee will 
make every effort to regain contact with the participant (where possible, 3 telephone 

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calls and, if necessary, a certified letter to the participant’s last known mailing 
address or local equivalent methods). These contact attempts should be documented 
in the participant’s medical record or study file.  
 
Should the participant continue to be unreachable, he or she will be considered to have 
withdrawn from the study with a primary reason of lost to follow-up. 
11. STATISTICAL ANALYSIS 
11.1. Sample Size Considerations 
This is a feasibility study and accordingly there is not a pre-specified null hypothesis to be 
tested against for the study endpoints. Data collected from this study will provide preliminary 
device safety and effectiveness data for the use of the EchoMark/EchoSure System in 
patients receiving arteriovenous fistulae for hemodialysis access. Descriptive statistics will 
be reported for the study data. Inferential statistical analysis will be conducted in an 
exploratory manner. The sample size for this study is planned to be up to 20 subjects at up to 
4 investigational sites, with data points collected at multiple timepoints for each subject. 
 
Statistical methods for the study are outlined below. 
 
11.2. Data Analysis Plan 
11.2.1 General Principles 
All statistical analyses will be performed using Statistical Analysis System (SAS) for 
Windows (version 9.4, SAS Institute Inc. Cary, NC), STATA (version 16, StataCorp, 
College Station, TX) or other widely accepted statistical or graphical software. All 
statistical analysis will be conducted by an independent statistician. 
 
Descriptive statistics will be used to present the data and to summarize results. Discrete 
variables will be presented using frequency distributions and cross tabulations. 
Continuous variables will be summarized by presenting the number of observations (N), 
mean, standard deviation, median, minimum, and maximum values. In general, data for 
all study subjects combined will be presented. The primary analysis for all baseline 
characteristics and study outcomes will include all available data for all enrolled subjects. 
Individual data will be presented in subject listings. 
 
Summaries of the following endpoints present the number and percentage of unique 
subjects within an event, unless specified otherwise: protocol deviations; subject status; 
adverse events. Thus, multiple occurrences of the same event are counted only once per 
subject, unless specified otherwise. 
11.2.2 Subject Disposition 
The number and percentage of subjects screened, screen failure, enrolled, treated, and 
completed will be summarized. Screen failure percentage is calculated from number of 
screened subjects and other percentages are calculated among number of enrolled 
subjects. A subject will be considered enrolled once they have signed the study patient 

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informed consent form. Subjects who discontinue from the study will be summarized 
with reason and listed by their primary reason for discontinuation. 
11.2.3 Study Conduct 
Protocol deviations from the investigation plan will be summarized by deviation type as 
well as total. Protocol deviations by investigational site will also be provided. 
11.2.4 Analysis Samples 
The primary and observational analysis samples will include all enrolled subjects with 
successful EchoMark LP implantation.  
11.2.5 Analysis of Population Demographics, Baseline and Procedural 
Characteristics 
Descriptive statistics will be summarized for baseline demographics, medical history, 
baseline disease characteristics, and procedural characteristics. 
11.2.6 Analysis of Primary Safety Endpoint 
For the composite primary safety endpoint, the proportion of subjects with device success 
and free from device- and/or procedure-related SAEs (per CEC adjudication) at 30 days. 
The summaries for each individual safety data point will also be provided. 
11.2.7 Analysis of Primary Feasibility (Technical Success) 
Definition of feasibility endpoints are described in Section 4.2. 
 
For composite endpoints, i.e., technical success and implantation success, the number 
and percentage of subjects with success will be summarized. Descriptive statistics for 
components of each endpoint will also be provided. 
11.2.8 Analysis of Observational Endpoints 
Observational endpoints are defined in Section 4.2. 
 
For discrete endpoints, the number and percentage of subjects with success will be 
summarized. Descriptive statistics for components of each endpoint will also be 
provided. 
 
For continuous variables (e.g., volume flow, depth, and diameter), results will be 
summarized with the with the numbers of observations, means, medians, standard 
deviations, minimums, and maximums. Change from baseline will be included using 
these same descriptive statistics. 
11.2.8.1 Comparison of EchoSure volume flow, diameter and depth to Duplex 
values: 
The degree of correlation between paired EchoSure values and Duplex values that 
pass the quality checks by an Independent RVT will be analyzed.  
 
The comparison data points are: 

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• EchoSure vessel depth at EchoMark vs Duplex vessel depth at EchoMark 
• EchoSure vessel diameter at EchoMark vs Duplex vessel diameter at 
EchoMark 
• EchoSure volume flow at EchoMark vs Duplex volume flow at cannulation 
zone (standard of care) 
 
All Duplex volume flow, depth and diameter  data points will undergo quality 
checks performed by an Independent RVT to qualify for inclusion in the 
comparison analyses. The quality checks will assess if the Duplex data was 
collected per protocol and meet defined requirements that ensure a uniform 
technique.  
 
Duplex volume flow data points that do not pass the quality checks will not be 
included in the analysis. The paired EchoSure flow values for failing Duplex values 
will also not be included. 
 
Duplex diameter and depth values that do not pass the quality checks will be 
corrected by an Independent RVT. The corrected Duplex depth and diameter data 
points will be included in the analysis along with their paired EchoSure values. 
 
All sites and their sonographers will be trained on the Duplex data collection 
protocol and quality requirements. Each site will be required to submit a set of 
images for quality checks by an Independent RVT as a part of site qualification.  
 
Degree of correlation between paired EchoSure values and Duplex values 
(volumetric flow, vessel diameter, vessel depth, etc.)  that pass quality checks will 
undergo the following analyses:  
• Pearson Correlations to assess correlation   
• Bland Altman testing using percentages will be used to assess for bias and 
the limits of agreement 
• Distribution of correlation percentage between EchoSure and Duplex values  
 
Additional statistical analyses may be conducted as deemed necessary. 
 
11.2.8.2 Comparison of EchoSure depth measurements to Independent Reviewer 
measured depth results. 
All EchoSure images will be adjudicated for the reported depth measurements. An 
Independent Reviewer will manually measure the vessel depth on the EchoSure 
images. The Independent Reviewer will only receive anonymized EchoSure images.  
Degree of correlation between paired EchoSure values and the Independent 
Reviewer values (depth) will undergo the following analyses:  
• Pearson Correlations to assess correlation. 
• Bland Altman testing using percentages will be used to assess for bias and 
the limits of agreement. 

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• Distribution of correlation percentage between EchoSure and Independent 
Reviewer values. 
 
Additional statistical analyses may be conducted as deemed necessary. 
 
11.2.8.3 Time to Radiographic Maturation 
Time to radiographic maturation is defined as the number of days from baseline 
procedure to date of radiographic maturation (date of ultrasound imaging). 
 
Radiographic maturation is defined as fistula diameter ≥ 5mm, fistula flow ≥ 500 
mL/min as assessed by physician based on ultrasound imaging and adjudicated by 
CEC. 
11.2.8.4 Time to Clinical Maturation 
Time to clinical maturation is defined as the number of days from baseline 
procedure to date of clinical maturation (first date of 4-week window with 75% 
successful 2 needle cannulation). 
 
Clinical maturation is defined as 75% of dialysis sessions with 2 needle cannulation 
for 4 weeks. 
11.2.8.5 Radiographic Maturation Success Rate 
Radiographic maturation success rate is defined as the percentage of subjects that 
achieve radiographic maturation by end of study. 
 
Radiographic maturation is defined as fistula diameter ≥ 5mm, fistula flow ≥ 500 
mL/min as assessed by physician based on ultrasound imaging and adjudicated by 
CEC. 
11.2.8.6 Clinical Maturation Success Rate 
Clinical maturation success rate is defined as the percentage of subjects that achieve 
clinical maturation by end of study. 
 
Clinical maturation is defined as 75% of dialysis sessions with 2 needle cannulation 
for 4 weeks. 
11.2.8.7 6-Month Patency Rate 
6-month patency rate is defined as the percentage of subjects that have patent access 
at 6 months if both radiographic and clinical maturation definitions have been met. 
 
6-month patency rate as defined by the status (yes/no) of an arteriovenous dialysis 
access with detectable blood flow through and beyond the anastomosis shown by 
either an imaging modality or physical examination (presence of a palpable thrill or 
audible bruit along some point of the arteriovenous dialysis access beyond the 
arteriovenous anastomosis). 

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11.2.8.8 12-Month Patency Rate 
12-month patency rate is defined as the percentage of subjects that have patent 
access at 12 months if both radiographic and clinical maturation definitions have 
been met. 
 
12-month patency rate as defined by the status (yes/no) of an arteriovenous dialysis 
access with detectable blood flow through and beyond the anastomosis shown by 
either an imaging modality or physical examination (presence of a palpable thrill or 
audible bruit along some point of the arteriovenous dialysis access beyond the 
arteriovenous anastomosis). 
11.2.8.9 30-day occurrence of Interventions or Hospitalizations 
Occurrence of events occurring within 30 days of implantation that require 
reinterventions (open or endovascular), hospitalizations, or prolongation of existing 
hospitalization 
11.2.8.10 
Occurrence of Events: 
Occurrence is defined as the overall number of each event listed below 
that occur in the defines time period. 
 
• Occurrence of reported reduction of blood flow that prevents the 
ability to cannulate or requires further assessment and/or intervention 
from baseline to 12 months. 
• Occurrence of reported inability to cannulate fistula beginning once 
the fistula is deemed radiographically and clinically mature to 12 
months. 
• Occurrence of the development of steal syndrome from baseline to 12 
months. 
• Occurrence of bleeding requiring surgical intervention (including 
PRBC transfusion) from baseline to 12 months. 
• Occurrence of infiltration requiring procedural intervention from 
baseline to 12 months. 
• Occurrence of hematoma requiring procedural intervention from 
baseline to 12 months. 
• Occurrence of the inability to use the EchoSure component of the 
system, from baseline to 4 months, due to: 
o Migration of the EchoMark device 
o Early resorption of the EchoMark device as defined as 
breakdown of the EchoMark shape prior to 4 months from 
index procedure.  
• Occurrence of pain caused by the study devices beginning at baseline 
to 12 months. 
• Occurrence of infection (not limited to infection requiring implant 
explantation) beginning at baseline to 12 months. 

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• Occurrence of infection confirmed by either implant explantation or 
purulent fluid on pathologic assessment during incision and drainage 
beginning at baseline to 12 months.  
 
11.2.8.11 Composite of new major device related adverse events (MAEs) at 12 
months 
The proportion of subjects with device success and free from device- 
and/or procedure-related SAEs (per CEC adjudication) at 12 months. The 
summaries for each individual safety data point will also be provided. 
Composite of new major device related adverse events (MAEs) at 12 
months post EchoMark LP implantation, as adjudicated by the Clinical 
Events Committee (CEC), including: 
• Device or procedure-related death 
• Device related infection 
• Device related interventions 
• Device related hospitalizations 
• Fistula failure  
• Fistula rupture  
• Aneurysm 
11.2.9 Interim Analysis 
An interim analysis will be conducted when the last subject enrolled reaches the 90 day 
follow-up visit. 
 
Informal interim analyses may be performed if deemed necessary by CEC, DSMB, or 
Sponsor. The Sponsor may access the study data at any time during the study, as 
necessary for engineering and safety reporting purposes. 
11.2.10 Handling of Missing Data 
Data will only be absent from analyses of study outcomes in the event that they were not 
available for collection. In general, missing values in any of the endpoints will not be 
inputted when summarizing these endpoints using descriptive statistics. 
12.  REGULATORY, ETHICAL, AND OVERSIGHT CONSIDERATIONS 
12.1. Informed Consent Process 
Consent forms will be Institutional Review Board (IRB)-approved and the participant will be 
asked to read and review the document. The investigator or approved study personnel will 
explain the research study to the participant and answer any questions that may arise. Each 
study candidate that meets the study inclusion/exclusion criteria will be advised in detail 
regarding the purpose, procedure, and potential risks of the study, their rights as research 
participants, and the requirements for participation is this study. Participants will have the 
opportunity to carefully review the written consent form and ask questions prior to signing.  

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Participants must be informed that participation is voluntary and that they may withdraw 
from the study at any time, without prejudice. A copy of the informed consent document will 
be given to the participants for their records. The informed consent process will be conducted 
and documented in the source document and the form signed, before the participant 
undergoes any study-specific procedures. The rights and welfare of the participants will be 
protected by emphasizing to them that if they decline to participate in this study the quality of 
their medical care will not be adversely affected. 
12.2. Confidentiality and Privacy 
Participant confidentiality and privacy will strictly be enforced by all participating 
investigators, staff, and the sponsor. This confidentiality is extended to cover the clinical 
information relating to participants. Therefore, all study documentation, data, and other 
information generated will be held in strict confidence. No information concerning the study, 
or the data will be released to any unauthorized third party without prior written approval of 
the sponsor.  
All research activities will be conducted in as private a setting as possible. 
The study monitor, other authorized representatives of the sponsor, representatives of the 
Institutional Review Board (IRB), or regulatory agencies may inspect all documents and 
records required to be maintained by the investigator, including but not limited to, medical 
records (office, clinic, or hospital) and pharmacy records for the participants in this study. 
The clinical study site will permit access to such records. 
The study participant’s contact information will be securely stored at each clinical site for 
internal use during the study. At the end of the study, all records will continue to be kept in a 
secure location for as long a period as dictated by the reviewing IRB, Institutional policies, or 
sponsor requirements. 
Study participant research data, which is for purposes of statistical analysis and scientific 
reporting, will be transmitted to and stored at Sonavex. This will not include the participant’s 
contact or identifying information. Individual participants and their research data will be de-
identified and assigned a unique study identification number. The study data entry and study 
management systems used by clinical sites and by Sonavex staff will be secured and 
password protected. At the end of the study, all study databases will be de-identified and 
archived. 
12.3. Study Device Use and Instruction 
The EchoMark is an implantable ultrasound marker for identifying a surgical site in 
soft tissue. The implants are composed of a polymeric bioabsorbable material and feature two 
peaks which are easily distinguishable on an ultrasound image. 
 
 

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12.3.1 Preparation 
Prepare the EchoMark by pre-loading non-resorbable sutures into at least two corners of 
the EchoMark. The sutures should be 3-0 or 4-0 Prolene or equivalent non-resorbable 
sutures. 
 
 
 
 
 
12.3.2 Implantation 
After mobilizing the vein from the underlying muscle fascia layer,
 
 
 
Implant the EchoMark beneath the outflow vein so that there is 3cm of length, at 
minimum, between the anastomosis and the closest edge of the device. Ensure that the 
EchoMark is placed proximal to the patient’s elbow crease and out of the elbow bending 
area. The vessel should run in a straight line through the EchoMark channel. Check for 
vessel or any other tissue structure impingement due to EchoMark placement prior to 
securing. Reposition the implant until optimal configuration is achieved.  
Secure the EchoMark in place to prevent future movement using 3-0 or 4-0 Prolene or 
equivalent non-resorbable sutures. 
 
 
 
 
 
 
 
12.3.3 Post-Procedure 
With the implantation of any foreign material such as EchoMark, there is risk of allergic 
reaction, infection, inflammation, migration, or extrusion. There is also a possibility that 
the fistula may slide out of the EchoMark, which may prevent the EchoSure device from 
measuring the flow, diameter and depth accurately. When the EchoMark implant is 
secured properly the likelihood of this risk is low. 

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rules of an approved charter that will be written and approved at the organizational meeting. 
The CEC will meet at least once a month. The CEC confirms that an event took place, 
ensures accurate counting, assessing, rating, etc. of events. The CEC will adjudicate and 
provide a final analysis of all safety endpoints and all reported events including and 
EchoMark/EchoSure (device) related adverse events.  
12.8. Duplex Quality Assessment 
An independent registered vascular technologist (RVT) will assess the quality of the duplex 
images.  
The Independent RVT will receive only anonymized duplex scans during the study period, 
and will not receive any EchoSure scans. The Independent RVT will provide the following 
analyses to assess the quality of the duplex scans: 
Quality Assessments & Measurements: 
• B-Mode 
o Check accuracy of cursor placement for all caliper measurements of vessel depth 
and diameter 
o Correct caliper measurements that do not meet acceptance criteria 
• Pulse Wave (PW) – Volume Flow Measurements 
o Check PW settings accuracy of cursor placement, angle and sample gate settings 
 Measure angle offset if acceptance criteria not met 
o Identify unacceptable volume flow measurements when acceptance criteria not 
met 
12.9. Clinical Monitoring 
Clinical site monitoring will be conducted to ensure that the rights and well-being of study 
participants are protected, that the reported trial data is accurate, complete, and verifiable, 
and that the conduct of the trial is in compliance with the currently approved 
protocol/amendment(s), with International Conference on Harmonisation Good Clinical 
Practice (ICH GCP), and with applicable regulatory requirement(s).  
All selected monitors will be designated by the sponsor and will have the proper education 
and qualifications to perform the monitoring duties.  
The basic operations to be performed by the monitors will include: 
1. A pre-investigation visit to confirm 
a. the investigator(s) and research site are prepared 
b. the investigator(s) is(are) aware of the applicable responsibilities.  
c. the study staff is adequately qualified, educated, and/or trained to conduct the study 
2. Periodic or interim visits to review and confirm 

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a. regulatory documentation for compliance with all applicable regulations and 
requirements 
b. all changes to research have been submitted and approved by the IRB 
c. the continued adequacy of the facility and its resources for the conduct of the study 
d. the investigator is following the protocol 
e. the study team membership and delegation of responsibilities are current and IRB 
approved 
3. Close-out monitoring to 
a. reconcile any outstanding regulatory documentation issues 
b. resolve outstanding research participant matters 
c. correct any residual data-queries 
d. An inspection of a portion, but not excluding all, of the research subject record for 
1. proper informed consent procedures 
2. subject eligibility, with source documentation to confirm 
3. protocol compliance 
4. data integrity, consistency, and correctness 
5. safety reporting 
6. protocol deviations are noted and reported 
Monitors will be responsible for the generation and distribution of a written report 
identifying the monitoring findings including: 
1. What regulatory compliance issues were observed and corrected 
2. What research record deficiencies were noted and corrected 
12.10. Quality Assurance and Quality Control 
Each clinical site will perform internal quality management of study conduct, data collection, 
documentation and completion.  An individualized quality management plan will be 
developed and enforced at each site. 
Quality control (QC) procedures will be implemented beginning with the data entry and data 
QC checks will be run on the database. Any missing data or data anomalies will be 
communicated to the site(s) for clarification/resolution. 
Following written Standard Operating Procedures (SOPs), the monitors will verify that the 
clinical trial is conducted and data are generated, documented (recorded), and reported in 

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compliance with the protocol, International Conference on Harmonization Good Clinical 
Practice (ICH GCP), and applicable regulatory requirements.  
The investigational site will provide direct access to all trial related sites, source 
data/documents, and reports for the purpose of monitoring and auditing by the sponsor, and 
inspection by local and regulatory authorities 
12.11. Data Handling and Record Keeping 
Data collection is the responsibility of the clinical trial staff at the site under the supervision 
of the site investigator. The investigator is responsible for ensuring the accuracy, 
completeness, legibility, and timeliness of the data reported. All source documents should be 
completed in a neat, legible manner to ensure accurate interpretation of data.   
Hardcopies of the study visit worksheets will be provided for use as source document 
worksheets for recording data for each participant enrolled in the study. 
Clinical data and clinical laboratory data will be entered into an electronic 21 CFR Part 11-
compliant data capture system (EDC). The data system includes password protection and 
internal quality checks, such as automatic range checks, to identify data that appear 
inconsistent, incomplete, or inaccurate. Clinical data will be entered directly from the source 
documents. 
Study participant research data, which is for purposes of statistical analysis and scientific 
reporting, will be transmitted to and stored at the sponsor company. This will not include the 
participant’s contact or identifying information. Individual participants and their research 
data will be de-identified and assigned a unique study identification number. The study data 
entry and study management systems used by clinical sites and by company staff will be 
secured and password protected. At the end of the study, all study databases will be de-
identified and archived. 
Study documents should be retained for a minimum of 2 years after the last approval of a 
marketing application in an International Conference on Harmonization (ICH) region and 
until there are no pending or contemplated marketing applications in an ICH region. No 
records will be destroyed without the written consent of the sponsor, if applicable. It is the 
responsibility of the sponsor to inform the investigator when these documents no longer need 
to be retained. 
12.12. Protocol Deviations 
A protocol deviation is any noncompliance with the clinical trial protocol or the International 
Conference on Harmonization Good Clinical Practice (ICH GCP). The noncompliance may 
be either on the part of the participant, the investigator, or the study site staff. As a result of 
deviations, corrective actions are to be developed by the site and implemented promptly.  
These practices are consistent with ICH GCP:  

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• 4.5 Compliance with Protocol, sections 4.5.1, 4.5.2, and 4.5.3  
• 5.1 Quality Assurance and Quality Control, section 5.1.1  
• 5.20 Noncompliance, sections 5.20.1, and 5.20.2.  
It is the responsibility of the site investigator to use continuous vigilance to identify and 
report deviations within 5 working days of identification of the protocol deviation, or within 
5 working days of the scheduled protocol-required activity.  All deviations must be addressed 
in study source documents, reported to the sponsor.  Protocol deviations must be sent to the 
reviewing Institutional Review Board (IRB) per their policies. The site investigator is 
responsible for knowing and adhering to the reviewing IRB requirements. A deviation log 
will be kept up-to-date throughout the study.  
12.13. Coverage of Subject Expenses 
Subjects will be compensated for their travel expenses and time during follow-up visits 
associated with completing the protocol requirements. The subjects will be compensated a 
flat rate for each follow-up visit and $100.00 for the 12 month visit. The compensation 
schedule is included in each site’s informed consent form.  
12.14. Publication and Data Sharing 
Study updates and results will be communicated to the investigators and the sponsor.  
A study report will be developed within 6 months after the last subject enrolled has exited the 
study. The study report will be distributed to the sponsor, investigators, and to all parties 
implicated in the study. Study results may be submitted for publication in scientific journals 
and as presentations at congresses. 
12.15. Conflicts of Interest 
Any conflict of interest of persons who have a role in the design, conduct, analysis, publication, 
or any aspect of this trial will be disclosed and managed. Furthermore, persons who have a 
perceived conflict of interest will be required to have such conflicts managed in a way that is 
appropriate to their participation in the design and conduct of this trial. 
 

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2 Hoyt K, Hester FA, Bell RL, Lockhart ME, Robbin ML. Accuracy of volumetric flow rate 
measurements: an in vitro study using modern ultrasound scanners. J Ultrasound Med. 2009 Nov 
3 Thamer et al. Medicare Costs Associated With Arteriovenous Fistulas Among US Hemodialysis 
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4 Lok CE, Foley R. Vascular access morbidity and mortality: trends of the last decade. Clin J Am Soc 
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5 Woodside KJ, Bell S, Mukhopadhyay P, et al. Arteriovenous Fistula Maturation in Prevalent 
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6 Robbin ML, Greene T, Allon M, et al. Prediction of Arteriovenous Fistula Clinical Maturation from 
Postoperative Ultrasound Measurements: Findings from the Hemodialysis Fistula Maturation Study 
[published correction appears in J Am Soc Nephrol. 2020 Mar;31(3):665]. J Am Soc Nephrol. 
2018;29(11):2735-2744. doi:10.1681/ASN.2017111225 
7 Chan C, Ochoa CJ, Katz SG. Prognostic Factors for Arteriovenous Fistula Maturation. Ann Vasc Surg. 
2018;49:273-276. 
8 Shenoy S, Allon M, Beathard G, et al. Clinical Trial End Points for Hemodialysis Vascular Access: 
Background, Rationale, and Definitions. Clin J Am Soc Nephrol. 2018;13(3):490-494. 
doi:10.2215/CJN.13321216