COVID-19 studies are our top priority.

For new and updated trial submissions, we are processing trials as quickly as possible and appreciate your patience. We recommend submitting your trial for registration at the same time as ethics submission.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial details imported from

For full trial details, please see the original record at

Registration number
Ethics application status
Date submitted
Date registered
Date last updated

Titles & IDs
Public title
U Clip Study - Study to Compare U Clip Anastomosis With Conventional Continuous Prolene Anastomosis
Scientific title
A Pilot, Randomised, Blinded Study to Compare U Clip Anastomosis With Conventional Continuous Prolene Anastomosis for Creating of Autologous Arteriovenous Fistulae
Secondary ID [1] 0 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Haemodialysis 0 0
Condition category
Condition code

Study type
Description of intervention(s) / exposure
Treatment: Devices - U Clip
Treatment: Surgery - Conventional prolene anastomosis

Experimental: U clip - Anastomosis with U clips

Active Comparator: 2 - Prolene anastomosis

Treatment: Devices: U Clip
Interuppted nitional clips

Treatment: Surgery: Conventional prolene anastomosis
Continuous prolene anastomosis

Intervention code [1] 0 0
Treatment: Devices
Intervention code [2] 0 0
Treatment: Surgery
Comparator / control treatment
Control group

Primary outcome [1] 0 0
A functioning fistula which is used for haemodialysis on three or more occasions.
Timepoint [1] 0 0
Until commencement of dialysis with the fistula
Secondary outcome [1] 0 0
Fistula patency as assessed clinically.
Timepoint [1] 0 0
For the life of the fistula
Secondary outcome [2] 0 0
Need for fistula intervention in order to maintain patency.
Timepoint [2] 0 0
For the life of the fistula

Key inclusion criteria
1. Requirement for AV fistula creation for haemodialysis

2. Pre operative upper limb venous and arterial duplex scan showing intended arterial
lumen diameter of 2mm or more and vein diameter of 3mm or more.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
1. Use of prosthetic graft for fistula creation.

2. Donor arterial lumen diameter less then 2mm

3. Recipient venous diameter less than 3mm.

4. Proximal venous thrombosis.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s

Intervention assignment
Other design features
Phase 1/Phase 2
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Unknown status
Data analysis
Reason for early stopping/withdrawal
Other reasons
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 0 0
Launceston general Hospital - Launceston
Recruitment postcode(s) [1] 0 0
- Launceston

Funding & Sponsors
Primary sponsor type
Royal Hobart Hospital

Ethics approval
Ethics application status

Brief summary
The requirements for haemodialysis are increasing. There is now acceptance that the most
durable AV fistulae are those created from the patients own veins. Use of the radiocephalic
arteriovenous fistula as an autologous vascular access dates back to the 1960's. (Brescia MJ,
Cimino JE. Appel K, Hurwich BJ. Chronic hemodialysis using venipuncture and a surgically
created arteriovenous fistula. N Engl J Med 1966; 275: 1089 - 1092.) Once established, it has
good long term survival and a low complication rate. However, the success rate at creation of
a useable AV fistula are not good. In a meta-analysis published in 2005, the primary failure
rate of a radiocephalic fistula was 15.3% and the primary and secondary patency rates were
62.5% and 66.0% at one year. (Rooijens PPGM, Tordoir JHM, Stijnen T, Burgmans JPJ, Smet AAEA
and Yo TI. Radiocephalic wrist arteriovenous fistula for hemodialysis: meta-analysis
indicates a high primary failure rate. Eur J Vasc Endovasc Surg 2004; 28, 583-589). Reasons
for this are multiple but it appears as though the main determinants are the quality of the
patients veins and the technical skill of the surgeon. Low patency rates are also seen in
females and those with small veins and arteries. Creating an anastomosis between a small vein
and artery is technically challenging. This is traditionally preformed with a continuous
prolene suture. Recently, Medtronic have been marketing the U Clip Anastomotic Device. This
is a self closing devise which could be called a vascular clip. Reported advantages of this
clip include better patency rates and faster operations. However, to our knowledge there is
no randomised evidence to support this with regards to AV fistulas.

The vascular anastomosis originally developed by Alexis Carrel used interrupted sutures. Over
time this was replaced by a continuous suture technique which was felt to be quicker and had
similar patency rates. However, microvascular, paediatric and neurovascular surgeons have
shown that there are advantages to an interrupted technique. (Hattori H, Killen DA, Green JW.
Influence of suture material and technic on patency of anastomosed arteries of less than
1.5mm. Am Surg. 1970; 36: 352 - 354. Cobbett JR. Microvascular surgery. Surg Clin N Am. 1962;
47: 521.). The reasons for the improved patency with interrupted anastomoses are firstly
increased anastomotic compliance and flow rate and secondly elimination of the pursestring
effect and puckering seen with continuous sutures.

In a prospective but non randomised study to compare interrupted U clips with historical
published results, the patency rate of coronary anastomoses was 100% at 6 months using the U
clips compare to a patency rate of 90 -100% in the published series. (Wolf RK, Alderman EL,
Caskey MP et al. Clinical and six month angiographic evaluation of coronary arterial graft
interrupted anastomoses by use of a self closing clip device: a multicentre prospective
clinical trial. J Thorac cardiovasc Surg 2003; 126(1): 168 - 178.)

Reports from single centres have concluded that the U Clips offer the opportunity to create
superior interrupted anastomoses for AV fistula, even in patients who would otherwise be
considered poor candidates for fistula creation. (Ross JR. Creation of native arteriovenous
fistulas with interrupted anastomoses using a self closing clip device - one clinics
experience. Journal of vascular Access 2002; 3: 140 - 146). In this report with small
numbers, the radiocephalic fistulas had an 8 week maturation rate of 93%. Of the 28 patients
having a radiocephalic fistula, 10 had veins of between 1.0 - 1,5mm diameter.

The aim of this pilot study will be to assess if there is a clinical difference in the
maturation rates of autologous AV fistulae when a clipped anastomosis is compared to a
conventional prolene anastomosis.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 0 0
Address 0 0
Country 0 0
Phone 0 0
Fax 0 0
Email 0 0
Contact person for public queries
Name 0 0
Stuart R walker, MBBS
Address 0 0
Country 0 0
Phone 0 0
03 6227064
Fax 0 0
Email 0 0
Contact person for scientific queries

Summary results
For IPD and results data, please see