Short summary

For patients in HD the cannulation of their arteriovenous fistula is a matter of vital importance. One of the two recommended cannulation techniques is the buttonhole technique, where two needles are placed at the exact same puncture site in the fistula at every hemodialysis treatment for 6-12 dialyses, until a tunnel track is created. A new method where 4-6 needles are inserted one at a time in the exact same puncture site makes it possible to create the tunnel in 1-3 dialyses.This method has been used in several units in Denmark; however, it is unknown whether the new method is superior to the standard method.

Rationale

Patients diagnosed with end stage renal disease on dialysis require a vascular access for hemodialysis (HD).The vascular access has been described as both the Achilles' heel and the lifeline of hemodialysis therapy. Vascular access complications are the most common cause of hospitalization among patients in HD. An arteriovenous fistula (AVF) is a surgical connection made between an artery and a vein, created by a vascular specialist and is typically placed in the arm. AV fistulas are the preferred vascular access for long-term dialysis because they last longer than other dialysis access types and are less prone to infection and clotting. In order to be able to carry out an adequate and uncomplicated dialysis treatment, two needles have to be placed in the fistula. It requires specialized technical skills to install well-functioning needles in the vessels of an AVF. The buttonhole technique is one of the two recommended techniques. For the buttonhole technique, two puncture sites are selected in the fistula. In the same spot a needle is inserted with the same angle and direction until a fibrous tunnel is formed.  Cannulation is then possible with blunt needles which are gentler and has fewer complications. It requires 6-12 cannulations to create a buttonhole tunnel (6-12 dialyses) It is crucial for the future survival of the tunnel tracks, that a maximum of one to two health professionals insert the needles until the tunnel track is created. This is a logistic challenge and may result in using a cannulation technique that is not recommended. A less time-consuming method to create the buttonhole tunnel track may increase the use of the buttonhole technique. A new method where the same tunnel tracks are created in 1-3 dialyses by repeated cannulations (4-6 needles) in the same two puncture sites in the fistula has been used in several dialysis units in Denmark. By using this method, the experiences so far indicate that fewer dialysis sessions are needed to create the tunnel tracks with 4-10 sessions. Thus, the logistic challenges of ensuring continuity in persons creating the tunnel track will be reduced. The purpose of the research project is to investigate whether a new method for creating buttonhole tunnels will:

• Increase the number of well-functioning buttonholes.

• Be less painful for the patient.

• Reduce the number of dialysis sessions needed to create the buttonhole tunnel track.

• Cause unchanged or fewer fistula associated complications and infections.

Description of the cohort

Inclusion Criteria:

  - patients in chronic hemodialysis

  - at least 5 hemodialysis treatments with a blood flow of minimum 250 ml/min have been carried out

  - ability to speak and understand danish

  - age minimum 18 years

Exclusion Criteria:

 - patients with an artificial heart valve

 - patients in high dose immunosuppressive treatment

 - patients with infections in their buttonholes

 - patients who are unable to provide informed consent

  - ability to speak and understand danish

Study design:

A randomized, multi-center study. 

The study participants are randomized into two arms:

The control group: needling into the same site in the AVF with 1 sharp needle at each dialysis (6-12 dialyses) creating a buttonhole tunnel track, where cannulation with a blunt needle is possible. 

The intervention group: repeated needling into the same site in the AVF with sharp needles (4-6 pieces) at each dialysis (1-3 dialyses) creating a buttonhole tunnel track where cannulation with a blunt needle is possible.

Data and biological material

Baseline data: 

Age, sex and body mass index, comorbidities (Diabetes, cardiovascular disease and chronic lung disease), medical treatments with Prednisolone, immunosuppressive and/or anticoagulants, arteriovenous fistula age and placement, dialysis filter, blood flow ml/min.

Data registered at each dialysis session during the period of creating the buttonhole tunnel track:

Patient experienced pain at each cannulation measured by the numerical rating scale (NRS), numbers of needles and types (sharp or blunt) inserted, person cannulating.

The buttonhole tunnel track creation is defined as completed when two consecutive dialyses have been carried out on blunt needles with no use of sharp needles. Failure if the period is longer than 24 dialyses.

Follow up for 12 month after the tunnel is created of the following variables:

• Numbers of needles and types (sharp or blunt) inserted, person cannulating.

• Buttonhole non survival definition: the need for cannulations carried out using sharp needles in the buttonhole for three consecutive dialyses or if blunt needles have not been inserted in the buttonhole for 6 dialyses.

• Buttonhole infection           

• AV fistula associated infections, complications and failure    

Collaborating researchers and departments

Research Unit of Health Science, Hospital of Southwest Jutland, Esbjerg & Department of Regional Health Research University of Southern Denmark (SDU)

• Research leader, Associate professor Bibi Gram

Department of Nephrology, Dialysis Clinic, Kolding Hospital

•  Specialist in hemodialysis and vascular access Nanna Lagoni