Maria-Teresa Parisotto
Fresenius Medical Care, Germany
Title: Cannulation technique influences arteriovenous fistula and graft survival
Biography
Biography: Maria-Teresa Parisotto
Abstract
Introduction and Aim of the study
· There is a close link between the availability of a well-functioning vascular access and patient survival on haemodialysis
· Every effort should be made to maintain the functionality of the vascular access for long-term use.
· Practices of access cannulation vary from clinic to clinic, mainly for historical reasons.
· The aim of this study is to investigate the impact of cannulation technique on the survival of the arteriovenous fistula (AVF) and grafts (AVG).
Methods
In April 2009, a cross sectional survey was conducted in 171 dialysis units located in Europe, Middle East and Africa to collect details on vascular access cannulation practices.
On the basis of this survey1, a cohort of patients was selected for follow-up, inclusion being dependent on the availability of corresponding access survival/intervention data in the clinical database.
Access survival was analyzed using the Cox regression model (adjusted for within country effects) defining as events the need for first surgical access survival intervention.
Patients were censored for transplantation, death, loss of follow-up, or end of the study period (March 31, 2012). Results were adjusted for age, gender and diabetes mellitus
Results
Out of the 10,807 patients enrolled for the original survey, access survival data was available for 7,058 (65%) of patients, these residing in Portugal, UK, Italy, Turkey, Romania, Slovenia, Poland and Spain.
Mean age was 63.5+15.0 years; 38.5% were female; 27.1% were diabetics; 90.6% had a native fistula and 9.4% had a graft. Access location was distal for 51.2% of patients. During the follow-up, 51.1% were treated with antiaggregants and 2.8% with anti-coagulants.
Prevalent needle sizes were 15 G and 16 G for 63.7% and 32.2% of the patients, respectively (14 G: 2.7%, 17 G: 1.4%). Cannulation technique was area for 65.8% and rope-ladder for 28.2%, and the direction of puncture was antegrade for 57.3%. Median blood flow was 350-400 mL/min.
Conclusions
The study revealed that area cannulation technique, despite being the most commonly used, was inferior to both rope-ladder and buttonhole for the maintenance of Vascular Access functionality.
With regard to the effect of needle and bevel direction, the combination of antegrade position of arterial needle with bevel up or down was significantly associated with better access survival than retrograde positioning with bevel down.
There was an increased risk of access failure for graft versus fistula, proximal vs distal location, right arm vs left arm, and the presence of a venous pressure greater than 150 mmHg. The higher HR associated with a venous pressure greater than 150 mmHg should open a discussion on currently accepted limits