Improving Arteriovenous Fistula Patency
Condition: Thrombosis
MeSH terms: Thrombosis; Arteriovenous Fistula; Fistula
Study type: Interventional

Summary: 
      All vascular access guidelines recommend monitoring and surveillance protocols to prevent
      vascular access complications in hemodialysis units.

      However, in the case of second generation screening techniques which determine access blood
      flow measurement (QA), there is a huge controversy about it´s efficiency.

      Although multiple observational studies find a decrease in the thrombosis rate and an
      increased primary assisted patency survival related to the use of these techniques, a
      recently published meta-analysis find contradictory results in the randomized controlled
      trials, affirming that the measurement of QA is useless in grafts and questionable in native
      arteriovenous fistulae (AVF).

      We have designed a multicenter, prospective, open label, controlled, randomized trial, to
      prove the usefulness of the QA measurement using two complementary second generation
      techniques, Doppler ultrasound and Transonic dilution method, compared to the classical
      monitoring and surveillance methods.

      The primary endpoint will be a reduction in the thrombosis rate with an increased assisted
      primary patency survival, and a cost effectiveness economic analysis.

      As secondary endpoints we will analyze the impact over non-assisted primary patency survival
      and secondary patency survival.
    

Detailed description: 
      Definition:

      Multicenter, prospective, open label, controlled, randomized trial, to prove the usefulness
      of the QA measurement using two complementary second generation techniques, Doppler
      ultrasound and Transonic dilution method, compared to the classical monitoring and
      surveillance methods.

      For Patient Registries:

      Clinical data repository (CDR) paper notebook will contain all baseline patient
      characteristics and the information related to vascular access. These data will be collected
      by the different investigators and reviewed and included in data base by the study´s monitor.

      This information will be included in a centralized computer database (SPSS 15.0 computer
      system) and encoded in order to preserve patients´ confidentiality.
    

Intervention name(s): Second generation surveillance of AVF; vital signs; physical examination of AVF; ktv test; urea method
Intervention type(s): Device; Procedure; Procedure; Procedure; Procedure
Intervention description(s): Doppler ultrasound and transonic dilution method technique will be performed in the experimental group quarterly.
QA will be measured by both techniques and haemodynamic repercussion stenosis will be evaluated by doppler ultrasound.; Effective blood flow, venous pressure, arterial pressure, at the beginning and at the end of the dialysis session; Predialysis physical examination of AVF every dialysis session.; Weekly ktv measurement using biosensors. In patients who have been dialyzed in monitors with no biosensors, ktv will be measured monthly using monocompartimental Daugirdas equation; Quarterly recirculation with urea method.
Other intervention name(s): Doppler ultrasound: M-Turbo. Sonosite.; Transonic dilution method: Transonic System Inc HD-03
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Thrombosis; Arteriovenous fistulae; Hemodialysis; Doppler ultrasound; Vascular access blood flow; Surveillance