Thrombosis
Conditions
Keywords
Thrombosis, Arteriovenous fistulae, Hemodialysis, Doppler ultrasound, Vascular access blood flow, Surveillance
Brief 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.
Interventions
DEVICESecond generation surveillance of AVF
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.
PROCEDUREvital signs
Effective blood flow, venous pressure, arterial pressure, at the beginning and at the end of the dialysis session
PROCEDUREphysical examination of AVF
Predialysis physical examination of AVF every dialysis session.
PROCEDUREktv test
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
PROCEDUREurea method
Quarterly recirculation with urea method.
Sponsors
Hospital Infanta Sofia
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 95 Years
Healthy volunteers
No
Inclusion criteria
* Informed consent signature. * Age between 18 and 95 years old. * Functioning native AVF. * Patients with end stage renal disease (ESRD) undergoing hemodialysis program for at least three months.
Exclusion criteria
* Coagulopathy or hemoglobinopathy of any cause. * Hospitalization of any cause in the previous month. * VA related complications or dysfunction in the previous three months.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Improved primary patency rate in arteriovenous fistulae with the use of doppler ultrasound and transonic dilution method | Up to 3 years follow up | Differences in assisted primary patency rates (thrombosis free access survival) in AVF between the two groups: control group in which classical monitoring and surveillance techniques are applied and experimental group in which Doppler ultrasound and transonic were performed every three months in addition to classical methods. Cost efficacy analysis in both groups will be done, measuring all vascular access (VA) related health care spending (VA hospitalization costs, central venous catheter (CVC) placements, surgeries and endovascular procedures will be recorded). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Compared non-assisted primary patency rates (intervention free access survival) and secondary patency rates (access survival until abandonment) between the two groups. | Up to 1 year follow up | — |
| Evaluate the efficacy and efficiency of second generation methods | Up to 2 years follow up | It will be evaluated the positive and negative predictive value of each second generation technique, doppler ultrasound and Transonic dilution method. The accuracy of these techniques will be compared to determine which one show more benefits detecting pathology of AVF. |
| Reproducibility in Doppler ultrasound technique | Up to 3 years follow up. | There will be always two observers for each doppler ultrasound (same observers for same AVF). Differences among different quarterly measures in stable AVF will be evaluated, as well as the differences between the two observers in QA measurement. |
| Possible influence of different baseline items in the risk of thrombosis of native AVF | Up to 3 years follow up | It will be evaluated if there is any influence of age, body mass index, use of antiplatelet therapy, anticoagulant therapy or the use of pentoxifylline in the risk of thrombosis of AVF |
Countries
Spain
Outcome results
None listed