Improving Arteriovenous Fistula Patency (METTRO)

Hospital Infanta Sofia

Status: Completed

Conditions: Thrombosis

Treatments: Procedure: physical examination of AVF; Device: Second generation surveillance of AVF; Procedure: ktv test; Procedure: vital signs; Procedure: urea method

Study type: Interventional

Funder types: Other

Identifiers

NCT02111655

3598 (Other Identifier)

210443-031132-261233

Details and patient eligibility

About

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.

Full 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.

Enrollment: 212 patients

Sex: All

Ages: 18 to 95 years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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212 participants in 2 patient groups

Clasical Surveillance of AVF

Other group

Description:

Classical evaluation of AVF includes: 1. Vital sings and predialysis physical examination of AVF every dialysis session. 2. Effective blood flow, venous pressure, arterial pressure, at the beginning and at the end of the dialysis session. 3. Weekly ktv test using biosensors or monthly if using monocompartimental Daugirdas equation. 4. Quarterly recirculation with urea method. Following Spanish Nephrology VA guidelines will be consider as alarm criteria: 1.25% Increased venous pressure. 2.25% Decreased pump blood flow. 3.0,2 ktv decreased compared with previous measurement. 4.\> 10% recirculation using urea method. 5.Prolonged coagulation time or cannulation difficulties in 3 consecutive dialysis sessions. 6.Pathologic physical examination with any other criteria.

Treatment:

Procedure: ktv test

Procedure: physical examination of AVF

Procedure: urea method

Procedure: vital signs

Second generation surveillance of AVF

Experimental group

Description:

In addition to the classical surveillance and monitoring methods, in the experimental group Doppler ultrasound and transonic dilution method will be performed on a quarterly basis. In addition to the classical alarm criteria and derived from the results in Doppler ultrasound an transonic dilution method the following alarm criteria would also be considered in the experimental group: 1. 25% or higher decreased in QA compared with previous measurement. 2. QA lower than 500 ml/min. 3. Stenotic area with a higher than 50% reduction of blood vessel lumen would be considered as alarm criteria only if it comes with a haemodynamic repercussion criteria defined as Peak systolic velocity (PSV) higher than 400 cm/sc, aliasing, or PSV ratio stenosis/pre-stenosis higher than 3.

Treatment:

Procedure: ktv test

Procedure: physical examination of AVF

Procedure: urea method

Procedure: vital signs

Device: Second generation surveillance of AVF