Optimizing Access Surgery In Senior Hemodialysis Patients (OASIS)

Maastricht University Medical Centre (MUMC)

Status: Active, not recruiting

Conditions: Dialysis Access Malfunction; Central Venous Catheter Related Bloodstream Infection; Vascular Access Complication; Arteriovenous Graft; Hemodialysis Access Failure; Arteriovenous Fistula

Treatments: Procedure: Central venous catheter placement; Procedure: Arteriovenous graft placement; Procedure: Arteriovenous fistula creation

Study type: Interventional

Funder types: Other

Identifiers

NCT05911451

NL7933 (Other Identifier)

NL70385.068.19

Details and patient eligibility

About

The number of elderly hemodialysis patients is growing. Vascular access complications are a major determinant of the quality of life and health care costs for these vulnerable patients. The three different types of vascular access, i.e. autologous arteriovenous fistulas, arteriovenous grafts, and central venous catheters, have never been compared in randomized controlled trials. This project will deliver the much-needed evidence to determine the optimal strategy for vascular access creation in elderly hemodialysis patients in order to deliver better health care at lower costs.

Full description

Objective: To compare surgical strategies for vascular access creation in elderly hemodialysis patients.

Hypothesis: Arteriovenous grafts and central venous catheters lead to fewer interventions, more quality of life, and lower health care costs than autologous arteriovenous fistulas.

Study design: Parallel group, multicenter randomized controlled trial.

Study population: Patients >65 years with a life expectancy <2 years who are expected to start hemodialysis treatment within 6 months or who have started hemodialysis treatment with a catheter in the past 6 months.

Study groups:

1. Autologous arteriovenous fistula creation
2. Arteriovenous graft implantation
3. Central venous catheter placement

Sample size calculation: 3x65 patients for superiority with multiplicity correction based on a clinically relevant difference of 0.80 interventions/year. Due to slow enrollment, follow-up time per participant was much longer than anticipated at trial initiation. After enrollment of 166 participants, calculations based on actual event and mortality rates showed that the trial had sufficient statistical power to detect a relative difference in event rate of 0.67, corresponding to an absolute difference below the minimal clinically relevant difference of 0.80 access-related interventions per year. Therefore, enrollment was closed at 166 participants.

Data analysis: Poisson regression analysis with time as off-set variable.

Enrollment: 166 patients

Sex: All

Ages: 65+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Adult patients aged 65 years or older

2. End-stage renal disease with unlikely recovery of kidney function according to the attending nephrologist

3. Hemodialysis is the intended long-term modality of treatment for end-stage renal disease

4. Fit for vascular access surgery as determined by the local multidisciplinary vascular access team 5a. Expected to start hemodialysis treatment within 6 months at the time of treatment assignment; or 5b. Treated with hemodialysis for 6 months or less at the time of treatment assignment using a tunneled or non-tunneled central venous catheter for vascular access

5. Planning to remain in one of participating dialysis centers for at least 1 year 7. Suitable vascular anatomy for all types of vascular access based on duplex ultrasound of the arms, defined as:

• at least one suitable configuration for an arteriovenous fistula using minimal arterial and venous diameters of 2mm for radiocephalic fistulas and 3mm for brachiocephalic and brachiobasilic fistulas;
• at least one suitable configuration for an arteriovenous graft using minimal arterial and venous diameters of 3mm and 4mm, respectively; and
• at least one open internal jugular vein for a central venous catheter.

Exclusion criteria

1. Patent arteriovenous fistula or graft already in place
2. Prior unsuccessful arteriovenous fistula or graft vascular access surgery
3. Kidney transplantation planned within 6 months
4. Metastatic malignancies or other condition associated with a life expectancy of <6 months, in the opinion of the attending nephrologist
5. Unable to provide informed consent
6. Dusseux risk score <5, indicating an usually long life expectancy for elderly patients starting hemodialysis treatment (the Dusseux risk score was adapted for patients between 65 and 70 years by assigning -3 points to this age category)

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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166 participants in 3 patient groups

Arteriovenous fistula

Active Comparator group

Description:

Patients allocated to usual care will be treated according to current guidelines on vascular access creation. These guidelines recommend placing autologous arteriovenous fistulas at the most distal site with adequate blood vessels, preferably in the non-dominant arm. Patients who have already been on hemodialysis treatment using a central venous catheter must be operated within 6 months of dialysis initiation. Because the study aims to compare the different surgical strategies for vascular access creation in a real-life situation, the study will not interfere with clinical practice at the study sites.

Treatment:

Procedure: Arteriovenous fistula creation

Arteriovenous graft

Experimental group

Description:

Patients who are allocated to the arteriovenous graft strategy will have a commercially available prosthetic tube graft implanted for hemodialysis access. Patients who have already been on hemodialysis treatment using a central venous catheter must be operated within 6 months of dialysis initiation. Because the study aims to compare the different surgical strategies for vascular access creation in a real-life situation, the study will not interfere with clinical practice at the study sites.

Treatment:

Procedure: Arteriovenous graft placement

Central venous catheter

Experimental group

Description:

Patients who are allocated to the central venous catheter strategy will have a dialysis catheter inserted. Because the study aims to compare the different surgical strategies for vascular access creation in a real-life situation, the study will not interfere with clinical practice at the study sites.

Treatment:

Procedure: Central venous catheter placement