Dialysis AV Fistula Angioplasty / Declotting

Background and indications

Angioplasty and declotting of arteriovenous fistula (AVF) or dialysis graft is a common intervention to maintain vascular access for hemodialysis patients. AVFs and grafts develop stenoses (mainly venous — anastomosis, draining vein) causing dysfunction (insufficient flow, elevated venous pressure, inadequate maturation). Acute AVF thrombosis requires urgent declotting.

Pre-procedure assessment

Assessment includes AVF Doppler ultrasound (stenosis mapping, flow measurement — flow < 600 mL/min significant), and clinical evaluation (diminished thrill, elevated dialysis venous pressure, prolonged post-dialysis bleeding time).

Procedure

Under local anesthesia, direct AVF access by puncture is performed. Complete fistulography is obtained (from arterial anastomosis to right heart). Stenoses are treated by high-pressure balloon angioplasty (6-8 mm). For recurrent or elastic stenosis, cutting balloon or stent may be used. For acute thrombosis, thromboaspiration and/or pharmacomechanical thrombolysis is performed before angioplasty. The procedure takes 30-90 minutes.

Results and scientific evidence

Technical success rate is 90-98%. Post-angioplasty primary patency is 50-60% at 6 months and 30-40% at 12 months (reinterventions are expected). Secondary patency (with iterative reinterventions) is 80-90% at 2 years. KDOQI (Kidney Disease Outcomes Quality Initiative) guidelines recommend surveillance and preemptive angioplasty to extend AVF lifespan.

Risks and complications

Venous rupture (2-5%, treated by prolonged balloon or covered stent), access site hematoma (3-5%), early thrombosis (5-10%), residual stenosis (10-15%). Serious complications are rare.

Recovery

Same-day discharge. Dialysis resumed next day if needed. Control Doppler ultrasound at 1 and 3 months.

Practical information

The procedure is performed as an outpatient. It is performed by an interventional radiologist, in coordination with the nephrologist.