Dialysis Access · IR Playbook

Endovascular Evaluation and Treatment of Dialysis Access Stenosis (Fistulography/PTA)

Fistulography evaluates the complete arteriovenous fistula or graft circuit, and fistuloplasty treats a culprit stenosis to restore reliable haemodialysis. Intervene only when clinical access dysfunction accompanies an angiographic stenosis of at least 50%; an incidental stenosis without clinical indicators is not an indication for pre-emptive angioplasty. Technical success is 30% or less residual stenosis with improved circuit flow and no flow-limiting complication; recurrence is common, particularly at the cephalic arch.

Learning objectives

• Recognise clinical indicators that justify fistulography and distinguish them from surveillance-only abnormalities
• Survey the complete dialysis circuit from arterial inflow through the central venous outflow
• Select and perform reference-vessel-sized angioplasty safely and recognise the 30% residual-stenosis endpoint
• Escalate resistant, recurrent and cephalic-arch lesions without sacrificing future access options
• Recognise and immediately manage rupture, thrombosis, embolisation and stent-related complications

Indications

• Clinical or dialysis dysfunction with suspected stenosis: new cannulation difficulty, aspiration of clots, inability to achieve prescribed blood flow, rising venous pressures, recirculation or otherwise unexplained reduction in delivered dialysis dose
• Abnormal examination suggesting inflow or outflow disease: weak or resistant pulse, discontinuous or systolic-only thrill, high-pitched systolic bruit, failure of pulse augmentation, failure of the fistula to collapse on arm elevation or ipsilateral limb oedema
• Prolonged bleeding from needle sites beyond the patient's usual pattern, particularly when recurrent across dialysis sessions
• Failure of fistula maturation when a correctable stenosis or competing outflow lesion is suspected and endovascular treatment accords with the access plan
• Recurrent dysfunction after prior angioplasty requiring reassessment for elastic recoil, resistant stenosis, cephalic-arch disease, in-stent restenosis or a lesion better managed surgically

Relative contraindications

• Active local or systemic infection involving the access
• Uncorrected clinically important coagulopathy or thrombocytopenia
• Severe contrast hypersensitivity without an adequate prophylaxis or alternative-imaging strategy
• No safe puncture segment because of skin breakdown, large haematoma, aneurysm or pseudoaneurysm
• Lesion anatomy in which surgery is more durable or endovascular treatment would compromise the cannulation zone or future access
• Severe cardiopulmonary instability or inability to tolerate the required analgesia or sedation

Equipment

• High-frequency linear ultrasound transducer with sterile cover and fluoroscopy with digital subtraction capability
• 21 G echogenic needle, 0.018-inch wire and 4–5 Fr micropuncture set
• 5–7 Fr short vascular sheaths; larger sheath matched to the selected covered-stent delivery system
• 0.035-inch hydrophilic angled guidewire, 0.035-inch stiff support wire and 4–5 Fr angled or multipurpose catheter
• Low-osmolar iodinated contrast with saline for dilution; use the smallest volume that provides diagnostic images
• Noncompliant or high-pressure PTA balloons, commonly 4–12 mm diameter and 20–80 mm length, selected 1:1 to the measured reference vessel and within device instructions
• Purpose-built ultrahigh-pressure balloon and scoring or cutting balloon for selected resistant lesions
• Drug-coated balloon sized to the prepared reference vessel for selected recurrent native AVF lesions
• Self-expanding covered stent with diameter and length matched to the reference vein and adequate healthy landing zones
• Inflation device with pressure gauge, three-way stopcocks, heparinised saline flushes and roadmap syringes
• Prolonged-inflation balloon and covered stent immediately available for rupture rescue
• Purse-string suture, haemostatic pad and transparent dressing for access-site haemostasis

Procedure steps

1. Correlate examination and dialysis findings with prior imaging, identify the likely culprit segment and review the ESKD Life-Plan before any implant. If clinical dysfunction is absent, perform diagnostic assessment only when justified and do not prophylactically dilate an incidental narrowing.Pearl: The exam answer is clinical indicator plus at least 50% stenosis, not stenosis alone.
2. Mark the anastomosis, cannulation zone, aneurysms and proposed puncture under ultrasound. Position the arm comfortably, prepare a wide sterile field and infiltrate local anaesthetic away from the access lumen.
3. Puncture the AVF or AVG under ultrasound with a 21 G needle and introduce a 5–7 Fr sheath in the direction that gives the most coaxial route to the target. Confirm intraluminal position before advancing wires or the sheath.Pearl: Antegrade access favours outflow and cephalic-arch treatment; retrograde access favours the anastomosis and inflow.
4. Inject small contrast runs through the sheath or catheter and image the access outflow through the central veins. Use appropriate projections to separate overlapping veins and profile the cephalic arch; document stenosis location, length, collateralisation and reference diameter.
5. Obtain reflux imaging of the feeding artery, anastomosis and juxta-anastomotic segment by brief controlled outflow compression, or position a catheter close to the anastomosis when reflux is inadequate. Release compression immediately after the run and confirm distal arterial perfusion when inflow intervention is contemplated.
6. Cross the culprit stenosis gently with an angled hydrophilic wire and catheter, then exchange for a support wire if required. Measure the adjacent normal vessel and choose a balloon approximately 1:1 to that reference rather than guessing from the stenotic lumen.Pearl: For a graft-vein anastomotic lesion, size to the adjacent normal outflow vein and respect the graft diameter and device instructions.
7. Centre a noncompliant or high-pressure balloon across the lesion and inflate gradually under fluoroscopy within the rated burst pressure until the waist is abolished or no further safe expansion is possible. Deflate fully before repositioning and repeat overlapping treatment only where necessary; no evidence-based universal inflation duration exists.Pearl: Treat pain proactively while maintaining communication because balloon inflation pain may be severe.
8. If the balloon waist persists, recheck balloon size and wire position, then use a longer inflation, purpose-built ultrahigh-pressure balloon or scoring/cutting balloon according to lesion morphology and operator experience. Consider a drug-coated balloon only after satisfactory vessel preparation, mainly for a selected recurrent native AVF lesion; evidence does not support routine use for every stenosis.
9. Use high-pressure balloon angioplasty as initial treatment of a clinically significant cephalic-arch stenosis. For flow-limiting recoil, rupture not controlled by tamponade or selected recurrent disease, deploy a self-expanding covered stent only after confirming that landing zones preserve the axillary vein, important branches and future access; avoid a bare-metal stent when a covered stent is appropriate.Pearl: Frequent early cephalic-arch recurrence should trigger multidisciplinary consideration of cephalic-vein transposition or other surgical revision, not endless angioplasty.
10. Repeat fistulography in the same projection and document 30% or less residual stenosis, brisk flow, reduced collaterals and absence of significant recoil, extravasation or flow-limiting dissection. Re-examine the pulse, thrill and distal hand and ensure that the original clinical problem is expected to improve.Pearl: Technical success is anatomical; clinical success requires improved access function at dialysis.
11. Remove the sheath with manual compression, a purse-string suture or a haemostatic pad while preserving access flow. Confirm a palpable thrill and distal perfusion after haemostasis, apply a visible dressing and communicate the puncture and any stent location to the dialysis unit.

Complications

• Access-site bleeding or haematoma
• Venous rupture or perforation
• Acute access thrombosis
• Distal arterial embolisation or hand ischaemia
• Flow-limiting dissection or severe venous spasm
• Severe contrast reaction or cardiopulmonary decompensation
• Access infection
• Stent-graft migration, thrombosis or edge restenosis

Exam pearls

• Clinical dysfunction plus at least 50% stenosis is the treatment indication; do not angioplasty an incidental lesion
• 30% or less residual stenosis is the standard angiographic technical endpoint
• Balloon diameter is chosen approximately 1:1 to the adjacent normal reference vessel
• A complete fistulogram includes both arterial inflow and central venous outflow
• Cephalic-arch stenosis is a classic recurrent lesion in brachiocephalic AVF; covered stents outperform bare-metal stents in available comparative evidence
• Before any stent graft, protect the cannulation zone, axillary and basilic outflow and the patient's future access Life-Plan
• Loss of thrill after sheath removal is an emergency until access thrombosis or excessive compression is excluded

Viva questions

When should a dialysis-access stenosis be treated?

Treat when a clinical or dialysis indicator of access dysfunction is present and imaging confirms a culprit stenosis of at least 50%. Angiographic stenosis without clinical dysfunction is not, by itself, an indication for pre-emptive angioplasty.

What must a complete fistulogram show?

It should evaluate the feeding artery, arterial anastomosis, juxta-anastomotic segment, entire cannulation or graft segment, peripheral venous outflow, cephalic arch when relevant and central veins to the right atrium.

How do you assess arterial inflow from a venous access?

Use brief controlled venous-outflow compression to reflux contrast across the anastomosis, or place a catheter close to the anastomosis if reflux is inadequate. Avoid forceful prolonged compression and confirm distal hand perfusion.

How do you size the angioplasty balloon?

Size approximately 1:1 to an adjacent normal reference vessel, not to the stenotic lumen. Oversizing increases rupture risk and undersizing causes residual stenosis and recoil.

What defines technical success after fistuloplasty?

The usual anatomical endpoint is 30% or less residual stenosis with brisk flow and no significant recoil, extravasation or flow-limiting dissection. Clinical success is improvement of dialysis access function.

How do you manage a resistant balloon waist?

Confirm position and sizing, then consider prolonged inflation, a purpose-built high- or ultrahigh-pressure balloon, or a scoring/cutting balloon. Escalation must remain within device limits and stop when rupture risk outweighs benefit.

Why is cephalic-arch stenosis difficult and how is it treated?

The arch is curved, constrained by fascia and exposed to high-flow turbulence, producing resistant stenosis, recoil and frequent restenosis. Start with high-pressure PTA; consider a covered stent for rupture, significant recoil or selected recurrence, and surgical transposition when recurrence is frequent.

What is the role of drug-coated balloons?

A DCB is used only after successful vessel preparation and may improve target-lesion patency in selected native AVF lesions, but trials have been heterogeneous. Current guidance does not support routine DCB use for every access stenosis.

References