01Principles and purposeThe professional or clinical skill and the decisions it supports.
A fistula is an artery-to-vein connection created to deliver repeated haemodialysis blood flow. Arterial pressure and flow enlarge and remodel the outflow vein, but successful surgery is only the beginning: the vein must become palpable, sufficiently straight and superficial, robust enough for repeated cannulation, and able to deliver dialysis without compromising the hand. Primary failure includes a fistula that never becomes usable; delayed maturation may result from inadequate inflow, juxta-anastomotic or outflow stenosis, accessory veins that divert flow, excessive depth, poor vessel quality, hypotension or a combination of factors.
UKKA 2023 moves away from one access rule for every patient. It advises fistula formation when anatomy is suitable and prolonged haemodialysis is likely, while recognising that a graft or catheter may better fit urgent need, limited prognosis, a short anticipated dialysis period or an individual's treatment priorities. NICE NG107 advises planning early and aims for fistula creation around 6 months before anticipated dialysis; UKKA frames referral and, if suitable, formation as appropriate when dialysis is likely within 12 months. The difference reflects uncertainty in predicting kidney decline, service lead times and the time needed for formation, maturation and possible salvage.
Key points
- Choose access through a multidisciplinary shared decision that combines clinical examination, ultrasound anatomy, likely haemodialysis duration, timing, future sites and the person's priorities.
- In adults, assess fistula maturity between 2 and 6 weeks; if non-maturity persists beyond 6 weeks, investigate for correctable inflow, outflow, accessory-vein or depth problems rather than simply waiting.
- Do not cannulate by calendar alone: confirm a palpable cannulation segment, appropriate depth and course, adequate inflow and outflow, and no ischaemia, infection or unstable swelling.
- Preserve veins early by avoiding unnecessary cannulas and vessel puncture proximal to the wrist in the planned or non-dominant arm when lifetime kidney-failure risk is high.
- Counsel that fistula outcome is poorer when either planned artery or vein is below 2.0 mm; this is a risk discussion, not a stand-alone prohibition.
- Favour a distal site initially when anatomy and patient preference support it, because a distal-first sequence preserves proximal options.
- Consider central venous imaging when prior central catheters, devices, multiple access failures or clinical features raise the risk of central venous stenosis.
- Avoid peri-operative and maturation-period hypotension by reviewing medicines, dialysis target weight and intercurrent illness while balancing cardiovascular and fluid needs.
02Situations and prioritiesThe context, relevant information and actions that matter most.
A continuous thrill begins at the anastomosis and extends along an enlarging vein; the segment becomes easier to see and feel, compressible between pulses, with a bruit that does not become sharply high pitched at one point.
A weak or short thrill, excessive pulsatility at the anastomosis, coolness or poor distal pulses, and low access flow raise concern for arterial or juxta-anastomotic disease.
A strongly pulsatile fistula, focal high-pitched bruit, failure to collapse with arm elevation, collateral veins or limited enlargement suggests venous stenosis or diverted flow.
Adequate flow may coexist with excessive depth, tortuosity, a short usable segment or obesity; these are practical maturation failures because safe reproducible needling remains impossible.
Absent thrill, rapidly enlarging haematoma, severe swelling, rest pain, weakness or sensory change demands urgent assessment for thrombosis, bleeding, compartment pressure or severe steal.
03Assessment and interpretationHow to gather information, assess the situation and recognise uncertainty.
Consider the information, its meaning and its limitations before deciding what follows.
- 01
Structured look, feel and listen assessment - Why
- Assess both the access circuit and hand at each review, mapping the thrill, pulse, vein course, wound, swelling, distal perfusion and neurological function.
- Interpretation and limitations
- A continuous thrill, usable superficial segment and warm functional hand support progression; an absent thrill, focal pitch change, abnormal pulsatility or distal deficit directs urgent or targeted imaging.
- 02
Duplex ultrasound — preferred anatomy test when examination is uncertain - Why
- Measure artery and vein diameter and quality before formation, then assess inflow, anastomosis, outflow, depth, flow, stenosis and accessory veins during maturation.
- Interpretation and limitations
- Measurements predict probability rather than give a universal pass mark. UKKA cautions that either vessel below 2.0 mm has poorer outcome and that maturity remains an individual clinical judgement.
- 03
Central venous imaging - Why
- Define central outflow before formation when prior central venous catheterisation, cardiac devices, arm or chest collaterals, previous access failure or asymmetrical swelling raises suspicion.
- Interpretation and limitations
- Duplex cannot reliably exclude central lesions; conventional or cross-sectional venography can identify stenosis that would cause venous hypertension or jeopardise a new access.
- 04
Dialysis-readiness assessment - Why
- Combine examination, ultrasound if needed, needling-zone length, depth and staff or self-cannulation capability before the first cannulation attempt.
- Interpretation and limitations
- No isolated diameter, flow or elapsed-time rule proves safe usability. Proceed when the team can consistently access the vein while avoiding miscannulation and preserving the circuit.
04Worked approachesCases with ordered reasoning, an action and a check of the outcome.
01Worked case — planning through verificationProgressive CKD with haemodialysis likely within a yearUse when an adult's kidney trajectory and treatment choice make haemodialysis probable but dialysis has not yet started.+
- 1Confirm kidney-replacement goals, likely timing, transplant or peritoneal options, dominant hand, work and hobbies, prior lines or devices, cardiovascular reserve and acceptable treatment burden.
- 2Protect potential veins, examine pulses and both arms, and arrange duplex mapping; obtain central venous imaging when history or signs suggest central outflow disease.
- 3Discuss distal-first fistula, graft and catheter trade-offs with the multidisciplinary team; explain poorer fistula outcome if either vessel is under 2.0 mm without treating that value as an absolute ban.
- 4Form the agreed access with enough lead time for healing and salvage, then check the wound, thrill and hand promptly and monitor maturation with repeated look-feel-listen assessment.
- 5Perform the adult maturity assessment between 2 and 6 weeks; if the fistula remains non-mature beyond 6 weeks, arrange duplex-led investigation and decide on angioplasty, accessory-vein management, superficialisation, surgical revision or a new plan.
- 6Verify readiness immediately before first needling, document the cannulation segment and technique, use trained support and review the first sessions for infiltration, haemostasis, delivered dialysis and evolving dysfunction.
02Routine maturation pathwayStable new fistula without red flagsUse after uncomplicated formation when the thrill is present, the wound is healing and the hand remains warm, comfortable and functional.+
- 1Review blood pressure, dialysis target weight and medicines that may contribute to avoidable hypotension while preserving necessary cardiovascular treatment.
- 2Teach daily patient checks for thrill, wound change, swelling, pain and hand symptoms, including whom to contact if the thrill disappears.
- 3Arrange formal 2–6 week assessment and escalate persistent non-maturity beyond 6 weeks instead of relying on a fixed waiting period.
03Rescue pathwayEarly abnormal examination or failed developmentUse for an absent or deteriorating thrill, focal abnormal bruit, failure of vein enlargement, collateral veins, excessive depth or difficult first needling.+
- 1Classify urgency: acute loss of thrill, severe ischaemia, bleeding or expanding haematoma receives immediate same-day assessment; stable non-maturation receives expedited access-team review.
- 2Use duplex to identify inflow stenosis, anastomotic lesion, outflow obstruction, accessory drainage, inadequate flow, depth or haematoma, adding central venography when indicated.
- 3Select correction according to anatomy and the person's overall access plan, then reassess thrill, hand perfusion and practical cannulation readiness before use.
05Feedback, follow-up and evidenceReview outcomes, seek feedback and identify what to improve.
- After formation, document wound condition, access thrill and bruit, radial or ulnar perfusion, hand temperature, capillary refill, motor and sensory function, swelling and pain trajectory.
- During maturation, repeat look-feel-listen checks and record vein enlargement, usable length and depth, inflow and outflow signs, collateral veins and any change after dialysis-related hypotension.
- At 2–6 weeks in adults, record a maturity decision and next action; beyond 6 weeks, document the investigation and salvage or alternative-access plan rather than leaving non-maturity unowned.
- During first cannulations, track successful two-needle use, infiltration or haematoma, needle-site rotation, haemostasis time, achieved blood flow and patient-reported pain or confidence.
- Continue an access-lifecycle record of procedures, central venous devices, failed sites and future options so each rescue decision preserves the wider kidney-replacement plan.
06Special situationsVariants, exceptions and circumstances that change the usual approach.
Timing guidance uses different frames
NICE aims for creation around 6 months before anticipated dialysis, whereas UKKA suggests referral and suitable formation when dialysis is likely within 12 months. Apply both through trajectory, uncertainty and local lead times.
Maturity is functional
A fistula can have measurable flow yet remain unusable because it is deep, tortuous or too short. Cannulation success and sustainable dialysis are the clinical endpoint.
Diameter is continuous risk
The UKKA 2.0 mm statement supports counselling about poorer outcomes; it does not prove that every smaller vessel fails or that every larger vessel succeeds.
Children need longer horizons
UKKA allows longer maturation-assessment intervals in children and highlights greater preparation and support for needling; vessel preservation is bilateral because lifetime access need may be long.
Pregnancy lies outside scope
UKKA 2023 explicitly does not cover access initiated during pregnancy. Planning needs joint renal, obstetric, anaesthetic and vascular expertise, with maternal haemodynamics and dialysis trajectory considered individually.
07Common pitfallsFrequent interpretation and management errors.
- 01
Referring only when dialysis is imminent leaves no time for shared choice, surgery, maturation, investigation and salvage and increases avoidable catheter use.
- 02
Declaring a fistula mature because six weeks have elapsed substitutes a calendar for examination and exposes the vein to infiltration and haematoma.
- 03
Using a rigid ultrasound cut-off as the only decision ignores vessel quality, patient goals, access urgency, cannulation feasibility and future-site preservation.
- 04
Forming access in an arm with unrecognised central venous obstruction can produce severe venous hypertension and consume a future access site.
- 05
Treating absent thrill, rest pain or neurological deficit as an issue for the next routine clinic risks irreversible access loss or hand injury.