EVAR

1. Purpose & indications

Purpose. Line the aneurysmal aorta and iliac outflow with a modular graft so systemic pressure is carried through the graft rather than the aneurysm sac. The graft must seal against healthy artery above and below the aneurysm; simply placing a stent inside the sac does not exclude it.

When to consider it. Use standard EVAR when AAA repair is indicated, anatomy fits the selected device's IFU, and the balance of operative risk, frailty, life expectancy and patient preference favours endovascular repair. Being unfit for open repair does not automatically make EVAR beneficial. ESVS advises against elective repair when life expectancy is limited; it uses <2–3 years as a pragmatic definition. [1,8]

PRACTICE DIVERGENCE

• ESVS: EVAR should be considered the preferred option for most patients with suitable anatomy and reasonable life expectancy; open repair should be considered preferable when life expectancy is long (both Class IIa B). [1]
• UK guidance: NICE recommends open repair for suitable patients; consider EVAR when abdominal copathology or person-specific factors favour it, and EVAR or conservative management when anaesthetic risk or medical comorbidity contraindicates open repair. [2]
• Practical interpretation: document this divergence and the individual balance of early operative risk, durability, surveillance burden and patient preference in the MDT discussion.

Think again before standard EVAR: an inadequate/hostile proximal neck; no healthy distal landing zone; severe iliac access disease; narrow terminal aorta with limb competition; systemic infection or a relevant device-material allergy; or inability to undertake meaningful imaging follow-up. Alternatives include open repair, complex endovascular repair, an iliac branch strategy or conservative care according to the clinical context. Do not solve an unsuitable seal by choosing a smaller graft, accepting an unplanned renal/internal iliac occlusion, or assuming that endoanchors will compensate for anatomy outside the planned IFU.

Consent. Explain early benefits and long-term trade-offs; death, MI, renal injury, bleeding and access injury, embolisation/limb ischaemia, bowel or pelvic ischaemia, endoleak, migration, limb occlusion, reintervention, infection, rupture and possible open conversion. State clearly that EVAR requires long-term imaging and sometimes further treatment.

2. Anatomy & planning

Read the CT as a route with two foundations

Use thin-slice arterial-phase CTA with centreline reconstruction from the visceral aorta through both common femoral arteries. Measure perpendicular to the centreline using the measurement convention specified by the selected IFU: for example, Cook Zenith Flex describes aortic/iliac treatment diameters outer-wall to outer-wall, whereas Medtronic's published Endurant sizing chart uses inner-wall measurements. [4,6] Do not transfer a diameter from one vendor's worksheet to another.

1. Proximal seal: identify the lowest relevant renal artery (including accessory renal arteries); measure neck length, diameter at and below that level, taper/reverse taper, angulation, thrombus and calcification. The covered fabric must begin below the planned renal ostium while obtaining sufficient circumferential apposition. A suprarenal bare fixation stent can cross the renal level on some devices; the fabric edge is the critical marker for renal coverage.
2. Body and bifurcation: measure renal-to-aortic-bifurcation distance, aneurysm length and terminal-aortic diameter. Choose a body that leaves usable space for the gate and two limbs without compression. Record the planned main-body side and contralateral cannulation side.
3. Distal seal on each side: locate the common iliac bifurcation, measure healthy circumferential landing length and diameter, and mark the origin and patency of each internal iliac artery. Preserve pelvic perfusion wherever feasible; if iliac aneurysm repair is required, preserve flow to at least one internal iliac artery (ESVS Recommendation 137, Class I C). [1] An aneurysmal common iliac may require a preplanned iliac branch or other pelvic-perfusion strategy.
4. Access: assess the CFA puncture zone, anterior-wall calcium, external/common iliac minimum lumen, stenosis, tortuosity and thrombus against the delivery system's outer profile. The larger body side may not be the easiest side to traverse. Plan percutaneous closure or cut-down and a conversion route before starting.
5. Modules: select body and limbs from the manufacturer's sizing chart. Calculate length to the chosen healthy distal seal, accounting for tortuosity, the device's overlap requirement and any extension. Check availability of all sizes and bailout components, including cuffs, limbs, covered stents and an AUI/conversion plan.

Anatomical red flags: short or conical neck, bulky circumferential neck thrombus/calcium, severe neck angulation, narrow distal aorta, short common iliacs, hostile access or a dominant accessory renal artery. Preserve an accessory renal artery ≥4 mm or supplying >1/3 of the kidney when feasible without compromising seal (ESVS Recommendation 62, Class IIa C). [1]

Common graft families: what actually changes

Do not memorise these as interchangeable sizing rules. The exact graft, component, region and IFU revision govern the case. What matters for training is understanding how seal, fixation, sizing convention and the point of no return differ between devices. Medtronic Endurant product/IFU portal · Cook Zenith Flex IFU · Gore Excluder AAA.

3. Setup

• Team brief: review CTA and a one-page implant plan together: body side, renal reference, planned neck diameter and length, exact device codes, contralateral gate strategy, both distal landing points, internal iliac preservation, access profile/closure and bailouts. Announce each irreversible release step.
• Patient: supine on a radiolucent table; prep and drape abdomen and both groins widely enough for bilateral cut-down or urgent open conversion. Record baseline pedal pulses/signals. Discuss anaesthesia (general, regional or local with sedation as appropriate), haemodynamic goals, urinary catheter and arterial monitoring according to case complexity.
• Imaging and kit: hybrid/fluoroscopy suite, high-quality roadmap/DSA, ultrasound, contrast-sparing plan, calibrated catheter, angiographic and shaped catheters, soft and stiff 0.035-inch wires, compatible large-bore access/closure kit, selected graft modules, moulding balloon, extension cuffs/limbs, covered stents and open vascular instruments. Confirm renal and iliac bifurcation views can be obtained.
• Prophylaxis: give peri-operative IV antibiotic prophylaxis (ESVS Recommendation 42, Class I A). For elective EVAR, give IV heparin 50–100 IU/kg (Recommendation 46, Class I C); ACT-guided additional dosing may be considered (Recommendation 47, Class IIb B). Follow local timing and anticoagulation protocols, and identify heparin allergy/HIT before the case. [1]
• Safety before opening: check device size, expiration, packaging integrity, compatibility of modules and side orientation; flush/de-air delivery systems exactly as their IFUs direct. Prepare a response to contrast allergy/renal risk and ensure blood and open-conversion capability are available.

4. Perform — step by step

Phase A — Establish safe bilateral arterial access

1. Image the CFA. Use ultrasound to identify the CFA from inguinal ligament to bifurcation and choose a soft anterior-wall segment over the femoral head, below the inferior epigastric artery and above the bifurcation. A skin crease is an unreliable landmark. Ultrasound guidance for percutaneous EVAR access is Class I A (ESVS Recommendation 61). [1]
2. Puncture and verify. Obtain bilateral wire access with controlled single-wall punctures. Pass a soft wire without force; confirm its course fluoroscopically. Use a small sheath and confirm puncture level by femoral angiography when indicated before committing to large-bore closure. If the puncture is high, low or through anterior calcium, correct the access plan now.
3. Prepare closure and working access. For a suture preclose, deploy the selected devices before upsizing and protect the sutures; an open cut-down follows its own repair plan. Maintain at least one secure wire route throughout large-sheath exchange. Introduce stiff wires only after a catheter has safely traversed the iliacs and reached the aorta. Watch the wire tip, especially across an angulated neck: it must not injure the aorta or enter a branch.

Phase B — Define the renal reference and begin main-body deployment

1. Map the landing zone. Put a calibrated angiographic catheter above the renal arteries, obtain a projection that opens the lowest renal origin and minimise parallax. Perform an aortogram and mark the lowest renal artery, relevant accessory renals, proximal neck and planned fabric edge. Confirm that the planned body/gate orientation matches CT.
2. Advance the main-body system. Under fluoroscopy, pass the selected delivery system from the planned side over a stable wire. Never overcome iliac resistance by force: reassess stenosis, calcification, tortuosity and profile, and use a planned adjunct, conduit or alternate strategy if needed.
3. Position deliberately. Place the proximal covered fabric at the intended infrarenal seal point, preserving renal perfusion. Check axial position, rotation/gate orientation, wire and catheter geometry, and haemodynamics. With suprarenal-fixation systems, recognise that bare fixation and fabric have different levels.
4. Release in the exact IFU order. Stabilise the delivery system and watch the fabric edge. Reconfirm the renal reference before each irreversible release. Main-body release, gate cannulation and limb deployment may be interleaved: do not assume the body should be fully released or the delivery system removed before cannulation. Follow the exact device sequence and retain the required support. [4,8]

Verified example: Zenith Flex T_ZAAAF_REV4 confirms contralateral gate cannulation angiographically before suprarenal release, then deploys the contralateral limb before distal main-body release. Do not transfer this sequence to Endurant or Gore. [4]

Phase C — Cannulate and bridge the contralateral gate at the IFU-defined stage

1. Cannulate the short contralateral gate from the opposite groin. Use a shaped catheter and soft wire under fluoroscopy. If standard cannulation is difficult, change projection and catheter; an upper-limb snare or other planned technique may be needed in experienced hands. Avoid repeatedly probing the fabric or pushing a stiff wire through an uncertain path.
2. Prove intragraft position. Establish that both the wire and catheter have passed through the gate into the graft lumen before exchanging to a stiff wire. Catheter rotation is an adjunct, not a universal substitute for the confirmation required by the IFU. For the cited Zenith Flex IFU, angiographically confirm the catheter is inside the graft body; use additional projections if the course remains uncertain. [4,8] An unrecognised wire outside the graft can create a catastrophic false limb deployment.
3. Deploy the contralateral limb. Confirm the body gate marker, overlap length, distal common iliac landing point and internal iliac origin. Deploy to the chosen healthy distal seal with overlap per IFU; watch for deployment into a short common iliac or an angulated segment.

Phase D — Finish the ipsilateral side and apposition

1. Complete the remaining body-release and delivery-system removal steps at their IFU-defined stage, retaining wire access. Complete the ipsilateral limb or add the planned separate limb (for example, Endurant IIs) to its distal landing point. Confirm both sides' overlap, internal iliac patency and length after the wires straighten the anatomy. A very narrow distal aorta may require explicit assessment for limb competition.
2. Mould the seal and junctions selectively. Use a compliant moulding balloon according to the graft IFU at the proximal covered seal, modular overlaps and distal seals. Keep the balloon within the IFU-defined graft segment; use gentle, controlled inflation and avoid aggressive oversizing in a calcified or fragile neck/iliac artery. Fully deflate before moving it. In a narrow terminal aorta, balloon strategy should protect both limbs rather than collapsing one.
3. Release wire-induced distortion. Where safe, replace or relax stiff wires before the final check so the iliacs resume their natural geometry and a kink or inadequate distal apposition is not hidden.

Phase E — Completion and closure

1. Perform completion angiography in views that show renal origins, proximal seal, the full sac, all modular joins, both limbs, distal seals and internal iliac origins. Ask explicitly: Is there a type I or III leak? Are renals and both limbs patent? Is there stenosis, kinking, dissection or distal embolisation? A low-flow type II leak is a different problem from an attachment or component leak.
2. Correct important defects before finishing (see section 7), then repeat the relevant images. Document graft model, component sizes, overlap, adjuncts and any endoleak.
3. Close access with a planned bailout. Follow the selected closure device’s IFU or open-repair plan. Retain wire access for bailout as long as the closure method permits; coordinate wire removal, haemostasis and distal-perfusion checks according to that method. If bleeding persists, use temporary pressure/balloon control and move promptly to endovascular or open femoral repair. Confirm pedal signals/pulses and groin haemostasis before leaving the suite.

5. Technical pearls & pitfalls

• Plan the landing zones before sizing the modules. The aortic neck and healthy iliac segments, not the aneurysm outline, determine the construct.
• Fabric edge is not fixation edge. Bare suprarenal stents of Endurant/Zenith may cross the renal level; covering the renal ostium with fabric is a different event. Mark the lowest relevant renal branch and verify it repeatedly.
• Permitted repositioning is device-specific. Zenith's barbed suprarenal fixation, Endurant tip capture and Gore C3 reconstraining have different constraints. A partially deployed graft is not automatically retrievable; rehearse the permitted repositioning window and the irreversible steps from the exact IFU.
• A gate is only cannulated when proved. A wire that appears to run centrally on one projection can still be outside the graft. Prove the course before advancing a large limb system.
• Overlap is a structural requirement. Calculate and verify it using the exact component IFUs. Excessive overlap can narrow the flow divider; insufficient overlap risks type III endoleak or separation.
• Preserve pelvic perfusion by design. If a common iliac seal requires crossing the internal iliac origin, decide the branch/embolisation/alternative strategy before deployment. Bilateral internal iliac loss markedly raises pelvic-ischaemia concern.
• Access is part of the repair. A technically perfect graft with a high puncture, iliac rupture or occluded CFA is not a successful operation. Use the separate Percutaneous Access, Sheaths & Closure Devices guide for puncture and closure detail.
• Do not routinely embolise side branches just to prevent type II endoleak. ESVS advises against routine pre-emptive IMA/lumbar embolisation and routine non-selective sac embolisation for standard EVAR (Recommendation 64, Class III B). An early type II leak without sac growth is usually a surveillance issue. [1]
• The completion angiogram is performed with a question in mind. Re-image after each correction, and include oblique views when an attachment site, gate or iliac bifurcation is uncertain.

6. Completion

Before leaving, verbally verify and document:

• Proximal: covered edge at planned level, renal/accessory renal perfusion, no type Ia leak, adequate neck apposition.
• Body and joins: true-gate cannulation, adequate overlap, no type III leak, no narrow flow divider.
• Distal: both limbs patent without twist, kink or significant stenosis; healthy bilateral distal seal, no type Ib leak; planned internal iliac perfusion.
• Sac and branches: any visible type II leak described accurately; no unrecognised extravasation.
• Access and patient: intact CFA/iliac flow, groin haemostasis, unchanged lower-limb pulses/signals, haemodynamic stability, urine output and renal risk accounted for.
• Follow-up: implant record and imaging appointment arranged before discharge.

7. Complications & rescue

Type II endoleak comes from a patent branch, usually a lumbar artery or the IMA. Do not call an uncertain completion leak type II until type I/III has been excluded. Persistence alone is not an indication to treat. ESVS considers intervention when sac growth is ≥10 mm from baseline or the smallest prior diameter, using the same modality and measurement method; NICE uses sac expansion as the trigger but gives no numerical threshold. [1,2]

8. Postoperative management

• Immediate: monitor haemodynamics, bleeding/groins, distal perfusion, urine output/creatinine and new abdominal, back or neurological symptoms. High-risk EVAR patients should have early HDU/ICU monitoring (ESVS Recommendation 69). [1]
• Medication and recovery: continue cardiovascular risk reduction: smoking cessation, blood-pressure control, statin and appropriate antiplatelet therapy. Established aspirin or clopidogrel monotherapy can usually continue. Elective AAA repair should not routinely proceed while the patient remains on DAPT or oral anticoagulation; make an indication-specific interruption/restart plan. After recent PCI, consider delaying repair until monotherapy; if repair cannot wait, EVAR under DAPT may be considered. Assess VTE/bleeding risk and use thromboprophylaxis when indicated. [1]
• Early imaging: obtain CTA within 30 days to assess endoleak, component overlap and sealing-zone length (ESVS Recommendation 113, Class I B). DUS can help when CTA is unsuitable, but it cannot fully assess overlap, seal length or migration. [1]
• Long-term surveillance — risk-stratify after the 30-day CTA:
  • Low risk: no endoleak, within IFU, adequate overlap and ≥10 mm proximal and distal seal. Low-frequency imaging is reasonable during the first five years; the ESVS algorithm suggests imaging again at five years.
  • High risk: type II endoleak, seal <10 mm/insufficient overlap, outside IFU, proximal neck >30 mm, iliac diameter >20 mm, angulation >60°, or a new/investigational device. Consider annual CTA or DUS and re-stratify each time.
  • All EVAR patients: continue long-term imaging because late device failure and disease progression still occur. Compare sac size with the postoperative baseline and the smallest prior measurement using the same modality where possible. If the patient would no longer accept or be suitable for elective reintervention, reconsider the value of continued surveillance. [1,4]
• Suspected endoleak: NICE recommends CTA; if CTA is contraindicated, use contrast-enhanced ultrasound. A negative colour duplex alone does not exclude an endoleak. [2]
• Discharge handover: record exact implanted components and MRI/implant information, access repair, renal function, any residual type II leak, warning symptoms and the booked surveillance scan. A reassuring completion angiogram does not replace follow-up.

9. Remember / 60-second mental rehearsal

CTA plan → bilateral safe CFA access → renal map → body fabric below lowest renal → IFU-directed interleaving of release and proven gate cannulation → both limbs → mould seals/joins → completion angiogram → IFU-directed groin closure with bailout ready → distal pulses → CTA within 30 days and long-term surveillance.

Five questions before release

1. Where is the covered fabric edge relative to every renal ostium?
2. Is the body/gate oriented for cannulation and two patent limbs?
3. Which repositioning manoeuvres remain permitted, and what is the next irreversible step on this exact delivery system?
4. Where will each limb land, and is overlap sufficient?
5. If the plan fails now, what is the access, cuff, covered-stent or open bailout?

FRCS viva prompts: Explain the difference between a type I, II and III endoleak; demonstrate true-gate cannulation; compare Endurant II versus IIs; explain Zenith's top-cap/barbed-fixation point of no return versus Gore C3 reconstraining; and state what the 30-day CTA adds beyond a completion angiogram.

References

1. Wanhainen A, Van Herzeele I, Bastos Goncalves F, et al. ESVS 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms. Eur J Vasc Endovasc Surg. 2024;67:192–331. doi:10.1016/j.ejvs.2023.11.002.
2. National Institute for Health and Care Excellence. Abdominal aortic aneurysm: diagnosis and management. NG156. Recommendations. Accessed 25 September 2026.
3. Medtronic. Endurant II/IIs stent graft system—UK product information and manual portal. Configuration and material information; this landing page is not a verified UK IFU revision.
4. Cook Medical. Zenith Flex AAA Endovascular Graft with the Z-Trak Introduction System: Instructions for Use. T_ZAAAF_REV4. Manufacturer IFU.
5. W. L. Gore & Associates. GORE EXCLUDER AAA Endoprosthesis. Regional eIFU portal. Accessed 25 September 2026.
6. Medtronic. Aortic Product Catalogue (Western Europe). Endurant sizing tables.
7. Medtronic. Endurant II AAA Stent Graft System — UK important safety information. Accessed 25 September 2026.
8. Loftus I, Hinchliffe RJ, editors. Vascular and Endovascular Surgery: A Companion to Specialist Surgical Practice. 7th ed. Elsevier; 2024. Chapter 13.