03 / Vascular Surgery · percutaneous
EVAR (endovascular aneurysm repair)
Relining an abdominal aortic aneurysm from inside: a fabric-covered stent graft delivered up the femoral arteries and deployed across the sac, excluding it from pressure without opening the abdomen.
Indication: Infrarenal AAA at threshold (about 5.5 cm, or rapid growth), with anatomy that offers a sealing zone below the renal arteries and iliac access that admits the device.
Read the imaging first
Practice before you scrub
Measure what matters
A 74-year-old smoker, screening ultrasound abnormal, now a CT of the abdomen. (Fictional educational case.)
- Diameter decides tempo: surveillance below threshold, repair conversation at 5.5 cm, and symptoms or rapid growth jump the queue.
- The same CT is the EVAR plan: neck length, angulation and access vessels are measured to the millimetre before any device is chosen.
On the tray for this operation
Test yourself on the tray
Stage
1 / 4
Planning on the CT
The CT angiogram is measured: neck length and angle below the renals, sac dimensions, iliac diameter and tortuosity, and the device is chosen and sized to the millimetre.
Watch for: Under- or oversizing the graft · Missing an accessory renal artery
Why are we operating?
EVAR relines the aneurysmal aorta from within: a fabric-and-stent graft, delivered through the femoral arteries and deployed across the sac, takes the pressure off a wall that was preparing to burst. It converted aneurysm repair from a laparotomy with cross-clamp physiology into a percutaneous procedure, at the price of anatomy-dependence and a lifetime of surveillance.
Pulls toward surgery
Gives the team pause
Shared foundations
What the surgeon is thinking
Planning on the CT
Why is the CT measurement session the real operation?
The graft seals by radial force against healthy aorta above and below the sac: neck length, diameter, angulation and iliac landing zones are measured to the millimetre, and the device is chosen with deliberate oversize. A well-planned EVAR is mostly execution; a badly planned one cannot be rescued by skill on the day.
Femoral access
What do the femoral arteries have to survive?
A delivery system many times a catheter's calibre: percutaneous closure devices or surgical cutdown must both leave a femoral artery that still works. Access complications are the procedure's commonest, which is why the access plan (calcification, tortuosity, diameter) was part of the CT session too.
Deployment
What is at stake in the deployment's millimetres?
The renal arteries: the graft's fabric must land immediately below them, high enough to seal, low enough to spare the kidneys. Deployment happens under angiography with the renals marked, breath and blood pressure controlled, because fabric across a renal ostium converts an aneurysm repair into a renal infarction.
Completion and surveillance
What is the completion angiogram interrogating?
The seal: contrast outside the graft but inside the sac is an endoleak, and its type decides its meaning. Type I (seal zone failure) and type III (component separation) re-pressurise the sac and are fixed now; type II (branch back-bleeding) is usually watched. The angiogram is the procedure's exam, marked before anyone leaves.
Decision points
The completion run shows contrast at the proximal seal zone (type Ia endoleak).
Fix now: balloon, cuff, or extension
A seal-zone leak means the sac is still pressurised, the operation's entire purpose unmet: moulding, a proximal cuff or an extension is applied before leaving.
Accept and image early
Not for type I: this is the leak that ruptures. Acceptance is type II's occasional privilege, not type I's.
Endoleak typology is the postoperative language of EVAR: type decides tempo. The graft's job is depressurising the sac, and any leak that keeps systemic pressure in the sac is unfinished business tonight, not follow-up's problem.
Surveillance at year 3 shows the sac has grown 8 mm with a type II endoleak.
Intervene on the type II
A growing sac changes a watchable leak into a treatable one: embolisation of the feeding lumbar or IMA territory.
Continue surveillance
For the stable or shrinking sac: most type II leaks are innocent bystanders, and intervention has its own costs.
The sac's diameter is the arbiter: leaks are treated when the sac says so. This is also the honest counselling point from the first clinic visit: EVAR is a treaty with follow-up obligations, not a discharge.
Leaving the OR
The handoff
- Procedure
- EVAR: bifurcated graft, percutaneous bilateral femoral access
- Completion
- No type I or III endoleak; small type II noted for surveillance
- Access
- Closure devices both groins; feet warm, signals present
- Watch for
- Groin haematoma or expansile swelling, distal perfusion, urine output and creatinine after contrast
A fictional educational patient, handed over the way real ones are.
The postoperative course
- POD 0Groins and feet on a schedule: haematoma, pseudoaneurysm and embolisation are the early complications, all announced peripherally.
- POD 1Mobilising, kidneys checked after the contrast load, most patients heading home: the contrast with open repair's ICU stay is the procedure's selling point.
- WeeksFirst surveillance imaging establishes the baseline: sac size and endoleak status, the two numbers that own the future.
- LifelongSurveillance per protocol, forever: the discharge letter's most important sentence is the imaging schedule, and post-implantation syndrome or new back pain always earns a scan.
Watch it done
NEJM procedure: deployment of an endovascular graft in an abdominal aortic aneurysm
The journal's procedure video: access, the main body, the contralateral limb and the completion angiogram.
Source: NEJM Group · Watch on YouTubeEndovascular aneurysm repair (EVAR)
The plain-language overview of the stent graft and life after it.
Source: University Hospitals · Watch on YouTube