Indications

80% of infrarenal AAA are now done with EVAR
Open repair reserved for those with complex anatomy or coexisting disease processes preventing EVAR

Relative contraindications

Absolute contraindications

Requirements

Adequate iliofemoral access - patency, diameter, ?calcification/thrombus, tortuosity
Adequate seal zone proximally between graft and normal aorta - 10-15mm depending on device
Adequate seal zone distally, proximal to iliacs - 10-15mm dependent on device

Preparation:

External CT scans imported to PACS at earliest opportunity
Confirm with consultant which EVAR device they require and ensure that the liaison nurses are in contact with the relevant company, and that the stock has arrived
Document lower limb pulses and neurologic status on admission
Book angio suite
- In most cases straightforward EVAR can be done in angio suite 2
- Any cases requiring adjunctive procedures should be done in suite 1
Confirm that anaesthetics is available
Confirm theatre scrub nurses are available

Document pulses at end of procedure
Check for and document neurologic function once patient awake
Especially check for:
- Bleeding/haematoma (consider femoral USS to exclude pseudoaneurysm)
- Hypotension/anaemia
- Neurologic changes (spinal cord ischaemia)
- Acute ischaemia or change in pulse status

CT aortogram (EVAR follow-up protocol) at 6 weeks (unless already done prior to discharge, in which case do an EVAR surveillance USS at 6 weeks)
Ensure screening for thoracic and popliteal aneurysm has been done
Remind family members to be screened for AAA
Long term risk factor management with GP
Lifelong surveillance with alternating EVAR surveillance USS and CT aortogram - usually 6 monthly (check for residual aneurysm sac size, evidence of endoleak, graft separation and migration, and progressive suprarenal or iliac artery aneurysm)

Endoleak (persistent blood entry into aneurysmal sac after EVAR). There is continued pressurisation of the sac - can lead to continued growth and rupture

Type I: persistent blood flow into the sac either from around the graft proximally (IA) or distally (type IB)
- Late:
  - Typically secondary to caudad migration of the stent graft, or continued dilation of the neck
  - Proximal extension may be deployed to achieve a proximal seal
Type II: persistent sac filling from back-bleeding side branches (IMA, lumbar arteries, middle sacral artery)
- Occurs in 10-20% of EVAR patients
- Relatively benign course - up to 80% resolve spontaneously within 6-12 months, with low risk of aneurysm rupture. No association between type II endoleak and risk of aneurysm rupture or need for surgical conversion.
- Typically not treated unless sac enlargement is documented.
- Embolisation can be performed using coils or glue - either via SMA or through sac
- If endovascular techniques fail, operative explant may be required
Type III: fabric erosion or leak between the stent-graft components - occurs in modular components
- Effectively treated with re-lining
Type IV - porosity of graft fabric
- Noted within 30 days of graft implantation
- No treatment usually required
Type V: 'endotension' - elevated sac aneurysm pressure without a demonstrable endoleak
- Aetiology likely to be undetected endoleak or transmission of systemic pressure through thrombus

Graft occlusion - limb thrombosis or kinking - 3%
- Claudication in buttock/thigh/calf
- Rest pain
- Acute ischaemia
- Mostly occurs early on
Ischaemic complications
- Direct vessel occlusion by stent-graft, or occlusion of the stent-graft itself; atheroembolic events during catheter manipulation or device deployment; inadequate collateralisation of mesenteric or pelvic circulation
Spinal cord ischaemia - 0.25%
- Dreaded complication, not really understood exactly why it happens
AKI - common
Late conversion to open - 1%
Infection