Post-EVAR Surveillance: Duplex Protocol and Endoleak Classification
Duplex Surveillance Protocol After EVAR
A baseline after EVAR is established in the first month — usually, a CTA is performed on day 30 (Chaikof E.L. et al., SVS 2018). Subsequently, if there is no endoleak and no growth of the aneurysm sac, annual follow-up with duplex or CTA is adopted. Surveillance after EVAR is lifelong.
ESVS 2019 (Wanhainen A. et al.) provides for risk-stratified surveillance after EVAR. In case of doubt about the presence of an endoleak, contrast-enhanced ultrasound (CEUS) is added to the standard duplex: according to fragment data, it is more sensitive than standard duplex and approaches CTA in diagnostic accuracy.
Endoleak: Definition
An endoleak is the persistence of blood flow in the aneurysm sac outside the lumen of the endograft, meaning the sac is again "under pressure." This is a specific and significant complication of EVAR. Endoleaks are anatomically classified by the source of leakage.
Anatomical Classification of Endoleaks
| Type | Source of Leakage |
|---|---|
| I (Ia / Ib) | Seal failure at the proximal (Ia) or distal (Ib) graft fixation zone |
| II | From collateral branches |
| III | From collaterals / graft structural defect |
| IV–V | Other types (complete classification I–V) |
According to sources, type I endoleaks, as well as types II and III with sac growth, require treatment (Chaikof E.L. et al., SVS 2018). Detailed numerical thresholds for individual types are not provided in the fragments [to be clarified].
Frequently asked questions
When is baseline imaging performed after EVAR?
In the first month, usually CTA on day 30 (SVS 2018).
How often to monitor a stable aneurysm?
If there is no endoleak and no sac growth — annual follow-up with duplex or CTA; lifelong surveillance.
When to add CEUS?
In case of doubt about the presence of an endoleak: CEUS is more sensitive than standard duplex and approaches CTA.
What is an endoleak?
The persistence of blood flow in the aneurysm sac outside the lumen of the endograft — the sac is again under pressure.
Which endoleaks require treatment?
Types I, as well as II and III with sac growth (SVS 2018).