Reliability of duplex ultrasound in post Endovascular Aneurysm Repair surveillance
Research type
Research Study
Full title
Reliability of duplex ultrasound in post Endovascular aneurysm repair (EVAR) surveillance
IRAS ID
174449
Contact name
Dominic Pang
Contact email
Sponsor organisation
NHS Grampian Research and Development
Duration of Study in the UK
0 years, 5 months, 1 days
Research summary
Endovascular aneurysm repair (EVAR) is a minimally invasive surgery, as opposed to conventional open surgery to treat abdominal aortic aneurysms (AAA). This involves deployment of stent-graft through endovascular technique to seal off the aneurysm sac. Although a novel technique, post EVAR complication is common and an ongoing concern. Endoleak is a complication where the stent-graft fails to completely occlude the aneurysm sac. Undetected, this may result in uncontrolled sac expansion and eventual aneurysm sac rupture and albeit uncommon, is a significant end-point associated with a high mortality. As such, post EVAR surveillance is necessary.
There remains no consensus on post EVAR surveillance programme protocols across UK. Computed Tomo-Angiography (CTA), which is the gold standard for this purpose has its limitations. Duplex ultrasound (DUS) offers a cheaper, non-contrast and non-radiation alternative to CTA. However, its utility is limited by its poor sensitivity in detecting endoleaks as described in current literature with sensitivity of 77% and specificity of 94%.
Historically, all endoleaks were thought to progress towards rupture, hence, identifying all endoleaks were important to direct re-intervention. Recognising the natural history of these endoleaks led to change in current endoleak management, in particular, isolated Type 2 endoleaks without sac size expansion. These in fact represent the bulk of endoleaks reported, and are increasingly managed conservatively with favourable outcomes. Identifying these type of endoleaks may no longer clinically be important, as they do not change the clinical management or put the patient at risk. As such, published evidence that describes the technical utility of DUS ability in identifying all endoleaks may be misleading.
This retrospective study examines the ability of DUS in identifying clinically significant endoleaks.
REC name
East Midlands - Leicester South Research Ethics Committee
REC reference
15/EM/0326
Date of REC Opinion
14 Jul 2015
REC opinion
Favourable Opinion