What is the post-operative surveillance protocol for patients undergoing Endovascular Aneurysm Repair (EVAR) of infra-renal Abdominal Aortic Aneurysm (AAA) in the UK?

From the Guidelines

The post-operative surveillance protocol for patients undergoing Endovascular Aneurysm Repair (EVAR) of infra-renal Abdominal Aortic Aneurysm (AAA) in the UK should involve a CT angiogram (CTA) at 1 month post-procedure, followed by duplex ultrasound at 12 months, and then annually thereafter, with additional cross-sectional imaging with CT or MRI every 5 years postoperatively, as recommended by the most recent guidelines 1.

The surveillance protocol is designed to detect potential complications, such as endoleaks, aneurysm sac enlargement, and stent migration, which can occur after EVAR. The use of duplex ultrasound for annual surveillance is recommended, as it is specific for the detection of endoleaks and can be used to monitor aneurysm sac size 1. However, CT or MRI should be used every 5 years to assess for stent migration, component separation, and other complications that may not be detectable by ultrasound.

The protocol may be modified based on individual patient factors, device-specific recommendations, and findings during follow-up. For example, if complications are detected on ultrasound, such as endoleaks or aneurysm sac enlargement, a CTA should be performed for further evaluation 1. Additionally, patients with complex EVAR may require a modified surveillance protocol that combines cross-sectional imaging and duplex ultrasound of target vessels 1.

Some key points to consider in the surveillance protocol include:

• The importance of lifelong follow-up, as complications can occur many years after the initial procedure
• The need for blood pressure control, with a target of <140/90 mmHg to reduce stress on the repair
• The use of antiplatelet therapy, typically aspirin 75mg daily, indefinitely following EVAR, unless contraindicated
• The potential for modification of the surveillance protocol based on individual patient factors and device-specific recommendations.

Overall, the surveillance protocol should be tailored to the individual patient's needs and should be based on the most recent guidelines and evidence-based recommendations 1.

From the Research

Post-Operative Surveillance Protocol for EVAR of Infra-Renal AAA in the UK

The post-operative surveillance protocol for patients undergoing Endovascular Aneurysm Repair (EVAR) of infra-renal Abdominal Aortic Aneurysm (AAA) in the UK involves:

• Lifelong follow-up due to the continued risk of complications, especially if the first postoperative imaging shows abnormal findings 2
• Initial post-EVAR computed tomography angiography (CTA) scan to predict future secondary procedures 3
• Surveillance imaging to detect EVAR complications, including endoleak, graft translocation, thrombosis, and infection 4

Surveillance Imaging Modalities and Timing

The surveillance imaging modalities used in the UK include:

• Computed tomography (CT) scans, usually performed at postoperative months 1,6, and 12, and then annually 5, 6
• Ultrasound, which is utilized more frequently after the first year of follow-up 6
• Plain films, which are used in conjunction with ultrasound after the first year 6
• The timing of follow-up imaging varies, but most patients receive imaging at 1,6, and 12 months, and thereafter most respondents plan on indefinite yearly follow-up 6

Responsibility for Organizing Follow-Up

The responsibility for organizing follow-up is shared among healthcare professionals, with:

• Radiologists being responsible for organizing follow-up in the majority of cases (46%) 6
• Other healthcare professionals, such as vascular surgeons and interventional radiologists, also being involved in organizing follow-up

Evidence-Based Practice

The current practice of EVAR surveillance in the UK is based on a combination of evidence-based guidelines and empirical protocols 6. Studies have shown that a normal initial post-EVAR CTA scan is highly predictive of long-term freedom from secondary intervention 3, and that surveillance imaging can be safely reduced in patients with no abnormalities on their initial post-EVAR CTA scan 5. However, more research is needed to determine the optimal surveillance protocol for patients undergoing EVAR in the UK.