Surveillance following endovascular aortic aneurysm repair (EVAR)

The clinical and cost-effectiveness of protocols using contrast-enhanced ultrasound and/or colour duplex ultrasound in the long-term surveillance of endovascular abdominal aortic aneurysm repair

An abdominal aortic aneurysm is a swelling or bulge that causes the wall of the main blood vessel (aorta) to weaken and become pouched or sac-shaped. Large aneurysms can burst, causing massive internal bleeding, which can lead to death. EVAR of the aneurysm has become the preferred treatment option for abdominal aortic aneurysm. EVAR is minimally invasive but it is associated with potential complications of which the most common is the occurrence of an endoleak (blood flow in the aneurysm sac). Consequently, patients who receive EVAR treatment must be followed up for the rest of their life.

CTA is an imaging modality widely used for the surveillance after EVAR. CTA is considered to be very accurate but it is not very good at detecting the direction of blood flow from an endoleak. It also carries the risk of repeated exposure to radiation and to a toxic contrast agent. CDU and CEU have been suggested as possible safer imaging alternatives to CTA but have not been widely adopted. The optimal surveillance strategy with regard to the choice of imaging modalities and the frequency of testing has not been established yet.

This study included a systematic review of the literature to assess the current evidence for the clinical effectiveness and cost-effectiveness of surveillance strategies using CDU and CEU compared with CTA in the surveillance after EVAR. A model based economic evaluation was also conducted as part of the assessment. Publication of the final report is currently pending.

The results of the project will be used by the National Institute for Health and Care Excellence (NICE) to issue clinical guidance in England and Wales on the optimal surveillance strategy after EVAR.

This review is registered with PROSPERO International prospective register of systematic reviews (PROSPERO 2016:CRD4201603475).

Outcome and Translation

The findings from this study will be available to help inform clinical guidelines and research recommendations on surveillance following EVAR.

HERU researchers involved in this research project: Graham Scotland and Rodolfo Hernández

External collaborators: C Ramsay, M Brazelli, M Campbell (HSRU, University of Aberdeen)

Publications

Brazzelli, M., Hernández, R., Sharma, P., Robertson, C., Shimonovich, M., MacLennan, G., Fraser, C., Jamieson, R. and Vallabhaneni, S.R. (2018) 'Contrast-enhanced ultrasound and/or colour duplex ultrasound for surveillance after endovascular abdominal aortic aneurysm repair: a systematic review and economic evaluation', Health Technology Assessment, 22(72).

Presentations

Hernández, R., Robertson, C., Shimonovich, M., Sharma, P., Fraser, C., MacLennan, G., Jamieson, R., Rao Vallabhaneni, S. and Brazelli, M. (2018) 'New diagnostic technologies? Markov model favours ultrasound post EVAR', HTAi Annual Meeting, Vancouver, Canada, 1-5 June 2018.

Robertson, C., Shimonovich, M., Sharma, P., Fraser, C., Hernández, R., MacLennan, G., Jamieson, R., Rao Vallabhaneni, S. and Brazelli, M. (2018) 'Including patient perspectives in health technology assessment reports', HTAi Annual Meeting, Vancouver, Canada, 1-5 June 2018.

Robertson, C., Shimonovich, M., Sharma, P., Fraser, C., Hernández, R., MacLennan, G., Jamieson, R., Rao Vallabhaneni, S. and Brazelli, M. (2018) 'Systematic review of abdominal aortic aneurysm surveillance imaging', HTAi Annual Meeting, Vancouver, Canada, 1-5 June 2018.

Robertson, C., Shimonovich, M., Sharma, P., Fraser, C., Hernández, R., MacLennan, G., Jamieson, R., Vallabhaneni, S. and Brazelli, M. (2018) 'Including patient perspectives in health technology assessments supplements clinical findings and provides valuable information for health services design and delivery', Cochrane Colloquium, Edinburgh International Conference Centre, Edinburgh, 16-18 September 2018.