Cost-effectiveness of computed tomography versus ultrasound-based surveillance following endovascular aortic repair of intact infrarenal abdominal aortic aneurysms

Vy T Ho; Ann T Nguyen; Jordan R Stern; Steven M Asch; Douglas K Owens; Joshua A Salomon; Ronald L Dalman; Jason T Lee

doi:10.1016/j.jvs.2022.02.057

Cost-effectiveness of computed tomography versus ultrasound-based surveillance following endovascular aortic repair of intact infrarenal abdominal aortic aneurysms

J Vasc Surg. 2022 Sep;76(3):707-713.e1. doi: 10.1016/j.jvs.2022.02.057. Epub 2022 Mar 9.

Authors

Vy T Ho¹, Ann T Nguyen², Jordan R Stern³, Steven M Asch⁴, Douglas K Owens², Joshua A Salomon², Ronald L Dalman³, Jason T Lee³

Affiliations

¹ Division of Vascular Surgery, Department of Surgery, Stanford University, Stanford, CA. Electronic address: vivianho@stanford.edu.
² Center for Primary Care and Outcomes Research, Department of Medicine, Stanford University, Stanford, CA.
³ Division of Vascular Surgery, Department of Surgery, Stanford University, Stanford, CA.
⁴ Division of Primary Care and Population Health, Department of Medicine, Stanford University, Stanford, CA; Center for Innovation to Implementation, VA Palo Alto Health Care System, Palo Alto, CA.

PMID: 35278655
DOI: 10.1016/j.jvs.2022.02.057

Abstract

Background: While Society for Vascular Surgery guidelines recommend computed tomography angiography (CTA) or ultrasound for surveillance following infrarenal endovascular aortic repair (EVAR), there is a lack of consensus regarding optimal timing and modalities. We hypothesized that ultrasound-based approaches would be more cost-effective and developed a cost-effectiveness analysis to estimate the lifetime costs and outcomes of various strategies.

Methods: We developed a decision tree with nested Markov models to compare five surveillance strategies: yearly CTA, yearly CDU, yearly CEU, CTA at first year followed by CDU, and CTA at first year followed by CEU. The model accounted for differential sensitivity, specificity, and risk of acute kidney injury after CTA, and was implemented on a monthly cycle with a willingness-to-pay threshold of $50,000 per quality-adjusted life year (QALY) and 3% annual discounting.

Results: Under base case assumptions, the CTA-CDU strategy was cost effective with a lifetime cost of $77950 for 7.74 QALYs. In sensitivity analysis, the CTA-CDU approach remained cost-effective when CEU specificity was less than 95%, and risk of acute kidney injury following CTA was less than 20%. At diagnostic sensitivities below 75% for CEU and 55% for CDU, a yearly CTA strategy maximized QALYs.

Conclusions: A hybrid strategy in which CTA is performed in the first year and CDU is performed annually thereafter is the most cost-effective strategy for infrarenal EVAR surveillance in patients with less than a 20% risk of contrast-induced nephropathy. If the sensitivity of CEU and CDU are at the lower end of plausible estimates, a yearly CTA strategy is reasonable. Further research should aim to identify patients who may benefit from alternative surveillance strategies.

Keywords: Computed tomography; Duplex ultrasound examination; Endovascular aortic repair; Surveillance.

MeSH terms

Acute Kidney Injury* / etiology
Aortic Aneurysm, Abdominal* / diagnostic imaging
Aortic Aneurysm, Abdominal* / etiology
Aortic Aneurysm, Abdominal* / surgery
Blood Vessel Prosthesis Implantation* / adverse effects
Computed Tomography Angiography
Cost-Benefit Analysis
Endovascular Procedures* / adverse effects
Humans
Tomography, X-Ray Computed