Decision uncertainty and value of further research: a case-study in fenestrated endovascular aneurysm repair for complex abdominal aortic aneurysms

Abstract

BackgroundFenestrated endovascular aneurysm repair (fEVAR) is a new approach for complex abdominal aortic aneurysms, limited to a few specialist centers, with limited evidence base. We developed a cost-effectiveness decision model of fEVAR compared to open surgical repair (OSR) to investigate the likely direction of costs and benefits and inform further research projects on this technology.MethodsA systematic review with meta-analysis and a four-state Markov model were used to estimate the cost-effectiveness of fEVAR versus OSR. We used a recent coverage with evidence development framework to characterize the main sources of uncertainty and inform decisions about the type of further research that would be most worthwhile and feasible.ResultsSeven observational comparative studies were identified, of which four presented odds ratios adjusted for confounders. The odds ratios for operative mortality varied widely between studies. Assuming a central estimate of the odds ratio of 0.54 (95% CI 0.05–6.24), the decision model estimated that the incremental cost per quality adjusted life year (QALY) was £74,580/QALY with a probability of 9 and 16% of being cost-effective at standard cost-effectiveness thresholds of £20,000/QALY and £30,000/QALY, respectively. The Expected Value of Perfect Information over 10 years at a threshold of £20,000/QALY was £11.2 million. Operative mortality contributed to most of the uncertainty in the decision model.ConclusionsIn the case of “maturing technologies”, decision modelling indicates the likely direction of costs and benefits and guides the development of further research projects. In our analysis of fEVAR versus OSR, decision uncertainty, particularly around operative mortality, might be effectively resolved by a short-term RCT, or possibly a well-conducted comparative observational study. Decision makers may consider that a conditional coverage decision is warranted with assessments required to make this type of recommendation depending on local priorities and circumstances.Electronic supplementary materialThe online version of this article (10.1186/s12962-018-0098-7) contains supplementary material, which is available to authorized users.

Fenestrated Physician-Modified Endografts for Preservation of Main and Accessory Renal Arteries in Juxtarenal Aortic Aneurysms

“…Juxtarenal AAAs pose a challenge to endovascular aortic repair. Fenestrated custommade devices have been proven to be safe and effective in the elective setting but there are limitations in regards to production time as well as costs [5,11,13,15]. PMEGs have shown excellent results in experienced centers in the emergency as well as the elective setting [27,32].…”

“…Custom-made devices have a production and delivery time of up to 16 weeks, during which a substantial proportion of patients experience aneurysm rupture [15]. Additionally, a custom-made device costs approximately three times more than an off-the-shelf EVAR stent graft which is modified [13,14]. In times of rising economic health care burden these interventions are an important driver of health care costs.…”

“…Fenestrated endovascular aortic repair (FEVAR) is a well-established, safe and durable treatment option for juxtarenal AAAs [11,12]. The production of these custom-made devices may take up to 16 weeks, generating relevant costs and potentially lethal treatment delays [13][14][15]. In contrast, the use of off-the-shelf fenestrated or branched devices, readily available in emergencies, may be limited by patients' anatomy and concerns regarding longterm branch stability in the setting of misaligned fenestration/branches and bridging stents have been raised [16][17][18].…”

The Use of Decision Analytic Modeling in the Evaluation of Surgical Innovations: A Scoping Review

“…An example is Ciani et al, who employed PSA, OWSA, and VOI analysis to determine the expected cost-effectiveness and the value of further research for a new approach for complex abdominal aortic aneurysms. 27 They also discuss the circumstances under which additional research seems worthwhile by taking into account the significant irrecoverable costs in the implementation process, the need for approval of future trials, and factors such as learning curve.…”