Cost-effectiveness analysis on treatment versus imaging surveillance for vertebrobasilar dolichoectatic aneurysms

Vertebrobasilar dolichoectatic aneurysms are a rare type of intracranial aneurysm and are generally associated with a poor prognosis due to high rates of morbidity and mortality secondary to ischemic stroke, mass effect, and intracerebral hemorrhage (ICH) or subarachnoid hemorrhage from rupture. When symptomatic, these lesions often mandate treatment. The aim of this study was to explore the most cost-effective management strategy for dolichoectatic aneurysms.

A decision algorithm was built with a Markov model to compare immediate treatment versus regular follow-up at different intervals (6-month and 1- and 2-year intervals) for dolichoectatic aneurysms. Input data for the model were extracted from the current literature. Costs, effects, incremental cost-effectiveness ratios, and net monetary benefits (NMBs) were analyzed. Deterministic sensitivity analysis and probabilistic sensitivity analysis with Monte Carlo simulation were performed to evaluate the robustness of the model.

On base case analysis, early treatment for dolichoectatic aneurysms, either through open surgery or endovascular procedure, is the most cost-effective strategy (cost $388,946.24, effectiveness 11.0 quality-adjusted life years), showing the highest NMB. The conclusion remains robust in deterministic sensitivity analysis as well as in Monte Carlo simulation with near 97% cost-effectiveness acceptability. When annual risks of stroke, ICH, growth, and rupture are all very low, a strategy of follow-up every 6 months or annually can be considered.

The cost-effectiveness of MR angiography (MRA) surveillance is only observed in scenarios with an annual ischemic risk < 3.3%, with 6-month follow-up MRA being more cost-effective than that at 1- or 2-year intervals. In contrast, preventive treatment consistently offers a higher NMB when risk increases. The risk of treatment based on patient and aneurysm specific factors should also be considered in the decision to treat.