Introduction: Recurrence of intracranial aneurysms following endovascular therapy in 20% of patients remains the only major disadvantage of this treatment. For this reason, a significant amount of research has been carried out, focused on reducing the incidence of recurrence. In recent years, a variety of cell therapy modalities using fibroblasts, smooth muscle cells, endothelial progenitor cells and Mesenchymal Stem/Stromal Cells (MSCs) have been tested in animal models as a means to improve the outcome of the treatment. However, it remains unclear whether preventing recurrence using cell therapy is a more cost-effective alternative to retreating recanalized aneurysms. In this study, we have used a Markov model approach to determine efficacy thresholds at which combined coiling and cell therapy becomes a more cost-effective treatment than coiling alone.
Hypothesis: Combined coiling and cell therapy will be more cost-effective than coiling alone, if it reduces the need for retreatment by 50% or more.
Methods: The cell therapy was assumed to be aimed at reducing the need for retreatment. A Markov model was used to compare coiling alone with combined coiling and autologous/allogeneic cell therapy. Model inputs were mostly taken from meta-analyses. Sensitivity analysis was performed to predict efficacy thresholds that make cell therapy more cost-effective than coiling alone. Robustness of the model was assessed through further sensitivity testing focused on variables with the highest impact on the outcome.
Results: Sensitivity analysis showed that coiling with autologous cell therapy becomes more cost-effective than coiling alone, if it reduces the need for retreatment by 39.9% or more. When allogeneic cell are used, a reduction of 13.3% or more in the need for retreatment is enough the make combined coiling and cell therapy more cost-effective.
Conclusions: Our preliminary analysis suggests that efficacy thresholds at which combined coiling and cell therapy becomes more cost-effective than coiling alone are modest - especially for allogeneic MSC therapies. This makes combined coiling and cell therapy a viable alternative to the current standard-of-care from a cost-utility standpoint, and justifies further research and investment in the field.