The material costs associated with endovascular treatment of cerebral aneurysms include access catheters, equipment utilization, personnel costs, and embolization materials. The costs of coiling aneurysms in general has been discussed, however, detailed analysis of aneurysm embolization costs as a function of aneurysm size is lacking.
Methods We reviewed the material logs and aneurysm descriptions for a total of 221 aneurysms spanning January 30, 2009 to June 2, 2011, excluding aneurysms that had incomplete chart data, coil costs, ethyl vinyl alcohol embolization and spurious size measurements. We tabulated the total embolisate costs at prices available to the institution as of September 2011, and analyzed the costs of coiling as a function of calculated volume, the variance of costs as a function of volume, and performed a regression analysis in order to model projected costs for a given aneurysm size.
Findings Curves modeled are presented in graph form. As expected, there is a strong correlation of aneurysm size by estimated volume to cost with a p<0.000001. A plot of the residuals is also given, showing from projected cost for a given volume. Given the apparent increase in variance as a function of volume, a log-log transform was applied to the data with regression analysis performed. For every doubling in aneurysm volume, there is a projected 36% increase in cost.
Conclusion Neurointerventions are reimbursed at a flat per-aneurysm basis, irrespective of embolysate costs. The variance in coiling costs shown, indicates that aneurysm embolization costs vary according to volume in a relatively predictable fashion. This understanding may be useful in modifying future coding. Additionally, there is a degree of variance in costs for a given estimated volume, which may indicate material choice and strategy may affect embolization as well. Further analysis of this observation may be helpful in optimizing coil selection for therapies.