Introduction: An increasing number of unruptured aneurysms are being detected as the quality and utilization of imaging modalities expands. Often these aneurysms are small and located within the cavernous or pre-communicating ICA. Treatment is typically withheld for these aneurysms and some pattern of serial follow up imaging is undertaken via either CTA or MRA. It is currently not clear if either of these options provides a cost-effective method of surveillance. This study aims to quantify the price and utility of these follow up imaging strategies.
Methods: A literature review of rupture and growth rates for aneurysms < 5mm in the cavernous or paraclinoid ICA was undertaken. Various reports of payment amounts for CT or MR angiography were collected. Using this information a decision analysis for cost utility of CTA or MRA was created to determine the expenditures involved in detecting aneurysmal growth to a size that may require treatment (i.e. > 5mm).
Results: Reported rupture rates of ICA aneurysms < 5mm range from 0.0-0.14%. Growth rates for these aneurysms vary from 0.00-0.31mm/year in 1.0-6.9% of followed lesions. The average insurance company payment in the US for a head CTA is $6200 (range $1500 in Redding, CA to $10,700 in Bishop, CA) and $3300 for a brain MRA (range $500 in Auburn, IN to $10,800 in Dyersburg, TN).
Conclusions: Small cavernous or paraclinoid ICA aneurysms demonstrate low rates of rupture or growth. Serial imaging with either CTA or MRA to follow these lesions is expensive. The cost of these studies often varies considerably depending on the geographic region, but MRA is on average cheaper than CTA. A decision analysis with cost-utility information will stratify the expenditures necessary to follow these aneurysms over varying rupture and growth rates as well as imaging prices.
Patient Care: This research will help reduce health care expenditures by guiding cerebrovascular neurosurgeons to a more cost effective means of small ICA aneurysm follow up.
Learning Objectives: By the conclusion of this session, participants should be able to 1)Describe the natural history of small ICA aneurysms, 2)Understand the varying price structure for intracranial imaging, 3)Understand the importance and process of decision analyses, 4)Choose a cost-effective means for the follow up of small ICA aneurysms