Yield of screening for new aneurysms after treatment for subarachnoid hemorrhage

Abstract

Objective: Patients who have been successfully treated for subarachnoid hemorrhage (SAH) are at risk for new episodes. The authors studied the effect of screening with CT angiography (CTA) for new aneurysms. Methods: In a decision model, the authors compared the strategies “screening” and “no screening” after SAH. A literature review yielded the risks of aneurysm recurrence, complications of CTA, and re-treatment. The authors estimated the expected number of quality-adjusted life-years (QALYs), the number of SAH, and the mortality and disability rates for both strategies. They evaluated screening at intervals of 2, 5, and 10 years after SAH, using 10 years and remaining life expectancy as time horizon. Results: The expected number of QALYs 10 years after clipping was virtually the same for no screening (8.33), screening once after 5 years (8.28), and screening every 2 years (8.27). With screening every 2 years, the expected rate of new SAH decreased from 1.9 to 0.5%, and mortality decreased from 0.9 to 0.6%; however, the disability rate increased from 0.5 to 1.9%. Results were comparable with remaining life expectancy as time horizon and for screening after initial treatment with coils. The key estimates of the analyses were the incidence and rupture rate of new aneurysms, the risk of dying from recurrent SAH, the utility of disability, and the risk of complications from DSA and re-treatment. Conclusions: Presently, screening for new aneurysms after subarachnoid hemorrhage cannot be recommended. Screening may prevent new episodes of subarachnoid hemorrhage but with too high a cost in terms of complications from preventive treatment.