Clipping and Coiling of Unruptured Intracranial Aneurysms Among Medicare Beneficiaries, 2000 to 2010

Background and Purpose-Endovascular coiling therapy is increasingly popular for obliteration of unruptured intracranial aneurysms, but older patients face higher procedural risks and shorter periods during which an untreated aneurysm may rupture causing subarachnoid hemorrhage (SAH). We assessed trends in clipping and coiling of unruptured intracranial aneurysms, outcomes after clipping and coiling of unruptured intracranial aneurysms, and in SAH among Medicare beneficiaries. Methods-Using 2000 to 2010 Medicare Provider Analysis and Review data, we identified 2 cohorts of patients admitted electively for clipping or coiling of an unruptured aneurysm: (1) utilization cohort (2000-2010): patients >= 65 years enrolled >= 1 month in a given year and (2) outcomes cohort (2001-2010): patients >= 66 years of age enrolled in Medicare for >= 1 year. We calculated rates of clipping, coiling, and SAH per 100 000 Medicare beneficiaries. We tested for trends in the risk of in-hospital mortality and complications, discharge destination, 30-day mortality, 30-day readmissions, and length of hospitalization. Results-Characteristics of patients undergoing clipping (n=4357) or coiling (n=7942) did not change appreciably. Overall, 30-day mortality, in-hospital complications, and 30-day readmissions decreased, generally reaching their lowest levels in 2008 to 2010 (1.6%, 25.0%, and 14.5% for clipping and 1.5%, 13.8%, and 11.0% for coiling, respectively). Procedural treatment rates per 100 000 beneficiaries increased from 1.4 in 2000 to 6.0 in 2010, driven mainly by increased use of coiling but SAH rates did not decrease. Conclusions-Although outcomes tended to improve over time, increased preventative treatment of unruptured intracranial aneurysms among Medicare beneficiaries did not result in a population-level decrease in SAH rates.