Effect of endovascular services and hospital volume on cerebral aneurysm treatment outcomes

Background and Purpose-Endovascular coil embolization and angioplasty for cerebral vasospasm are offered by some centers for the treatment of unruptured and ruptured cerebral aneurysms. Whether the availability of these therapies improves outcomes at these institutions has not been evaluated. Methods-We assessed institutional factors in the outcomes of patients treated for cerebral aneurysms in the academic medical centers of the University Health Systems Consortium. In-hospital deaths (primary outcome), length of stay, and hospital charges were evaluated in multivariable models adjusted for age, sex, race, admission source, and admission status. Results-There were 2623 unruptured and 9534 ruptured aneurysm cases treated at 70 centers in the University Health Systems Consortium hospital discharge database during 1994-1997. Patients treated at institutions that more frequently used coil embolization were less likely to die in the hospital (relative risks [RRs] for every 10% of endovascular-treated cases: ruptured aneurysms: RR, 0.91; 95% CI, 0.86 to 0.96; P=0.001; unruptured aneurysms: RR, 0.84; 95% CI, 0.78 to 0.91; P<0.001). Patients treated at institutions that used angioplasty for vasospasm had a 16% reduction in risk of in-hospital death compared with patients treated at other institutions (RR, 0.84; 95% CI, 0.71 to 0.98; P=0.03). Hospital treatment volume was not independently associated with in-hospital death. Conclusions-Patients treated for cerebral aneurysms at institutions offering endovascular services have lower rates of in-hospital mortality. Whether this is due to improved outcomes with endovascular therapy or is a marker for other aspects of multidisciplinary care cannot be answered in this analysis.