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

Background and Purpose-Endovascular coil embolization and angioplasty for c erebral vasospasm are offered by some centers for the treatment of unruptur ed and ruptured cerebral aneurysms. Whether the availability of these thera pies improves outcomes at these institutions has not been evaluated. Methods-We assessed institutional factors in the outcomes of patients treat ed 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 dischar ge database during 1994-1997. Patients treated at institutions that more fr equently used coil embolization were less likely to die in the hospital (re lative risks [RRs] for every 10% of endovascular-treated cases: ruptured an eurysms: 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 tha t 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 offerin g endovascular services have lower rates of in-hospital mortality. Whether this is due to improved outcomes with endovascular therapy or is a marker f or other aspects of multidisciplinary care cannot be answered in this analy sis.