Study Suggests That Technological Advances Have Not Improved Outcomes for Unruptured Intracranial Aneurysms

August 29, 2011—Online ahead of print in Stroke, Brad E. Zacharia, MD, et al published findings from a study that evaluated patient outcomes related to changing patterns of treatment of unruptured intracranial aneurysms (UIAs). The background of the study is that UIAs are being identified more frequently, and endovascular coil embolization has become an increasingly popular treatment modality.

As detailed in Stroke, the investigators conducted a retrospective, longitudinal cohort study of hospital discharges for UIA that were identified from the New York SPARCS (Statewide Planning and Research Cooperative System) database in 2005 to 2007 (n = 3,132) and from 1995 to 2000 (n = 2,200). The investigators examined the rates of endovascular coiling and surgical clipping along with hospital variables and discharge outcome. Anatomic specifics of UIA were unavailable for analysis.

The investigators reported that the case treatment rate of UIA increased from 1.59 (1995 to 2000) to 3.45 per 100,000 (2005 to 2007; P < .0001), and the case treatment rate for coiling of UIA increased from 0.36 to 1.98 per 100,000 (P < .0001). Compared with the old epoch, there were more UIAs clipped at high-volume centers (55.8% vs 78.8%; P < .0001) but fewer coiled at high-volume centers (94.8% vs 84.5%; P < .0001) in the new epoch. Coiling and increasing hospital UIA treatment volume were associated with good discharge outcomes. However, there was no significant improvement in overall good outcomes when comparing 1995 to 2000 versus 2005 to 2007 (79% vs 81%; P = .168) and a worsening of good outcomes for clipping (76.3% vs 71.7%; P = .0132).

The investigators concluded that despite coiling being associated with an increased incidence of good outcomes relative to clipping of UIA, the increase in coiling has failed to improve overall patient outcomes. The shift in coiling venue from high-volume centers to low-volume centers and decreasing microsurgical volume accompanied by a worsening in microsurgical results contribute to this. This argues for greater centralization of care, the investigators stated.