Skip to main content

01-09-2011 | Article

UIA outcomes ‘stagnant’ despite increase in coiling


Free abstract

MedWire News: Study findings show that despite endovascular coil embolization providing better patient outcomes in the management of unruptured intracranial aneurysms (UIA) relative to clipping, overall outcomes have failed to improve over the years.

"As the technology driving endovascular coiling has been refined and training programs formalized, we would have expected an improvement in coiling outcomes, yet they have remained stagnant over the past 10 years," say Brad Zacharia (Columbia University Medical Center, New York, USA) and co-authors writing in Stroke journal.

The researchers performed a retrospective, longitudinal cohort study of patients with UIA identified from the New York Statewide Database; 3132 patients were discharged during 2005-2007, and 2200 were discharged during 1995-2000.

Treatment rates between the earlier and later time periods showed a significant increase, from 1.79 to 3.45 cases per 100,000. Significantly more UIA patients were treated with endovascular coiling in the later time period compared with the earlier period, at 57.0% versus 20.3%. Indeed, the increase in treatment rates was driven almost completely by coiling.

Analysis of surgical settings showed a significant rise in surgical clipping of UIA in high-volume centers across the time periods (from 55.8% to 78.8%) but a decrease in endovascular coiling in this setting (from 94.8% to 84.5%). This decrease continued during 2005-2007, from 89.8% to 80.9%.

There was no significant improvement in patient outcomes between the two periods, however. Direct comparison of clipping showed a significant decrease in good patient outcomes (from 76.3% to 71.7%) while the outcome for coiling remained stable (from 89.7% to 87.7%).

"With the perceived ease of coiling of UIA and attendant socioeconomic pressures, endovascular technology may continue to spread from major academic centers to smaller community hospitals ill-equipped to provide comprehensive cerebrovascular care, which may lead to inferior outcomes not only due to technical shortcomings, but errors in judgment regarding who to treat and how to treat them," say the researchers.

Multivariate regression analysis identified White race (odds ratio [OR]=1.67), treatment volume of hospital (OR=1.04 per additional 10 cases), and definitive treatment by endovascular coiling (OR=3.94) as significant predictors of good discharge outcome following UIA treatment.

Predictors of worse outcomes following UIA treatment included older age (OR=0.61 per 10-year increase in age) and direct admission from the emergency room (OR=0.41).

The researchers found that as the percentage of patients with UIAs treated by endovascular coiling increased at a given center, the risk for poor outcome significantly increased (OR=0.92 per 10% additional coiling).

"Decentralization of endovascular treatment of cerebral aneurysms to low-volume centers with relatively less procedural experience and lack of comprehensive cerebrovascular programs may account for the lack of improvement in observed outcomes despite an increase in endovascular management," conclude the researchers.

By Ingrid Grasmo