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13-10-2011 | Article

Stenting aneurysms does not improve long-term outcomes


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MedWire News: Stenting unruptured aneurysms to assist coiling does not enhance long-term angiographic outcomes, study results suggest.

Stents placed in the necks of aneurysms to facilitate coiling have hemodynamic and biologic effects that, in theory, "can cause blood to become stagnant and lead to progressive thrombosis and the promotion of endothelialization that can help the aneurysmal neck close," explain O-Ki Kwon (Seoul National University Bundang Hospital, Seongnam, South Korea) and team.

"Accordingly, these additional effects of stents may enhance the durability of coiled aneurysms. Clinically, however, it is unclear whether these effects really improve long-term outcome, especially when one considers that the stents designed for neck modeling have large porosities."

The team's study, which appears in the American Journal of Neuroradiology, focused on difficult-to-coil unruptured aneurysms, which are often managed with stent-assisted coil embolization in practice.

Kwon et al examined data from 126 patients who had aneurysms with a neck size exceeding 4 mm, but a dome-to-neck ratio of less than 1.5. Forty of these aneurysms were managed with stent-assisted coiling, and the others were treated with multiple microcatheter or balloon-assisted techniques.

At 2 years after treatment, angiographic improvement due to progressive occlusion had occurred in 42.5% of the stent-assisted group versus 39.5% of the nonstent group. Recanalization was slightly less frequent in the stent than nonstent group, at 17.5% versus 21.0%. But neither of these differences were statistically significant.

On closer examination, almost all of the angiographic improvement (>90%) had occurred in sidewall-type aneurysms, which were slightly, although not significantly, more common in the stent than nonstent group, at 72.5% versus 61.6%.

By contrast, 68.0% of recanalizations occurred in bifurcation aneurysms, which were slightly less common in the stent than nonstent group, at 27.5% versus 38.4%.

"These results suggest that the hemodynamic and biologic effects of stents used during coil embolization are not enough to expect additional improvement of occlusion status and prevention of the recanalization in real patients," conclude the researchers. "Therefore, even when a stent is used, compact coil packing should be used to treat unruptured saccular aneurysms to achieve best long-term outcomes."

They note, however, that only a randomized controlled trial can definitively establish if stenting aneurysms affect long-term outcomes.

By Eleanor McDermid