Oct 1 2012
By Eleanor McDermid, Senior medwireNews Reporter
Stent-assisted coiling may be the best treatment option for basilar tip aneurysms (BTAs), say US researchers.
Use of a stent is associated with large reductions in the rate of recurrence and the need for retreatment, report Stavropoula Tjoumakaris (Thomas Jefferson University Hospital, Philadelphia, Pennsylvania) and team.
"These findings are crucial because the high rate of aneurysm recanalization has been the major limitation of endovascular therapy," they write in Neurosurgery.
"Because BTAs are end-vessel aneurysms, they are exposed to the direct flow of the cerebral circulation, which explains their high propensity to recur. The use of a stent diverts flow away from the aneurysm sac, thus favoring stasis and thrombosis."
An additional problem with coiling is that protruding coil loops can lead to thrombosis of one or both posterior cerebral arteries. This occurred in three of 147 patients treated with coil embolization in the current study, and another seven patients had other thromboembolic complications, giving a rate of 6.8% overall and a permanent morbidity rate of 3.4%.
Six of 88 patients who underwent stent-assisted coiling had thromboembolic complications, giving an identical event rate of 6.8% and a permanent morbidity rate of 4.5%.
"This important finding contradicts previous reports suggesting a higher occurrence of thromboembolic events with stent-assisted techniques," say the researchers.
Three of the thromboembolic events in the stented group were caused by in-stent thrombosis, and all three affected patients had permanent morbidity. "Nevertheless, the percentage of intraoperative in-stent thrombosis was relatively low… and falls within the range reported previously," say Tjoumakaris et al. "The routine use of dual antiplatelet therapy for stent-assisted procedures is a key factor in preventing in-stent thrombosis."
Patients in the stented group had significantly lower recanalization rates than those who were not stented, at 17.2% versus 38.9%, as well as reduced retreatment rates, at 7.8% versus 27.8%. And rates were lower still for the 16 patients treated with Y stents versus those treated with single stents, at 8.3% versus 19.2% for recanalization and 0.0% versus 9.6% for retreatment.
Also, no patient treated with a stent had recurrent bleeding, compared with four (2.7%) in the nonstented group.
"Given that rehemorrhage is a rare occurrence, larger studies with longer follow-up periods are required to confirm the trend observed in the present report," says the team.
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