Neuroform Atlas stent-assisted coiling of ruptured intracranial aneurysms: A multicenter study

Abstract

Purpose: To assess efficacy, safety and to discuss optimal medical therapy of stent-assisted coiling of ruptured intracranial aneurysms.

Methods: Ruptured intracranial aneurysms treated with stent-assisted coiling in eight different institutions were retrospectively reviewed. Medical treatment regimens varied among the centers, mainly regarding heparin administration and post-procedural single or double antiplatelet therapy. Clinical and angiographic results, including complications and outcomes were analyzed and related to the different therapies.

Results: Sixty-one consecutive patients (male/female 23/38), aged 59.1 years (36-86) underwent stent-assisted coiling for ruptured intracranial aneurysm without antiplatelet pre-medication. Intravenous acetylsalicylic acid (ASA) 500mg was administered to all patients immediately after stent deployment. At the same time heparin was given as bolus in 15 patients (24.6%) as part of local protocol. Intravenous glycoprotein 2b/3a inhibitors (antiGP2b3a) were used as bail-out therapy for stent thrombosis. Stent thrombosis occurred in 22 patients (36.1%), of which 4 (6.5%) lead to incomplete and 18 (29.6) to complete occlusion of the stent. Heparin administration had no effect on thrombosis rate. Thrombosis resolution occurred in all cases with intravenous antiGP2b3a (7 tirofiban, 15 abciximab), without increasing overall complication rate. Single antiplatelet therapy with ASA (28 patients, 45.9%) or double antiplatelet therapy including ASA and clopidogrel (33 patients, 54.1%) were administered after procedure, depending on local protocols and on neurointerventionists' experience. Overall complication rate, including ischemia and hemorrhage was higher in patients in which only ASA was administered (21.4% vs. 12.1%). No late stent thrombosis was seen, regardless of whether a single or double antiplatelet regimen was used. Nevertheless, the small sample size suggests caution in interpreting these results. Moreover, a possible bias may arise from the decision whether to modify the maintenance therapy or not depending on the severity of the intracranial hemorrhage in a case-by-case assessment. At three months, 34 out of 38 patients with HH grade 1-2 (89.4%), and 11 out of 23 with Hunt-Hess grade of 3-4 (47.8%) were independent (Modified Ranking Scale 0-2).

Conclusion: Stent assisted coiling of ruptured intracranial aneurysms is a feasible option when simple coiling is not possible. Optimal medical treatment is still controversial because balance between hemorrhagic and ischemic risks is difficult to evaluate. In our series, heparin bolus had no effect on subsequent stent thrombosis. In all cases peri-operative stent thrombosis was successfully managed using bail-out intravenous antiGP2b3a, which did not increase post-procedural hemorrhage rates. A non-significant trend towards increased complications rate was noticed in patients treated with single antiplatelet therapy versus double antiplatelet therapy.

Keywords: Endovascular treatment; Optimal medical therapy; Ruptured intracranial aneurysms; Stent-assisted coiling.