Consideration on Thromboembolic Complications of Stent Assisted Coil Embolization of Unruptured Aneurysms

Objective: We retrospectively analyzed thromboembolic complications for unruptured cerebral aneurysms treated with stent assisted coil embolization (SAC). Patients and methods: Between 2010 September and 2012 March, 36 unruptured broad neck aneurysms in 35 patients were treated by SAC following dual antiplatelet medication with aspirin and clopidogrel. Aspirin and clopidogrel were started 1–14 days before the procedure. After the procedure, diffusion weighted MR imaging (DWI) was performed within seven days. DWI findings were graded into A to D depending on the number and the size of bright spots: A, no bright lesions; B, 1–5 small (＜10 mm) lesions; C, six or more small lesions; D, any large (≧10 mm) lesions. Results: Angiography showed complete occlusion was achieved in 13 aneurysms (36%), neck remnant in nine (25%), and body filling in 14 (39%). Symptomatic thromboembolic complications occurred in six cases (17%). The symptoms were transient in four of the six patients, and two patients had persisting minor symptoms (modified Rankin Scale 1 and 2). The DWI grade of SAC cases was A in two patients, B in six, C in 16, and D in eight. Among SAC cases, there was a tendency of higher incidence of Grade D when clopidogrel was started earlier than three days before the procedure. Conclusions: SAC is a feasible and effective technique for treating broad neck aneurysms. Starting clopidogrel three or more days before the procedure may half reduce thromboembolic complications.