Thrombus Formation at the Neck of Cerebral Aneurysms during Treatment with Guglielmi Detachable Coils

Thromboembolic events are a common source of complications during Guglielmi detachable coil (GDC) treatment of intracranial aneurysms. Thrombus formation at the coil-parent artery interface is not commonly reported but is an important potential source of emboli. We describe nine cases in which thrombus propagated from GDCs into the parent artery during coil therapy of cerebral aneurysms and subsequent treatment of the thrombus. A retrospective review of a procedural database was performed to identify cases in which thrombus occurred during GDC treatment of cerebral aneurysms during a 30-month period. All images were reviewed at the time of the procedure. Nine cases of thrombus forming at the coil-parent artery interface and five cases of distal emboli were identified among 210 cases. All patients underwent anticoagulation with heparin during GDC treatment procedures. Thrombus was identified at the coil-parent artery interface during GDC treatment in nine (4.3%) of 210 cases. In each case, the thrombus was recognized before distal embolic complication occurred and was successfully treated with heparin alone (five patients) or with heparin plus a glycoprotein IIb-IIIa inhibitor (four patients). Potential clinical complications can be avoided by early recognition of thrombus at the coil-parent artery interface and by administering appropriate medical therapy.