Thromboembolic events associated with balloon-assisted coil embolization: evaluation with diffusion-weighted MR imaging

Abstract

Background and purpose: Thromboembolic events may occur during or after the treatment of intracranial aneurysms with Guglielmi detachable coils (GDCs). The purpose of this study was to determine the frequency of thromboembolic events associated with balloon-assisted coil placement and to investigate possible risk factors for these events during balloon-assisted coil placement and embolization.

Methods: Twenty patients with cerebral aneurysms treated with balloon-assisted coil placement and embolization at our institution were included. All patients underwent diffusion-weighted (DW) imaging within 6 hours after the procedure. Two neuroradiologists reviewed all DW images to detect ischemic lesions.

Results: Hyperintense lesions compatible with thromboembolic events were detected on DW images of four (20%) patients. Three lesions were in the territory of posterior circulation, and one was in the territory of anterior circulation. The occurrence of new lesions was strongly associated with the number of times the microcatheter or coil was repositioned and removed and with the size of the aneurysmal neck (P < .01). DW imaging findings did not suggest a strong correlation between the occurrence of new ischemic lesions and potential risk factors (maximum balloon inflation time, number of times the balloon was inflated, etc.) associated with balloon-assisted coil placement and embolization (P > .05).

Conclusion: The risk of thromboembolic events during the treatment of intracranial aneurysms with balloon-assisted techniques is not more significant than when conventional GDC techniques are used. The only variables found to influence this risk during or after balloon-assisted coil placement were microcatheter repositioning, coil removal and repositioning, and size of the aneurysmal neck.

Fig 1.

Right vertebral AP arteriograms obtained in a 40-year-old woman with severe headache and a right SCA aneurysm. A, Image shows a wide-necked aneurysm of the right SCA. Distal portion of the SCA and its branches are seen clearly. B, Immediate postembolization image shows nearly complete aneurysmal occlusion with coils, with a minimal neck remnant around the right SCA orifices. Distal portion of the SCA and its branches (arrows) are not seen clearly because of thromboembolic events during the procedure. C and D, Images from a second procedure. Image in C shows wide-necked aneurysmal recurrence of the right SCA 3 months after the first procedure. Immediate postembolization image in D shows nearly complete aneurysmal occlusion with coils, with minimal neck remnant around the right SCA orifices (arrow). Right SCA (arrowheads) is not seen clearly because of resistant thromboembolic event during the procedure.

Fig 2.

Images obtained in a 34-year-old man with SAH (grade 2) and a right SCA aneurysm. A, Right vertebral AP arteriogram shows a large, wide-necked aneurysm of the right SCA. B, Unsubtracted view shows the inflated microballoon at the neck of aneurysm (arrow) and microcatheter delivering the coil into the aneurysm (arrowhead). C, Immediate postembolization right vertebral AP arteriogram shows complete aneurysmal occlusion with coils. Distal portion of SCA and its branches are seen clearly without thromboembolic phenomena. D and E, DW image(D) and ADC map (E) 4 hours after the procedure show ischemic areas in the right and left SCA territories (arrows).