Treatment of intracranial broad-neck aneurysms with a new self-expanding stent and coil embolization

Abstract

Background and purpose: Endovascular treatment of broad-neck intracranial aneurysms with detachable coils requires special techniques. Placement of a stent over the aneurysm neck and secondary coil embolization prevents coil migration and allows attenuated packing of the coils. However, access for the stent-delivery system can be technically limited in tortuous anatomy. We present six cases of broad-neck aneurysms treated with a new self-expanding stent and coil embolization.

Methods: Three aneurysms of the supraophthalmic internal carotid artery and three aneurysms of the basilar tip with extension to the origin of a posterior cerebral artery were treated. The stent was a new self-expanding stent with a 3F over-the-wire microcatheter delivery system. Coil embolization was performed with electrolytically detachable coils. Time-of-flight MR angiography was performed after treatment in five cases. Three other patients could not be treated with the stent because deployment was not possible after correct positioning of the delivery system.

Results: Access with the stent-delivery system was easy, and the aneurysm neck was covered sufficiently. After stent placement, total coil embolization was achieved in four and subtotal coil embolization was achieved in two. Parent arteries remained open, and no secondary coil migration was seen. On follow-up MR imaging, the stent was clearly visible and patency of the parent vessel and emerging branches was assessable.

Conclusion: This new stent is a safe and efficient tool for the endovascular treatment of intracranial broad-neck aneurysms. Access to smaller vessels was easy, but the mechanism of deployment had to be improved. Follow-up MR imaging was sufficient.

Fig 1.

Close-up views of the stent show its segmented, open-cell design and itspositioning over the neck of an aneurysm with catheter access to the aneurysm.

Fig 2.

Case 1. Far left, Broad-neck aneurysm of the right ICA, paraophthalmic segment. Middle left, Exchange microguidewire is passed by the aneurysm into a peripheral branch of the MCA. Middle right and far right, The stent is deployed (not visible) in the ICA and proximal MCA. The aneurysm is occluded totally with coils, as shown on the fluoroscopic angiogram (middle right) and digital subtraction angiogram (DSA) (far right).

Fig 3.

Case 1. Lateral fluoroscopic view of the middle cranial fossa shows a stent in the right ICA and proximal MCA. Stent markers (asterisks) placed proximally and distally enable visualization of the deployed stent. Coils in the supraophthalmic aneurysm are seen between the stent markers in projection on the anterior clinoid process.

Fig 4.

Case 1. Left and middle, Maximum intensity projection (MIP) TOF 3D angiograms show that the stent in the right ICA and MCA does not disturb flow signal intensity. Right, Sagittal multiplanar reconstruction (MPR) of the right ICA demonstrates the visibility of the stent as a thin black line at the vessel wall. The coils in the aneurysm of the ophthalmic segment cause susceptibility artifacts.

Fig 5.

Case 2. Left, Broad-neck right ICA aneurysm at the origin of a fetal PCA after incomplete coiling 5 weeks earlier. Middle, After deployment of the stent in ICA and MCA. Right, After complete coiling, a dislocated single loop of the last Ultrasoft-coil is present in the parent vessel.

Fig 6.

Case 2. Broad-neck right ICA aneurysm at the origin of a fetal PCA after stent placement and complete embolization. Left, MIP TOF 3D angiogram. Middle, Primary section of the TOF shows the origin of the right PCA. Right, Sagittal MPR of the right ICA shows the origin of the PCA and the neck of the embolized aneurysm. The stent is visible as a thin black line at the vessel wall distal to the aneurysm.

Fig 7.

Case 3. Angiograms show recurrence of a basilar tip aneurysm. Top row, Images before deployment of a stent in the distal BA and proximal right PCA and coil embolization. Bottom row, Images after treatment.

Fig 8.

Case 3. MIP TOF 3D angiograms show the BA and both the PCA and superior cerebellar artery after treatment. The basilar-tip aneurysm is occluded with coils. Susceptibility artifacts of the coils and the distal stent markers mimic stenosis (which is not visible on DSA).

Fig 9.

Case 3. Sagittal MPR images show the BA and occluded tip aneurysm with the stent in the distal BA (a), the origin of the right PCA and SUCA (b and c), the P1 segment with the stent and SUCA (d), and the P1 segment with the distal end of the stent and the stent markers causing susceptibility artifacts (e).

Fig 10.

Case 6. Left, DSA of a broad-neck aneurysm of the left ICA, paraophthalmic segment. Right, The stent is deployed (not visible) in the distal ICA, the aneurysm is subtotally occluded with coils.

Fig 11.

Case 6. Left, MIP TOF 3D angiogram of the broad-neck aneurysm of the left ICA, paraophthalmic segment after endovascular therapy. A small remainder is noted at the neck (asterisk). Middle, Sagittal MPR. Right, Coronal MPR.