Microguidewire Looping to Traverse Stented Parent Arteries of Intracranial Aneurysms

Abstract

Objective: Stents are widely used in coil embolization of intracranial aneurysms, but on occasion, a microcatheter must traverse a stented segment of artery (so-called trans-cell technique) to select an aneurysm, or double stenting may necessary. In such situations, microguidewire passage and microcatheter delivery through a tortuous stented parent artery may pose a technical challenge. Described herein is a microguidewire looping technique to facilitate endovascular navigation in these circumstances.

Methods: To apply this technique, the microguidewire tip is looped before entering the stented parent artery and then advanced distally past the stented segment, with the loop intact. Rounding of the tip prevents interference from stent struts during passage. A microcatheter is subsequently passed into the stented artery for positioning near the neck of aneurysm, with microguidewire assistance. The aneurysm is then selected, steering the microcatheter tip (via inner microguidewire) into the dome.

Results: This technique proved successful during coil embolization of nine saccular intracranial aneurysms (internal carotid artery [ICA], 6; middle cerebral artery, 2; basilar tip, 1), performing eight trans-cell deliveries and one additional stenting. Selective endovascular embolization was enabled in all patients, resulting in excellent clinical and radiologic outcomes, with no morbidity or mortality directly attributable to microguidewire looping.

Conclusion: Microguidewire looping is a reasonable alternative if passage through a stented artery is not feasible by traditional means, especially at paraclinoid ICA sites.

Keywords: Aneurysm; Coil; Embolization; Microguidewire; Stent.

Fig. 1

Microguidewire looping technique (to navigate stented parent artery). A: Microguidewire loop shaped before or at proximal stented segment after proper configuring of wire tip. B and C: Looped microguidewire tip advanced to distal parent artery, passing through stented segment. D: Microcatheter follows (microguidewire-assisted), advanced near neck of aneurysm. E: Microguidewire withdrawal to tip of microcatheter. F: Microcatheter eased into sac of aneurysm under microguidewire torque.

Fig. 2

Configuring microguidewire loop. A and B: Acute-angled tip required. C and D: Use of proximal stent struts to loop microguidewire tip. E, F and G: Looping via small branch vessel (eg, meningohypophyseal trunk).

Fig. 3

A: Angiographic image of distal ICA aneurysm. B: Frame coil formed and properly configuration by jailed method, after stent deployment. C: Unsuitably oriented jailed microcatheter withdrawn to proximal stent position, but traditional means fail to advance microguidewire. D: Microguidewire loop formed before proximal stent reached. E: Looping technique enables microguidewire advancement. F: Passage of microcatheter to point near aneurysm. G: Aneurysm selected via inner microguidewire torque. H: Additional coil insertion occludes aneurysm, with minimal residual filling. ICA: internal carotid artery.

Fig. 4

A: Angiographic image of wide-necked paraclinoid ICA aneurysm. B: Frame and filler coils inserted by jailed method, after stent deployment. C: Last coil protrudes into parent artery, requiring additional stenting for stabilization. D, E and F: Microcatheter for stent delivery advanced into MCA via looped microguidewire. G: Additional stenting deployed and aneurysm satisfactorily occluded. H: Complete occlusion of aneurysm 1 year later in follow-up angiographic image. ICA: internal carotid artery, MCA: middle cerebral artery.