Precision microcatheter shaping in vertebrobasilar aneurysm coiling

Abstract

Background: Inventing an optimal curve on a microcatheter is required for successful intracranial aneurysm coiling. Shaping microcatheters for vertebrobasilar artery aneurysm coiling is difficult because of the vessel's long, tortuous and mobile anatomy. To overcome this problem, we devised a new method of shaping the microcatheter by using the patient's specific vessel anatomy and the highly shapable microcatheter. We report our preliminary results of treating posterior circulation aneurysms by this method.

Methods: An unshaped microcatheter (Excelsior XT-17; Stryker Neurovascular, Fremont, CA, USA) was pretreated by exposure to the patient's vessel for five minutes. The microcatheter was placed in the vicinity of the targeted aneurysm and was left in contact with the patient's vessel before extraction. This treatment precisely formed a curve on the microcatheter shaft identical to the patient's vessel anatomy. Following the pretreatment, the tip of the microcatheter was steam shaped according to the long axis of the target aneurysm. Five consecutive vertebrobasilar aneurysms were treated using this shaping method and evaluated for the clinical and anatomical outcomes and microcatheter accuracy and stability.

Results: All of the designed microcatheters matched the vessel and aneurysm anatomy except in one case that required a single modification. All aneurysms were successfully catheterized without the assistance of a microguidewire, and matched the long axis of the aneurysm. All microcatheters retained stability until the end of the procedure.

Conclusions: A precise microcatheter shaping for a vertebrobasilar artery aneurysm may be achieved by using the patient's actual vessel anatomy and the highly shapable microcatheter.

Keywords: Microcatheter shaping; coiling; intracranial aneurysm.

Figure 1.

(a) A basilar tip aneurysm pointing anteriorly in case 3. An Excelsior XT-17 microcatheter was left in contact with this vessel for five minutes. (b) After contact with the vessel for five minutes, the microcatheter has formed the curve of the vertebrobasilar artery. Note the extradural vertebral artery curve replicated on the microcatheter (arrows). (c) The tip of the microcatheter is steam shaped anteriorly to align the long axis of the aneurysm (arrow).

Figure 2.

Accuracy (upper row) and stability (lower row) of the microcatheters. The upper row of each figure shows the accuracy of the microcatheter in two different views except in (d). The lower row shows the stability of the microcatheter at the end of the coiling. (a) to (e) correspond to cases 1 to 5, respectively. Arrowheads in each figure demonstrate the trajectory of the microcatheter. (a) A basilar trunk aneurysm in case 1. Arrowheads in the upper and lower rows show accuracy and stability of the microcatheter. (b) A basilar tip aneurysm in case 2. Arrows in the upper row show the bleb at the base of the aneurysm. Note the second microcatheter accurately pointing toward the bleb at the beginning and the end of the coiling. (c) A basilar tip aneurysm in case 3. Arrowheads in each figure demonstrate the accuracy (upper row) and stability (lower row) of the microcatheter. (d) A left superior cerebellar (SCA) aneurysm in case 4. Arrow in the upper figure points to the origin of the SCA arising from the aneurysmal dome. Arrowheads demonstrate the tip of the microcatheter facing the SCA orifice. Arrow in the lower figure shows the precise coil placement at the SCA origin to prevent occlusion of the artery. (e) A basilar tip aneurysm in case 5. Arrowheads show the trajectory of the microcatheter. Note the slight microcatheter deviation to the left. The anteroposterior direction of the microcatheter matched the long axis of the aneurysm throughout the coiling (right column).

Figure 3.

(a) A three-dimensional rotational angiogram in oblique view demonstrating a large basilar left superior cerebellar artery (SCA) aneurysm incorporating the basilar artery trunk and the origin of the SCA (arrow). Note the extremely tortuous vertebrobasilar artery preventing subtle microcatheter manipulation and unpredictable microcatheter tip direction. (b) Cone beam computed tomography with contrast injection after microcatheter and stent placement. An Excelsior 1018 microcatheter is inserted in the aneurysm and half-jailed with an LVIS Jr stent. A precisely designed Excelsior XT-17 microcatheter (arrowheads) is placed at the orifice of the SCA (arrow) to prevent occlusion of this artery. Note that the tip of the microcatheter is pointing toward the orifice of the SCA. (c) Extraction of the protection coil under roadmap imaging. The mass of the protection coil that had been temporarily placed at the SCA orifice is indicated by the arrow. The removed coil is seen in the microcatheter (arrowheads). Note the precise coil placement at the SCA origin. (d) Post-coiling angiogram demonstrates complete occlusion of the aneurysm as well as preservation of the SCA (arrowheads).