Bilateral Approach for Stent-assisted Coiling of Posterior Inferior Cerebellar Artery Aneurysms - Two Cases

Abstract

Aneurysms of the posterior inferior cerebellar artery (PICA) are rarely encountered. In particular, due to frequent anatomic complexity and the presence of nearby critical structures, PICA origin aneurysms are difficult to treat. However, recent reports of anecdotal cases using advanced endovascular instruments and skills have made the results of endovascular treatment rather outstanding. PICA preservation is the key to a successful endovascular treatment, based on the premise that a PICA origin aneurysm is well occluded. To secure PICA flow, stenting into the PICA would be the best method, however, it is nearly impossible technically via the ipsilateral vertebral artery (VA) if the PICA arose at an acute angle from the sac. In such a case, a bilateral approach for stent-assisted coiling can be a creative method for achievement of two goals of both aneurysm occlusion and PICA preservation: ipsilateral approach for coil delivery and contralateral cross-over approach for stent delivery via a retrograde smooth path into the PICA.

Retrograde access to the posterior inferior cerebellar artery in balloon-assisted coiling of posterior inferior cerebellar artery aneurysms

“…We have previously reported on the retrograde access technique on 25 patients during the World Federation of Interventional and Therapeutic Neuroradiology (WFITN) meeting in 2011 11. Case reports and a small case series dedicated to this technique have been described since then 2 3 5 12 13. These cases showed the feasibility of the technique in stent-assisted coiling of PICA aneurysms using the contralateral vertebral artery to access the PICA to place the stent 5 12 13…”

Flow-Diverter Stent for the Treatment of a Non-Origin Posterior Inferior Cerebellar Artery Aneurysm

“…The choice of the treatment also depends on the patency of the contralateral VA 10 . If the contralateral VA is wide in caliber, a contralateral and retrograde approach to the PICA might be easier than the ipsilateral antegrade approach 8 . However, retrograde stenting in conjunction with antegrade coiling of the aneurysm might be considered in the proper circumstances 6,11 .…”

“…Wide neck aneurysms are more challenging and balloon or stent-assisted techniques can be entertained. The goal of these techniques is to occlude the aneurysm with preservation of the PICA flow 8 . Selective catheterization of the PICA may be difficult or risky because of the acute angle of the PICA in relation to the vertebral artery 6,9 .…”

Personalized Approach to the Treatment of Posterior Inferior Cerebellar Artery Aneurysms

“…Appearance of low-profile intracranial stents-both flow diverters and assisting ones-let us use stenting within PICA itself, if the diameter of vessel is appropriate. [4][5][6] During evaluation of any new PICA aneurysm, we should consider an optimal tactics among this wide variety of options, regarding anatomical characteristics of the aneurysm itself, parent arteries, and clinical presentation.…”