Patency of the posterior communicating artery after flow diversion treatment of internal carotid artery aneurysms.

BACKGROUND AND PURPOSE

Cerebral aneurysm treatment with the Pipeline Embolization Device (PED) often mandates device placement across the ostia of arteries of the Circle of Willis. We determined the patency rates of the posterior communicating artery (Pcomm) after placement across its ostium a PED and studied neurologic outcomes in these patients.

METHODS

We analyzed, retrospectively, a consecutive series of patients in whom a PED was placed across the ostium of Pcomm while treating the target aneurysm. Pcomm arterial flow after PED placement was graded on a 3-point scale at post-operative angiography and follow-up angiography. Data on pretreatment aneurysm rupture status, concomitant coiling, number of PEDs used, and neurologic status at follow-up were collected.

RESULTS

Eleven patients with 13 aneurysms were included in this study. All patients had an ipsilateral posterior cerebral artery arising from the basilar artery (P1). In the immediate post-procedural setting, four patients (36%) had diminished Pcomm flow rates. After a mean follow-up of 12.6±6.7 months, three Pcomm arteries (27%) were occluded and two Pcomm arteries (18%) had diminished flow. Of patients with diminished flow/occluded Pcomm at follow-up, 80% (4/5) had diminished flow at initial post-procedure angiography compared to none of the six patients without diminished/occluded flow immediately post treatment. No patients suffered new neurologic symptoms at follow-up.

CONCLUSIONS

Approximately one half of Pcomm arteries demonstrated occlusion or decreased flow at follow-up if the ostia are covered with a flow diversion device. Covering the Pcomm ostium in patients with a P1 did not result in any neurologic deficits.