Duplicate PICA and anomalous origin of Posterior Meningeal Artery – an uncommon association with a paediatric cerebellar AVM

Abstract

Duplication of the posterior inferior cerebellar artery (PICA) is a rare anatomical variation and its presence in association with an arteriovenous malformation (AVM) is not yet documented. We report a right-sided, duplicated PICA in association with a cerebellar AVM, clinically presented as repeated primary third and fourth ventricular bleed in a paediatric age female. Considering very early age of presentation, repeated bleeding episodes, presence of intranidal aneurysm and involvement of brainstem structures, therapeutic embolization was done in two sessions. After the first session of targeted embolization carried out through the anatomically distinct and hypertrophied distal PICA segment which was able to substantially reduce the AVM flow, a proximal vessel became distinct. This vessel arose about 0.5 cm proximal to the rostral PICA and divided into a prominent posterior meningeal artery (PMA) characterised by its vertical disposition directed postero-laterally. The other division ran a medial course aligned towards the main PICA trunk. Literature search reveals that till date only 5 cases has been documented and such vessels have a right sided predilection of occurrence. The medullary feeder seems to occur most often from the rostral vessel which in our case was the dominant AVM feeder requiring very cautious and controlled embolization technique. We achieved significant obliteration of the AVM at short term follow-up without any significant neurodeficit.