EMBOLIZATION FOLLOWED BY SPONTANEOUS THROMBOSIS AS RESOLUTION FOR A TRILOBED ANEURYSM OF THE BASILAR ARTERY IN A CHILD

Rizzi P.A. MD, Messina R. MD, Chiumarulo L. MD, Dicuonzo F PhD, De Tommasi A PhD

Neurosurgery and Neuroradiology Departments - Policlinico of Bari – University of study of Bari

Introduction: Pediatric intracranial aneurysms are rare diseases, accounting for less than 5% of all intracranial aneurysms. Morphology, clinical and radiological presentation of these aneurysms differ slightly from those found in adults. Aneurysm location in the posterior circulation is more common in children. Such aneurysms are giant, fusiform and dissecting. Spontaneous resolution through thrombosis of dissecting aneusysm has been reported.

CASE: A 15-month-old girl came to our attention following a generalized seizure. A CT scan showed subarachnoid hemorrhage in the basal cisterns with ventricular involvement. Neurological clinical findings were: Children's Coma Scale of 11/15, rigor nucalis, anisocoria right>left, right III n. palsy. Angio CT scan showed a trilobed dissecting aneurysm of the basilar artery with ectasia at the origin of the right SCA and peripheric haematoma close to the brainstem. and obstructive hydrocephalus with ventricular dilatation. The child was intubated and treated with external ventricular drainage before angiography. Angiography showed the irregular profile, large size and the three lobes of aneurysm. The right SCA origin was involved by the smallest lobe. The narrowing of basilar artery before the aneurysm was due to severe spasm. The aneurysm was filled also by the right PComA on the selective catheterization of right ICA. Basilar artery spasm worsened during angiography requiring farmacologic management. Endovascular treatment was performed by coiling of small (n° 1 coil) and medium lobes(n° 2 coils). The largest lobe was not occluded because of recurrence of basilar artery spasm. This lobe was still evident on selective right ICA angiography at the end of the procedure.

Results: One day after, new angiography showed a complete exclusion of the dissecting aneurysm, that was not filled neither from anterior nor from posterior circulation. The Angio MRI several days after treatment showed a mural thrombus on posterior aspect of aneurysm. Ten months after Angio MRI confermed total exclusion of the aneurysm, normal cerebral blood flow and a small ischemic lesion in the right calcarine area probably due to severe spasm or thromboembolism. The PCAs and the SCAs was filled by the PcomAs. The hydrocephalus was treated through V-P shunt. The infant is actually free from evident neurological deficits. Looking at the characteristics of the aneurysm, we believe that it was a dissecting aneurysm. Infact mural thrombosis, irregular morphology, narrow proximal stenosis of the basilar artery and stagnation of contrast agent inside are suggestive of dissection. The third lobe of the aneurysm was occlused by thrombosis, probably aided by coils.

Conclusions: Dissecting aneurysms are dynamic lesions with variable and unpredictable behavior and close follow-up and/or early treatment is warranted. Our case demonstrates that the thrombosis of a dissecting aneurysm may be a mechanism for spontaneous repair in paediatric aneurysms which therefore requires further elucidation.

DYSRAPHIA - CRANIO-SPINAL MALFORMATIONS