Posterior fossa arteriovenous malformations: Significance of higher incidence of bleeding and hydrocephalus.
OBJECTIVE
Hydrocephalus associated with different types of intracranial arteriovenous malformations (AVMs) has been scarcely studied. In the present report we investigate this association with posterior fossa AVMs (pfAVMs). We hypothesized that there is an increased risk of hydrocephalus and required permanent cerebrospinal fluid (CSF) shunt in patients with pfAVMs that may be linked to the increased risk of bleeding of these lesions. We also review the factors associated with this increased risk of hemorrhagic presentation and we assess how it affects management strategies and functional outcomes in these patients.


METHODS
Out of a prospective registry of 374 patients with brain AVMs diagnosed in our center from 1993 to 2013, 60 (16%) had a pfAVM. We described these patients' demographics, their AVM characteristics, clinical presentation, and hydrocephalus incidence and compared the results with those of the supratentorial AVM (spAVM) patients recorded during the same period.


RESULTS
Out of the 60 patients with pfAVMs, 10 (16.7%) presented AVMs located in the brainstem. Hemorrhagic presentation (49/60; 82%) was significantly higher in pfAVMs than in spAVMs (122/314; 38.8%; p<0.05). Hydrocephalus was a common complication in pfAVM patients who had a statistically significant higher need for both temporary external ventricular drain (EVD) (6.7 vs. 20%; p<0.05) and permanent CSF shunts (3.5 vs. 20%; p<0.05). The initial mortality was high (12/60; 20.3%) and half of these patients died before any treatment option could be offered. However, out of those who survived, 70% (42/60) had already shown good clinical outcome at the 6-month follow-up.


CONCLUSIONS
Hemorrhagic presentation and hydrocephalus have a higher incidence in pfAVM patients, which initially results in more neurological deficits and an elevated mortality even before receiving any treatment. However, a large number of survivors present good functional outcomes at early follow-up, justifying an aggressive management strategy with microsurgery as the first treatment option in most cases, and radiosurgery as an alternative, especially in brainstem AVMs.
['Torné|Ramon|R|', 'Rodríguez-Hernández|Ana|A|', 'Arikan|Fuat|F|', 'Romero-Chala|Fabián|F|', 'Cicuéndez|Marta|M|', 'Vilalta|Jordi|J|', 'Sahuquillo|Juan|J|']
D000293:Adolescent D000328:Adult D000368:Aged D001933:Brain Stem D002531:Cerebellum D002557:Cerebrospinal Fluid Shunts D002648:Child D002675:Child, Preschool D004621:Embolization, Therapeutic D005260:Female D006801:Humans D006849:Hydrocephalus D007223:Infant D002538:Intracranial Arteriovenous Malformations D020300:Intracranial Hemorrhages D008297:Male D008866:Microsurgery D008875:Middle Aged D011379:Prognosis D011446:Prospective Studies D016634:Radiosurgery D012042:Registries D012422:Rupture, Spontaneous D013345:Subarachnoid Hemorrhage D014057:Tomography, X-Ray Computed D016896:Treatment Outcome D055815:Young Adult
Hydrocephalus Posterior fossa AVM Shunt Hemorrhagic presentation Associated aneurysms