Electromagnetic navigation-guided neuroendoscopic transfrontal
transaqueductal fenestration of expansive posterior fossa arachnoid cyst
with simultaneous endoscopic third ventriculostomy in an infant
V. L. Torres
Received: 24 April 2018 /Accepted: 21 May 2018
Springer-Verlag GmbH Germany, part of Springer Nature 2018
Introduction We present an infant with an expansive posterior fossa arachnoid cyst and severe clinical deterioration due to
decompensated obstructive hydrocephalus. Given the dilated Sylvius aqueduct, we favoured the endoscopic transfrontal
transaqueductal route to approach the cyst.
Case report A 12-month-old boy was acutely admitted for severe symptoms of intracranial hypertension. Imaging revealed
spacious cystic formation in the posterior fossa with expansive behaviour towards the brain stem, fourth ventricle and cerebellum
associated with obstructive triventricular hydrocephalus. The patient underwent electromagnetically navigated transfrontal
transaqueductal cyst fenestration with simultaneous ETV from two precoronal trajectories with a rigid endoscope.
Conclusion A transaqueductal approach with a rigid endoscope is rarely published, and we were amazed by the impact on the
child’s clinical improvement after this minimally invasive endoscopic procedure. The case is well documented with imaging and
perioperative neuroendoscopic views.
Keywords Posteriorfossa cyst
We present an infant with an expansive posterior fossa arach-
noid cyst and severe clinical deterioration due to decompen-
sated obstructive hydrocephalus who was successfully treated
by electromagnetic navigation-guided neuroendoscopic
transfrontal transaqueductal fenestration of the cyst wall and
endoscopic third ventriculostomy (ETV) simultaneously.
A transaqueductal approach with a rigid endoscope is rare-
ly published, and we were amazed by the impact on the child’s
clinical improvement after this minimally invasive endoscopic
A 12-month-old boy presented with severe intracranial hyper-
tension (ICH) signs, including headache, vomitus, somno-
lence, hypotonia, macrocephaly (51.5 cm), setting sun and
positive left-sided pyramidal signs.
Computed tomography (CT) revealed triventricular hydro-
cephalus (HCP) with expansive posterior fossa cyst and
diastasis of cranial sutures (Fig. 1a–c). External ventricular
drainage (EVD) was inserted with immediate control of ICH.
Magnetic resonance imaging (MRI) revealed severe
ventriculomegaly, thin and elevated corpus callosum and an
enlarged third ventricle with spacious suprapineal recess. The
cerebral aqueduct was short and widely opened with cerebro-
spinal fluid (CSF) flow void blocked by the wall of the posterior
fossa cyst. The brain stem was compressed ventrally. Cerebellar
hemispheres and vermis were displaced cranially (Fig. 1d, e).
We opted for a transfrontal transaqueductal approach with
fenestration of the cyst followed by endoscopic third
ventriculostomy. The patient was placed in a supine position
with the head placed in a horseshoe holder. Electromagnetic
neuronavigation (AxiEM, Medtronic) was used to plan opti-
mal trajectories. We introduced the peel away sheath (10 Fr)
* Petr Liby
Department of Neurosurgery, Second Faculty of Medicine, Charles
University and Motol University Hospital, V Úvalu 84, 150
06 Prague 5, Czech Republic
Universidade de Pernambuco (UPE), Recife, Pernambuco, Brazil
Department of Radiology, Second Faculty of Medicine, Charles
University and Motol University Hospital, Prague, Czech Republic
Child's Nervous System