© Springer International Publishing AG 2018 75
W.T. Couldwell (ed.), Skull Base Surgery of the Posterior Fossa,
https://doi.org/10.1007/978-3-319-67038-6_6
Endoscopic Endonasal Approach
for Posterior Fossa Tumors
André Beer-Furlan, Alexandre B. Todeschini,
Ricardo L. Carrau, and Daniel M. Prevedello
A. Beer-Furlan
Neurological Surgery, Rush University Medical
Center, 1725 W. Harrison St. Suite 855, Chicago,
IL 60612, USA
e-mail: [email protected]
A.B. Todeschini • D.M. Prevedello (*)
Neurological Surgery, The Ohio State University,
410 West 10th Avenue, Columbus, OH 43210, USA
e-mail: [email protected];
[email protected]
R.L. Carrau
Department of Otolaryngology, The Ohio State
University Wexner Medical Center, 320 West 10th
Avenue, B221, Columbus, OH 43210, USA
e-mail: [email protected]
6
Introduction
Driven by the revolution of endoscopic pituitary
surgery, the development of the expanded endo-
scopic endonasal approach (EEA) and the associ-
ated surgical tools have pushed the limits of
transnasal access to the ventral skull base. The
EEA rapidly became a safe alternative in the
armamentarium of skull base approaches, and it
has been increasingly used in the management of
ventral extradural and intradural posterior fossa
tumors. It provides the advantage of direct access
to pathologies with near-field magnification
while minimizing manipulation of neurovascular
structures and avoiding brain retraction, ulti-
mately decreasing morbidity [ 1 – 5 ].
In this chapter, the ventral posterior cranial
fossa tumors are divided in “extradural” and
“intradural” due to the differences in approach
selection, surgical strategy, complexity of the
surgery and microsurgical dissection, and skull
base reconstruction depending of the site of ori-
gin and type of tumor.
The “extradural” posterior fossa tumor group
is represented by chordomas and chondrosarco-
mas. Although sometimes there is intradural
tumor extension (Figs. 6.1 and 6.2), chordomas
and chondrosarcomas are mainly located extra-
durally within the skull base bone. Hence, a sig-
nificant part of the tumor resection is done during
the bone work of the approach. In addition, the
tumor resection is often completed without a
cerebrospinal fluid leak facilitating skull base
reconstruction and reducing postoperative
complications.
The “intradural” posterior fossa tumors that
are suitable to EEA resection are represented
mainly by meningiomas (Fig. 6.3). In general,
EEA for intradural tumors involves more chal-
lenging microsurgical dissection and skull base
reconstruction. Ventral posterior fossa intradural
epidermoid and dermoid cysts may be resected
through EEA, but our previous experience sug-
gests that the transnasal corridor may increase
the risk of infection and abscess occurrence
within the residual tumor, so we do not recom-
mend it. Schwannomas are also another common
type of intradural posterior fossa tumor.