Mohamed S. Kabil, MD Hrayr K. Shahinian, MD, FACS

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TUMOR CHARACTERISTICS
INTRODUCTION TO ENDOSCOPIC SKULL BASE SURGERY
Mohamed S. Kabil, MD Hrayr K. Shahinian, MD, FACS
Introduction From its original reliance on
microsurgical techniques, the field of skull base
surgery is currently being transformed into an
endoscopy-based specialty that is distinguished
by excellent outcomes, shorter operating times,
faster recoveries, fewer complications, and
overall decreased patient morbidity. At the Skull
Base Institute in Los Angeles, California, these
techniques are routinely used in the surgical
management of anterior, middle, and posterior
skull base tumors, both primary and recurrent, as
well as for various neurovascular compression
syndromes, such as trigeminal neuralgia,
hemifacial spasm, and others. In our experience,
these endoscopic techniques have provided
superior access and resulted in better surgical
results and an unsurpassed intraoperative
definition of neurovascular conflicts and tumor
morphologies. More than 90 of all patients
undergoing endoscopic skull base surgery are
discharged from the hospital within 48 hours of
their operation. The Evolution from the Open
Craniotomy to Fully Endoscopic Skull Base
Surgery For decades, surgeons interested in the
field of skull base surgery have debated which
techniques provide the best access to the skull
base with the least amount of associated risk.
Traditional approaches to the anterior, middle,
and posterior skull base have included complex
transcranial or transfacial operations. These
procedures, facilitated by progress in the
designs of surgical instruments and advances in
perioperative intensive care, have afforded
excellent exposure, allowing for complete removal
of massive tumors. However, these open procedures
have also been associated with significant
morbidity and long-term convalescence the burden
on the patient has been great. As a result, the
evolution of skull base surgery over the past
decade has been characterized by an emphasis on
the development of minimally invasive techniques
that do not compromise surgical outcomes but do
significantly diminish the perioperative burden
on the patient. Endoscopic Skull Base Surgery
in Practice For the past decade at the Skull
Base Institute in Los Angeles, California, we
have been performing endoscope-assisted and fully
endoscopic surgery of the anterior, middle, and
posterior skull base. Applications of endoscopy
at our institution have included treatment of
primary and recurrent pituitary tumors (both with
and without suprasellar extension), treatment of
the various neurovascular compression syndromes
(trigeminal neuralgia, hemifacial spasm,
glossopharyngeal neuralgia, spasmodic
torticollis) at the cerebellopontine angle (CPA),
removal of vestibular schwannomas and other CPA
tumors, as well as resection of various other
skull base lesions, both malignant and benign.
For many indications, we now use only fully
endoscopic techniques via keyhole craniotomy
access points the need for extensive
craniotomies for intracranial exposure and
retraction has been all but obviated.
Visualization of the relevant anatomy has proven
to be improved over microscopic imaging.
Endonasal, transglabellar, supraorbital,
retrosigmoid, subtemporal, and other tailored
keyhole approaches have made virtually all skull
base tumors amenable to endoscopic resection.
ConclusionSelecting short, direct, and
precise routes to lesions at the base of the
skull without manipulating and exposing
unaffected areas is essential for keyhole
surgery. Rigid endoscopes of varying lengths and
angles of view have broadened the available
surgical exposure without the need for of
additional dissection or retraction the
resulting panoramic perspectives of the surgical
field have allowed for thorough evaluations of
the extent of intracranial disease. Progress is
continuing, changing many scenarios in daily
clinical life. It is our hope that this work will
contribute to the ongoing evolution of minimally
invasive skull base surgery.
ENDOSCOPIC ENDONASAL APPROACH
OPEN TRANSCRANIAL APPROACH
ENDOSCOPIC SUPRAORBITAL APPROACH
PTERIONAL APPROACH
TRANSLABYRINTHINE APPROACH FOR ACOUSTIC NEUROMAS
ENDOSCOPIC RETROSIGMOID APPROACH
INTRODUCTION TO ENDOSCOPIC SKULL BASE SURGERY