Introduction: Large anterior skull base (ASB) meningiomas are occasionally highly vascular, and
are supplied predominantly by the anterior and posterior ethmoidal arteries which
are branches of the ophthalmic artery. Effective preoperative embolization of these
lesions is thwarted by concerns of retrograde embolization of the ophthalmic artery
with visual loss or blindness. The standard goal of early intraoperative devascularization
of these meningiomas at the basal dural attachment is often difficult until there
has been substantial tumor decompression. As such, resection of these lesions is often
coupled with lengthy operative times and significant blood loss. Endoscopic transnasal
approaches provide direct access to the ethmoidal arteries, and ASB meningiomas are
largely devascularized early on in the course of surgical resection. However, endoscopic
resection of larger ASB meningiomas has been associated with lengthy resection times,
subtotal resection, and increased rate of postoperative CSF leak. In an effort to
decrease operative time and blood loss we have adopted a surgical strategy that incorporates
endoscopic transnasal devascularization of the tumor as a means to complement the
strengths of an open surgical approach. We present our institutional experience with
two cases in which we treated large (>4 cm) ASB meningiomas with a combined approach—endoscopic
transnasal sacrifice of the anterior and posterior ethmoidal arteries followed by
open subfrontal resection.
Methods: Two patients with large ASB meningiomas underwent endoscopic transnasal ligation
of the bilateral anterior and posterior ethmoidal arteries. Immediately afterwards,
both patients underwent a subfrontal approach (one bifrontal craniotomy, one unilateral
FTOZ) for tumor resection.
Results: Endoscopic transnasal ligation was performed successfully in both patients. Subsequent
surgical resection was completed in ~4.5 hours with an estimated blood loss of 150cc
in each case. A complete resection was obtained in one of the patients, and a small
dural tail remained in the other (contralateral to the side of approach).
Conclusion: Endoscopic transnasal sacrifice of the anterior and posterior ethmoidal arteries
immediately prior to open surgical resection appears to be a safe alternative for
resection of large ASB meningiomas and may translate into shorter operative times
with lower blood loss. It is a novel strategy that combines the advantages of endoscopic,
microscopic, transfacial and transcranial techniques in a single operation.
