ASOPRSFall Scientific SymposiumSyllabus
177
T24
SurgicalManagement ofOrbital ArteriovenousMalformation: CaseReport
and LiteratureReview
DavidMyung, AndreaKossler, LisaChen. Ophthalmology, Byers Eye Institute at Stanford, PaloAlto, CA, UnitedStates
Introduction:
Arteriovenousmalformations (AVMs) of the orbit are progressively enlarging, abnormal connections that bypass normal
capillaries between the arterial and venous circulation.They differ fromAV fistulas in that AVMs are congenital, have a central nidus,
and both numerous feeding and draining vessels.The risk of hemorrhage, occlusion, and damage to surrounding structuresmakes
surgical management of orbital AVMs extremely challenging. Hereinwe describe the successful treatment of a rapidly growing, left
orbital AVM in a 46 year oldwoman by surgical excision alone.Amultidisciplinary approach tomanagement was taken in the context
of a literature review on reportedmanagement by excision versus chemoembolization.
Methods:
The patient initially presentedwith several months of progressive pain proptosis, and ophthalmoplegia.Vision at initial
presentationwas 20/20 but shewas experiencing 10/10 pain and significant limitation in abduction, supraduction, and infraduction.
Hertel measurements revealed 5mm proptosis of the left eye. Slit lamp examination revealed engorged episcleral vessels of the
left eye but an otherwise unremarkable exam and visual field testingwas normal.The patient underwent anMRI which revealed an
enhancing, left intraconal oval heterogenous 2.6 x 1.8 x 1.9 cmmasswith significant mass effect on left optic nerve, stretched and
medially displaced,with dilated veins coursing into themass anteriorly and posteriorly, peripheral rim enhancement and enhancing
vessels extending towards and away from themass, and aT1 hyperintense andT2 hypointense consistent with thrombus. CT
angiogram followed by cerebral angiogram revealed that themass to be anAVM proximal to the central retinal artery that was
causing significant engorgement of the angular and inferior ophthalmic veins. Over the course of threemonths, themasswas found
to have increased in size and proptosis had progressed from5mm to 10mm, and visually acuity had declined to 20/40. Discussions
with both neuroradiology, neurointerventional radiology, and neurosurgery services at Stanford led to the conclusion that endovascular
intervention via chemoembolizationwas not possiblewithout significant circulatory compromise to the optic nerve and retina, that
Cyberknife therapywas unlikely to provide substantial benefit, and that surgical excisionwas the only viable treatment option.The
patient then underwent microscope-assisted resection of theAVM via an anterolateral craniotomy approach, followed by superior and
lateral wall reconstructionwith titanium plate andmedpore implant, and intraoperative angiography.
Results:
The patient at post-operativemonth 1, the patients vision had returned to 20/20, her proptosis had reduced from 10mm
to 1.5mm, and her ophthalmoplegia had improved to only a small abduction deficit. Cerebral angiography at that time revealed no
recurrence of theAVM lesion and patent retrobulbar circulation.
A review of 25 cases in the literature revealed the following. Eight out of 25 cases led to improvement of which 4 underwent surgical
excision alone, 1 underwent embolization and surgical excision, 1 underwent embolization alone, 1 underwent ligation of feeder
vessels, and 1 underwent spontaneous thrombosis. Seven out of the 25 cases led toNLP vision; of these cases, two that underwent
embolization endedwith exenteration, one underwent attempted surgical excision alone leading tomassive hemorrhage and
enucleation, one underwent gamma knife radiosurgery, one underwent observationwith steroids and another underwent observation
alone. Of the remaining 10 cases, two refused intervention, two underwent observation alone and another surgical excisionwithout
change, one underwent partial surgical excisionwith recurrence.Therewere four cases inwhich no post-operative result was
mentioned, of which one underwent partial excision, one underwent embolization, one underwent observation alone, and one
underwent ligation of feeder vessels.
In contrast to arteriovenous fistulas (AVFs),AVMs are congenital lesionswithmultiple large feeding arteries, a central nidus, and
numerous dilated draining veins.Management of AVMs of the orbit may be difficult due to the threat of hemorrhage, vascular
occlusion during treatment, and collateral damage to surrounding organs.WemanagedAVM of the orbit and periorbital tissues
in four patients. Neuroimaging studies, clinical decisionmaking, operative experience, and long-term postoperative resultswere
retrospectively reviewed. Four cases of AVM of the orbit and periorbital tissueswere successfully treatedwith preoperative
DetailedProgram
—Thursday,October 16, 2014
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