Preoperative embolization of meningiomas fed by ophthalmic branch arteries

Outcomes of Preoperative Transophthalmic Artery Embolization of Meningiomas: A Systematic Review with a Focus on Embolization Agent

BACKGROUND

Transophthalmic artery embolization of intracranial meningiomas is thought to be associated with a high complication risk.

PURPOSE

With advances in endovascular techniques, we systematically reviewed the current literature to improve our understanding of the safety and efficacy of transophthalmic artery embolization of intracranial meningiomas.

DATA SOURCES

We performed a systematic search using PubMed from inception until August 3, 2022.

STUDY SELECTION

Twelve studies with 28 patients with intracranial meningiomas embolized through the transophthalmic artery were included.

DATA ANALYSIS

Baseline and technical characteristics and clinical and safety outcomes were collected. No statistical analysis was conducted.

DATA SYNTHESIS

The average age of 27 patients was 49.5 (SD, 13) years. Eighteen (69%) meningiomas were located in the anterior cranial fossa, and 8 (31%), in the sphenoid ridge/wing. Polyvinyl alcohol particles were most commonly (n = 8, 31%) used to preoperatively embolize meningiomas, followed by n-BCA in 6 (23%), Onyx in 6 (23%), Gelfoam in 5 (19%), and coils in 1 patient (4%). Complete embolization of the target meningioma feeders was reported in 8 (47%) of 17 patients; partial embolization, in 6 (32%); and suboptimal embolization, in 3 (18%). The endovascular complication rate was 16% (4 of 25), which included visual impairment in 3 (12%) patients.

LIMITATIONS

Selection and publication biases were limitations.

CONCLUSIONS

Transophthalmic artery embolization of intracranial meningiomas is feasible but is associated with a non-negligible complication rate.

Skull Base Neurointerventional Techniques

Neurodiagnostic and neurointerventional radiology (NIR) play a central role in the diagnosis and treatment of skull base disorders. Noninvasive imaging modalities, including computed tomography and magnetic resonance imaging, are important in lesion localization, evaluation of lesion extent, and diagnosis, but cannot always be definitive. Image-guided skull base biopsy and percutaneous and endovascular treatment options are important tools in the diagnosis and treatment of head, neck, and skull base disorders. NIR plays an important role in the treatment of vascular disorders of the skull base. This article summarizes the imaging evaluation and interventional therapies pertinent to the skull base.

Detailed Arterial Anatomy and Its Anastomoses of the Sphenoid Ridge and Olfactory Groove Meningiomas with Special Reference to the Recurrent Branches from the Ophthalmic Artery

BACKGROUND AND PURPOSE

Detailed arterial anatomy of the sphenoid ridge and olfactory groove meningiomas is complicated due to the fine angioarchitecture and anastomoses between each feeder. Herein, we present details of the arterial anatomy and the relationships of feeders in these lesions.

MATERIALS AND METHODS

This study included 20 patients admitted to our department between April 2015 and March 2020. Conditions of subjects consisted of 16 sphenoid ridge meningiomas and 4 olfactory groove meningiomas. We mainly analyzed arterial anatomy using 3D rotational angiography and slab MIP images of these lesions. We also analyzed the anastomoses of each feeder.

RESULTS

We found that 19 (95%), 15 (75%), and 15 (75%) lesions had feeders from the ophthalmic, internal carotid, and external carotid arteries, respectively. As feeders from the ophthalmic artery, recurrent meningeal arteries were involved in 18 lesions (90%). Fifteen lesions (75%) had anastomoses between each feeder.

CONCLUSIONS

Most of the meningiomas in the sphenoid ridge and olfactory groove had feeders from the ophthalmic and internal carotid arteries. There were various anastomoses between each feeder. This is the first report to demonstrate the detailed arterial anatomy and frequency of recurrent branches from the ophthalmic artery and their anastomoses using detailed imaging techniques.

A Case of Anterior Cranial Fossa Dural Arteriovenous Fistula with Transient Ocular Movement Disorder after Embolization

Objective

We report a case of anterior cranial fossa dural arteriovenous fistula (dAVF) in which ocular movement was impaired after Onyx embolization from the ophthalmic artery (OphA).

Case Presentation

A 76-year-old male was admitted to our hospital for treatment of an incidentally found anterior cranial fossa dAVF. Onyx was injected from the right anterior ethmoidal artery (AEA) to close the shunt. Onyx refluxed to the third portion of the OphA to make a plug, but was unable to reach the venous side beyond the shunt; therefore, a small shunt remained. Although his visual acuity and field were normal, vertical diplopia developed after embolization and disappeared 1 month later. Diplopia worsened when the patient tilted his head to the right. Neuro-ophthalmological examination confirmed right superior oblique muscle impairment. The cause of diplopia was considered to be ischemic injury of the superior oblique muscle associated with embolization of the AEA, which provides nutrients to the superior oblique muscle and trochlear nerve.

Conclusion

Embolization from the OphA beyond the third portion may cause external ophthalmoplegia, although it may heal spontaneously.

Vascular involvement in anterior clinoidal meningiomas : Biting the 'artery' that feeds

OBJECTIVES

Anterior clinoidal (AC) meningiomas often encase internal carotid artery (ICA) and it branches. The aim of this study was to determine the efficacy of preoperative angiogram as a predictor of vessel wall adherence and feeders. Furthermore, defining the dangerous areas would provide insights to decrease vascular injury and achieve maximal safe resection.

PATIENTS AND METHODS

21 cases of AC Meningiomas were evaluated for feeders, displacement, encasement/ narrowing of ICA and its branches. Intraoperative vascular involvement was noted. The reason and site of vascular injury, if any was evaluated.

RESULTS

Blush from ICA was seen in 15 patients. The ICA in its entirety beyond the bifurcation was encased in 11 patients. The radiological vascular encasement including narrowing didn't corroborate with intra-operative finding of vessel wall adherence. The tumor could be separated along the length of encased narrowed vessel except from ICA bifurcation in 6, where it had infiltrated adventitial layer. The adherent zone extended into anterior cerebral artery in 2 and middle cerebral artery in 2. There was major vessel injury in 2 patients and perforator injury in 2. GTR was achieved in 18 patients.

CONCLUSION

These tumours are often fed by supraclinoid ICA. It is possible to resect the tumor from vessel wall despite complete encasement/ narrowing on preoperative angiograms. The tumor often lethally embraces the ICA bifurcation making it the most dangerous zone for resection. This is possibly due to an arterial twig that arises close to the bifurcation to irrigate the clinoidal dura and the tumor infiltrates the adventitia at its origin.

[An anatomical study on the applicability of direct endoscopic exclusion of the ethmoid arteries for devascularization of the anterior skull base structures]

The anterior skull base structures are the site of initial growth of histologically different tumors. The difficulties in their removal are often associated with significant vascularization, which may limit the amount of resection due to abundant intraoperative blood loss. Midline tumors are primarily fed by the ethmoid arteries that are not accessible to embolization. The aim of this work was a comparative experimental study of various direct approaches to the ethmoid arteries.

MATERIAL AND METHODS

The study was conducted on anatomical specimens of 12 cadaveric heads of deceased people without pathology of the anterior skull base structures, orbits, nasal cavity, and paranasal sinuses (24 sides). In all specimens, the internal and external carotid arteries were stained with silicone. During anatomical dissection, four surgical approaches for exclusion of the ethmoid arteries were studied: 1) transorbital approach to the arteries using a bicoronal incision; 2) endoscopic retro-caruncular approach; 3) endoscopic endonasal transethmoidal approach to the ethmoid artery canals; 4) endoscopic endonasal transethmoidal transorbital approach to the ethmoid arteries in the orbit.

RESULTS

We described a surgical technique for exclusion of the ethmoid arteries using the approaches and analyzed their advantages and disadvantages. We formulated an algorithm for choosing the method for direct endoscopic exclusion of the ethmoid arteries, depending on the surgical approach chosen for removal of the tumor and features of the tumor extracranial spread.

CONCLUSION

The decision on tumor devascularization is based on assessment of tumor blood supply (CT angiography or MR angiography data). Our study demonstrated the advantages and disadvantages of various approaches to the ethmoid arteries for their exclusion in order to early devascularize anterior skull base tumors. All these approaches are less traumatic and characterized by a good cosmetic and functional outcome.

Acute Vision Loss After Ophthalmic Artery Embolization of Meningioma

A 40-year-old man presented with acute-onset painless visual loss after preoperative embolization for a large skull base meningioma through the ophthalmic artery. We describe the clinical presentation of an isolated ipsilateral afferent and efferent pupillary defect in this patient who had radiographic documentation of embolization material in the intraorbital ophthalmic artery. Although ophthalmic and retinal artery occlusions have been described previously after endovascular embolization, our patient had a unique clinicoradiologic presentation.

Dural Artery from Supraclinoid Internal Carotid Artery to Anterior Clinoid Process: Origin, Course, and Clinical Implications

BACKGROUND

Dura of the anterior clinoid process (ACP) is presumably supplied by the ophthalmic and external carotid artery branches. There is a less recognized artery described by Yasargil that arises directly from the supraclinoid internal carotid artery (ICA) and supplies the ACP dura. We studied the origin and course of this direct branch in patients in whom the carotid cistern was dissected for lesions not involving the carotid cistern and ACP dura. The management implications of this arterial twig have been described.

METHODS

Thirty patients operated through the transsylvian route for suprasellar lesions were included. The arterial branch from the supraclinoid ICA to the clinoidal dura was dissected and studied under high magnification.

RESULTS

A thin solitary artery could be delineated in 21 patients. In 14 patients, it originated from the dorsomedial surface of the ICA at its bifurcation close to the A1 origin. In the remaining 7, it was seen arising from the dorsomedial surface of the ICA, 2-4 mm proximal to bifurcation. The artery coursed from medial to lateral and pierced the clinoidal dura, 1-3 mm lateral to the entry of the carotid artery. The artery had no branches.

CONCLUSIONS

The knowledge of this arterial twig to the clinoidal dura is important as this supply may be responsible for feeding the tumor arising from the dura arising from the anterior clinoid, making preoperative embolization impossible. In addition, the tumor may grow along with this vessel and infiltrate the adventitia of the ICA at the origin of this vessel.

Embolisation of Branches of the Ophthalmic Artery

Nine patients presenting various orbital and skull base pathologies embolised through the ophthalmic artery are reported.

All cases were catheterised beyond the bend around the optic nerve (second portion of the intraorbital ophthalmic artery). Embolisation was carried in all with n-butyl cyano-acrylate without post interventional visual disturbance.

Relying on the classic description as well as previous personal work on the ophthalmic artery anatomy and angiographic anatomy, all procedures were performed under general anaesthesia without functional testing. The central retinal artery and the long ciliary arteries arise from the first or second portion of the ophthalmic artery. For embryological reasons no branch to the visual tract can arise from the ophthalmic trunk distal to the origin of the superficial recurrent meningeal artery or the lacrimal artery.

Therefore distal catheterisation at least beyond the second portion, (and injection without reflux) makes safe embolisation possible in all variations of internal carotid origin of the ophthalmic stem.

Independent from the expected goal of the embolisation, the use of particles in this territory should in our opinion be discouraged.

Contemporary endovascular embolotherapy for meningioma

Preoperative endovascular tumor embolization has been used for 40 years. Meningiomas are the most common benign intracranial tumor in which preoperative embolization has been most extensively described in the literature. Advocates of embolization report that it reduces operative blood-loss, and softens the tumor, thus making surgery safer and easier. Opponents suggest that it adds additional risk and cost for patients without controlled studies showing conclusive benefit. The literature suggests a 3 to 6% neurological complication rate related to embolization. The combined external and internal carotid artery blood supply and complex anastomoses of the meninges can make embolization challenging. Positive outcomes require thorough knowledge of the pertinent vascular anatomy, familiarity with the neurovascular equipment and embolics, and meticulous technique. There remains debate on several aspects of embolization, including tumors most appropriate for embolization, embolic agent of choice, ideal size of embolic, and the choice of vessel(s) to embolize. This detailed review of pertinent vascular anatomy, embolization technique, results, and complications should allow practitioners to maximize treatment outcomes in this setting.

Extracranial ligation of ethmoidal arteries before resection of giant olfactory groove or planum sphenoidale meningiomas: 3 illustrative cases with a review of the literature on surgical techniques

Object

There are several surgical techniques for reducing blood loss—open surgical and endoscopic—prior to resection of giant anterior skull base meningiomas, especially when preoperative embolization is risky or not technically feasible. The authors present examples of an institutional experience using surgical ligation of the anterior and posterior ethmoidal arteries producing persistent tumor blush in partially embolized tumors.

Methods

The authors identified 12 patients who underwent extracranial surgical ligation of ethmoidal arteries through either a transcaruncular or a Lynch approach. Of these, 3 patients had giant olfactory groove or planum sphenoidale meningiomas. After approval from the institution privacy officer, the authors studied the medical records and imaging data of these 3 patients, with special attention to surgical technique and outcome. The variations of ethmoidal artery foramina pertaining to this surgical approach were studied using preserved human skulls from the Hamann-Todd Osteological Collection at the Museum of Natural History, Cleveland, Ohio.

Results

The extracranial ligation was performed successfully for control of the ethmoidal arteries prior to resection of hypervascular giant anterior skull base meningiomas. The surgical anatomy and landmarks for ethmoidal arteries were reviewed in anthropology specimens and available literature with reference to described surgical techniques.

Conclusions

Extracranial surgical ligation of anterior, and often posterior, ethmoidal arteries prior to resection of large olfactory groove or planum sphenoidale meningiomas provides a safe and feasible option for control of these vessels prior to either open or endoscopic resection of nonembolized or partially embolized tumors.

The role of preoperative embolization for intracranial meningiomas

Object

As endovascular techniques have become more advanced, preoperative embolization has become an increasingly used intervention in the management of meningiomas. To date, however, no consensus has been reached on the use of this technique. To clarify the role of preoperative embolization in the management of meningiomas, the authors conducted a systematic review of case reports, case series, and prospective studies to increase the current understanding of the management options for these common lesions and complications associated with preoperative embolization.

Methods

A PubMed search was performed to include all relevant studies in which the management of intracranial meningiomas with preoperative embolization was reported. Immediate complications of embolization were reported as major (sustained) or minor (transient) deficits, death, or no neurological deficits.

Results

A total of 36 studies comprising 459 patients were included in the review. Among patients receiving preoperative embolization for meningiomas, 4.6% (n = 21) sustained complications as a direct result of embolization. Of the 21 patients with embolization-induced complications, the incidence of major complications was 4.8% (n = 1) and the mortality rate was 9.5% (n = 2).

Conclusions

Preoperative embolization is associated with an added risk for morbidity and mortality. Preoperative embolization may be associated with significant complications, but careful selection of ideal cases for embolization may help reduce any added morbidity with this procedure. Although not analyzed in the authors' study, embolization may still reduce rates of surgical morbidity and mortality and therefore may still have a potential benefit for selected patients. Future prospective studies involving the use of preoperative embolization in certain cases of meningiomas may further elucidate its potential benefit and risks.

Acute visual loss after preoperative embolization of an ethmoidal metastasis

An unintentional embolization of retinal arteries is rare and has been documented as a complication after embolization of arteries supplying head and neck tumors. However, occlusion of the central retinal artery with severe loss of vision has never been reported to be a complication from embolization of tumor-supplying ethmoidal branches of the ophthalmic artery. A 40 year-old male patient with a history of right nephrectomy for renal cell carcinoma underwent preoperative radiological embolization of an ethmoidal metastasis after having experienced a life-threatening sinus bleeding. Repeated probing of the ophthalmic artery with an endovascular microcatheter for particle embolization of the tumor-supplying arteries was performed under anticoagulation with heparin. Postoperatively, a standard ophthalmological examination including extended vascular evaluation by angiography was performed. After extended probing of the ophthalmic artery a marked reduction in its blood flow occurred. Despite post-interventional imaging showing persisting perfusion of the central retinal and ciliary arteries, the patient developed complete loss of vision on this side four days later. At this time fundoscopy and fluorescein angiography revealed a recanalized central artery occlusion, while indocyanin angiography showed infarctions of the choroid. Radiological intervention via the ophthalmic artery can result in complete loss of vision, even after limited and transient obstruction of the vessel.

Preoperative onyx embolization of meningiomas fed by the ophthalmic artery: a case series

Embolization of head and neck hypervascular tumors is a well-established therapeutic technique. Preoperative embolization reduces intraoperative blood loss, shortens the length of surgery, and decreases surgical morbility and mortality. This study assesses the safety and efficacy of preoperative embolization of meningiomas fed by the OPH by using Onyx liquid embolic agent.

Intraorbital Arteriovenous Malformation Treated by Transarterial Embolization: Technical Case Report

Background And Importance:

Intraorbital arteriovenous malformations (AVMs) are rare, and their clinical management is controversial. A case of orbital AVM successfully treated by transarterial embolization with diluted glue is reported.

Clinical Presentation:

A 53-year-old man developed a left pulsating exophthalmos, chemosis, and ocular pain, revealing the presence of a left intraorbital AVM. A microcatheter was selectively placed into the feeders arising from the left ophthalmic artery. Diluted glue was injected toward the nidus through the microcatheter, with monitoring by digital subtraction angiogram. These procedures were performed for 2 individual proper feeders. Superselective angiography for the central retinal artery was also performed instead of a retinal Wada test. His orbital symptoms improved immediately after the procedure without further visual disturbance. Follow-up digital subtraction angiogram revealed the disappearance of the AVM.

Conclusion:

Transarterial embolization can be considered one of the radical treatments for orbital AVMs.

Embolization of Skull Base Meningiomas and Feeding Vessels Arising From the Internal Carotid Circulation

BACKGROUND:

Practice patterns regarding the preoperative embolization of skull base tumors vary widely among institutions and are driven by surgeon preference and concerns about safety.

OBJECTIVE:

We present a recent experience at our institution with a specific focus on procedural decision-making, embolization of vessels arising from the internal carotid circulation, and complication rates.

METHODS:

During a 7.5-year period, 262 meningiomas were referred for embolization. of which 119 (45%) originated from the skull base. Tumors were categorized by location, feeding artery origin, and arteries embolized. Complication rates were reviewed.

RESULTS:

Sixty-four of 119 patients with skull base tumors (54%) underwent embolization of at least 1 feeding artery. Feeding arteries arose from the external carotid artery (ECA) circulation in 26 (22%), the internal carotid artery (ICA) circulation in 30 (25%), a combination of ECA/ICA/Vert in 54 (45%), and had only pial supply in 10 (8%). In total, 15 of 85 (18%) ICA feeding vessels were embolized. This included 9 of 28 vessels from the meningohypopheseal trunk, 3 of 4 vessels from the anterior temporal artery, 1 of 35 vessels from the ophthalmic artery, 1 of 8 vessels directly from the ICA, and 1 of 5 vessels from the inferolateral trunk. Complete devascularization occurred in 6 of 64 patients; subtotal devascularization was seen in 58 of 64. The overall angiographic complication rate for all meningiomas embolized in the study period was 2.5% (5/199). None of the complications occurred in the skull base group.

CONCLUSION:

Preoperative embolization of skull base meningiomas and ICA feeding vessels can be done with low complication rates when intraprocedural decision-making favors complication avoidance over complete devascularization.

Pre-operative embolisation of internal carotid artery branches and pial vessels in hypervascular brain tumours

BACKGROUND

Pre-operative embolisation is an effective method used to reduce intra-operative bleeding and operative difficulty in hypervascular brain tumour surgery. However, embolisation of the internal carotid artery (ICA) and pial tumour feeding branches has certain limitations.

METHODS

From March 2000 to November 2006, 8 patients underwent superselective embolisation for hypervascular brain tumour. Seven tumours were extra-axial (6 meningiomas, 1 solitary fibrous tumour) and 1 was intra-axial (metastatic hepatocellular carcinoma).

RESULTS

In all patients, feeding vessels from ICA branches or pial arteries were successfully embolised using superselective microcatheterisation. A provocative test was applied in 4 patients who had tumours adjacent to the motor cortex. Angiographic devascularisation was slight to extensive. Mean devascularisation on post-embolisation MRI ranged from 40 to 80% (mean 63.8%). One patient (12.5%) suffered an embolisation-related complication (loss of choroidal brush), but was not clinically worse because of the pre-existing blindness.

CONCLUSIONS

Superselective embolisation of ICA branches or pial vessels should be performed if several conditions are met, especially angiographic findings, pre-existing neurologic deficits, provocative test, and technical feasibility. If the ICA embolisation for hypervascular tumour is successfully achieved, the bleeding loss and operative risk can be reduced.

A microsurgical study of the anatomy and course of the ophthalmic artery and its possibly dangerous anastomoses

OBJECT

The authors studied the microsurgical anatomy of the ophthalmic artery (OphA), paying particular attention to its possibly dangerous anastomoses with the middle meningeal artery (MMA).

METHODS

The microsurgical anatomy of the OphA and its anastomoses with the MMA were studied in 14 vessels from seven adult cadaveric heads. The origination order of the OphA branches varies in relation to whether the artery, along its intraorbital course, crosses above or below the optic nerve (ON). The central retinal artery is the first branch to course from the OphA when it crosses over the ON, and it is the second branch to course from the OphA when the artery crosses under the ON. Anastomoses between branches of the MMA and the OphA were present in the majority of the specimens examined.

CONCLUSIONS

Detailed knowledge of the microanatomy of the OphA and recognition of anastomoses between the external carotid artery and the OphA are critically important in avoiding disastrous complications during endovascular procedures.

Artères ophtalmiques issues des carotides externes

The ophthalmic artery arises from the internal carotid at the level of the carotid siphon; in 3.5-5% of the population, it arises from the middle meningeal artery, a branch of the internal maxillary artery, terminal of the external carotid artery. We report a rare case of bilateral malformation in a 28-year-old patient. Our study covers the possible dual origin of orbital blood vascularization. This variation in the anatomic distribution is important to know, particularly if embolization is intended as inadvertent occlusion of the ophthalmic artery, because it may lead to permanent loss of vision.

Anterior ethmoidal artery: microsurgical anatomy and technical considerations

OBJECTIVE

Vascular lesions of the anterior cranial fossa can receive significant blood supply from the anterior ethmoidal artery. Embolization of this blood supply exposes the parent vessel, the ophthalmic artery, to possible embolic complications, which can lead to loss of vision. A study of the microsurgical anatomy can help delineate the course of the anterior ethmoidal artery and find the best points for proximal control of the blood supply to these lesions. Clinical cases are presented to illustrate how lesions with prominent anterior ethmoidal artery feeders are best approached through fronto-orbital single-flap craniotomies.

METHODS

Eight cadaveric dissections to demonstrate the microsurgical anatomy of the anterior ethmoidal artery were performed to study the relevant anatomy. Two clinical cases are presented that demonstrate clinical application of this anatomy through fronto-orbital single-flap craniotomies.

RESULTS

Eight arteries were studied in four cadaveric heads. The dissections show the course of the anterior ethmoidal artery from the ophthalmic artery in the orbit, through the anterior ethmoidal foramen into the ethmoid air cells, to the cribriform plate, where it turns superiorly to become the anterior falx artery. The first surgical case is of a giant tuberculum sellae meningioma that was resected with coagulation and division of the anterior ethmoidal arteries at the anterior ethmoidal foramina at the laminae papyraceae of both medial orbital walls. The second surgical case is of a large deep right frontal arteriovenous malformation that was resected with coagulation and division of the anterior ethmoidal artery at the anterior ethmoidal foramen of the lamina papyracea of the right medial orbital wall.

CONCLUSION

The cadaveric dissections and our surgical experience show that the anterior ethmoidal artery has three important sites for surgical access: 1) the anterior ethmoidal foramen at the lamina papyracea of the medial orbital wall; 2) the anterior ethmoid canal at the lateral ethmoid wall; and 3) extradurally, at the cribriform plate. These three sites are best accessed through a fronto-orbital single-flap craniotomy, which can be unilateral or bilateral, depending on the pathological findings. The described orbital-cranial approach in this article is not being advocated to replace the standard pterional and frontal approaches; rather, we suggest it as an option in these complex cases that require early proximal control of the anterior ethmoidal artery feeders.

Clinicopathologic assessment and grading of embolized meningiomas: a correlative study of 64 patients

BACKGROUND

Preoperative embolization of meningiomas is commonly performed to minimize intraoperative bleeding, thereby facilitating surgery and reducing the necessity for transfusion. However, the resulting necrosis and compensatory proliferation reportedly have hampered subsequent histologic grading.

METHODS

The clinicopathologic features of 64 meningiomas embolized between 1989 and 1997 were assessed. Tumors were graded according to recently published criteria.

RESULTS

A good embolization result (> 75% reduction in angiographic blush) was achieved in 52%. Histologically, embolized meningiomas showed higher frequencies of necrosis (89%), nuclear atypia (72%), macronucleoli (58%), sheeting (31%), high mitotic index (30%), and brain invasion (14%) when compared with nonembolized counterparts. Median mitotic and MIB-1 indices were slightly elevated (1.5 of 10 high-power fields and 1.6%, respectively). A significant degree of necrosis (> 10%) was found in 43% and was only roughly correlated with extent of angiographic blush reduction or embolization particle size. Histologic grade was benign in 57.8%, atypical in 40.6%, and anaplastic in 1.6%. At last follow-up, there were 13 recurrences, 11 in the atypical/anaplastic (41%) versus 2 in the benign (5%) subsets (P = 0.001).

CONCLUSIONS

The authors conclude that 1) their grading scheme accurately stratifies embolized meningiomas, 2) extent of necrosis is difficult to predict using standard clinical parameters, and 3) their high incidence of atypical meningioma more likely reflects patient selection biases rather than artifacts induced by the embolization procedure.

Anterior ischemic optic neuropathy after combined ophthalmic artery embolization and craniofacial surgery--case report

A 57-year-old man developed visual loss following craniofacial surgery for an inflammatory ethmoidal sinus mass. Surgery was preceded by endovascular occlusion of the ophthalmic artery distal to central retinal artery (CRA). Routine angiography obtained immediately after endovascular ophthalmic artery occlusion showed patency of the CRA. He complained of visual loss one day after craniofacial surgery (2 days after embolization). Repeat emergency angiography confirmed the patent CRA. Ophthalmic examination and fluorescein angiography showed that the visual loss was due to anterior ischemic optic neuropathy (AION). Preservation of the CRA is critical during ophthalmic artery embolization to avoid visual complications. Neurosurgeons should be aware of the possibility of AION as a complication of ophthalmic artery embolization.