An update on the variations of the orbital blood supply and hemodynamic

The meningo-orbital band from an endoscopic transorbital approach: an anatomical study

Introduction

The meningo-orbital band (MOB) is an intricate dural structure extending between the periorbita, the frontal dura, and the temporal dura. The endoscopic transorbital approach (ETOA) provides a more thorough understanding of its anatomy.

Materials and methods

Anatomical dissections were performed on 15 human head specimens (30 orbits) at the Laboratory of Surgical Neuroanatomy (LSNA) at the University of Barcelona. The specimens were preserved using a Cambridge solution for optimal fixation. An endoscopic transorbital approach (ETOA) was used to isolate the meningo-orbital band (MOB). A rigid 4-mm endoscope with an HD camera and light source was used for the procedure. Multislice helical CT scans were performed both before and after the dissections to document the anatomical features. Additionally, a specialized software (The ImagingSource®) was used to calculate the variability in the angle between the first two bone pillars of the ETOA: the sagittal crest (SC) and the lesser sphenoid wing (LSW). The vascularization of the MOB was studied by longitudinally cutting the band and using red and blue latex injections into the carotid arteries and jugular veins, respectively, to highlight the cerebral vasculature.

Results

In the endoscopic transorbital approach (ETOA), key structures, including the greater and lesser sphenoid wings, are excised, exposing the meningo-orbital band (MOB). The MOB extends from the periorbita medially to the frontal and temporal dura laterally and is firmly attached to the anterior clinoid process (ACP). Anatomical dissection reveals the MOB's complex three-dimensional structure and its relationships with cranial nerves III, IV, and V1 along the lateral wall of the cavernous sinus and the superior orbital fissure (SOF). The ACP serves as a protective barrier between the MOB and the paraclinoid segment of the internal carotid artery (ICA). Additionally, the MOB is vascularized by the MOB artery (MOBA), a branch of the middle meningeal artery, which bifurcates into the frontal and temporal branches.

Conclusion

This study highlights the key anatomical relationships of the meningo-orbital band (MOB) with critical structures, including cranial nerves III, IV, and V1, as well as the ICA. These findings are essential for refining surgical planning and improving the safety and precision of skull base surgery.

Permanent Vision Loss Due to Vascular Variation After Ear Hyaluronic Acid Injection: Two Case Reports and Literature Reviews

BACKGROUND

In line with modern aesthetic principles, a prominent and voluminous auricle is considered to enhance facial structure by making it appear smaller and more refined. Recently, there has been a growing trend toward using injectable treatments as an alternative to traditional surgical procedures for correcting lying ears. This shift has led to an increase in reported complications associated with these interventions.

OBJECTS

This report aims to investigate the mechanisms leading to vision loss following hyaluronic acid (HA) injections in the ear and to propose preventive measures and countermeasures.

METHOD

We present two rare cases of blindness following HA injections into the ears. The first patient experienced vision loss in both eyes, while the second suffered unilateral blindness in the left eye. In both cases, local hyaluronidase injections were promptly administered. Ophthalmological evaluations revealed central retinal artery occlusion, followed by arterial thrombolysis treatments performed 3 and 6 h post-diagnosis, respectively. Postoperative management included daily interventions to reduce intraocular pressure, promote vasodilation, enhance nerve nourishment, and provide hyperbaric oxygen therapy.

RESULTS

Digital subtraction angiography revealed structural variations in the ophthalmic arteries of both patients, which we hypothesize to be the primary cause of their blindness. In Case 1, the bilateral ophthalmic arteries and, in Case 2, the left ophthalmic artery were found to primarily originate from the external carotid artery. After treatment, Patient 1 exhibited a detectable index in the right eye, whereas the left eye was limited to light perception. Patient 2 showed recovery, with only defects in the inferior quadrant of the left eye.

CONCLUSION

The administration of filler injections in the auricular region is considered a high-risk aesthetic procedure due to the dense network of blood vessels and nerves, and significant anatomical variations. The use of large volumes of HA in this confined space can compress vascular structures and nerves, potentially leading to visual impairment. Therefore, ear filler injections are not recommended as a routinely substitute for the surgical correction of lying ears.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors   www.springer.com/00266 .

Double ophthalmic arteries originating from the internal carotid artery and persistent primitive trigeminal artery

PURPOSE

Ophthalmic artery (OphA) embryogenesis is a complex process with various origins. We describe herein a case in which the OphA stemmed from the persistent primitive trigeminal artery (PPTA), which has never been reported.

METHODS

A man in his 70s was admitted to our hospital following the sudden onset of altered consciousness. A computed tomography (CT) scan revealed a cerebellar hemorrhage, brainstem compression, and hydrocephalus. The patient underwent emergency craniotomy for hematoma evacuation and decompression. Digital subtraction angiography (DSA) was performed 14 days postoperatively to determine the source of the bleeding.

RESULTS

DSA of the right vertebral artery revealed retrograde filling of the left PPTA, originating from the distal two-thirds of the basilar artery (BA) and extending to the cavernous segment of the left internal carotid artery (ICA) as well as a small artery extending from the intermediate part of the PPTA into the orbit and passing through the superior orbital fissure (SOF). DSA of the left common carotid artery showed the typical supracavernous origin of the OphA.

CONCLUSION

This is the first reported case of double OphAs originating from the ICA and PPTA. It is possible that the OphA traversing the SOF had an anastomosis with the primitive trigeminal artery (PTA) during the embryonic period. Persistence of only the BA side of the PTA results in the OphA originating from the BA, whereas persistence of only the ICA side results in the OphA originating from the meningohypophyseal trunk.

Modified craniotomy procedures and virtual reality technology for accurate localization of the frontal branch of MMA in revascularization surgery

The frontal branch of middle meningeal artery (MMA) can easily be damaged during revascularization surgery. To precise locate it and minimize its injury, we propose a set of modified craniotomy procedures combined with simple virtual reality (VR) technology based on three-dimensional (3D) Slicer simply, economically, and efficiently. Patients with Moyamoya disease (MMD) and internal carotid artery occlusion (ICAO) who received revascularization from January 2015 to December 2022 were divided into two groups based on the methods used to locate the MMA: traditional methods and precise MMA locating with VR technology. Patient demographics and clinical characteristics were analyzed to compare the preservation rates of MMA. The distances between this artery and bony anatomical landmarks were also measured to better understand its localization. There was no significant difference in baseline characteristics between the two groups. The precise MMA locating group exhibited a significantly higher preservation rate of the frontal branch of MMA (p = 0.037, 91.7% vs. 68.2%). Over 77% of patients had their frontal branch of MMA partially or completely surrounded by bony structures to varying degrees. Therefore, the combination of modified craniotomy procedures, 3D Slicer, and simple VR technology represents an economical, efficient, and operationally simple strategy.

Early single-center experience with middle meningeal artery embolization using Zoom™ 45 Catheter

BACKGROUND

Middle meningeal artery (MMA) embolization for subdural hematomas (SDH) and dural arteriovenous fistulas (dAVFs) has gained momentum in the neuroendovascular space. However, there is variability in the technique for safe and effective embolization. The aim of this report is to describe the technical feasibility and clinical performance of using Zoom™ 45 catheter for MMA access to facilitate embolization.

METHODS

We analyzed all cases of MMA embolization in which the Zoom™ 45 catheter was used and performed in our institution from February 2021 to March 2023 for SDH and dAVFs.

RESULTS

A total of 32 patients were included. Mean age was 64.0 ± 18.0 years, 75.0% (4/32) were male, and 56.7% (17/30), were black. The technical success was achieved in 93.8% (30/32) of cases, with selective embolization utilizing microcatheter directly into frontal and parietal branches for most patients (96.9%, 31/32). Identification of dangerous collaterals, such as lacrimal and petrous branches, prior to embolization, was achieved in most patients (96.9%, 31/32). Bilateral MMA embolization was done in 50.0% (16/32) of patients. The transradial approach and transfemoral approach were used in 53.1% (17/32) and 46.9% (15/32) of patients, respectively. The most common embolization material was n-butyl cyanoacrylate (84.4%, 27/32). There were no access site complications or complications related to the MMA embolization procedures and used devices.

CONCLUSIONS

The use of Zoom™ 45 Catheter seems to be technically feasible, safe, and effective for facilitating MMA access for embolization in the context of SDH and dAVFs.

Orbital infarction syndrome following mechanical thrombectomy in internal carotid artery occlusion: a case report

BACKGROUND

Orbital ischemic syndrome is a rare entity. The clinical signs typically demonstrate acute loss of visual acuity, chemosis, proptosis, ptosis, and total ophthalmoparesis. We report a case of a man who suffered an acute internal carotid artery occlusion and developed orbital ischemic syndrome after a mechanical thrombectomy.

CASE PRESENTATION

A 57-year-old Vietnamese (Kinh ethnicity) man was brought to the emergency room with complaints of a speech disturbance, facial palsy, and severe weakness of the left arm and leg, which had started 4 hours earlier, after waking up. The National Institutes of Health Stroke Scale 12 (NIHSS 12) revealed the neurological score at admission. A head computed tomography scan showed no intracranial bleeding and an Alberta Stroke Program Early Computed Tomography Score (ASPECTS) of 8 on the right brain. Computed tomography angiography showed an occlusion of the right internal carotid artery. After that, a mechanical thrombectomy was performed, and the internal carotid artery was completely reperfused. After 10 hours, he experienced orbital pain, proptosis, ptosis, chemosis, and ophthalmoplegia of the right orbit. He also had acute loss of visual acuity, and fundoscopic examination revealed papilledema, no retinal hemorrhage, and no bruit in orbital auscultation. Intraocular pressure in the right eye was measured at 50.5 mmHg. Computed tomography angiography showed no carotid-cavernous fistula, but slight enlargement of the right medial and lateral rectus muscles. He was treated with steroids and hyperosmolar agents and recovered 7 days later, but had persistent loss of visual acuity in the right eye.

CONCLUSION

Orbital ischemic syndrome is a rare complication after mechanical thrombectomy treatment in acute ischemic stroke that can lead to loss of visual acuity.

Clinical anatomy of the spina musculi recti lateralis: A frequently overlooked variation of the greater wing of the sphenoid

BACKGROUND

The spina musculi recti lateralis (SMRL) is often visible along the lateral rim of the superior orbital fissure (SOF). Aim of this study is to characterize SMRL morphology and topography relative to known bony landmarks.

METHODS

Orbits from 291 adult dry skulls and from 60 CT scans were analyzed to measure the distance between the SMRL and the SOF or the inferior orbital fissures (IOF) as well as its height, width and orientation. Processes other than SMRLs were also recorded. Fetal skulls were observed for comparison with adult samples.

RESULTS

Forty-one per cent of orbits on dry skulls and 43.3% by CT showed an SMRL. Additional 32.9% of orbits on dry skulls had processes with a different shape. On average, SMRL were orientated almost along the transverse plane and showed implant bases as wide as 141.9° or as narrow as 36.8°. SMRLs were close to the infero-posterior angle of the orbital plate of the sphenoid, 1.21 ± 0.84 mm in front of the SOF, 5.8 ± 1.9 mm above the IOF and 12 ± 2.3 mm from the anterior end of the SOF. They were 1.58 ± 0.64 mm high and did not show any age or sex-related prevalence. By CT, the SMRL appeared as the insertion site for the lateral rectus, tendinous ring and, sometimes, inferior rectus.

CONCLUSIONS

The SMRL is a process of the sphenoidal orbital plate rather than of the SOF. It is also a reliable landmark for the insertion of the tendinous ring and lateral rectus. Orbital surgeons should be aware of this common variant of the orbital apex.

Persistent trigeminal artery variant and presumed ophthalmic artery simultaneously arising from the inferolateral trunk incidentally diagnosed by magnetic resonance angiography

PURPOSE

To describe a case of persistent trigeminal artery variant (PTAV) and presumed ophthalmic artery (OA) simultaneously arising from the inferolateral trunk (ILT).

METHODS

A 53-year-old woman with an initial episode of convulsion underwent cranial magnetic resonance imaging (MRI) and MR angiography (MRA) of the intracranial region for the evaluation of brain and vascular lesions. The MR machine was a 3-T scanner.

RESULTS

MRI revealed no pathological brain lesions. On MRA, the left anterior inferior cerebellar artery (AICA) arose from the cavernous segment of the internal carotid artery (ICA), indicative of the PTAV. The arising point was more distal than the usual point, and the presumed OA also arose simultaneously from the short common trunk, which was considered the ILT.

CONCLUSION

There are two types of PTA: lateral (usual) and medial (intrasellar) PTA. The lateral-type PTA and PTAV arise from the ICA of the distal precavernous-proximal cavernous segment and take a course similar to that of the posterior fossa. The medial type arises slightly more in the distal cavernous segment than in the lateral type. The OA rarely arises from the cavernous segment of the ICA and enters the orbit via the superior orbital fissure. The origin of this type of OA is considered to be the ILT. We herein report a case of a PTAV and presumed OA arising simultaneously from an ILT. No similar case has been reported in the relevant English language literature.

External carotid artery to ophthalmic artery flow associated with internal carotid artery stenosis

PURPOSE

One of the most devastating complications of facial filler injection is sudden ischemic blindness. However, its mechanisms and predisposing factors are poorly understood. The purpose of this study was to investigate the prevalence of external carotid artery (ECA) to ophthalmic artery (OA) anterograde flow in patients with internal carotid artery (ICA) stenosis and in a control population without carotid disease.

METHODS

In this cross-sectional cohort study, two groups of patients who underwent catheter cerebral angiography over a 5-year period were identified: patients with symptomatic ICA stenosis and a control group of patients with refractory epistaxis undergoing embolization. Angiograms were reviewed by an interventional neuroradiologist. The primary outcome measure was the presence of ECA to OA flow, defined as choroidal blush before filling of the circle of Willis. Secondary outcome measures included the percentage and location of ICA stenosis and ECA anastomotic branches involved.

RESULTS

The study included 149 patients with ICA stenosis and 69 control patients. ECA to OA flow was more prevalent in patients with ICA stenosis (34.9%) compared to controls (2.9%) (p < .001). Logistic regression demonstrated that for each 10% increase in ICA stenosis over 70%, there was 2.8 times increased risk of ECA to OA flow (p < .001).

CONCLUSIONS

ECA to ICA anterograde flow can be demonstrated in approximately 3% of control patients and in over 1/3 of patients with symptomatic carotid stenosis. This provides a plausible pathway for small filler particles to pass with blood flow from the facial to the ophthalmic circulation.

Angiographic analysis of ophthalmic artery flow direction in children undergoing chemosurgery for retinoblastoma compared to age-matched controls

PURPOSE

Catheter-based intra-arterial chemotherapy (IAC) has revolutionized the treatment of retinoblastoma (RB). Variability in ophthalmic artery (OA) flow, either retrograde from external carotid artery branches, or anterograde from the internal carotid artery, necessitates multiple IAC techniques. We evaluated the direction of OA flow and identify OA flow reversal events over the course of IAC treatment as well in comparison to OA flow direction in non-RB children.

MATERIALS AND METHODS

We performed a retrospective analysis of OA flow direction in all RB patients treated with IAC, along with an age-matched control group who underwent cerebral angiography at our center from 2014 to 2020.

RESULTS

IAC was administered to a total of 18 eyes (15 patients). Initial anterograde OA flow was demonstrated in 66% (n  =  12) of eyes. Five OA reversal events were identified (3/5 anterograde-to-retrograde). All five events were in patients receiving multiagent chemotherapy. No correlation was found between OA flow reversal events and the initial IAC technique. A control group of 88 angiograms representing 82 eyes (41 patients) was utilized. The anterograde flow was observed in 76 eyes (86.4%). Our control group included 19 patients with sequential angiograms. One OA flow reversal event was identified.

CONCLUSION

OA flow direction is dynamic in IAC patients. Anterograde and retrograde OA directional switches do occur and may necessitate delivery technique variation. In our analysis, all OA flow reversal events were associated with multiagent chemotherapy regimens. Both anterograde and retrograde OA flow patterns were observed in our control cohort, suggesting bidirectional flow can occur in non-RB children.

Bilateral visual loss after selective artery embolization in the neck for hemorrhage of malignant tumor

INTRODUCTION AND IMPORTANCE

Currently, selective arterial embolization (SAE) has been widely applied for the treatment of many diseases due to its minimal invasiveness. But the complications caused by SAE can be serious.

CASE PRESENTATION

Here, we report a case of a patient who experienced bilateral blindness 4 h after selective arterial embolization (SAE). A 67-year-old man, with a 13-year history of nasopharyngeal carcinoma, was admitted to our hospital for nasopharyngeal carcinoma hemorrhage and was scheduled for SAE. The patient did not have any thromboembolic complications. His had a platelet count of 43 × 109/L (range 150-400 × 109/L) and a prothrombin time (PT) of 9.3 s. The surgery was completed under local anesthesia. However, 4 h after the surgery, the patient complained of visual loss. We performed a fundoscopy examination, which showed bilateral ophthalmic artery embolism.

CLINICAL DISCUSSION

Bilateral ophthalmic artery embolism is fatal to vision. When this occurs, it would be difficult to save the eyes. So, the relevant selection of the optimal properties of the used PVA and coil embolization materials is important during SAE.

CONCLUSION

It is important to improve the existing understanding of the involvement various vessels during embolization of head and neck tumors. Furthermore, special and paramount attention is to be paid to the specific pre-operative angio-architecture, particular patient condition, and the prudent choice of embolic material to prevent the occurrence of ectopic embolization.

Bridging a Century-Old Problem: The Pathophysiology and Molecular Mechanisms of HA Filler-Induced Vascular Occlusion (FIVO)-Implications for Therapeutic Interventions

Biocompatible hyaluronic acid (HA, hyaluronan) gel implants have altered the therapeutic landscape of surgery and medicine, fostering an array of innovative products that include viscosurgical aids, synovial supplements, and drug-eluting nanomaterials. However, it is perhaps the explosive growth in the cosmetic applications of injectable dermal fillers that has captured the brightest spotlight, emerging as the dominant modality in plastic surgery and aesthetic medicine. The popularity surge with which injectable HA fillers have risen to in vogue status has also brought a concomitant increase in the incidence of once-rare iatrogenic vaso-occlusive injuries ranging from disfiguring facial skin necrosis to disabling neuro-ophthalmological sequelae. As our understanding of the pathophysiology of these injuries has evolved, supplemented by more than a century of astute observations, the formulation of novel therapeutic and preventative strategies has permitted the amelioration of this burdensome complication. In this special issue article, we review the relevant mechanisms underlying HA filler-induced vascular occlusion (FIVO), with particular emphasis on the rheo-mechanical aspects of vascular blockade; the thromboembolic potential of HA mixtures; and the tissue-specific ischemic susceptibility of microvascular networks, which leads to underperfusion, hypoxia, and ultimate injury. In addition, recent therapeutic advances and novel considerations on the prevention and management of muco-cutaneous and neuro-ophthalmological complications are examined.

Ophthalmic artery arising from the presumed meningohypophyseal trunk of the cavernous internal carotid artery diagnosed by magnetic resonance angiography

PURPOSE

The purpose of the study is to describe a case of ophthalmic artery (OA) arising from the presumed meningohypophyseal trunk (MHT) of the cavernous internal carotid artery (ICA).

CASE REPORT

A 63-year-old woman suspected of having cerebral infarctions underwent cranial magnetic resonance (MR) imaging and MR angiography. MR angiography showed a right OA that was found to arise from the superolateral aspect of the proximal cavernous ICA. This OA entered the orbit via the superior orbital fissure (SOF).

DISCUSSION

Rarely, an OA arises from the inferior aspect of the middle cavernous ICA at the level of the inferolateral trunk (ILT) and enters the orbit via the SOF. This OA variation was traditionally regarded as a persistent primitive dorsal OA but is now believed to be due to the persistence of the lateral branch of the primitive maxillary artery. The present case had an OA arising from the superolateral aspect of the more proximal cavernous ICA than the origin of the ILT, which was suggested to be the origin of the MHT. Persistence of the proximal segment of the trigeminal artery may play an important role in the formation of this extremely rare variation.

CONCLUSION

To identify this extremely rare OA variation, careful observation of source images and the creation of volume-rendering MR angiography images are important.

Orbital compartment syndrome secondary to retrobulbar hematoma after infratrochlear nerve block for nasolacrimal probing

After infratrochlear nerve block for nasolacrimal probing, sudden vision loss, proptosis, pain, loss of light reflexes, and a total limitation of ocular movement was observed in a 71-year-old female patient. She was diagnosed with retrobulbar hemorrhage and orbital compartment syndrome (OCS). Lateral canthotomy, cantholysis, and medial orbitotomy were performed on the patient. She was not taking any oral anticoagulant medication and did not have any disease other than hypothyroidism and systemic hy-pertension. All the clinical findings returned to normal right after the intervention except mild ptosis (~1 mm), which persisted for 2 months. All patients scheduled for periocular anesthesia should be questioned about using oral anticoagulant medications, and the possibility of serious complications should be kept in mind even for patients without any risk factors. Patients with OCS secondary to retrobulbar hemorrhage should be surgically managed within the critical window (90 min) to prevent any irrevers-ible optic nerve injury.

Morphometric study regarding ophthalmic and internal carotid arteries utilizing computed tomography angiography

The aim of the present study was to accurately measure the diameter of the ophthalmic artery (OA) and investigate whether bilateral variations in diameter can be recorded in relation to patient age and sex. A retrospective study including 80 computed tomography angiographic (CTA) examinations and a total of 160 arteries was conducted to demonstrate the morphometric aspects of the OAs analyzed bilaterally by CTA examinations, while considering the references of the internal carotid artery (ICA) caliber. Precise measurements performed on the OA and the ICA below and above the ophthalmic emergence revealed an OA diameter of 1.38±0.24 mm and a narrowing of the ICA between the origin of the OA of 1.5±0.25 mm. Variations in the OA and the ICA calibers were studied in subjects with normal cervical vasculature on CTA. After a thorough statistical study, variations in OA and ICA caliber on each side were identified, between both sex and age-related groups, revealing morphometric parameters of the OA in relation to the ICA.

Blood Supply of Cranial Nerves Passing Through the Cavernous Sinus: An Anatomical Study and Its Implications for Microsurgical and Endoscopic Cavernous Sinus Surgery

Background

Despite improvements in surgical techniques, cranial nerve (CN) deficits remain the most frequent cause of disability following cavernous sinus (CS) surgery. The most common tumor affecting the CS is meningioma. They originate from lateral wall and have their blood supply from meningohypophyseal trunk (MHT) and inferolateral trunk (ILT). Pituitary adenomas commonly invade the CS through its medial wall and receive blood supply form medial branches of the internal carotid artery (ICA) (superior and inferior hypophyseal arteries). Some tumors may grow within the CS (e.g. trigeminal schwannomas, hemangiomas). These tumors are fed by all the intracavernous ICA branches. Tumors involving the CS may also displace the neurovascular structures, therefore, a better understanding of intracavernous neurovascular anatomy may reduce the postoperative morbidity associated with approaching CS tumors. In this anatomical study, the anatomic variations and their clinical implications of the intracavernous CNs' blood supply were evaluated through transcranial and endonasal routes.

Methods

Twenty sides of ten adult cadaveric formalin-fixed, latex-injected specimens were dissected in stepwise fashion under microscopic and endoscopic magnification. The origin and course of the intracavernous ICA branches supplying the intracavernous CNs are studied.

Results

The proximal segment of the oculomotor nerve receives blood supply from the ILT in 85%, and the tentorial artery of the MHT in 15% of specimens. The distal segment is exclusively supplied by the ILT. The proximal trochlear nerve receives blood supply from the ILT (75%) and the tentorial artery (25%); the distal segment is exclusively supplied by the superior orbital branch. The proximal third of the abducens nerve receives its vascularity exclusively from the dorsal meningeal artery, and its middle and distal thirds from the ILT. The ophthalmic and proximal maxillary segments of the trigeminal nerve also receive blood supply from the ILT. The distal maxillary segment is supplied by the artery of the foramen rotundum. All ILT branches terminate on the inferomedial aspects of the intra-cavernous CNs. Extensive anastomoses are found between ILT branches and the branches arising from external carotid artery.

Conclusion

Understanding the anatomy of the intracavernous ICA's branches is important to improving surgical outcomes with tumors involving the CS.

Vision Loss and Blindness Following Fillers

Facial aging associated with volume loss can be addressed with soft tissue fillers. This minimally invasive technique has quickly gained popularity and is commonly performed in many outpatient settings. The composition of injectable dermal fillers includes marketed hyaluronic acid, calcium hydroxyapatite, polylactic acid, silicone and polymethylmethacrylate. Complications, such as vision loss, are rare, but can result in a devastating and irreversible sequala from iatrogenic vascular occlusion. Understanding the facial anatomy, specific filler characteristics, and having a safe injection technique is crucial to assure optimal aesthetics results while avoiding complications. Injectors need to be able to recognize early complications and treat them appropriately, especially if vision loss is encountered. This review will focus on vision loss from fillers, techniques to prevent such complications and possible treatment strategies.

Ocular Perfusion Following Orbital Apex Exenteration

A 68-year-old man with a history of type 2 diabetes mellitus and kidney transplantation on chronic immunosuppression presented with right-sided proptosis and vision loss. He was hospitalized 4 months prior for invasive sinus aspergillosis. MRI revealed abnormal enhancement in the right orbital apex, inferior medial right orbit, anterior cranial fossa floor, and anterior aspect of the falx cerebri. The patient was successfully managed with extensive sinus surgery, bifrontal craniotomy with resection of dura, cribriform plate resection, and a right orbital apex exenteration. The globe and anterior orbital structures were preserved to cover the large surgical sinodural-orbital defect and avoid complex reconstructive surgery. Orbital perfusion was maintained by exploiting the robust anastomoses between branches of external carotid and ophthalmic artery.

Role of the ophthalmic artery in the endovascular treatment for intracranial vascular diseases

The ophthalmic artery (OA) is a crucial artery. Centered at the OA, there are numerous extracranial-intracranial anastomoses. The OA and its collaterals can be involved in some intracranial vascular diseases. So, it is very important to understand its specific anatomy, variation, and role in different neurovascular diseases. The OA has various anomalies both in the origin and collateral circulation. When performing endovascular treatment (EVT), the OA may suffer unexpected embolization through the numerous dangerous anastomoses. In case of a dural arteriovenous fistula or brain arteriovenous malformation mainly fed by the OA, the OA can be the passage of EVT, during which the central retinal artery could be injured. During interventional recanalization of steno-occlusive diseases of the internal carotid artery, dissection at the cavernous segment could progress to the OA segment and occlude the origin of OA. Under the circumstance of moyamoya disease, the OA can provide collateral flow to the anterior cerebral artery. When performing EVT for OA aneurysm concurrent with moyamoya disease, the parent OA should be preserved. After placement of a flow-diverting device for ophthalmic ICA aneurysm, the covered OA could experience spontaneous occlusion, leading to visual disturbance. Hence, the OA is an extremely important artery in the EVT for intracranial vascular diseases. In this article, we would extensively review the related literature to increase our understanding of the role of OA in intracranial vascular diseases. In addition, some illustrative cases would also be provided.

A systematic review of the surgical anatomy of the orbital apex

PURPOSE

The orbital apex is the narrowest part of the orbit, housing the link between the intracranial cavity and orbit. Knowledge of orbital apex anatomy is crucial to selecting a surgical approach and reducing the risk of complications. Our purpose is to summarize current knowledge on surgical anatomy and attempt to reach a consensus on definition of the orbital apex.

METHODS

The online databases of Embase, the Cochrane library, Web of Science and PubMed (MEDLINE) were queried in a comprehensive bibliographic search on the (surgical) anatomy of the orbital apex and consisted of a combination of two subjects, using indexed terms and free text: "Orbital Apex" and "Orbital Anatomy."

RESULTS

A total of 114 relevant papers were included in this review. Numerous anatomical variations are described in the literature. Variations of the optic canal include duplication (0.64%) and keyhole anomaly (2.65%). Variations in pneumatization of the anterior clinoid process were unilateral in almost 10%, bilateral in 9%, and normal in 72%. A rare variant of the superior orbital fissure (SOF) is Warwick's foramen, which appears as if the lowest portion of the SOF was separated from the main fissure by a transverse bony bridge.

CONCLUSION

The definition of the orbital apex varies in the literature, and further research would most likely identify additional variations. A universal definition reporting these variations and pathology and imaging findings is essential for determining the optimal surgical approach to the orbital apex.

Anatomic and Embryologic Analysis of the Dural Branches of the Ophthalmic Artery

The ophthalmic artery has one of the most fascinating embryologic developments among the craniofacial arteries. Most of the ophthalmic artery orbital branches develop from the formation and regression of the stapedial artery and share their origin with dural branches of the ophthalmic artery. The concomitant embryologic development of the ophthalmic artery and middle meningeal artery explains adequately the important varieties of anastomosis between these 2 arteries. It also explains the presence of many dural branches from the ophthalmic artery. In this review, we focused on dural branches of the ophthalmic artery with the description of rare variations possible, in particular the ophthalmic artery origin of the middle meningeal artery and the ophthalmic artery origin of the marginal tentorial artery.

Angiographic investigation of orbital vascular variations in the rabbit and implications for endovascular intra-arterial chemotherapy models

BACKGROUND

The New Zealand White rabbit (NZWR) is the first small-animal experimental model of intra-arterial chemotherapy (IAC) for retinoblastoma treatment. The NZWR has dual ophthalmic arteries (OA): the external OA (EOA) arises from the external carotid artery and the internal OA (IOA) from the internal carotid artery. We describe the technique that we have refined for OA catheterization in rabbits, and describe the angioanatomical variations in the OA supply to the NZWR eye and implications for IAC delivery, which were identified as part of a larger project exploring IAC effects in a rabbit retinoblastoma model.

METHODS

We developed techniques to perform angiography of the external and internal carotid arteries and superselective angiography of the EOA and IOA in NZWR using transfemoral access and a microwire/microcatheter system. EOA and IOA supply to the eye was determined angiographically and recorded before selective OA catheterization and angiography.

RESULTS

114 rabbits underwent carotid angiographic evaluation and OA catheterization (161 total eyes evaluated, 112 right, 49 left). Most eyes had a single dominant arterial supply; either IOA or EOA. EOA was dominant in 73% (118/161), and IOA was dominant in 17% (27/161). Co-dominant supply was seen in 10% (16/161). Of the rabbits with bilateral OA catheterization, 25/47 (53%) had bilateral dominant EOA.

CONCLUSION

Successful catheterization of the OA in the NZWR can be readily accomplished with nuanced technique. The external OA is the dominant arterial supply in the majority of NZWR eyes. These findings allow for successful reproduction of OA catheterization studies of IAC for retinoblastoma in NZWR.

Evaluation of the anastomoses between the ophthalmic artery and the middle meningeal artery by superselective angiography

PURPOSE

There are three anastomoses between the ophthalmic artery (OA) and the middle meningeal artery (MMA): the anastomotic branch with MMA, the recurrent meningeal branch and the anterior falx artery. We aimed to evaluate the anastomotic branches between the OA and the MMA on superselective angiograms of pediatric patients with retinoblastoma.

MATERIALS AND METHODS

We evaluated 126 angiographies performed on children with retinoblastoma. The mean diameter and angiographic visibility percentage of the anastomotic branches between the OA and the MMA were examined according to age group and sex.

RESULTS

The mean diameter of anastomotic branch with MMA was measured 0.58 ± 0.13 mm and we found this branch in 15 of 126 angiographic images (11.9%). We detected the recurrent meningeal branch in 47 of total images (37.3%). The recurrent meningeal branch arose 85.1% from the lacrimal artery, 8.5% from the anastomotic branch with MMA and 6.4% directly from the OA. The mean diameter of this artery was measured 0.21 ± 0.06 mm. Anterior falx artery was found in 86 of 126 angiographic peocedures (68.3%) and the mean diameter was measured 0.22 ± 0.06 mm.

CONCLUSION

Knowledge of the anastomoses between the OA and the MMA system are all necessary to perform safe and successful endovascular and surgical procedures involving the orbital region.

Orbital infarction syndrome after mechanical thrombectomy in acute ischaemic stroke

Orbital infarction syndrome (OIS) encompasses the ischaemic infarction of all intraorbital and intraocular structures (optic nerve, extraocular muscles and orbital fat) which leads to a painful loss of visual acuity, ophthalmoparesis, chemosis, proptosis and ptosis. The rich anastomotic orbital vascularisation from internal carotid artery (ICA) and external carotid artery makes this disorder a rare cause of visual loss in stroke patients. We describe a case of a woman who suffered an acute occlusion of her right ICA and developed an OIS after mechanical thrombectomy.

Upper Eyelid Isolated Arterio-Venous Malformation Treated With Embolization in a Patient With Keloid-Prone Skin

Ocular adnexal aterio-venous malformations (AVMs) are rare congenital disabling anomalies, which may enlarge causing disfiguring deformity and rarely severe hemorrhage. These lesions are generally treated by preliminary endovascular embolization to shrink the arterio-venous malformation, followed by surgical gross total resection. The authors report a case of eyelid arterio-venous malformation in a 12-year-old girl, which progressively increased in size in few months. The patient complained mild itching, blurring of the vision, and mild tenderness. Magnetic resonance imaging showed an expansive mass with multiple arterial vessels at the left superior eyelid and left forehead. The diagnosis of arterio-venous malformation was then confirmed by digital subtraction angiography. Primary surgical excision was excluded because of the high risk of intrasurgical bleeding. Embolization through superselective cannulation of the left external carotid feeder vessels was performed resulting in flow exclusion up to the 80% of the nidus. Subsequent surgical resection was not recommended due to clinical evidence of keloid-prone skin.

Iatrogenic ophthalmic artery occlusion and retinal artery occlusion

Iatrogenic ophthalmic artery occlusion (IOAO) is a rare but devastating ophthalmic disease that may cause sudden and permanent visual loss. Understanding the possible etiologic modalities and pathogenic mechanisms of IOAO may prevent its occurrence. There are numerous medical etiologies of IOAO, including cosmetic facial filler injection, intravascular procedures, intravitreal gas or drug injection, retrobulbar anesthesia, intraarterial chemotherapy in retinoblastoma. Non-ocular surgeries and vascular events in arteries that are not directly associated with the ophthalmic artery, can also cause IOAO. Since IOAO has a limited number of treatment modalities, which lead to poor final visual prognosis, it is imperative to acknowledge the information regarding medical procedures that are etiologically associated with IOAO. We accumulated all searchable and available IOAO case reports (our cases and previous reported cases from the literature), classified them according to their mechanisms of pathogenesis, and summarized treatment options and responses of each of the causes. Various sporadic cases of IOAO can be categorized into three mechanisms as follows: intravascular event, orbital compartment syndrome, and increased intraocular pressure. Embolic IOAO, which is considered the primary cause of the condition, was classified into three subgroups according to the pathway of embolic movement (retrograde pathway, anterograde pathway, pathway through collateral channels). Despite the practical limitations of treating spontaneous (non-iatrogenic) retinal artery occlusion, this article will contribute in predicting and improving the prognosis of IOAO by recognizing the treatable factors. Furthermore, it is expected to provide clues to future research associated with the treatment of retinal artery occlusion.

Anomalous origin of the middle meningeal artery from the inferolateral trunk with an arterial circle around a hypoplastic internal carotid artery in an infant with a dural arteriovenous fistula

Deviations from normal embryologic development can manifest in different anatomical variants of the ophthalmic artery. We present a case of an infant treated for a high-flow dural arteriovenous fistula of the superior sagittal sinus, in whom an arterial circle involving the ophthalmic artery, the middle meningeal artery, the inferolateral trunk and a hypoplastic segment of the internal carotid artery was found. The embryologic development is briefly reviewed with emphasis on the possible genesis of this interesting constellation.

Embryology and anatomical variations of the ophthalmic artery

PURPOSE

The ophthalmic artery (OA) has one of the most complex anatomy and the most fascinating embryological development.

METHODS

The complexity of the embryologic development of the OA resides in the implication of three different embryological systems: the carotid system, the stapedial system, and the ventral pharyngeal system.

RESULTS

This explains very well the numerous variations in origin of the OA and the importance of vascular anastomoses developed with branches of the external carotid artery and with the middle meningeal artery.

CONCLUSION

In this review, authors propose a comprehensive description of different hypotheses on the embryologic development of the OA and, in a second part, explain all anatomical variations and clinical implications of this artery.

Unusual ophthalmic artery origin: Implications for intraarterial chemotherapy of retinoblastoma

We report two pediatric retinoblastoma patients with unusual ophthalmic artery (OA) origins who were referred to our interventional neuroradiology department for intraarterial chemotherapy. The first patient had double OAs arising from the ipsilateral internal carotid artery and a central retinal artery (CRA) arising from the more cranially located artery, whereas the second patient had an OA originating from the A1 segment of the ipsilateral anterior cerebral artery. In both cases the CRA arose from the artery entering the orbit through the optic foramen. Both patients tolerated the procedures well. To the best of our knowledge, our retinoblastoma patients with unusual OA origins are the first in the literature in which detailed knowledge of the orbital vasculature and especially CRA origin carried immediate clinical implications, altering access strategies. These variations were proved both by flat-panel detector computed tomography findings and superselective injections of OAs with unusual origins. Our results show that in patients with retinoblastoma, a detailed angiographic work-up may be necessary to evaluate the orbital vasculature and possible abnormal origin of the OA. Recognition of possible variations of OA origin and its branching patterns is of the utmost importance for successful treatment and avoidance of adverse events among retinoblastoma patients.

Anomalous Origins of Ophthalmic Arteries on Three-Dimensional Time-of-Flight Magnetic Resonance Angiography and Their Clinical Importance

AIM

The purpose of this paper was to evaluate rare cases of anomalous origins of the ophthalmic artery (OA) according to magnetic resonance angiography (MRA) findings.

METHODS

This retrospective study included 80 patients diagnosed with anomalous OA origins between March 2015 and July 2018 from a sample of 16,024 patients. The patients included 47 females and 33 males with a mean age of 38.16 years (range 18-62 years). Three-dimensional time-of-flight (3D-TOF) MRA was performed for all patients.

RESULTS

Eighty (0.5%) patients had anomalous OA origins. The most common type of OA origin anomaly was the right OA originating from the middle meningeal artery (0.17%). Twelve (0.07%) patients had OAs with an extradural origin.

CONCLUSIONS

Anomalous origins of the OA are rare. 3D-TOF MRA is a noninvasive imaging method that can be applied for the diagnosis of OA anomalies. Some OA variations can have a protective effect against ocular complications in vaso-occlusive events. Therefore, it is critical to know the variant anatomy of OAs.

Three-Dimensional Computed Tomographic Study on the Periorbital Branches of the Ophthalmic Artery: Arterial Variations and Clinical Relevance

BACKGROUND

Filler injection is a popular cosmetic procedure, but it can entail vascular complications. Periorbital injections have the highest risk within the entire injection area.

OBJECTIVES

The authors sought to systematically screen for periorbital arterial variations prior to treatment.

METHODS

The external carotid arteries of 10 cadaveric heads were infused with adequate lead oxide contrast. The facial and superficial temporal arteries of another 11 cadaveric heads were injected with the contrast in sequential order. Computed tomography (CT) scanning was performed after injection of contrast, and 3-dimensional (3D) CT scans were reconstructed using validated algorithms.

RESULTS

Three types of periorbital blood vessels were found to derive from the ophthalmic artery, including 30% directly originating from the ophthalmic artery, 65% originating from its trochlear branch, and 5% originating from its supraorbital branch. In the forehead, the ophthalmic artery, originating from the internal carotid arteries, formed anastomoses between the frontal branch of the superficial temporal artery, originating from the external carotid artery, with the deep and superficial branches of the supratrochlear and supraorbital arteries, respectively. The lateral orbit and malar plexus can be classified into 4 types based on the trunk artery: the zygomatic orbital artery (27%), the transverse facial artery (23%), the premasseteric branch of the facial artery (19%), and all 3 contributing equally (31%).

CONCLUSIONS

Postmortem 3D CT can map periorbital arterial variations. The branching pattern of the ophthalmic artery, the ophthalmic angiosome in the forehead, and the distribution of the lateral orbit and malar plexus were identified at high resolution to guide clinical practice.

Intra-arterial chemotherapy for retinoblastoma: the dosimetric impact

PURPOSE

Purposes are (1) to measure main radiation parameters and (2) to propose a method to estimate the absorbed doses of internal organs starting from DAP values. Measuring the exposition of internal organs by repeated irradiations on an anthropomorphic phantom with the same settings used in vivo, we could establish correlations between (1) DAP and the dose recorded by a dosimeter placed along the X-ray beam entrance pathway; (2) the dose recorded by the same dosimeter and the absorbed dose in internal organs.

METHODS

Forty-four consecutive patients (16 males, 28 females) (mean age 35.4 months) treated at our institution with IAC (216 procedures: 196 via the ICA and 20 into branches of the ECA) were included in this prospective study. IAC was divided into 5 phases. Fluoroscopic time, DAP, and ESD were measured.

RESULTS

The mean DAP was 595 ± 445 cGy cm² and the mean fluoroscopic time was 540 ± 403 s. ESD was on average 9.59 mGy (range 0.8-165 mGy). The absorbed dose was lower than 12.1 mGy in the left retina (the more exposed organ) in 75% of single treatments and lower than 25 mGy in 95% of treatments. In the cases of 3 and 6 sessions, the left retina of 75% of patients absorbed respectively less than 36.3 and 72.7 mGy, whereas the left retina of 95% of patients received less than 75.2 and 150.4 mGy. Other organs were less exposed.

CONCLUSION

This paper describes a method of absorbed dose estimation providing ranges used clinically in a single practice and the basis for further prospective studies.

Microsurgical Anatomy of the Central Retinal Artery

BACKGROUND

The central retinal artery (CRA) has been described as one of the first branches of the ophthalmic artery.It arises medial to the ciliary ganglion and after a sinuous path within the orbital cavity it penetrates the lower surface of the dura mater that covers the optic nerve, approximately 1 cm behind the eyeball. However, the numerous anatomic descriptions that were made of the CRA have been insufficient or unclear in relation to certain characteristics that are analyzed in the present study.

METHODS

An electronic literature search was made in the PubMed database and a cadaver dissection was performed on 11 orbits fixed in formaldehyde.

RESULTS

Results were obtained regarding the source, collateral branches, curves, direction, length of the optic nerve, dural perforation site, distance, path and relations, diameter, and area of the central artery of the retina.

CONCLUSIONS

Our anatomic study innovates in 2 aspects of the CRA: area and curves. Not only was there a simple count of the number of curves, but it also analyzed the angle presented by each of the curves based on photos obtained in high definition, with a digital program to reduce the margin of error. These curvatures of the CRA were classified according to their spatial disposition within the orbital cavity based on a pattern that was easy to understand. Data were obtained from the area of the CRA on the penetration of the CRA into the dural sheath of the optic nerve.

Embryologic and Fetal Development of the Human Orbit

PURPOSE

To review the recent data about orbital development and sort out the controversies from the very early stages during embryonic life till final maturation of the orbit late in fetal life, and to appreciate the morphogenesis of all the definitive structures in the orbit in a methodical and timely fashion.

METHODS

The authors extensively review major studies detailing every aspect of human embryologic and fetal orbital morphogenesis including the development of extraocular muscles, orbital fat, vessels, nerves, and the supportive connective tissue framework as well as bone. These interdisciplinary studies span almost a century and a half, and include some significant controversial opposing points of view which the authors hopefully sort out. The authors also highlight a few of the most noteworthy molecular biologic studies regarding the multiple and interacting signaling pathways involved in regulating normal orbital morphogenesis.

RESULTS

Orbital morphogenesis involves a successive series of subtle yet tightly regulated morphogenetic events that could only be explained through the chronological narrative used by the authors. The processes that trigger and contribute to the formation of the orbits are complex and seem to be intricately regulated by multifaceted interactions and bidirectional cross-talk between a multitude of cellular building raw materials including the developing optic vesicles, neuroectoderm, cranial neural crest cells and mesoderm.

CONCLUSIONS

Development of the orbit is a collective enterprise necessitating interactions between, as well as contributions from different cell populations both within and beyond the realm of the orbit. A basic understanding of the processes underlying orbital ontogenesis is a crucial first step toward establishing a genetic basis or an embryologic link with orbital disease.

Morphology and Navigational Landmarks of the Cranio-orbital Foramen in a Portuguese Population

PURPOSE

The cranio-orbital and accessory foramina are located in the lateral wall of the orbit and adjacent to the superior orbital fissure. In the literature, there is a lack of consistency concerning the location and morphology of these foramina in different populations. Therefore, considering its clinical importance during orbital surgeries, it was the authors' aim to determine the incidence, location, and number of cranio-orbital and accessory foramina in a Portuguese population and compare the findings with data from other studies.

METHODS

A total of 310 orbits from 155 dry skulls from the collection of the Museum of Anatomy of the Faculty of Medicine of Porto were studied. The characterization of both cranio-orbital and accessory cranio-orbital foramina was performed.

RESULTS

The cranio-orbital foramen was present in at least 1 orbit per skull in 58.17% with a median diameter of 0.60 ± 0.33 mm. No relation was found between the presence of this foramen and the gender of the individuals or a tendency for laterality. However, it was found that the presence of 1 or more accessory foramina was related to higher diameters of the cranio-orbital foramen.

CONCLUSIONS

There might be a relationship between the localization, diameter, and communication of foramina with the cranial fossae. Foramina located on the greater wing of the sphenoid bone presented a larger diameter and communicated with the middle cranial fossa. High diameters of the main vessel in the cranio-orbital foramen may imply more developed branches and collateral irrigation of the orbital structures using 1 or more accessory foramina. Surgeons should be aware of the location of the cranio-orbital foramen to reduce potential sources of hemorrhage during orbital dissections.

Orbital Infarction Syndrome Following Mechanical Thrombectomy Secondary to Embolization in New Territory

BACKGROUND

Orbital infarction syndrome (OIS) is a rare entity defined as ischemia of all intraorbital and intraoccular structures including the optic nerve, extraocular muscles, and orbital fat. This entity is rare due to rich anastomotic orbital vascularization from both the internal carotid artery and external carotid artery. We report a case of a patient who suffered emboli to previously nonaffected territories to the ophthalmic artery and external carotid artery, which resulted in orbital infarction syndrome, and describe techniques to avoid such complications.

CASE DESCRIPTION

A 66-year-old male presented to our institution with an acute ischemic stroke secondary to occlusion of the internal carotid artery terminus and M1 segment. The vessel was revascularized after 1 pass using a stent retriever. Postoperative angiography demonstrated sluggish flow in the distal right ophthalmic artery, as well as occlusion of the distal external carotid artery. Twenty-four hours following the procedure, the patient was noted to have complete ophthalmoplegia of the right eye, proptosis, and conjunctival chemosis. Computed tomography angiography demonstrated persistent occlusion of the distal right ophthalmic artery and external carotid artery. The right optic nerve was swollen, as were all extraocular muscles. A final diagnosis of orbital infarction syndrome was made given the clinical presentation, imaging findings, and occlusion of all vascular supply to the orbit on both conventional angiography and 24-hour computed tomography angiography.

CONCLUSIONS

OIS is a rare entity that has not been previously described as a complication of mechanical thrombectomy for acute ischemic stroke. OIS should be considered when patients present with blindness, orbital pain, and total ophthalmoplegia post thrombectomy.