Visualization of the ophthalmic artery by phase-contrast magnetic resonance angiography: a pilot study

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.

Double Ophthalmic Arteries Arising from the Internal Carotid Artery and the Accessory Meningeal Artery: A Case Report of a New Anatomic Variation

BACKGROUND

Variant origin of the ophthalmic artery (OA) is uncommon. The majority of variant origins are from the middle meningeal artery and from the infraclinoid segment of the internal carotid artery. An OA arising from the accessory meningeal artery is an extremely rare vascular variation that has not been described previously in the English literature.

CASE DESCRIPTION

We report the first case of double origin of the OA from the supraclinoid segment of the internal carotid artery and from the accessory meningeal artery branch of the maxillary artery. A 33-year-old woman was referred to our clinic with suspicion of a middle cerebral artery aneurysm. She had nonspecific neurologic symptoms. The patient underwent cerebral magnetic resonance imaging and magnetic resonance angiography.

CONCLUSIONS

Being aware of variant origin of the OA from the accessory meningeal artery is very important for transarterial chemoembolization in the external carotid artery territory. Reconstructed images from magnetic resonance angiography are very useful to reveal the variant origin of the OA.

Ophthalmic Arteries Arising from the Bilateral Anterior Cerebral Arteries Diagnosed by Three-Dimensional Time-of-Flight Magnetic Resonance Angiography

BACKGROUND

The ophthalmic artery (OA) is a very important branch of the supraclinoid segment of the internal carotid artery. Origination of the OA from the anterior cerebral artery is an extremely rare condition. Being unaware of the origin anomalies of OAs can lead to unfavorable results, especially in cases in which craniofacial surgery or cerebral therapeutic angiography is planned.

CASE DESCRIPTION

An anomalous origin of the ipsilateral OAs from the A1 segments of the bilateral anterior cerebral arteries was detected by three-dimensional time-of-flight magnetic resonance angiography.

CONCLUSIONS

Anomalous origin of the OA from the anterior cerebral artery may be explained by a failure in the caudal migration of the ventral OA. Because of high soft tissue resolution and absence of radiation, three-dimensional time-of-flight magnetic resonance angiography is preferred for detection of orbital and cerebral vascular anomalies.

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.

Survival of Nasal Tip Flap on Only the Columellar Attachment

The nose has a robust blood supply derived from both internal and external carotid arteries. The main blood supply of the nasal tip and skin is derived primarily from the lateral nasal arteries, with a variable contribution from the columellar arteries. We present a patient with cut nose resulting from a homicidal attack in which the lower two-thirds of the nose was severed starting at the bony-cartilaginous junction of the dorsum of the nose down to the tip of the nose. The skin-cartilage flap was attached only to the columella and to the caudalmost 3 mm of the left ala nasi. The detached skin-cartilage flap was replaced and sutured anatomically, and the flap completely survived in spite of cutting of both lateral and dorsal nasal arteries.

4D Flow MR Imaging of Ophthalmic Artery Flow in Patients with Internal Carotid Artery Stenosis

Background and Purpose:

To assess the clinical feasibility of time-resolved 3D phase contrast (4D Flow) MRI assessment of the ophthalmic artery (OphA) flow in patients with internal carotid artery stenosis (ICS).

Materials and Methods:

Twenty-one consecutive patients with unilateral ICS were recruited. 4D Flow MRI and acetazolamide-stress brain perfusion single photon emission computed tomography (SPECT) were performed. The flow direction on the affected-side OphA was categorized into native flow (anterograde or unclear) and non-native flow (retrograde flow) based on 4D Flow MRI. In the affected-side middle cerebral artery (MCA) territory, the ratio of rest cerebral blood flow to normal control (RCBF_MCA) and cerebral vascular reserve (CVR_MCA) were calculated from SPECT dataset. High-risk patients were defined based on the previous large cohort study (RCBF_MCA < 80% and CVR_MCA < 10%).

Results:

Eleven patients had native OphA flow (4 anterograde, 7 unclear) and the remaining 10 had non-native OphA flow. RCBF_MCA and CVR_MCA each were significantly lower in non-native flow group (84.9 ± 18.9% vs. 69.8 ± 7.3%, P < 0.05; 36.4 ± 20.6% vs. 17.0 ± 15.0%, P < 0.05). Four patients in the non-native flow group and none in the native flow group were confirmed as high-risk (Sensitivity/Specificity, 1.00/0.65).

Conclusion:

The 6 min standard 4D Flow MRI assessment of OphA in patients with ICS can predict intracranial hemodynamic impairment.

Anatomy of the Ophthalmic Artery: Embryological Consideration

There are considerable variations in the anatomy of the human ophthalmic artery (OphA), such as anomalous origins of the OphA and anastomoses between the OphA and the adjacent arteries. These anatomical variations seem to attribute to complex embryology of the OphA. In human embryos and fetuses, primitive dorsal and ventral ophthalmic arteries (PDOphA and PVOphA) form the ocular branches, and the supraorbital division of the stapedial artery forms the orbital branches of the OphA, and then numerous anastomoses between the internal carotid artery (ICA) and the external carotid artery (ECA) systems emerge in connection with the OphA. These developmental processes can produce anatomical variations of the OphA, and we should notice these variations for neurosurgical and neurointerventional procedures.

Different ophthalmic artery origins: Embryology and clinical significance

This retrospective study gives a summary of ophthalmic artery (OA) variations to serve as guidelines for surgical interventionists and trainees. Pubmed and Medline searches were conducted. The OA usually arises intradurally (superomedial, anteromedial, or rarely superolateral) from the internal carotid artery (ICA). Rare extradural origin (primitive dorsal OA) (PDOA) remnant and extremely rare interdural origin (primitive ventral OA) (PVOA) remnant are of significance when sectioning the dural ring. Rarely, a persistent PDOA with ICA origin, or a PDOA remnant with inferolateral trunk origin, enters the orbit via the superior orbital fissure (SOF) for sole or partial orbital supply. Extremely rare, the PDOA and PVOA persist and form double OAs that arise from the ICA and run via the SOF and optic foramen. Occasionally, the OA arises from the middle meningeal artery (MMA), when both the PDOA and VDOA regress and enter the orbit via the SOF. Sole orbital supply via the external carotid artery (ECA), i.e. meningo-ophthalmic artery and/or MMA branches, or dual OAs (ECA and ICA origins) may occur. Other rare OA origins include anterior or posterior communicating artery; anterior or middle cerebral artery; basilar artery; posterior inferior cerebellar artery; and the carotid bifurcation. Primitive arteries (persistent or remnant), and/or abnormal anastomoses play pivotal roles in manifestations of OA variations. Of clinical importance are orbital collateral routes and dangerous extracranial-intracranial anastomoses. Awareness of OA origins and collateral routes is imperative for transarterial embolizations or infusion chemotherapy in the ECA territory to prevent visual complications.

Double ophthalmic arteries arising from the internal carotid artery

Rarely, the ophthalmic artery (OA) arises from the cavernous segment of the internal carotid artery (ICA) inferolaterally and enters into the orbit via the superior orbital fissure. This anomalous OA that originates from the inferolateral trunk is regarded as a persistent dorsal OA. Extremely rarely, both normal OA and persistent dorsal OA arise from the ICA. We report the first case of such double OAs, one of which arose from the cavernous segment of the ICA superolaterally and we believe that it originated from the meningohypophyseal trunk rather than the inferolateral trunk.