Anomalous meningeal branches of the ophthalmic artery feeding meningiomas of the brain convexity

Characterization of the pterygomeningeal artery based on branching pattern and muscular distribution

PURPOSE

The pterygomeningeal (accessory meningeal) artery arises from the middle meningeal or maxillary artery. Although there is the potential that this artery may be wounded by the surgery for the temporomandibular joint disorder, the current state of anatomical knowledge is insufficient. This study investigated the appearance and the branching pattern of this artery as a means to its characterization.

METHODS

The pterygomeningeal artery was dissected in 14 cadavers and its branches and their distributions to the muscles inside the mandible were examined.

RESULTS

The maxillary artery passed lateral to the lateral pterygoid muscle. The pterygomeningeal artery arose from the middle meningeal or maxillary artery. It ascended anteriorly and coursed medial or lateral to the mandibular nerve. It passed above the pterygospinous ligament and then descended. The ascending trunk gave some lateral branches to the lateral pterygoid muscle. The branches sometimes passed lateral to the mandibular nerve even if the pterygomeningeal artery coursed medial. The descending trunk was divided into middle and medial branches, which supplied the medial pterygoid muscle and the tensor veli palatini, respectively. The pterygomeningeal artery was sometimes equally bifurcate near the origin, and the counterparts passed lateral and medial to the mandibular nerve. The distributions of the medial and lateral counterparts were equivalent to those of the descending trunk and the lateral branches, respectively.

CONCLUSION

The pterygomeningeal artery contains three groups of muscular branches, which sometimes appear in a bifurcate form. Their positions relative to the mandibular nerve and the pterygospinous ligament characterize the artery; this information may help to avoid iatrogenic injury.

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.

Neuroanatomy of cranial dural vessels: implications for subdural hematoma embolization

Adoption of middle meningeal artery embolization in the management of chronic subdural hematomas has led to a renewed interest in dural vascular anatomy. The readily identifiable major dural arteries and potential hazards associated with their embolization are well described. Less emphasized are several levels of intrinsic dural angioarchitecture, despite their more direct relationship to dural based diseases, such as subdural hematoma and dural fistula. Fortunately, microvascular aspects of dural anatomy, previously limited to ex vivo investigations, are becoming increasingly accessible to in vivo visualization, setting the stage for synthesis of the old and the new, and providing a rationale for the endovascular approach to subdural collections in particular. In contrast with traditional anatomical didactics, where descriptions advance from larger trunks to smaller pedicles, we present a strategic approach that proceeds from a fundamental understanding of the dural microvasculature and its relationship to larger vessels.

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.

Stapedial Artery: From Embryology to Different Possible Adult Configurations

The stapedial artery is an embryonic artery that represents the precursor of some orbital, dural, and maxillary branches. Although its embryologic development and transformations are very complex, it is mandatory to understand the numerous anatomic variations of the middle meningeal artery. Thus, in the first part of this review, we describe in detail the hyostapedial system development with its variants, referring also to some critical points of ICA, ophthalmic artery, trigeminal artery, and inferolateral trunk embryology. This basis will allow the understanding of the anatomic variants of the middle meningeal artery, which we address in the second part of the review.

Middle Meningeal Artery: Anatomy and Variations

The middle meningeal artery is the major human dural artery. Its origin and course can vary a great deal in relation, not only with the embryologic development of the hyostapedial system, but also because of the relationship of this system with the ICA, ophthalmic artery, trigeminal artery, and inferolateral trunk. After summarizing these systems in the first part our review, our purpose is to describe, in this second part, the anatomy, the possible origins, and courses of the middle meningeal artery. This review is enriched by the correlation of each variant to the related embryologic explanation as well as by some clinical cases shown in the figures. We discuss, in conclusion, some clinical conditions that require detailed knowledge of possible variants of the middle meningeal artery.

A symptomatic atherosclerotic persistent pharyngo-hyo-stapedial artery: Treatment management and embryological considerations

The stapedial artery (SA) is an embryonic vessel connecting the internal carotid artery (ICA) to the branches of the future external carotid artery (ECA). It passes through the primordium of the stapes that progressively develops around the SA. Normally, SA disappears during the tenth week in utero. Approximately 0.4% of the population can have a persistent SA. It can persist as four types of embryological variations, of which the pharyngo-hyo-stapedial variant has been rarely described before. We reported a case of a 61-year-old woman presented with transient ischemic attacks (TIAs). Computed tomography angiography showed an unusual "duplicated" aspect of the left ICA. Digital subtraction angiography depicted a persistent pharyngo-hyo-stapedial artery with an atherosclerotic wall and was considered the cause of the TIAs. After failure of the antiplatelet therapy in preventing recurrent TIAs, stenting of the artery was planned and successfully performed. Patient was asymptomatic during 12-month follow-up. The pharyngo-hyo-stapedial artery is a very rare variation in which the SA is supplied by the inferior tympanic (rising from the ascending pharyngeal artery) and the hyoid artery (rising from the ICA). To our knowledge, this is a unique case of a pharyngo-hyo-stapedial artery in a patient presenting associated ischemic symptoms. Radiological and embryological findings are discussed.

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.

Microsurgical treatment of parafalcine meningiomas: a retrospective study of 126 cases

Objective

To discuss the diagnosis, operation methods, and clinical effects of parafalcine meningiomas.

Methods

The clinical and preoperative imaging characteristics, operative methods, and effects of operations of 126 cases of parafalcine meningiomas were respectively discussed.

Results

G1 resection was achieved in 13 cases, G2 in 105 cases, G3 in four cases, and G4 in four cases, with no deaths. Among these, there were 16 patients with dyskinesia of the contralateral extremities after surgery, but they recovered after several months.

Conclusion

In order to avoid postoperative complications, we consider it vital to analyze the patients’ condition, the anatomy of venous drainage in by digital subtractional angiography, the relationship between tumor location and brain tissue according to MRI, and to remove the tumor in an adequately exposed surgical field.

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.

A Functional Perspective on the Embryology and Anatomy of the Cerebral Blood Supply

The anatomy of the arterial system supplying blood to the brain can influence the development of arterial disease such as aneurysms, dolichoectasia and atherosclerosis. As the arteries supplying blood to the brain develop during embryogenesis, variation in their anatomy may occur and this variation may influence the development of arterial disease. Angiogenesis, which occurs mainly by sprouting of parent arteries, is the first stage at which variations can occur. At day 24 of embryological life, the internal carotid artery is the first artery to form and it provides all the blood required by the primitive brain. As the occipital region, brain stem and cerebellum enlarge; the internal carotid supply becomes insufficient, triggering the development of the posterior circulation. At this stage, the posterior circulation consists of a primitive mesh of arterial networks that originate from projection of penetrators from the distal carotid artery and more proximally from carotid-vertebrobasilar anastomoses. These anastomoses regress when the basilar artery and the vertebral arteries become independent from the internal carotid artery, but their persistence is not uncommon in adults (e.g., persistent trigeminal artery). Other common remnants of embryological development include fenestration or duplication (most commonly of the basilar artery), hypoplasia (typically of the posterior communicating artery) or agenesis (typically of the anterior communicating artery). Learning more about the hemodynamic consequence that these variants may have on the brain territories they supply may help understand better the underlying physiopathology of cerebral arterial remodeling and stroke in patients with these variants.

Variant middle meningeal artery origin from the ophthalmic artery: a case report

We present a rare case of a variant middle meningeal artery (MMA) originating from the ophthalmic artery. During cadaveric dissection of the cranial base of an adult female, it was noted that the foramen spinosum was absent unilaterally. After identifying the MMA, its origin was traced back to the ophthalmic artery within the orbit. Although exceedingly rare, a variant MMA originating from the ophthalmic artery should be kept in mind by surgeons during skull base procedures in order to avoid unwanted complications including potential retrograde thrombosis of the ophthalmic artery with MMA manipulation or coagulation.

Bilateral ophthalmic origin of the middle meningeal artery

The origin of the middle meningeal artery (MMA) may vary although it can arise from the ophthalmic artery (OA) with a 0.5% prevalence. We report the exceptional bilateral asymmetric origin from the OAs that has not previously been reported in the literature. Surgeons should be aware of this variation as it could be crucial in the setting of an endovascular approach for meningeal lesions, as in our observation. A 50-year-old male underwent a preoperative cerebral digital subtracted angiography that incidentally revealed MMAs arising from the OA on both sides. In fact, the origin was asymmetric because it was complete on the right side with the anterior and posterior branches of the MMA arising from the OA, whereas it was partial on the left side, with only the anterior branch arising from the OA. The CT scan showed the absence of the foramen spinosum only on the right side. This paper discusses the unique anatomic variation in the light of MMA embryology and its different origins. Knowledge of this variation may have a practical impact in cases of cerebral embolization.

Risks of presurgical embolization of feeding arteries in 137 intracranial meningeal tumors

BACKGROUND

Embolization of extra-axial tumors has shown its effectiveness in reducing perisurgical blood loss. However, the complication rate of this procedure is poorly reported. We aimed to evaluate the rate of procedure-related complications and their risk factors.

METHODS

From 1998 to 2011, 193 consecutive patients (141 females, 52 males; mean age = 52.9 years) were referred to our institution for presurgical embolization of an extra-axial tumor (meningiomas: n = 178; solitary fibrous tumors: n = 3; other: n = 12). Of 193 patients, 137 (71 %) underwent 141 embolizations (by microparticles: n = 133; by glue: n = 8). The remaining 56 patients (29 %) were not embolized due to unstable catheterization or dangerous anastomosis. Occurrence of neurological deficit was systematically assessed during and after embolization. The risk factors of procedure-related neurological complications were evaluated.

RESULTS

Neither intratumoral hemorrhage nor procedure-related death was reported. Two of the 137 patients (1.5 %) had ischemic events with permanent neurological deficit after microparticles embolization. One patient had cortical blindness and one had hemiparesis. Both complications involved the vertebrobasilar system. The first patient had direct intratumoral anastomosis between the middle and the posterior meningeal arteries (PMA); the second one had reflux in the vertebral artery during particles injection in the PMA. Occurrence of ischemic complication was not related to the size of the microparticles.

CONCLUSIONS

Though embolization of meningeal tumors is considered as a safe technique, serious neurological complications may occur. Opening of dangerous anastomosis or uncontrolled reflux caused two neurological complications (1.5 %). The size of the microparticles was not associated with the occurrence of neurological event.

A case of an aberrant internal carotid artery with a persistent stapedial artery: association of hypoplasia of the A1 segment of the anterior cerebral artery

Congenital vascular variants involving the temporal bones are rare. Awareness of these variants is important as they may mimic glomus tumors or complicate middle ear surgery. We present a case of a persistent stapedial artery associated with an aberrant carotid artery in the left temporal bone, which is highlighted in computed tomography imaging findings. We further discuss a possible relationship between hypoplasia of the A1 segment of the anterior cerebral artery and this congenital variant.

The middle meningeal artery: from clinics to fossils

INTRODUCTION

Although research today ranges from molecular to universe scale, many issues regarding gross anatomy remain totally neglected. Within the framework of the endocranial morphogenesis and evolution, understanding the role and variation of the middle meningeal artery relies upon the very limited, scattered, and descriptive information available. The meninges are supplied by branches originating from both the internal and external carotid arteries, often converging in the same networks and hence raising questions on the homology and embryogenesis of these vessels. The middle meningeal artery is often ligated during craniotomies, with no apparent impairment of the cerebral functional processes. The exact physiological role of this extended vascular system, together with the adaptations and selective pressure associated with its evolutionary characterization, have generally been ignored.

THE MIDDLE MENINGEAL VESSELS IN NONHUMAN PRIMATES

Anthropologists have made many attempts to quantify and qualify the differences and variation between and within human and nonhuman primates, with scarce results due to the blurry morphology of the vascular networks. Living apes and humans probably have meningeal vessels originating from different embryogenetic processes, further hampering easy phylogenetic comparisons. Generally, monkeys and apes display a larger component derived from the internal carotid artery and its ophthalmic branch.

EVOLUTION AND MORPHOLOGICAL VARIATION IN FOSSIL HOMINIDS

The fossil endocasts partially show the traces of the middle meningeal vessels, allowing some hypotheses on the evolution of these structures. In contrast with modern humans, some extinct groups show a dominance of the posterior branch over the anterior one. The most interesting features are associated with the variation of the middle branch, which supplies the parietal areas. In any case, the most striking difference between the modern and non-modern humans regard the definite increase in the number and complexity of the anastomoses and reticulation in the former. This may be either the simple result of a larger percentage of traces left by the soft tissue or be associated with a more developed vascular network.

PERSPECTIVES

Tools are needed to quantify and qualify the morphogenesis and variations of the middle meningeal artery. Supposing these vessels are not strictly necessary in the adult age, the evolutionary pressure shaping their structure may have been associated with early life stages. Apart from oxygenation, another function which deserves attention is thermoregulation, considering the metabolic loadings of the cerebral mass.

Intracranial involvement in plasmacytomas and multiple myeloma: a pictorial essay

INTRODUCTION

The purpose of this pictorial essay is to increase awareness of the clinical presentation, neuroradiological findings, treatment options, and neuroradiological follow-up of plasmacytomas and multiple myeloma with intracranial growth.

METHODS

This pictorial essay reviews the clinical features and neuroradiological findings in seven patients (four women, three men; age range at diagnosis 62-82 years) followed in two institutions. Six patients, one with IgG-kappa plasmacytoma, and five with IgG-kappa (n = 3), IgG-lambda (n = 1), and nonsecretory (n = 1) multiple myeloma, had been seen over a period of 9 years in one institution, and the other patient with IgG-kappa plasmacytoma had been seen over a period of 3.5 years in the other.

RESULTS

Intracranial involvement is rare, most frequently resulting from osseous lesions in the cranial vault, skull base, nose, or paranasal sinuses. Primary dural or leptomeningeal involvement is rarer. Some typical findings of a dural and/or osseous plasmacytoma include iso- to hyperdensity on CT scan, T1 equal to high signal intensity and T2 markedly hypointense signal on MRI, and high vascularity possibly documented on intraarterial digital subtraction angiography. However, the neuroradiological findings generally lack specificity, since they are generally no different from those of meningioma, metastasis, lymphoma, dural sarcoma, plasma cell granuloma, infectious meningitis, and leptomeningeal carcinomatosis.

CONCLUSION

The spectrum of clinical and neuroradiological evaluation shows that intracranial involvement from plasmacytoma and multiple myeloma must be taken into account in the differential diagnosis of cranial osseous and meningeal disease.

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.

Microsurgical anatomy of the dural arteries

OBJECTIVE

The objective was to examine the microsurgical anatomy basic to the microsurgical and endovascular management of lesions involving the dural arteries.

METHODS

Adult cadaveric heads and skulls were examined using the magnification provided by the surgical microscope to define the origin, course, and distribution of the individual dural arteries.

RESULTS

The pattern of arterial supply of the dura covering the cranial base is more complex than over the cerebral convexity. The internal carotid system supplies the midline dura of the anterior and middle fossae and the anterior limit of the posterior fossa; the external carotid system supplies the lateral segment of the three cranial fossae; and the vertebrobasilar system supplies the midline structures of the posterior fossa and the area of the foramen magnum. Dural territories often have overlapping supply from several sources. Areas supplied from several overlapping sources are the parasellar dura, tentorium, and falx. The tentorium and falx also receive a contribution from the cerebral arteries, making these structures an anastomotic pathway between the dural and parenchymal arteries. A reciprocal relationship, in which the territories of one artery expand if the adjacent arteries are small, is common.

CONCLUSION

The carotid and vertebrobasilar arterial systems give rise to multiple branches that supply the dura in a complex and overlapping pattern. A knowledge of the microsurgical anatomy of these dural arteries and their assessment on pretreatment evaluations plays a major role in safe and accurate treatment of multiple lesions.

A Case of Superficial Recurrent Ophthalmic Artery Supplying an Infratentorial Vascular Tumour

We present a case of ophthalmic artery contribution to a posterior fossa vascular tumour by the superficial recurrent ophthalmic artery. This branch arises from the second portion of the ophthalmic artery and is rarely seen on angiography. We review the anatomy and embryology of this arterial variant. Furthermore, this case illustrates the capacity of the ophthalmic artery to supply posterior fossa neoplasms.