Stapedial Artery: From Embryology to Different Possible Adult Configurations

Radiological evaluation of middle meningeal artery by 3D rotational angiography

PURPOSE

This study aimed to evaluate the topographic features and branches of the middle meningeal artery (MMA) by three-dimensional rotational angiography (3DRA) and describe its variations' radiological classification based on previous clinical examples of cadaver studies and literature.

METHODS

We consecutively evaluated 87 cerebral hemispheres, including 32 females and 49 right sides between May 2020 and December 2021 who had undergone unilateral or bilateral cerebral and carotid artery 3D rotational angiography imaging by CCA injection and between 18 and 76-years-old. Maximum intensity projection images with 10-30 mm slice thickness were used for the morphological evaluations and measurements of MMA and its foramen, canal, and branches.

RESULTS

The diameters of the common carotid artery, internal carotid artery, and external carotid artery were significantly smaller in females than in men (p = 0.021, 0.021, and <0.001, respectively). According to the branching pattern, the most common pattern of the MMA was Type Ia (49.4%). The ophthalmic artery completely originated from MMA in the 1 (1.1%) cerebral hemisphere. The MMA arises from the ophthalmic artery in 2 cerebral hemispheres (2.3%), and the ophthalmic artery and maxillary artery in 2 cerebral hemispheres (2.3%).

CONCLUSION

It was observed that the branching pattern may show differences when compared to the cadaver studies with a radiologic evaluation with 3D-RA.

Endovascular occlusion of a persistent stapedial artery prior to stapedotomy: a novel approach

BACKGROUND

The stapedial artery is an embryonic artery that transiently supplies the cranial vasculature of the human embryo. Postnatal persistence of the stapedial artery may cause conductive hearing loss and pulsatile tinnitus due to its course through the middle ear. We describe a patient with a persistent stapedial artery (PSA) managed by endovascular coil occlusion prior to stapedotomy.

METHODS

A 48-year-old woman presented with left-sided conductive hearing loss and pulsatile tinnitus. Ten years earlier the patient had undergone explorative tympanoplasty, which was aborted due to a large PSA. Digital subtraction angiography was performed to confirm the anatomy and endovascular occlusion of the proximal PSA was achieved by deployment of coils.

RESULTS

The pulsatile tinnitus improved immediately after the procedure. The size of the artery subsequently decreased and surgery could be performed with only a minor intraoperative bleeding. Successful stapedotomy resulted in postoperative normalization of her hearing with some minor residual tinnitus.

CONCLUSION

Endovascular coil occlusion of a PSA is feasible and safe in patients with favorable anatomy and facilitates middle ear surgery. It decreases the size of the artery and minimizes the risk of intraoperative bleeding in patients with a large PSA. The future role of this novel technique in the management of patients with PSA-related conductive hearing loss and pulsatile tinnitus remains to be determined.

Clinical Importance of the Persistent Primitive Trigeminal Artery in Vascular Lesions and Its Role in Endovascular Treatment

The persistent primitive trigeminal artery (PPTA) extends from the internal carotid artery to the basilar artery between the origins of the anterior inferior cerebellar artery and superior cerebellar artery. PPTAs have complex anatomical characteristics. Salas and Saltzman classifications are most often used in PPTAs. The PPTA can play many roles in vascular lesions, including intracranial aneurysms, brain arteriovenous malformations, trigeminal artery-cavernous fistulas, Moyamoya disease, and large vessel occlusion. For these lesions, surgical treatment is difficult due to the deep location and complex anatomy of the PPTA, but endovascular treatment (EVT) has emerged as a good alternative. Currently, a complete review of the clinical importance of the PPTA in terms of its role in the development and EVT of vascular lesions is lacking. Therefore, we conducted a PubMed search, performed a review of the relevant extracted literature and cataloged our experience with PPTAs. By review, we found that a thorough understanding of the anatomical and angiographic features of this PPTA is of utmost importance when making therapeutic decisions for any of these pathological conditions.

Pharyngo-tympano-stapedial middle meningeal artery variant supply to a falcotentorial dural arteriovenous fistula

The pharyngo-tympano-stapedial middle meningeal artery (PTS-MMA) variant has been described in one case report and never in the setting of arterial supply to a dural arteriovenous fistula, to our knowledge. We report the case of a middle-aged patient with severe, daily headache who presented to our institution for angiography and treatment. CT angiography and MRI demonstrated an enlarged left middle meningeal artery coursing to a large venous varix in the falcotentorial region. Dural arteriovenous fistula was confirmed by subsequent cerebral angiography. Endovascular treatment was performed but without complete obliteration of the fistula. Follow-up angiography demonstrated parasitized arterial supply from a right middle meningeal artery arising from the proximal cervical internal carotid artery coursing through the middle ear consistent with a PTS-MMA variant. The fistula was then treated surgically without recurrence at the 6-month follow-up.

The Middle Meningeal Artery: Branches, Dangerous Anastomoses, and Implications in Neurosurgery and Neuroendovascular Surgery

The middle meningeal artery (MMA) has always been the workhorse corridor for devascularization of dural-based intracranial lesions and, more recently, has been established as a target for the endovascular management of chronic subdural hematomas. The MMA anatomy is complex and deceitful, and its territory of irrigation (including cranial nerves) is poorly understood. Furthermore, MMA variations and anastomoses are more frequent than expected, which may predispose to procedure-related morbidity. A literature search was conducted in electronic databases per PRISMA guidelines for studies describing normal and abnormal MMA anatomy including variations in MMA origin and dangerous anastomoses. Our institutional case series of greater than 100 MMA embolizations for management of chronic subdural hematomas were reviewed for abnormal MMA anatomy, and clinically relevant case examples are presented. In this article, we provide a comprehensive review of the MMA to provide a better understanding and appreciation of this artery, including pearls and pitfalls, that we hope will aid the neurosurgeon and neurointerventionalist in safely tackling these lesions.

Sphenoidal artery: review of the literature and analysis of a dissected arterially injected fetal orbit

PURPOSE

The sphenoidal artery is considered a component of the complex and dangerous arterial anastomoses of the human orbitocranial region, particularly with the advent of interventional neuroimaging. The objective of this publication was to analyze the various descriptions of the sphenoidal artery in the literature as related to relevant photographs of a dissected arterially injected fetal middle cranial fossa and orbit.

METHODS

Publications dealing with middle meningeal-ophthalmic arterial anastomoses, focusing on the sphenoidal artery, were reviewed. A relevant dissection of a fetal specimen was analyzed.

RESULTS

The literature dealing with the sphenoidal artery is at times not in agreement. The nomenclature and anatomy of its passage through the superior orbital fissure or Hyrtl canal have variable descriptions. Photographs of the skull base of a dissected arterially injected fetal specimen show bilateral prominent orbital branches of the middle meningeal arteries. These branches entered both orbits in a course similar to the diagrammatic representations of the sphenoidal artery, and give rise to several major intraorbital arteries. This study provides the only photographic image in the literature of this variation in a human fetal anatomic dissection.

CONCLUSIONS

Review of the literature dealing with the sphenoidal artery shows inconsistent nomenclature and conflicting descriptions of its anastomotic connections, and varying evolutionary and embryologic theories. Analysis of the dissected fetal skull base indicates that the sphenoidal artery is not a distinct artery but just a middle meningeal orbital arterial branch, an important component of the complex and dangerous arterial anastomoses of the human orbitocranial region.