Localization of Maxillary Artery for Cerebral Revascularization: L-Shaped Perpendicular Two-Step Drilling Technique Stretching from the Foramen Ovale to Rotundum.

BACKGROUND: The use of the maxillary artery (MA) as a donor has increasingly become an alternative method for cerebral revascularization. Localization difficulties emerge due to rich infratemporal anatomical variations and the complicated relationships of the MA with neuromuscular structures. We propose an alternative localization method via the interforaminal route along the middle fossa floor. METHODS: Five silicone-injected adult cadaver heads (10 sides) were dissected. Safe and effective localization of the MA was evaluated. RESULTS: The MA displayed anatomical variations in relation to the lateral pterygoid muscle (LPM) and the mandibular nerve branches. The proposed L-shaped perpendicular 2-step drilling technique revealed a long MA segment that allowed generous rotation to the intracranial area for an end-to-end anastomosis. The first step of drilling involved medial-to-lateral expansion of foramen ovale up to the lateral border of the superior head of the LPM. The second step of drilling extended at an angle approximately 90° to the initial path and reached anteriorly to the foramen rotundum. The MA was localized by gently retracting the upper head of the LPM medially in a posterior-to-anterior direction. CONCLUSIONS: Considering all anatomical variations, the L-shaped perpendicular 2-step drilling technique through the interforaminal space is an attainable method to release an adequate length of MA. The advantages of this technique include the early identification of precise landmarks for the areas to be drilled, preserving all mandibular nerve branches, the deep temporal arteries, and maintaining the continuity of the LPM.

Fascinating wonderful network: Rete mirabile of the maxillary artery in cats - minireview.

Cats are one of the most common companion animals, and they differ from dogs in several important ways. Considering the central importance of anatomy in high-quality medicine, the treatment of the feline mandible, mostly during intraoral procedures requiring general anaesthesia, has many important features. In cats, the major artery of the brain is the maxillary artery that forms unique structure - the rete mirabile. The rete mirabile is a plexus like vascular structure that lies extracranially and communicates with brain arterial circle through the orbital fissure. The development of the brain vasculature is different in cats, and it includes obliteration mechanisms of the internal carotid artery. The course of the maxillary artery that forms the rete mirabile has a strong relationship to the angular process of the mandible. Emphasis should be placed on manipulation with the feline mandible, especially during open-mouth procedures, as mistakes can lead to blindness, deafness, and central neurological disorders due to compression of the maxillary artery by the angular process of the mandible. This paper focuses on the anatomy and function of the blood supply to the brain, which is very specific in domestic cats and other felids.

Radiological evaluation of maxillary artery and descending palatine artery in the pterygopalatine fossa by 3D rotational angiography.

PURPOSE: The aim of this study is to evaluate the branching patterns and topographical features of the third part of the maxillary artery (t-MA) and descending palatine artery (DPA) by 3-Dimensional Rotational Angiography (3DRA) images and to define the radiological classification of their variations, based upon the previous cadaveric studies and a review of the literature. METHOD: This study was conducted from May 2020 through June 2021. All consecutive adult patients who were examined with 3D-RA were enrolled in the study. The morphological evaluations and measurements of t-MA, DPA and their branches were made on maximum intensity projection images with 10-20 mm slice thickness. RESULTS: Eighty-five hemifaces, including 58 females and 45 right sides, were evaluated. The diameter of the t-MA was measured as 1.73 ± 0.30 mm. The most common pattern of the t-MA according to its course was loop type (63/85, 74.1%) and according to branching pattern was Type Ib (29/85, 34.1%). The mean diameter of DPA was 1.19 ± 0.20 mm. The DPA presented as a single trunk in 11/85 cases. Type II, which was defined as one lesser palatine artery originating from distal-DPA, was the most common morphological variation (51.8%). CONCLUSIONS: 3DRA imaging provides valuable information for vascular anatomical studies. The most common morphological variation related to t-MA, DPA is the distal branching pattern.

Pterygopalatine Fossa: Microsurgical Anatomy and its Relevance for Skull Base Surgery

Introduction The purpose of this study was to define the anatomical relationships of the pterygopalatine fossa (PPF) and its operative implications in skull base surgical approaches. Methods Ten cadaveric heads were dissected at the Dianne and M Gazi Yasargil Educational Center MicrosurgicaLaboratory, in Little Rock, AK, USA. The PPF was exposed through an extended dissection with mandible and pterygoid plate removal. Results The PPF has the shape of an inverted cone. Its boundaries are the pterygomaxillary fissure; themaxilla, anteriorly; themedial plate of the pterygoid process, and greater wing of the sphenoid process, posteriorly; the palatine bone,medially; and the body of the sphenoid process, superiorly. Its contents are the maxillary division of the trigeminal nerve and its branches; the pterygopalatine ganglion; the pterygopalatine portion of the maxillary artery (MA) and its branches; and the venous network. Differential diagnosis of PPF masses includes perineural tumoral extension along the maxillary nerve, schwannomas, neurofibromas, angiofibromas, hemangiomas, and ectopic salivary gland tissue. Transmaxillary and transpalatal approaches require extensive resection of bony structures and are narrow in the deeper part of the approach, impairing the surgical vision and maneuverability. Endoscopic surgery solves this problem, bringing the light source to the center of the surgical field, allowing proper visualization of the surgical field, extreme close-ups, and different view angles. Conclusion We provide detailed information on the fossa's boundaries, intercommunications with adjacent structures, anatomy of the maxillary artery, and its variations. It is discussed in the context of clinical affections and surgical approaches of this specific region, including pterygomaxillary disjunction and skull base tumors.

The blood supply of the inferior nasal concha (turbinate): a cadaveric anatomical study.

The blood supply of the lateral nasal wall acquires a great deal of interest for many reasons especially for the treatment of clinical conditions such as epistaxis that sometimes needs surgical interventions and endoscopic sinus and skull base surgeries that requires a good choice of endonasal flaps including inferior nasal concha (commonly named as inferior turbinate by clinicians) flap to close the dural defects. Successful treatment of epistaxis and closure of such defects depends on detailed anatomical knowledge of lateral nasal wall vasculature and a vital flap with good blood supply, respectively. Because of these we aimed to study the blood supply of inferior turbinate, regarding the sources and courses of the blood vessels. Forty formalin-fixed hemisected cadaveric heads were used at Hacettepe University Anatomy Dissection Laboratory. Anatomical dissection of the inferior nasal concha and the lateral nasal wall was done by dissecting microscope. Coloring dye injection to the arteries was performed. After a detailed examination of the lateral nasal wall; the position of the sphenopalatine foramen (SPF) and the sphenopalatine artery (SPA) were identified. The posterior lateral nasal artery (PLNA) found to give middle and inferior conchal (turbinate) arteries. The average length of the inferior turbinate artery (ITA) was 9.057 ± 1.674 mm, the diameter was 1.452 ± 0.172 mm, the distance from posterior end of inferior turbinate was 7.879 ± 1.52 mm. Anastomosis in the lateral nasal wall between the ITA and the anterior ethmoidal and the lateral nasal (branch of the facial artery) arteries were established. The blood supply of inferior nasal concha is mainly provided by ITA and its anastomotic contributors. Detailed knowledge related to it, before surgical interventions, may reduce intraoperative bleeding and increase endoscopic exposure.

Variant facial artery anatomy revisited: Conventional angiography performed in 284 cases.

A number of studies have evaluated the variable courses of facial artery. However, the results of these differed substantially from each other so not consistent relationships have yet been established. There has also yet to be a relevant study using conventional angiography.We assessed the variant branching pattern of the facial artery and its branches using conventional angiography.Two radiologists retrospectively reviewed 284 cases of angiographies of the external carotid artery in 198 patients. The courses of the facial artery and infraorbital branch of the maxillary artery were classified into 4 types and 2 types, according to the end branch.Among 284 cases of facial artery, type 1 (angular branch) made up 104 cases (36.6%), type 2 (lateral nasal branch) made up 138 cases (48.6%), type 3 (superior labial branch) made up 24 cases (8.5%), and type 4 (inferior labial branch) made up 18 cases (6.3%).Regarding the 284 total cases of maxillary artery, 163 cases (57.4%) had anastomosis with the angular artery or extended to the territory of the angular artery. In addition, 121 cases (42.6%) had nothing done in regard to the angular artery.The results may be helpful for avoiding complications related to facial and maxillary arteries during facial surgeries and cosmetic procedures.

Revisiting major anatomical risk factors of maxillary sinus lift and soft tissue graft harvesting for dental implant surgeons.

The anatomical variations of the maxillary sinus septa, greater palatine artery, and posterior superior alveolar arteries might cause unexpected complications when they are damaged. Dentists who know these structures well might hope to learn more practical knowledge to avoid and assess injury preoperatively. Therefore, this review paper aimed to review the reported anatomy and variations of the maxillary sinus septa, greater palatine artery/nerve, and posterior superior alveolar artery, and to discuss what has to be assessed preoperatively to avoid iatrogenic injury. To assess the risk of injury of surgically significant anatomical structures in the maxillary sinus and hard palate, the operator should have preoperative three-dimensional images in their mind based on anatomical knowledge and palpation. Additionally, knowledge of the average measurement results from previous studies is important.

Surgical Anatomy of the Donor Arteries for Extracranial-Intracranial Bypass Surgery: An Anatomic and Radiologic Study.

OBJECTIVE: To review the microsurgical anatomy of the donor arteries for extracranial-intracranial bypass, namely, the superficial temporal artery (STA), occipital artery (OA), and internal maxillary artery (IMA). METHODS: Seven cadaveric specimens were dissected to identify the relationships between each artery and its surrounding structures. Nineteen computed tomographic angiographic images of Japanese adult patients (38 sides) were analyzed to examine the course of each artery and to measure the diameters and distances from various anatomic landmarks to each artery. RESULTS: The courses of the STA, OA, and IMA, which must be exposed during revascularization procedures, were shown via cadaver dissection with special reference to the following relationships to surrounding structures: STA, soft tissue layers of the temporoparietal region and facial nerve; OA, suboccipital muscles; and IMA, mandibular nerve. In addition, we measured the diameter of the anastomotic site for each artery and its relationship with surrounding muscles. CONCLUSIONS: A precise understanding of the anatomic characteristics of the donor arteries and their relationships with surrounding structures provides safe access to these arteries.

Endosteal blood supply of the mandible: anatomical study of nutrient vessels in the condylar neck accessory foramina.

PURPOSE: In the mandible, the condylar neck vascularization is commonly described as mainly periosteal; while the endosteal contribution is still debated, with very limited anatomical studies. Previous works have shown the contribution of nutrient vessels through accessory foramina and their contribution in the blood supply of other parts of the mandible. Our aim was to study the condylar neck's blood supply from nutrient foramina. METHODS: Six latex-injected heads were dissected and two hundred mandibular condyles were observed on dry mandibles searching for accessory bone foramina. RESULTS: Latex-injected dissections showed a direct condylar medular arterial supply through foramina. On dry mandibles, these foramina were most frequently observed in the pterygoid fovea in 91% of cases. However, two other accessory foramina areas were identified on the lateral and medial sides of the mandibular condylar process, confirming the vascular contribution of transverse facial and maxillary arteries. CONCLUSIONS: The maxillary artery indeed provided both endosteal and periosteal blood supply to the condylar neck, with three different branches: an intramedullary ascending artery (arising from the inferior alveolar artery), a direct nutrient branch and some pterygoid osteomuscular branches.

The mental artery: anatomical study and literature review.

The mental artery is a terminal branch of the inferior alveolar artery arising from the maxillary artery. It often communicates with the submental and inferior labial arteries branching off the facial artery. To our knowledge, few reports have described its anatomy and clinical significance in detail. The aim of this paper was to clarify the anatomy of the mental artery. Ten sides from five embalmed Caucasian cadaveric heads were used. The facial artery was identified at the point passing through a notch for the facial vessels and was traced medially. The mental artery and its anastomoses with other arteries were observed in detail. It was detected on all sides. Fourteen anastomoses were found, eight with the inferior labial artery and six with the submental artery. On one side, the mental artery directly supplied the lower lip with no anastomosis. The inferior labial artery tended to anastomose with the mental artery superior to the mental foramen and was likely to anastomose with the submental artery anterior to the mental foramen. We clarified the detailed anatomy of the mental artery. Our results could provide dentists with information that will help them to make oral surgery safer and more successful.

Ultrasonographic assessment of the maxillary artery and middle meningeal artery in the infratemporal fossa.

PURPOSE: To investigate with Doppler ultrasonography the maxillary and middle meningeal arteries in the infratemporal fossa, and describe their hemodynamic characteristics. METHODS: We included 24 female and 11 male volunteers without vascular diseases, with a median age of 43 years. We used the acoustic window, enlarged by subjects half-opening their mouth, located below the zygomatic arch, in front of temporo-mandibular joint, to reach the maxillary and middle meningeal arteries. RESULTS: In the 35 subjects, 112 arteries were visualized successfully: 60 maxillary (85.7%), and 52 middle meningeal arteries (74.3%), at a depth of 2.40 and 2.50 cm, respectively. Their blood flow was directed anteriorly and away from the probe. While all the measured hemodynamic characteristics differed significantly between the maxillary and the middle meningeal artery (P < 0.001), there was no significant difference between male and female subjects, nor between the left or the right side. CONCLUSIONS: The maxillary and middle meningeal arteries can be insonated in the infratemporal fossa through the easily accessible acoustic window below the zygomatic arch, when the patient holds his mouth half open. They can be differentiated by their ultrasonographic characteristics and blood flow features.

Intraoral Endoscopic Ligation of Maxillary Artery in the Infratemporal Fossa.

Ligation of the sphenopalatine and posterior nasal arteries is indicated for posterior epistaxis as initial treatment or when conservative measures fail. In some patients, a transnasal approach or its alternative transantral approach are not possible due to tumor filling the nasal corridor, pterygopalatine fossa, or maxillary sinus. Aim of this study was to evaluate feasibility of endoscopically assisted transoral approach for the ligation of the maxillary artery (MA). Six fresh cadaver specimens (12 sides), previously prepared with intravascular injections of colored latex, were dissected. A combined transnasal and transoral approach exposed the MA from the deep belly of the temporalis muscle laterally to its terminal branches medially. Anatomical relationships of the MA with the deep belly of the temporalis muscle and the lower head of the lateral pterygoid muscle, and feasibility of access to the MA via a transoral approach were assessed. In all specimens, the MA was found at the point where horizontal fibers of the lower head of the lateral pterygoid muscle cross the vertical fibers of the deep belly of the temporalis muscle. In 5 specimens, the artery ran anteriorly and laterally to lower head of the lateral pterygoid muscle, and in 1 specimen, it ran posteriorly and medially to this muscle, diving between its fibers. The modified endoscopically assisted transoral approach is feasible to ligate the MA. It can be used for proximal vascular control in cases when transnasal and transantral approaches are not viable.

Trifurcated external carotid artery and complete gamma-loop of its maxillary branch.

The external carotid artery (ECA) normally bifurcates terminally with the superficial temporal artery (STA) and the maxillary artery (MA). From the horizontally coursing, mandibular segment of the MA leaves the middle meningeal artery (MMA). We hereby report a previously unknown anatomic possibility, incidentally found during an angio-CT scan in an adult female patient. Unilaterally, the ECA was terminally trifurcated, sending off the MA, STA, and MMA. On that side, the mandibular segment of the MA had a gamma-loop and the contralateral one had a U-loop; both these loops were inferior to the lateral pterygoid muscle, closely approaching the respective lingula of the mandible. These findings are relevant during surgery of the parotid gland and infratemporal fossa, approaches of the MMA, and inferior alveolar nerve blocks. The modified origin of the MMA could be explained by an altered development of the primitive stapedial artery.

Arterial Blood Supply of the Nose: An Angiographic Study.

OBJECTIVE: To define anatomical variations associated with arterial blood supply of the nose which has clinical implications on the management of different disorders, especially intractable posterior epistaxis. STUDY DESIGN: Case series. METHODS: Selective angiography of external and internal carotid arteries of 100 patients scheduled for routine angiography was done. RESULTS: Different anatomical variations were documented. The ophthalmic artery can arise from the middle meningeal artery in 1% while ethmoidal arteries can be absent in 5%. The maxillary artery courses as 2 loops in the pterygopalatine fossa in 64% of cases where the descending palatine artery originates before the first loop or on its top so that caution is needed in controlling epistaxis. The sphenopalatine artery has different patterns of branching and may have more than 2 branches in 18% of cases. In 19% of cases, there is cross-circulation between both sides through the nasal blood supply. CONCLUSION: Angiographic study of the nose is a very helpful tool for accurate knowledge of anatomical variations of the arteries with a tremendous effect on our surgical approaches and techniques for the management of different diseases in the nasal region, especially intractable posterior epistaxis.

Morphological and morphometric characterization of the "sphenoidal tubercle" / Caracterización morfológica y morfométrica del tubérculo esfenoidal

The sphenoidal tubercle is a bone elevation located in the anterior edge of the infratemporal crest of the sphenoid greater wing, where the temporal and lateral pterygoid muscles have their origin. This bone accident presents varied morphology so its description and denomination are a topic of discussion. 60 dry skulls obtained from the morphology laboratory of the Biomedical Basic Sciences Department of the University of Talca were used for a morphological and morphometric analysis of the sphenoidal tubercle including its morphology, diameters (anteroposterior, transverse and vertical) and the distance to the grooves for the maxillary artery and maxillary nerve. Sphenoidal tubercle had a prevalence of 98.4 % of all dry skulls analyzed with a bilateral presentation in the 76.6 % of the cases. According to its different forms of presentation established by Cáceres et al., (2016) the pyramidal form was the most frequent with a 25.7 %. The average diameters were of 4.12 mm anteroposterior, 5.50 mm transverse and 3.89 mm vertical. The average distance to the grooves of the maxillary artery and maxillary nerve were 9.04 mm and 7.6 mm, respectively. Sphenoidal tubercle is a constant bone accident with a variated morphology and measures. Due to its anatomical relations with important neurovascular elements such as the maxillary artery and the maxillary nerve, it may be used as a reference point for surgical access to the infratemporal fossa. From this analysis we establish that the denomination of "infratemporal process" is more accurate, because the development of this bone accident is from muscular traction performed by the lateral pterygoid muscle and the deep portion of the temporal muscle causing great variations in its morphology, probably due to external and functional parameters or even influenced by the biotype.

El tubérculo esfenoidal es una elevación ósea ubicada en el extremo anterior de la cresta infratemporal del ala mayor del hueso esfenoides, donde presta inserción al músculo temporal y pterigoideo lateral. Presenta morfología variada, por lo que su descripción y denominación resultan motivo de discusión. 60 cráneos secos obtenidos del Laboratorio de Morfología del Departamento de Ciencias Básicas Biomédicas de la Universidad de Talca, fueron utilizados para realizar un análisis morfológico y morfométrico del tubérculo esfenoidal evaluando forma, diámetros (anteroposterior, laterolateral y vertical) y distancia con el surco de la arteria y nervio maxilar. El tubérculo esfenoidal tuvo una prevalencia del 98,4 % del total de cráneos analizados, presentándose bilateralmente en el 76,6 % de los casos. De acuerdo a las diferentes formas de presentación establecidas por Cáceres et al (2016) la forma piramidal fue la más frecuente con un 25,7 %. Los diámetros promedio fueron de 4,12 mm anteroposterior, 5,50 mm laterolateral y 3,89 mm vertical. Las distancias promedio con el surco de la arteria y nervio maxilar fueron de 9,04 mm y 7,6mm, respectivamente. El tubérculo esfenoidal es un accidente óseo constante de morfología y dimensiones variadas. Debido a sus relaciones con elementos vasculares de importancia, tales como la arteria y nervio maxilar, podría ser utilizado como elemento de referencia para el acceso quirúrgico a la fosa infratemporal. A partir de su análisis planteamos que su denominación como "proceso infratemporal" sería más apropiado, debido a que se desarrollaría a partir de la tracción muscular ejercida por el musculo pterigoideo lateral y la porción profunda del músculo temporal, ocasionando variaciones notables en su morfología, probablemente debido a factores externos y funcionales o incluso influenciada por el biotipo.

Internal Maxillary Artery to Anterior Circulation Bypass with Local Interposition Grafts Using a Minimally Invasive Approach: Surgical Anatomy and Technical Feasibility.

BACKGROUND: The internal maxillary artery (IMA) is a reliable donor for extracranial-intracranial high-flow bypasses. However, previously described landmarks and techniques to harvest the IMA are complex and confusing and require extensive bone drilling, carrying significant neurovascular risk. The objective of our study was to describe a minimally invasive technique for exposing the IMA and to assess the feasibility of using the IMA as a donor for anterior-circulation recipient vessels using 2 different local interposition vessels. METHODS: Via a minimally invasive technique, the IMA was harvested in 10 cadaveric specimens and a pterional craniotomy was performed. Two interposition grafts-the superficial temporal artery (STA) and middle temporal artery-were evaluated individually. Transsylvian exposure of the second segment of middle cerebral artery (M2), the supraclinoid internal carotid artery, and the proximal postcommunicating anterior cerebral artery segment was completed. Relevant vessel calibers and graft lengths were measured for each bypass model. RESULTS: The mean caliber of the IMA was 2.7 ± 0.5 mm. Of all 3 recipients, the shortest graft length was seen in the IMA-STA-M2 bypass, measuring 42.0 ± 8.4 mm. There was a good caliber match between the M2 (2.4 ± 0.4 mm) and STA (2.3 ± 0.4 mm) at the anastomotic site. The harvested middle temporal artery was sufficient in length in only 30% cases, with a mean distal caliber of 2.0 ± 0.7 mm. CONCLUSIONS: This study confirmed the technical feasibility of IMA as a donor for an extracranial-intracranial bypass to the second segment of the anterior cerebral artery, M2, and the supraclinoid internal carotid artery. However, IMA-STA-M2 was observed to be the most suitable bypass model.

The Face ­ A Vascular Perspective. A literature review

Vascular supply is key for maintenance of healthy tissue conditions but also with regard to healing following trauma or therapeutic interventions. The face is probably the most exposed part of the body and any changes of vascularity are readily visible (skin blanching, ecchymosis, hematoma, edema). With regard to the arterial supply, all vessels reaching the facial skin originate from the bilateral common carotid arteries. The ophthal­mic artery is considered the major arterial shunt between the internal and external carotid artery systems. Main arterial contributors to the face include the facial, transverse facial, and infraorbital arteries. In general, homonymous veins accompany the arteries, but there are some exceptions (inferior ophthalmic vein, retromandibular vein). Furthermore, the facial vein demonstrates a consistently more posterior course compared to the facial artery. Lymphatic vessels including lymph nodes play an important role for facial drainage.

Arterial Vascularization of the Mandibular Condyle and Fractures of the Condyle.

BACKGROUND: Despite substantial displacements, fractures of the mandibular condyle rarely lead to necrosis. This illustrates the negligible role of the inferior alveolar artery in intraosseous supply to the condyle, and led to this systematization of its arterial vascularization. METHODS: Forty-two temporomandibular joints from nonembalmed cadaveric specimens were studied following injection of latex (n = 32) or India ink (n = 10). RESULTS: The intraosseous branches of the inferior alveolar artery that lead to the condyle were inconstant and often rudimentary. In this study, the arteries that consistently led to the condyle were the superficial temporal artery, the deep posterior temporal artery, and arterial branches leading to the lateral pterygoid muscle emanating directly from the maxillary artery. These arteries, along with the transverse facial artery and the masseteric artery (when they participated in condoyle vascularization), formed a quadrangle around the mandibular condyle. After India ink injection, the pterygoid muscle was the most strongly colored muscle, thus indicating substantial vascularization. CONCLUSIONS: Although there is a lack of consensus in the literature regarding the constancy and proportions of the arteries participating in vascularization of the condyle, the superficial temporal artery, the maxillary arterial branches leading to the lateral pterygoid muscle, and the deep posterior temporal artery were constant in this study. This study shows the important role of the lateral pterygoid in the vascularization of the condyle. In case of a fracture with substantial displacement, the vascularization emanating from the superficial temporal artery and the lower alveolar artery is ruptured or compromised.

Microsurgical anatomy of the maxillary artery for extracranial-intracranial bypass in the pterygopalatine segment of the maxillary artery.

The extracranial-intracranial (EC-IC) bypass using the maxillary artery (MA) has been successfully completed using a radial artery (RA) graft but the complicated anatomy and narrow exposure make it difficult. The purpose of this article is to define the microsurgical exposure of the MA through the middle fossa and describe the branches, diameter, and length of the MA available for the EC-IC bypass in the sphenopalatine fossa and anterior part of the infratemporal fossa. 5 cadaveric specimens were dissected bilaterally (10 MA dissections) to define the microsurgical anatomy of the MA through an intracranial approach. The exposable branches of the MA at the level of the infratemporal and sphenopalatine fossae were the anterior deep temporal, posterior superior alveolar, and infraorbital arteries. The origin of each branch could be exposed. The available section of the MA for use as a donor vessel is between the origin of the anterior deep temporal artery and the infraorbital artery. The mean exposable length of the MA was 19.4 mm. The mean outer diameter of the donor MA was 3.2 mm. Tension-free EC-IC bypass was possible using a RA graft between the MA and the middle cerebral artery, the MA and the supraclinoid internal carotid artery (ICA), or the MA and the petrous ICA. Exposure of the MA at the infratemporal and sphenopalatine fossae is complicated but provides length and diameter suitable as a donor artery for the EC-IC bypass. Clin. Anat. 31:724-733, 2018. © 2017 Wiley Periodicals, Inc.

Unusual origin and relations of the accessory meningeal artery: a case report / Origen inusual y relaciones de la arteria meníngea accesoria: reporte de un caso

SUMMARY: Accessory meningeal artery is a branch of the first part of the maxillary artery. It supplies the structures in the infratemporal fossa and the dura mater in the middle cranial fossa. Accessory meningeal artery arose from the middle meningeal artery, 25 mm below the base of the skull and entered the middle cranial fossa through the foramen ovale. The two roots of the auriculotemporal nerve looped around it. The knowledge of the variant origin and relations may be useful during the surgeries of the infratemporal fossa. It might also be useful to the radiologists.

RESUMEN: La arteria meníngea media es una rama accesoria que emerge al inicio de la arteria maxilar. Suministra la vascularización a nivel de la fosa infratemporal y la duramadre en la fosa craneal media. En este trabajo, surgió una arteria meníngea accesoria de la arteria meníngea media, a una 25 mm por debajo de la base del cráneo, accediendo en la fosa craneal media a través del foramen oval. Las dos raíces del nervio auriculotemporal la rodeaban. El conocimiento de esta variación y sus relaciones pueden ser útiles durante las cirugías de la fosa infratemporal, como así también puede ser útil para los radiólogos.