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Ethmoidal Arteries and Vascularized Anterior Skull Base Lesions
Perspectives Commentary on: Anterior and Posterior Ethmoidal Artery Ligation in Anterior Skull Base Meningiomas: A Review on Microsurgical Approaches by Cecchini World Neurosurg 84:1161-1165, 2015
Ethmoidal Arteries and Vascularized Anterior Skull Base Lesions Leonidas M. Quintana
A
nterior skull base vascularized tumors, such as meningiomas of the olfactory grooves and tuberculum sellae, and vascular lesions such as arteriovenous dural fistulas or arteriovenous malformations represent a special challenge to surgeons because of the complex anatomy and vascularization of this area. Although small lesions are easy to remove, large lesions, such as big meningiomas, can create complex situations. The most difficult aspects include not only the approach and removal but also the repair of the defects created by the resection of these lesions. One surgical technical nuance that always must be considered before the operation itself and that should be carefully planned is to prevent excessive bleeding of the lesion secondary to the arterial feeders from the neighboring anatomic structures.
With this surgical technique, neurosurgeons not only must always consider the surgical anatomy of the region to be treated but also the vascular surgical anatomy of the neighboring structures. Studying the microsurgical anatomy can help delineate the course of the anterior and posterior ethmoidal arteries and the arteries coming from the external carotid artery main branches and find the best points for proximal control of the blood supply to these lesions. This Perspective focuses on the importance of the ethmoidal arteries and vascularized anterior skull base lesions. The anterior ethmoidal artery branches from the ophthalmic artery and then accompanies the nasociliary nerve through the anterior ethmoidal canal to supply the anterior and middle ethmoidal cells, frontal sinus, and anterosuperior aspect of the lateral nasal wall. When entering the cranium, it gives off 1) a meningeal branch to the dura mater and 2) nasal branches. These
Key words Anterior skull base meningioma - Arterial ligation - Meningioma - Olfactory groove meningioma -
WORLD NEUROSURGERY 84 [4]: 881-883, OCTOBER 2015
descend into the nasal cavity through the slit by the side of the crista galli; running along the groove on the inner surface of the nasal bone, they supply branches to the lateral wall and septum of the nose and a terminal branch that appears on the dorsum of the nose between the nasal bone and the lateral cartilage. The posterior ethmoidal artery is smaller than the anterior ethmoidal artery. After branching from the ophthalmic artery, it passes between the upper border of the medial rectus muscle and superior oblique muscle to enter the posterior ethmoidal canal. It exits into the nasal cavity to supply the posterior ethmoidal cells and nasal septum, and it anastomoses with the sphenopalatine artery. There is often a meningeal branch to the dura mater while it is still contained within the cranium. This artery supplies the posterior ethmoidal air sinuses, dura mater of the anterior cranial fossa, and the upper part of the nasal mucosa of the nasal septum (Figure 1). There are some important reference points for microsurgical approaches to the anterior ethmoidal artery and the posterior ethmoidal artery over the medial orbital wall. The so-called rule of 7 can be useful to remember the location of the foramen in the medial orbital wall: The anterior ethmoidal canal is on average 21 mm posterior to the lacrimal crest or to the medial orbital ridge, the posterior ethmoidal canal is about 14 mm posterior to the anterior canal, and the optic canal is on average 7 mm posterior to the posterior ethmoidal canal (3). As pointed out by Cecchini in his article, “Anterior and posterior ethmoidal artery ligation in anterior skull base meningiomas: a review on microsurgical approaches,” the anterior skull base meningioma vasculature is complex and may require various surgical techniques to be managed. Tumors in this region may
Department of Neurosurgery, Valparaíso University School of Medicine, Valparaíso, Chile To whom correspondence should be addressed: Leonidas M. Quintana, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2015) 84, 4:881-883. http://dx.doi.org/10.1016/j.wneu.2015.06.025
www.WORLDNEUROSURGERY.org
881
PERSPECTIVES
Figure 1. Superior intraorbital view of the bulb, optic nerve, ophthalmic artery, and branching anterior and posterior ethmoidal arteries passing through the anterior and posterior ethmoidal canal to reach the cribriform plate and entering the anterior falx and surrounding dura mater. This figure also shows how difficult it is to perform an embolization selectively through the ophthalmic artery to the ethmoidal arteries.
recruit arteries that normally supply the margins of the superior orbital fissure, including the anterior branch of the middle meningeal artery, the recurrent meningeal branches of the ophthalmic and lacrimal arteries, the meningeal branches of the internal carotid artery, the tentorial branch of the meningohypophyseal trunk, the anterior branch of the inferolateral trunk, and the terminal branches of the internal maxillary artery. The presence of multiple anastomoses puts vision at high risk when endovascular embolization is performed (1, 6, 7), and the preoperative role of endovascular embolization is still controversial. It has been shown to reduce surgery time and intraoperative blood loss and consequently blood transfusion requirements (2, 5), although only complete embolization seemingly gives good results. Moreover, safe embolization is often limited by dangerous anastomoses found between the external carotid artery and internal carotid artery branches or by an aberrant origin of the middle meningeal artery from the ophthalmic artery or vice versa. Embolization of the anterior and posterior ethmoidal arteries can be dangerous because of the possible retrograde migration of embolic particles, which can result in blindness from occlusion of the ophthalmic artery (Figure 1) (1). Therefore, I summarize here the main microsurgical techniques employed to decrease the vascularization coming from the ethmoidal arteries to the anterior skull base lesion. These different approaches depend on the school where the surgical techniques are learned. There are 2 standard approaches to the anterior cranial base. Subfrontal intradural access has been
882
www.SCIENCEDIRECT.com
the standard approach, with the argument that adequate proximal control of anterior and posterior ethmoidal feeding vessels can be obtained by resecting the inferior part of the lesion and coagulating feeders above the cribriform plate. This approach may be unilateral; in this case, usually the frontopterional-transsylvian approach is added to minimize the retraction over the frontal lobe for the resection of the anterior cranial fossa lesion. Alternatively, a bifrontal craniotomy may be used that may be bilateral subfrontal or bifrontal, with an interhemispheric approach to the tuberculum sellae and cribriform plate. Also, feeders above the cribriform plate can be coagulated. Using this approach, the retraction over both frontal lobes also is minimized. This surgical technique may be completed with combined coagulation at the base of the tumor, slowly reaching the cribriform plate or the tuberculum sellae, and debulking of the tumor. The aforementioned approaches are 2 classic techniques. However, other authors have advocated a cranial base approach for very large vascular lesions (tumors or arteriovenous malformations) of the anterior cranial base to obtain early control of proximal ethmoidal arteries, which may decrease the amount of blood loss while minimizing frontal lobe retraction (8). Other authors have also favored extradural access to the ethmoidal arteries in the medial orbital wall with subperiosteal, subperiorbital dissection, which can be accomplished through a bicoronal skin flap (4). A single-piece fronto-orbital craniotomy allows for 3 extradural sites for proximal control.
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2015.06.025
PERSPECTIVES
Finally, Giulio Cecchini presents an interesting technique to approach the lesion, to ligate on the medial orbital wall the anterior and posterior ethmoidal arteries through an orbital
REFERENCES 1. Bendszus M, Monoranu CM, Schütz A, Nölte I, Vince GH, Solymosi L: Neurologic complications after particle embolization of intracranial meningiomas. AJNR Am J Neuroradiol 26:1413-1419, 2005.
surgical technique. All of these surgical techniques have been proven successful, and the specific technique should be applied in accordance with the experience of the neurosurgeon.
4. McDermott MW, Rootman J, Durity FA: Subperiosteal, subperiorbital dissection and division of the anterior and posterior ethmoid arteries for meningiomas of the cribriform plate and planum sphenoidale: technical note. Neurosurgery 36: 1215-1219, 1995.
2. Bendszus M, Rao G, Burger R, Schaller C, Scheinemann K, Warmuth-Metz M, Hofmann E, Schramm J, Roosen K, Solymosi L: Is there a benefit of preoperative meningioma embolization? Neurosurgery 47:1306-1311; discussion 1311-1312 2000.
5. Nania A, Granata F, Vinci S, Pitrone A, Barresi V, Morabito R, Settineri N, Tomasello F, Alafaci C, Longo M: Necrosis score, surgical time, and transfused blood volume in patients treated with preoperative embolization of intracranial meningiomas. Analysis of a single-centre experience and a review of literature. Clin Neuroradiol 24:29-36, 2014.
3. Martins C, Costa E Silva IE, Campero A, Yasuda A, Aguiar LR, Tatagiba M, Rhoton A: Microsurgical anatomy of the orbit: the rule of seven. Anat Res Int 2011:468727, 2011.
6. Perrini P, Cardia A, Fraser K, Lanzino G: A microsurgical study of the anatomy and course of the ophthalmic artery and its possibly dangerous anastomoses. J Neurosurg 106:142-150, 2007.
7. Singla A, Deshaies EM, Melnyk V, Toshkezi G, Swarnkar A, Choi H, Chin LS: Controversies in the role of preoperative embolization in meningioma management. Neurosurg Focus 35:E17, 2013. 8. White VD, Sincoff HE, Abdulrauf IS: Anterior ethmoidal artery: microsurgical anatomy and technical considerations. Neurosurgery 56(ONS Suppl 2):406-410, 2005.
Citation: World Neurosurg. (2015) 84, 4:881-883. http://dx.doi.org/10.1016/j.wneu.2015.06.025 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2015 Elsevier Inc. All rights reserved.
Photo by Gregory Trost, MD, USA. “The Abbaye de Senanque in Provence sans the famous lavender blooming.” Provence, France
WORLD NEUROSURGERY 84 [4]: 881-883, OCTOBER 2015
www.WORLDNEUROSURGERY.org
883
Ethmoidal Arteries and Vascularized Anterior Skull Base Lesions Leonidas M. Quintana
A
nterior skull base vascularized tumors, such as meningiomas of the olfactory grooves and tuberculum sellae, and vascular lesions such as arteriovenous dural fistulas or arteriovenous malformations represent a special challenge to surgeons because of the complex anatomy and vascularization of this area. Although small lesions are easy to remove, large lesions, such as big meningiomas, can create complex situations. The most difficult aspects include not only the approach and removal but also the repair of the defects created by the resection of these lesions. One surgical technical nuance that always must be considered before the operation itself and that should be carefully planned is to prevent excessive bleeding of the lesion secondary to the arterial feeders from the neighboring anatomic structures.
With this surgical technique, neurosurgeons not only must always consider the surgical anatomy of the region to be treated but also the vascular surgical anatomy of the neighboring structures. Studying the microsurgical anatomy can help delineate the course of the anterior and posterior ethmoidal arteries and the arteries coming from the external carotid artery main branches and find the best points for proximal control of the blood supply to these lesions. This Perspective focuses on the importance of the ethmoidal arteries and vascularized anterior skull base lesions. The anterior ethmoidal artery branches from the ophthalmic artery and then accompanies the nasociliary nerve through the anterior ethmoidal canal to supply the anterior and middle ethmoidal cells, frontal sinus, and anterosuperior aspect of the lateral nasal wall. When entering the cranium, it gives off 1) a meningeal branch to the dura mater and 2) nasal branches. These
Key words Anterior skull base meningioma - Arterial ligation - Meningioma - Olfactory groove meningioma -
WORLD NEUROSURGERY 84 [4]: 881-883, OCTOBER 2015
descend into the nasal cavity through the slit by the side of the crista galli; running along the groove on the inner surface of the nasal bone, they supply branches to the lateral wall and septum of the nose and a terminal branch that appears on the dorsum of the nose between the nasal bone and the lateral cartilage. The posterior ethmoidal artery is smaller than the anterior ethmoidal artery. After branching from the ophthalmic artery, it passes between the upper border of the medial rectus muscle and superior oblique muscle to enter the posterior ethmoidal canal. It exits into the nasal cavity to supply the posterior ethmoidal cells and nasal septum, and it anastomoses with the sphenopalatine artery. There is often a meningeal branch to the dura mater while it is still contained within the cranium. This artery supplies the posterior ethmoidal air sinuses, dura mater of the anterior cranial fossa, and the upper part of the nasal mucosa of the nasal septum (Figure 1). There are some important reference points for microsurgical approaches to the anterior ethmoidal artery and the posterior ethmoidal artery over the medial orbital wall. The so-called rule of 7 can be useful to remember the location of the foramen in the medial orbital wall: The anterior ethmoidal canal is on average 21 mm posterior to the lacrimal crest or to the medial orbital ridge, the posterior ethmoidal canal is about 14 mm posterior to the anterior canal, and the optic canal is on average 7 mm posterior to the posterior ethmoidal canal (3). As pointed out by Cecchini in his article, “Anterior and posterior ethmoidal artery ligation in anterior skull base meningiomas: a review on microsurgical approaches,” the anterior skull base meningioma vasculature is complex and may require various surgical techniques to be managed. Tumors in this region may
Department of Neurosurgery, Valparaíso University School of Medicine, Valparaíso, Chile To whom correspondence should be addressed: Leonidas M. Quintana, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2015) 84, 4:881-883. http://dx.doi.org/10.1016/j.wneu.2015.06.025
www.WORLDNEUROSURGERY.org
881
PERSPECTIVES
Figure 1. Superior intraorbital view of the bulb, optic nerve, ophthalmic artery, and branching anterior and posterior ethmoidal arteries passing through the anterior and posterior ethmoidal canal to reach the cribriform plate and entering the anterior falx and surrounding dura mater. This figure also shows how difficult it is to perform an embolization selectively through the ophthalmic artery to the ethmoidal arteries.
recruit arteries that normally supply the margins of the superior orbital fissure, including the anterior branch of the middle meningeal artery, the recurrent meningeal branches of the ophthalmic and lacrimal arteries, the meningeal branches of the internal carotid artery, the tentorial branch of the meningohypophyseal trunk, the anterior branch of the inferolateral trunk, and the terminal branches of the internal maxillary artery. The presence of multiple anastomoses puts vision at high risk when endovascular embolization is performed (1, 6, 7), and the preoperative role of endovascular embolization is still controversial. It has been shown to reduce surgery time and intraoperative blood loss and consequently blood transfusion requirements (2, 5), although only complete embolization seemingly gives good results. Moreover, safe embolization is often limited by dangerous anastomoses found between the external carotid artery and internal carotid artery branches or by an aberrant origin of the middle meningeal artery from the ophthalmic artery or vice versa. Embolization of the anterior and posterior ethmoidal arteries can be dangerous because of the possible retrograde migration of embolic particles, which can result in blindness from occlusion of the ophthalmic artery (Figure 1) (1). Therefore, I summarize here the main microsurgical techniques employed to decrease the vascularization coming from the ethmoidal arteries to the anterior skull base lesion. These different approaches depend on the school where the surgical techniques are learned. There are 2 standard approaches to the anterior cranial base. Subfrontal intradural access has been
882
www.SCIENCEDIRECT.com
the standard approach, with the argument that adequate proximal control of anterior and posterior ethmoidal feeding vessels can be obtained by resecting the inferior part of the lesion and coagulating feeders above the cribriform plate. This approach may be unilateral; in this case, usually the frontopterional-transsylvian approach is added to minimize the retraction over the frontal lobe for the resection of the anterior cranial fossa lesion. Alternatively, a bifrontal craniotomy may be used that may be bilateral subfrontal or bifrontal, with an interhemispheric approach to the tuberculum sellae and cribriform plate. Also, feeders above the cribriform plate can be coagulated. Using this approach, the retraction over both frontal lobes also is minimized. This surgical technique may be completed with combined coagulation at the base of the tumor, slowly reaching the cribriform plate or the tuberculum sellae, and debulking of the tumor. The aforementioned approaches are 2 classic techniques. However, other authors have advocated a cranial base approach for very large vascular lesions (tumors or arteriovenous malformations) of the anterior cranial base to obtain early control of proximal ethmoidal arteries, which may decrease the amount of blood loss while minimizing frontal lobe retraction (8). Other authors have also favored extradural access to the ethmoidal arteries in the medial orbital wall with subperiosteal, subperiorbital dissection, which can be accomplished through a bicoronal skin flap (4). A single-piece fronto-orbital craniotomy allows for 3 extradural sites for proximal control.
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2015.06.025
PERSPECTIVES
Finally, Giulio Cecchini presents an interesting technique to approach the lesion, to ligate on the medial orbital wall the anterior and posterior ethmoidal arteries through an orbital
REFERENCES 1. Bendszus M, Monoranu CM, Schütz A, Nölte I, Vince GH, Solymosi L: Neurologic complications after particle embolization of intracranial meningiomas. AJNR Am J Neuroradiol 26:1413-1419, 2005.
surgical technique. All of these surgical techniques have been proven successful, and the specific technique should be applied in accordance with the experience of the neurosurgeon.
4. McDermott MW, Rootman J, Durity FA: Subperiosteal, subperiorbital dissection and division of the anterior and posterior ethmoid arteries for meningiomas of the cribriform plate and planum sphenoidale: technical note. Neurosurgery 36: 1215-1219, 1995.
2. Bendszus M, Rao G, Burger R, Schaller C, Scheinemann K, Warmuth-Metz M, Hofmann E, Schramm J, Roosen K, Solymosi L: Is there a benefit of preoperative meningioma embolization? Neurosurgery 47:1306-1311; discussion 1311-1312 2000.
5. Nania A, Granata F, Vinci S, Pitrone A, Barresi V, Morabito R, Settineri N, Tomasello F, Alafaci C, Longo M: Necrosis score, surgical time, and transfused blood volume in patients treated with preoperative embolization of intracranial meningiomas. Analysis of a single-centre experience and a review of literature. Clin Neuroradiol 24:29-36, 2014.
3. Martins C, Costa E Silva IE, Campero A, Yasuda A, Aguiar LR, Tatagiba M, Rhoton A: Microsurgical anatomy of the orbit: the rule of seven. Anat Res Int 2011:468727, 2011.
6. Perrini P, Cardia A, Fraser K, Lanzino G: A microsurgical study of the anatomy and course of the ophthalmic artery and its possibly dangerous anastomoses. J Neurosurg 106:142-150, 2007.
7. Singla A, Deshaies EM, Melnyk V, Toshkezi G, Swarnkar A, Choi H, Chin LS: Controversies in the role of preoperative embolization in meningioma management. Neurosurg Focus 35:E17, 2013. 8. White VD, Sincoff HE, Abdulrauf IS: Anterior ethmoidal artery: microsurgical anatomy and technical considerations. Neurosurgery 56(ONS Suppl 2):406-410, 2005.
Citation: World Neurosurg. (2015) 84, 4:881-883. http://dx.doi.org/10.1016/j.wneu.2015.06.025 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2015 Elsevier Inc. All rights reserved.
Photo by Gregory Trost, MD, USA. “The Abbaye de Senanque in Provence sans the famous lavender blooming.” Provence, France
WORLD NEUROSURGERY 84 [4]: 881-883, OCTOBER 2015
www.WORLDNEUROSURGERY.org
883