A rare variation of the infraorbital nerve, entrapping the infraorbital artery

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Stoyanov This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3930783/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 23 Apr, 2024 Read the published version in Surgical and Radiologic Anatomy → Version 1 posted 7 You are reading this latest preprint version Abstract Anatomical variations are a common feature of the human anatomy. Variation can explain some pathological conditions and is important to keep them in mind during surgical procedures. The relations between nerves and their adjacent arteries have been proposed to play a role in the generation of peripheral trigger migraines. Close opposition between nerves and arteries can lead to vascular compression on the nerve that triggers episodes of pain. We did a routine dissection of the infratemporal fossa and orbital floor by opening the maxillary sinuous. Here we report a case where the infraorbital nerves form a nervous loop entrapping the infraorbital artery in the infraorbital channel. Similar cases of close nervous and arterial apposition are described for the auriculotemporal, and occipital nerves. We think that accumulating knowledge of these rare variations could expand our understanding of rare conditions such as primary infraorbital neuralgia. infraorbital nerve infraorbital nerve variation infraorbital artery entrapment vascular compression migraines Figures Figure 1 Introduction Recent studies on the anatomical variations of the infraorbital neurovascular bundle focus on its position relative to the orbital floor and the maxillary sinus [ 1 – 3 ]. This is very important for aural surgery since the infraorbital neurovascular bundle can often form an osseous channel that passes through the cavity of the maxillary sinus and can be easily damaged during surgical procedures [ 1 ]. The three most reported variants are: 1. The nerve is entirely located within the orbital roof, 2. The nerve is located just below the orbital roof, or 3. The nerve is located entirely in the cavity of the maxillary sinus [ 1 ]. The branching pattern of the infraorbital nerve (ION) after its exit through the infraorbital foramen is another very well-documented side of its anatomy, due to its importance in peripheral nerve blockade. Several cadaver studies focus on the prevalence of a true infraorbital channel versus an infraorbital groove [ 4 , 5 ]. Consulting Bergman's Comprehensive Encyclopaedia of Human Anatomic Variation, along with a literature search revealed a few distinct variants of the ION branching. One of the most reported cases is a bifurcated maxillary nerve. The split occurs just before the nerves enter the orbital cavity. Afterward, both branches can be located in one common or two separate osseous channels and exit via two infraorbital foramina [ 6 – 8 ]. Very few reports focus on the relations of the different elements of the infraorbital neurovascular bundle to each other. In this case, the relation of the nervous and vascular structures is very important. To our knowledge, only one group reported several major patterns in the positioning of the infraorbital nerve and artery in explanted neurovascular bundles of cadavers [ 9 ]. Most often the ION and infraorbital artery (IOA) were parallel to each other, but in some cadavers, the artery formed a “C shape” partially encircling the nerve. Additionally, the formation of a spiral in the ION and IOA was observed, in some cases even greater than 270 o [ 9 ]. Here we demonstrate a previously undescribed relationship of the infraorbital artery and nerve, found during routine cadaver dissection in the settings of medical student education. Results During a routine dissection of the pterygopalatine fossa, the maxillary sinus was opened by removing the medial wall. Next, the posterior and superior walls were removed to expose the pterygopalatine fossa and the infraorbital neurovascular bundle, respectively (Fig. 1 a). When we isolated the ION and IOA, it was initially impossible to separate the two structures to visualise them properly, as they seemed “fused” together. A careful dissection of the neurovascular bundle revealed the ION split in three branches, forming a trifurcation near the trunk of the maxillary nerve (Fig. 1 b). The IOA passed between two of the branches, getting trapped by a nervous loop, as these nerves later fused once more into one nerve, forming relations like the auriculotemporal nerve and the middle meningeal artery (Fig. 1 c). Interestingly, after the fusion of these two branches, they were easily dissected from the third one, ending up as two separate nerves in total. The neurovascular bundle then continues in a bony channel passing through an osseous septum in the maxillary sinus (Fig. 1 d). Legend: MxA - Maxillary artery, MxN - Maxillary nerve, MxS - Maxillary sinus, IOA - Infraorbital artery, ION - Infraorbital nerve, SphS - Sphenoidal sinus, * forceps placed in the nerve loop Discussion There are several reports on the variations in the branching pattern of the ION, but they do not assess the relations of the IOA and ION [ 6 – 8 ]. One group addressed the question and described in depth the relation between the IOA and ION [ 9 ]. Sometimes the IOA was much longer and tortuous, almost engulfing the nerve. The IOA and ION could also spiral round each other [ 9 ]. Interestingly, they did not find a case similar to ours. Here we report a variation, unpublished before in the literature, where the ION splits in tree branches. Later, two of them fuse together, entrapping the IOA in a loop. Another way one could describe this case is as a variation of the double ION, where one of the branches is pierced by the IOA. Although it appears that there is a lot of space for the artery and compression seems unlikely on the dissected hemi-head, before any intervention all the elements were held very tightly together by the surrounding connective tissue. ION neuralgia is a rare condition, most often after trauma in the area [ 10 , 11 ]. ION decompression is done to alleviate treatment-resistant headaches, when the pain is triggered around the innervation of the ION [ 10 , 11 ]. Interestingly, there are reported cases of primary ION neuralgia, e.g. in patients lacking history of craniofacial trauma [ 12 ]. It is currently unknown why this occurs. Since the infraorbital neurovascular bundle is in the infraorbital channel, variations in the relation between the nerve and artery could be crucial in explaining these primary neuralgias. Migraines can be of both peripheral and central origin [ 13 ]. One reason for peripheral trigger migraine can be nerve stimulation due to compression from a nearby blood vessel, fibrous septa, or muscle. Relieving the compression can lead to significant improvement of the symptoms in the vast majority of patients [ 14 – 16 ]. The four main target sites where nerves can undergo decompression surgery or neurolysis are: frontal, occipital, septal and temporal [ 15 – 18 ]. A practical proof of the contribution of vascular compression to the pathogenesis of migraines is the success of vascular depression as a surgical treatment option [ 14 – 16 ]. In the case of blood vessel compression, a longer and more tortuous trajectory of the blood vessel, combined with closer relation the nerve, could lead to compression. Previous cadaveric studies show that the compression of the auriculotemporal nerve may be partially due to its relation to blood vessels. The authors found crossing over or spiralling of the nerve and the adjacent artery [ 18 ]. Similar relations between the vascular and nervous components were also identified for the other trigger points: regarding the occipital neurovascular bundle, spiralling of the occipital artery and the major occipital nerve was observed in approximately 30% of the cases [ 19 ]. Declarations Acknowledgments We would like to express our gratitude to our dissection hall attendants for their general assistance in the dissection sector and diligent maintenance of our donors. I would like to thank Lora Veleva for redacting the English grammar and Andon Mladenov for helping with taking the photos. I also want to tank Stoyan Pavlov for the discussion on how to best present my data. We would also want to acknowledge our donors for their selfless contribution. The authors sincerely thank those who donated their bodies to science so that anatomical research could be performed. Results from such research can potentially increase mankind's overall knowledge that can then improve patient care. Therefore, these donors and their families deserve our highest gratitude. Declarations Author Contribution Stoyanov D. : writing manuscript; dissection. Ethical Approval The cadaver material was obtained in accordance with the Bulgarian Ministry of Health Regulation No. 2 of 18.05.2012. Funding Not applicable Availability of data and materials Not applicable References Ference EH, Smith SS, Conley D, Chandra RK (2015) Surgical Anatomy and Variations of the Infraorbital Nerve Mailleux P, Desgain O, Ingabire MI (2010) Ectopic infraorbital nerve in a maxillary sinus septum: another potentially dangerous variant for sinus surgery. J Belg Soc Radiol 93:308 Jakhere S, Kalmath V, Chillalshetti U (2018) Ectopic Infra Orbital Nerves: Case Series of a Dangerous Normal Variant. ;50 Nguyen DC, Farber SJ, Um GT, Skolnick GB, Woo AS, Patel KB (2016) Anatomical Study of the Intraosseous Pathway of the Infraorbital Nerve. J Craniofac Surg 27:1094–1097 Shadlinskii VB, Guseinov BM, Mustafaeva NA (2017) Branching Variants of the Infraorbital Nerve. Neurosci Behav Physi 47:651–654 Leo JT, Cassell MD, Bergman RA (1995) Variation in human infraorbital nerve, canal and foramen. Annals Anat - Anatomischer Anzeiger 177:93–95 Günay GK, Aycan K, Aksu M, Çoruh A (1998) Double infraorbital nerve as a variation: report of two cases. Eur J Plast Surg 21:405–407 Tubbs RS, Loukas M, May WR, Cohen-Gadol AA (2010) A Variation of the Infraorbital Nerve: Its Potential Clinical Consequence Especially in the Treatment of Trigeminal Neuralgia Case Report. Operative Neurosurg 67:onsE315 Ziccardi VB, Braun TW, Buckley M (1996) Relationship of the Infraorbital Nerve and Vessels in the Pathogenesis of Idiopathic Trigeminal Neuralgia: A Theoretical Discussion and Cadaveric Study. CRANIO® 14:114–120 Beigi B, Beigi M, Niyadurupola N, Saldana M, El-Hindy N, Gupta D (2017) Infraorbital Nerve Decompression for Infraorbital Neuralgia/Causalgia following Blowout Orbital Fractures: A Case Series. Craniomaxillofacial Trauma Reconstruction 10:22–28 Viennas LK, Wagner MS (2021) Infraorbital Nerve Decompression for Chronic Post Traumatic Neuralgia: A Novel Approach and Review of the Safety and Efficacy of Piezoelectric Surgery on Soft Tissues and Nerves. J Craniofac Surg 32:e483–e485 Mahli A, Coskun D (2017) Neurolysis for Treatment of Infraorbital Neuropathy. Case Rep Med 2017:1–4 Do TP, Hougaard A, Dussor G, Brennan KC, Amin FM (2023) Migraine attacks are of peripheral origin: the debate goes on. J Headache Pain 24:3 Guyuron B, Kriegler JS, Davis J, Amini SB (2005) Comprehensive Surgical Treatment of Migraine Headaches. Plast Reconstr Surg 115:1–9 Chen G, You H, Juha H, Lou B, Zhong Y, Lian X et al (2021) Trigger areas nerve decompression for refractory chronic migraine. Clin Neurol Neurosurg 206:106699 Guyuron B, Kriegler JS, Davis J, Amini SB (2011) Five-Year Outcome of Surgical Treatment of Migraine Headaches. Plast Reconstr Surg 127:603–608 Sanniec K, Borsting E, Amirlak B (2016) Decompression–Avulsion of the Auriculotemporal Nerve for Treatment of Migraines and Chronic Headaches. Plast Reconstr Surg - Global Open 4:e678 Chim H, Okada HC, Brown MS, Alleyne B, Liu MT, Zwiebel S et al (2012) The Auriculotemporal Nerve in Etiology of Migraine Headaches: Compression Points and Anatomical Variations. Plast Reconstr Surg 130:336–341 Janis JE, Hatef DA, Reece EM, McCluskey PD, Schaub TA, Guyuron B (2010) Neurovascular Compression of the Greater Occipital Nerve: Implications for Migraine Headaches. Plast Reconstr Surg 126:1996–2001 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 23 Apr, 2024 Read the published version in Surgical and Radiologic Anatomy → Version 1 posted Editorial decision: Revision requested 04 Mar, 2024 Reviews received at journal 11 Feb, 2024 Reviewers agreed at journal 11 Feb, 2024 Reviewers invited by journal 11 Feb, 2024 Editor assigned by journal 07 Feb, 2024 Submission checks completed at journal 07 Feb, 2024 First submitted to journal 05 Feb, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3930783","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":271601676,"identity":"91856860-6741-400d-b796-f770e8b530df","order_by":0,"name":"Stoyanov D. Stoyanov","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABCUlEQVRIiWNgGAWjYDCCwyi8CgQzgYAWAyjvDDFaDiBrYWwjQgvfce7EBwx//sgZHD978DHvvG2JDRLJzz4X1DDkyTtg1yJ5mHezAWObgbHBmbxkY95tt4Fa0oxnzzjGUGx4ALsWg8O82yQYGwwSNxzIMZOcCdSy/8wBY2YeNobEjQ14tDD8AWo5/waoZQ7QFp7jn5l5/hHSwgbUciPHTOJjA1ALe48xM28bQ+J8HN4H+yWxzdhY8sYbY4MPx24bA7UUM/P2SRQb4NDCd/7sxgcf/sjJ8Z3PMXyQUHNbtoGZfTMzzzebPHkcDgODBCBWOIAqJsFgcABTJQrANBOvLaNgFIyCUTCSAACNqV23PLQbDwAAAABJRU5ErkJggg==","orcid":"","institution":"Medical University of Varna","correspondingAuthor":true,"prefix":"","firstName":"Stoyanov","middleName":"D.","lastName":"Stoyanov","suffix":""}],"badges":[],"createdAt":"2024-02-05 11:44:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3930783/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3930783/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00276-024-03368-z","type":"published","date":"2024-04-23T22:39:52+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":50937423,"identity":"8c7ebf82-bb9a-488b-86f0-46f04dc3e2a3","added_by":"auto","created_at":"2024-02-09 21:18:15","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":4804466,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eVariable branching of the infraorbital nerve and its relation the infraorbital artery\u003c/strong\u003e a) An overview of the prosection. The dashed line surrounds the infraorbital neurovascular bundle. The maxillary sinus is opened by removing the medial wall. The posterior wall is also removed, exposing the pterygopalatine fossa. The maxillary artery is exposed, and the infraorbital artery is located. The inferior orbital wall is removed, exposing the neurovascular bundle, b) The three branches of the maxillary nerve are clearly visible held apart by the instruments (asterisks), c) Two of the branches later fused together (marked by arrowheads), forming a nerve loop around the IOA (arrow). The third nerve branch is in the background, d) The neurovascular bundle then continued in a bony channel (forceps is placed inside the channel), located in the maxillary sinus (arrow). \u003cbr\u003e\nLegend: MxA - Maxillary artery, MxN - Maxillary nerve, MxS - Maxillary sinus, IOA - Infraorbital artery, ION - Infraorbital nerve, SphS - Sphenoidal sinus, * forceps placed in the nerve loop\u003c/p\u003e","description":"","filename":"Fig1.png","url":"https://assets-eu.researchsquare.com/files/rs-3930783/v1/06155cb6ad0082e47402b16c.png"},{"id":55690452,"identity":"dfb6e31d-6556-4453-96b2-d335364a1457","added_by":"auto","created_at":"2024-05-01 22:40:00","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3860762,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3930783/v1/3eeb945d-797b-4e41-a81c-b9b21ae353a5.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A rare variation of the infraorbital nerve, entrapping the infraorbital artery","fulltext":[{"header":"Introduction","content":"\u003cp\u003eRecent studies on the anatomical variations of the infraorbital neurovascular bundle focus on its position relative to the orbital floor and the maxillary sinus [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. This is very important for aural surgery since the infraorbital neurovascular bundle can often form an osseous channel that passes through the cavity of the maxillary sinus and can be easily damaged during surgical procedures [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The three most reported variants are: 1. The nerve is entirely located within the orbital roof, 2. The nerve is located just below the orbital roof, or 3. The nerve is located entirely in the cavity of the maxillary sinus [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The branching pattern of the infraorbital nerve (ION) after its exit through the infraorbital foramen is another very well-documented side of its anatomy, due to its importance in peripheral nerve blockade. Several cadaver studies focus on the prevalence of a true infraorbital channel versus an infraorbital groove [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eConsulting Bergman's Comprehensive Encyclopaedia of Human Anatomic Variation, along with a literature search revealed a few distinct variants of the ION branching. One of the most reported cases is a bifurcated maxillary nerve. The split occurs just before the nerves enter the orbital cavity. Afterward, both branches can be located in one common or two separate osseous channels and exit via two infraorbital foramina [\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eVery few reports focus on the relations of the different elements of the infraorbital neurovascular bundle to each other. In this case, the relation of the nervous and vascular structures is very important. To our knowledge, only one group reported several major patterns in the positioning of the infraorbital nerve and artery in explanted neurovascular bundles of cadavers [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Most often the ION and infraorbital artery (IOA) were parallel to each other, but in some cadavers, the artery formed a \u0026ldquo;C shape\u0026rdquo; partially encircling the nerve. Additionally, the formation of a spiral in the ION and IOA was observed, in some cases even greater than 270\u003csup\u003eo\u003c/sup\u003e [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eHere we demonstrate a previously undescribed relationship of the infraorbital artery and nerve, found during routine cadaver dissection in the settings of medical student education.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eDuring a routine dissection of the pterygopalatine fossa, the maxillary sinus was opened by removing the medial wall. Next, the posterior and superior walls were removed to expose the pterygopalatine fossa and the infraorbital neurovascular bundle, respectively (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea). When we isolated the ION and IOA, it was initially impossible to separate the two structures to visualise them properly, as they seemed \u0026ldquo;fused\u0026rdquo; together. A careful dissection of the neurovascular bundle revealed the ION split in three branches, forming a trifurcation near the trunk of the maxillary nerve (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb). The IOA passed between two of the branches, getting trapped by a nervous loop, as these nerves later fused once more into one nerve, forming relations like the auriculotemporal nerve and the middle meningeal artery (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec). Interestingly, after the fusion of these two branches, they were easily dissected from the third one, ending up as two separate nerves in total. The neurovascular bundle then continues in a bony channel passing through an osseous septum in the maxillary sinus (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eLegend: MxA - Maxillary artery, MxN - Maxillary nerve, MxS - Maxillary sinus, IOA - Infraorbital artery, ION - Infraorbital nerve, SphS - Sphenoidal sinus, * forceps placed in the nerve loop\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThere are several reports on the variations in the branching pattern of the ION, but they do not assess the relations of the IOA and ION [\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. One group addressed the question and described in depth the relation between the IOA and ION [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Sometimes the IOA was much longer and tortuous, almost engulfing the nerve. The IOA and ION could also spiral round each other [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Interestingly, they did not find a case similar to ours. Here we report a variation, unpublished before in the literature, where the ION splits in tree branches. Later, two of them fuse together, entrapping the IOA in a loop. Another way one could describe this case is as a variation of the double ION, where one of the branches is pierced by the IOA. Although it appears that there is a lot of space for the artery and compression seems unlikely on the dissected hemi-head, before any intervention all the elements were held very tightly together by the surrounding connective tissue. ION neuralgia is a rare condition, most often after trauma in the area [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. ION decompression is done to alleviate treatment-resistant headaches, when the pain is triggered around the innervation of the ION [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Interestingly, there are reported cases of primary ION neuralgia, e.g. in patients lacking history of craniofacial trauma [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. It is currently unknown why this occurs. Since the infraorbital neurovascular bundle is in the infraorbital channel, variations in the relation between the nerve and artery could be crucial in explaining these primary neuralgias.\u003c/p\u003e \u003cp\u003eMigraines can be of both peripheral and central origin [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. One reason for peripheral trigger migraine can be nerve stimulation due to compression from a nearby blood vessel, fibrous septa, or muscle. Relieving the compression can lead to significant improvement of the symptoms in the vast majority of patients [\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. The four main target sites where nerves can undergo decompression surgery or neurolysis are: frontal, occipital, septal and temporal [\u003cspan additionalcitationids=\"CR16 CR17\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. A practical proof of the contribution of vascular compression to the pathogenesis of migraines is the success of vascular depression as a surgical treatment option [\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. In the case of blood vessel compression, a longer and more tortuous trajectory of the blood vessel, combined with closer relation the nerve, could lead to compression. Previous cadaveric studies show that the compression of the auriculotemporal nerve may be partially due to its relation to blood vessels. The authors found crossing over or spiralling of the nerve and the adjacent artery [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Similar relations between the vascular and nervous components were also identified for the other trigger points: regarding the occipital neurovascular bundle, spiralling of the occipital artery and the major occipital nerve was observed in approximately 30% of the cases [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe would like to express our gratitude to our dissection hall attendants for their general assistance in the dissection sector and diligent maintenance of our donors. I would like to thank Lora Veleva for redacting the English grammar and Andon Mladenov for helping with taking the photos. I also want to tank Stoyan Pavlov for the discussion on how to best present my data.\u003c/p\u003e\n\u003cp\u003eWe would also want to acknowledge our donors for their selfless contribution. The authors sincerely thank those who donated their bodies to science so that anatomical research could be performed. Results from such research can potentially increase mankind\u0026apos;s overall knowledge that can then improve patient care. Therefore, these donors and their families deserve our highest gratitude.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclarations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStoyanov D. : writing manuscript; dissection.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical Approval\u0026nbsp;\u003c/strong\u003eThe cadaver material was obtained in accordance with the Bulgarian Ministry of Health Regulation No. 2 of 18.05.2012.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eFerence EH, Smith SS, Conley D, Chandra RK (2015) Surgical Anatomy and Variations of the Infraorbital Nerve\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMailleux P, Desgain O, Ingabire MI (2010) Ectopic infraorbital nerve in a maxillary sinus septum: another potentially dangerous variant for sinus surgery. J Belg Soc Radiol 93:308\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJakhere S, Kalmath V, Chillalshetti U (2018) Ectopic Infra Orbital Nerves: Case Series of a Dangerous Normal Variant. ;50\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNguyen DC, Farber SJ, Um GT, Skolnick GB, Woo AS, Patel KB (2016) Anatomical Study of the Intraosseous Pathway of the Infraorbital Nerve. J Craniofac Surg 27:1094\u0026ndash;1097\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShadlinskii VB, Guseinov BM, Mustafaeva NA (2017) Branching Variants of the Infraorbital Nerve. Neurosci Behav Physi 47:651\u0026ndash;654\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLeo JT, Cassell MD, Bergman RA (1995) Variation in human infraorbital nerve, canal and foramen. Annals Anat - Anatomischer Anzeiger 177:93\u0026ndash;95\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eG\u0026uuml;nay GK, Aycan K, Aksu M, \u0026Ccedil;oruh A (1998) Double infraorbital nerve as a variation: report of two cases. Eur J Plast Surg 21:405\u0026ndash;407\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTubbs RS, Loukas M, May WR, Cohen-Gadol AA (2010) A Variation of the Infraorbital Nerve: Its Potential Clinical Consequence Especially in the Treatment of Trigeminal Neuralgia Case Report. Operative Neurosurg 67:onsE315\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZiccardi VB, Braun TW, Buckley M (1996) Relationship of the Infraorbital Nerve and Vessels in the Pathogenesis of Idiopathic Trigeminal Neuralgia: A Theoretical Discussion and Cadaveric Study. CRANIO\u0026reg; 14:114\u0026ndash;120\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBeigi B, Beigi M, Niyadurupola N, Saldana M, El-Hindy N, Gupta D (2017) Infraorbital Nerve Decompression for Infraorbital Neuralgia/Causalgia following Blowout Orbital Fractures: A Case Series. Craniomaxillofacial Trauma Reconstruction 10:22\u0026ndash;28\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eViennas LK, Wagner MS (2021) Infraorbital Nerve Decompression for Chronic Post Traumatic Neuralgia: A Novel Approach and Review of the Safety and Efficacy of Piezoelectric Surgery on Soft Tissues and Nerves. J Craniofac Surg 32:e483\u0026ndash;e485\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMahli A, Coskun D (2017) Neurolysis for Treatment of Infraorbital Neuropathy. Case Rep Med 2017:1\u0026ndash;4\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDo TP, Hougaard A, Dussor G, Brennan KC, Amin FM (2023) Migraine attacks are of peripheral origin: the debate goes on. J Headache Pain 24:3\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuyuron B, Kriegler JS, Davis J, Amini SB (2005) Comprehensive Surgical Treatment of Migraine Headaches. Plast Reconstr Surg 115:1\u0026ndash;9\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen G, You H, Juha H, Lou B, Zhong Y, Lian X et al (2021) Trigger areas nerve decompression for refractory chronic migraine. Clin Neurol Neurosurg 206:106699\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuyuron B, Kriegler JS, Davis J, Amini SB (2011) Five-Year Outcome of Surgical Treatment of Migraine Headaches. Plast Reconstr Surg 127:603\u0026ndash;608\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSanniec K, Borsting E, Amirlak B (2016) Decompression\u0026ndash;Avulsion of the Auriculotemporal Nerve for Treatment of Migraines and Chronic Headaches. Plast Reconstr Surg - Global Open 4:e678\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChim H, Okada HC, Brown MS, Alleyne B, Liu MT, Zwiebel S et al (2012) The Auriculotemporal Nerve in Etiology of Migraine Headaches: Compression Points and Anatomical Variations. Plast Reconstr Surg 130:336\u0026ndash;341\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJanis JE, Hatef DA, Reece EM, McCluskey PD, Schaub TA, Guyuron B (2010) Neurovascular Compression of the Greater Occipital Nerve: Implications for Migraine Headaches. Plast Reconstr Surg 126:1996\u0026ndash;2001\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"surgical-and-radiologic-anatomy","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sara","sideBox":"Learn more about [Surgical and Radiologic Anatomy](http://link.springer.com/journal/276)","snPcode":"276","submissionUrl":"https://submission.nature.com/new-submission/276/3","title":"Surgical and Radiologic Anatomy","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"infraorbital nerve, infraorbital nerve variation, infraorbital artery entrapment, vascular compression, migraines","lastPublishedDoi":"10.21203/rs.3.rs-3930783/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3930783/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAnatomical variations are a common feature of the human anatomy. Variation can explain some pathological conditions and is important to keep them in mind during surgical procedures. The relations between nerves and their adjacent arteries have been proposed to play a role in the generation of peripheral trigger migraines. Close opposition between nerves and arteries can lead to vascular compression on the nerve that triggers episodes of pain. We did a routine dissection of the infratemporal fossa and orbital floor by opening the maxillary sinuous. Here we report a case where the infraorbital nerves form a nervous loop entrapping the infraorbital artery in the infraorbital channel. Similar cases of close nervous and arterial apposition are described for the auriculotemporal, and occipital nerves. We think that accumulating knowledge of these rare variations could expand our understanding of rare conditions such as primary infraorbital neuralgia.\u003c/p\u003e","manuscriptTitle":"A rare variation of the infraorbital nerve, entrapping the infraorbital artery","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-02-09 21:18:10","doi":"10.21203/rs.3.rs-3930783/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-03-04T10:12:20+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-02-11T18:37:25+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"25a72889-eb17-45aa-ab81-753b38133ba9","date":"2024-02-11T10:36:14+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-02-11T08:08:56+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-02-07T16:36:02+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-02-07T14:19:39+00:00","index":"","fulltext":""},{"type":"submitted","content":"Surgical and Radiologic Anatomy","date":"2024-02-05T11:35:54+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"surgical-and-radiologic-anatomy","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sara","sideBox":"Learn more about [Surgical and Radiologic Anatomy](http://link.springer.com/journal/276)","snPcode":"276","submissionUrl":"https://submission.nature.com/new-submission/276/3","title":"Surgical and Radiologic Anatomy","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"4623b88e-79b4-425b-87e5-e3f7062d6330","owner":[],"postedDate":"February 9th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-05-01T22:39:52+00:00","versionOfRecord":{"articleIdentity":"rs-3930783","link":"https://doi.org/10.1007/s00276-024-03368-z","journal":{"identity":"surgical-and-radiologic-anatomy","isVorOnly":false,"title":"Surgical and Radiologic Anatomy"},"publishedOn":"2024-04-23 22:39:52","publishedOnDateReadable":"April 23rd, 2024"},"versionCreatedAt":"2024-02-09 21:18:10","video":"","vorDoi":"10.1007/s00276-024-03368-z","vorDoiUrl":"https://doi.org/10.1007/s00276-024-03368-z","workflowStages":[]},"version":"v1","identity":"rs-3930783","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3930783","identity":"rs-3930783","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}