Veronica Macchi1, Marì Regoli2, Sandra Bracco3, Claudio Nicoletti4, Aldo Morra5, Andrea Porzionato1, Raffaele De Caro1, Eugenio Bertelli6. 1. Department of Molecular Medicine, Institute of Human Anatomy, University of Padova, Via A. Gabelli 65, 35127, Padua, Italy. 2. Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100, Siena, Italy. 3. Unit of Neuroimaging and Neurointervention (NINT), Azienda Ospedaliera Universitaria Senese (AOUS), University of Siena, Policlinico "Santa Maria alle Scotte", Siena, Italy. 4. Gut Health and Food Safety Institute Strategic Program, Institute of Food Research, Norwich, UK. 5. Section of Radiology, Euganea Medica Center, Via Colombo 3, Sant'Agostino Di Albignasego, 35127, Padua, Italy. 6. Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100, Siena, Italy. eugenio.bertelli@unisi.it.
Abstract
PURPOSE: In addition to the optic canal and the superior orbital fissure, orbits are connected with the cranial cavity via inconstant canals including the orbitomeningeal foramen. This study has been carried out in order to define many anatomical and radiological details of the orbitomeningeal foramen that are relevant in the clinical practice. METHODS: Almost 1000 skulls and 50 computerized tomographies were examined to determine incidence, number, length, and caliber of the orbitomeningeal foramen as well as the topography of their orbital and cranial openings. A retrospective study of angiographies carried out on more than 100 children was performed to look for arteries candidate to run through the orbitomeningeal foramen. RESULTS: Orbitomeningeal foramina were detected in 59.46% of skulls and in 54% of individuals by computerized tomography. Orbits with two to five foramina were found. Canals were classified as M-subtype or A-subtype depending on their cranial opening. Large foramina, with the caliber ranging between 1 and 3 mm, were found in 12.17% of orbitomeningeal foramen-bearing orbits. By computed tomography the average caliber measured 1.2 ± 0.3 and 1.5 ± 0.5 mm (p < 0.005) at the orbital and cranial openings, respectively (p < 0.005). Angiographies showed meningo-lacrimal and meningo-ophthalmic arteries, meningeal branches of the lacrimal and supraorbital arteries, and some unidentified arteries that could pass through the orbitomeningeal foramina. CONCLUSIONS: Orbitomeningeal foramina are a common occurrence. When large they may house important arteries that can be the source of severe bleedings during deep dissection of the lateral wall of the orbit. Orbital surgeons should be aware of their existence.
PURPOSE: In addition to the optic canal and the superior orbital fissure, orbits are connected with the cranial cavity via inconstant canals including the orbitomeningeal foramen. This study has been carried out in order to define many anatomical and radiological details of the orbitomeningeal foramen that are relevant in the clinical practice. METHODS: Almost 1000 skulls and 50 computerized tomographies were examined to determine incidence, number, length, and caliber of the orbitomeningeal foramen as well as the topography of their orbital and cranial openings. A retrospective study of angiographies carried out on more than 100 children was performed to look for arteries candidate to run through the orbitomeningeal foramen. RESULTS: Orbitomeningeal foramina were detected in 59.46% of skulls and in 54% of individuals by computerized tomography. Orbits with two to five foramina were found. Canals were classified as M-subtype or A-subtype depending on their cranial opening. Large foramina, with the caliber ranging between 1 and 3 mm, were found in 12.17% of orbitomeningeal foramen-bearing orbits. By computed tomography the average caliber measured 1.2 ± 0.3 and 1.5 ± 0.5 mm (p < 0.005) at the orbital and cranial openings, respectively (p < 0.005). Angiographies showed meningo-lacrimal and meningo-ophthalmic arteries, meningeal branches of the lacrimal and supraorbital arteries, and some unidentified arteries that could pass through the orbitomeningeal foramina. CONCLUSIONS: Orbitomeningeal foramina are a common occurrence. When large they may house important arteries that can be the source of severe bleedings during deep dissection of the lateral wall of the orbit. Orbital surgeons should be aware of their existence.
Entities:
Keywords:
Meningo-lacrimal artery; Meningo-ophthalmic artery; Orbit; Orbital surgery; Orbitomeningeal foramen