| Purpose:The study has offered anatomy data for Endoscopic optic nerve decompressiontreating idiopathic intracranial hypertension and provided references for the clinicaloperations by the anatomical study of the optic canal and its surrounding structures indetail.Materials and methods:20cases of cadaver of Chinese adults head and neck which have been thawed、cleaned、perfused with red latex and fixed with10%formaldehyde,do with it by combininggross anatomy with local giant micro dissection. According to the surgical approach ofdecompression of Optic canal, study the Clinical application of anatomical morphology ofthe optic canal area and measure the important relative date to search and make sure thesurgery sign. Details: Observe the form of optic canal and the relationship between theoptic canal and the ethmoid sinus and sphenoidal sinus; Measure the data related to theoptic canal; Observe the Courser of ophthalmic artery. During the anatomy, use a digitalcamera to film and measure the data with a digital camera and a protractor.Results:1. Optic canal is the channel between the orbit and encephalic and its courser is fromthe inside to the outside under the front which is inverting the “八”. The left include angelbetween the the optic canal and median sagittal plane is (36.54±1.98) degree and the rightis (36.52±1.73) degree.There is not a difference between the left and right side.2. The three types of the relation between the medial wall of optic canal and ethmoid sinus and sphenoidal sinus are Beside the sphenoid sinus type (S type)、Beside the ethmoidsinus type (E type)and sphene ethmoid type(R type).3.The optic canal has four walls、two apertures and one stenosis. The four walls aremedial wall, external wall, superior wall, inferior wall and the two apertures are cranialaperture, orbital aperture and the stenosis is the center. The medial wall of the optic canalis measured to be the longest. The length of the medial wall of the optic canal of the lefteye is (10.94±0.74)mm and the right is (10.85±0.92)mm; The medial wall of the opticcanal is the thinnest, then the superior wall (except the orbital aperture); The cranialaperture is ellipse, the left transverse diameter of which is (6.18±0.57)mm and the right is(6.19±0.46)mm, The left sagittal diameter of the cranial aperture is (5.54±0.44)mm and theright is (5.55±0.47)mm, The left cross sectional area of the cranial aperture is(34.24±0.55)mm~2and the right is (34.85±0.68)mm~2, The orbital aperture is Vertical oval,the left transverse diameter of which is (5.37±0.48)mm and the right is (5.42±0.45)mm,The left sagittal diameter of the cranial aperture is (6.35±0.48)mm and the right is(6.41±0.45)mm, The left cross sectional area of the cranial aperture is (34.10±0.35)mm~2and the right is (34.74±0.56)mm~2; The nearly round middle section of optic canal isnarrowest, the left transverse diameter of which is (4.93±0.41)mm and the right is(4.88±0.39)mm, The left sagittal diameter of the cranial aperture is (4.91±0.29)mm and theright is (4.90±0.30)mm, The left cross sectional area of the cranial aperture is(24.21±0.53)mm~2and the right is (23.91±0.65)mm~2. There are not difference between theleft and right side.4. the optic canal protuberance have three types:full tube type(60%),half tube type(20%) and pressure trace type(20%).5. The Courser of ophthalmic artery in the optic canal: There is80%of ophthalmicartery goes inside below the cranial aperture and the100%of ophthalmic artery goes underthe optic nerve when it is in the middle of optic canal while the85%of the ophthalmicartery goes outside below the optic canal when arriving the orbital aperture of optic canal. Conclusion:The ophthalmic artery goes in the optic canal whose medial wall is the thinnest andlies immediately below the optic nerve or downwards and outwards it or underneath of it,so it would be safe to incise the junction of the inner wall and the superior wall which is inthe the posterior2/3of the optic canal in the decompression of optic canal. |
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