Anatomical Analysis of Intraorbital Structures Regarding Sinus Surgery Using Multiplanar Reconstruction of Computed Tomography Scans

Abstract

ObjectivesThis study aimed to investigate the anatomy of the intraorbital structures regarding to endoscopic sinus surgery and external frontal sinus surgery analyzing computer tomography (CT) scans.MethodsThe CT scans of 100 patients were retrospectively evaluated. The anatomic relationships between the intraorbital structures and paranasal structures were measured using multiplanar reconstruction of the CT scan.ResultsThe mean distances from the medial orbital floor (MOF) to the intraorbital structures were measured at the depth of the anterior ethmoid (AE), basal lamella (BL), and midportion of posterior ethmoid (PE) in the coronal planes respectively. The mean distances from the MOF to the medial rectus muscle and inferior rectus muscle at the depth of AE were approximately 8 mm and those distances in the BL and PE decreased rapidly. The mean distances from the MOF to the infraorbital nerve at the depth of the AE and BL were approximately more than 10 mm. The mean distances from the vertical axis, which passed through the MOF, to the superior oblique muscle and optic nerve at the depth of the PE were approximately 5 mm medially and 1 mm laterally. In addition, the mean distance from the midline to the trochlea of the superior oblique muscle was approximately 15 mm.ConclusionsThose measurements provide spatial information on the placements of the extraocular muscles within the orbit. The measurements will contribute to the avoidance of orbital complications during sinus surgery.

Finite Element Analysis Predicts Large Optic Nerve Head Strains During Horizontal Eye Movements

“…Note that the anterior part of the bony margin was not clearly visible in the MRI image; thus, we had to reconstruct it with information from other X-ray computed tomography images of healthy orbits (we used an anterior diameter of 35 mm). 17 Note also that the anterior portion of our 3D reconstructed eye geometry (anterior portion of the globe and fat) was simplified because we are not concerned with the stress/strain distributions in this area.…”

Surgical Anatomy of the Medial Wall of the Orbit in 14 Human Cadavers

“…They found that the mean distance between the medial orbital floor and the inferior margin of the MRM was 7.3 mm measured at the anterior ethmoid and 2.9 mm at the posterior ethmoid. According to several publications, 15,16 the mean distance between the inferior and superior margins of the MRM lies between 7.2 and 9 mm. Karaki et al 17 suggest that the location of the basal lamella of the middle turbinate (third lamella) is the most important landmark for an endoscopic endonasal approach to the orbital retrobulbar space.…”

“…There are several landmarks that can be useful to open this surgical corridor safely. Hwang et al 15 analyzed the orbit and paranasal sinuses of 100 patients by computed tomographic scan. They found that the mean distance between the medial orbital floor and the inferior margin of the MRM was 7.3 mm measured at the anterior ethmoid and 2.9 mm at the posterior ethmoid.…”

Endoscopic Sinus Surgery in Isolated Frontal Sinus Pathologies: A Tertiary Center Experience

“…Aksiyel ve sagittal kesitlerde frontal sinüsün değerlendirilmesi cerrahi sırasında ortaya çıkabilecek kanamaları ve komşu doku yaralanmalarını en aza indirebilir. 12 Literatürde frontal sinüse uygulanacak ESC sonrası epistaksis, orbital ekimoz, amfizem, diş ağ-rısı, adezyon gelişimi ve frontal ostiumda stenoz gelişimi gibi minör komplikasyonlar ve BOS fistülü, intraorbital hemoraji, körlük, menenjit, beyin absesi, anozmi ve ciddi epistaksis benzeri majör komplikasyonlar bildirilmiştir. [13][14][15] Çalışmamızda bir hastada (%5) postoperatif tampon uygulaması gerektiren epistaksis ve 2 hastada frontal sinus ostiumunda stenoz (%10) gelişti.…”