Is orbital floor a reliable and useful surgical landmark in endoscopic endonasal surgery?: a systematic review

Abstract

BackgroundThe orbital floor is considered as an important intraoperative reference point in endoscopic sinonasal surgery. The aim of this review is to evaluate its reliability and usefulness as a surgical landmark in endoscopic endonasal surgery.MethodsA literature search was performed on electronic databases, namely PUBMED. The following keywords were used either individually or in combination: orbital floor; maxillary sinus roof; endoscopic skull base surgery; endoscopic sinus surgery. Studies that used orbital floor as a landmark for endoscopic endonasal surgery were included in the analysis. In addition, relevant articles were identified from the references of articles that had been retrieved. The search was conducted over a period of 6 months between 1st June 2017 and 16th December 2017.ResultsOne thousand seven hundred forty-three articles were retrieved from the electronic databases. Only 5 articles that met the review criteria were selected. Five studies of the orbital floor (or the maxillary sinus roof) were reviewed, one was a cadaveric study while another 4 were computed tomographic study of the paranasal sinuses. All studies were of level III evidence and consists of a total number of 948 nostrils. All studies showed the orbital floor was below the anterior skull base irrespective of the populations. The orbital floor serves as a guide for safe entry into posterior ethmoids and sphenoid sinus.ConclusionsThe orbital floor is a reliable and useful surgical landmark in endoscopic endonasal surgery. In revision cases or advanced disease, the normal landmarks can be distorted or absent and the orbital floor serves as a reference point for surgeons to avoid any unintentional injury to the skull base, the internal carotid artery and other critical structures.

A new radiological classification for the risk assessment of anterior skull base injury in endoscopic sinus surgery

“…Understanding the computed tomography of paranasal sinus (CT PNS) variations in every patient and equipping oneself with the diverse anatomical knowledge is a prerequisite prior to surgery. The frequency of these variations may differ among different populations, but the orbital floor (OF) is always in constant position relative to the skull base that slopes posteriorly [2][3][4][5] . The OF or the medial maxillary sinus roof is known as an important intraoperative reference point to ensure a safe dissection and entry to the posterior sinuses (posterior ethmoid and sphenoid sinuses) [3][4][5][6] .…”

Anatomical Factors that Can Predict the Structure of Lamina Papyracea for Endoscopic Sinus Surgery

“…In order to avoid these, it is important to ascertain anatomical landmarks such as the lamina papyracea, skull base, and middle turbinate when performing surgery 18 . In particular, the lamina papyracea plays an important role as a signpost for approaches to the posterior ethmoid sinus and sphenoid sinus 19 . When opening the posterior ethmoid sinus, a safe method is considered to involve exposing risk areas, such as the lamina papyracea and skull base, sufficiently when opening the anterior ethmoid sinus, and to perforate the third basal lamella in such a manner that the spatial relationships of the posterior ethmoid sinus to other structures can be predicted (Fig.…”

Supreme Nasal Turbinate as an Additional Surgical Landmark in Endoscopic Sinus and Skull Base Surgeries

“…In endoscopic sinus and skull base surgeries (ESSBS), anatomical landmarks are useful to ensure proper identification of sinonasal structures, allow precise dissection and avoid complications. Structures such as middle turbinate (MT), orbital floor and superior turbinate (ST) are recognized as important surgical landmarks in ESSBS [1]. Sphenoid sinus may need to be cleared of disease or as an access to remove tumour at the skull base.…”