Seeing the light: Endoscopic endonasal intraconal orbital tumor surgery

Abstract

Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article. E xternal approaches to the orbit are well established, including the lateral, medial, and inferior orbitotomy. Orbitozygomatic craniotomy can be used for tumors that extend both intracranially and into the orbit and is used for exposure of the optic nerve and canal. 1 Since the 1980s, endoscopic measures have been used to enhance visualization in standard external approaches. 2 Endoscopic endonasal orbital and optic nerve decompressions have become accepted treatments for thyroid eye disease and traumatic optic neuropathy that is unresponsive to steroids. A few case reports of endoscopic decompression, biopsy, and resection of tumors that involve the orbit also have been reported. [3][4][5] The expanded endonasal approach (EEA) has been extended to resection of all types of skull base tumors, including posterior, middle, and anterior fossa masses. In this report, we describe the anatomic principles, indications, technical nuances, and limitations of the medial-inferior intraconal EEA to intraorbital tumor surgery, illustrated through a case series of six patients. This approach is ideally suited to benign soft-tissue masses (hemangioma/lymphangioma) in the medial-inferior quadrant of the orbit that do not extend superolaterally. The use of this technique would avoid the technical difficulties in approaching such masses and limit the dissection to the areas bordering the endonasal corridor.

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“…7,8 If extensive intraconal work is needed, the medial rectus muscle can be medialized and attached to the nasal septum to gain more working room. Furthermore, an anterior septal window can be created to allow a four-hand dissection through the contralateral nasal fossa.…”

Endonasal Endoscopic Approach for Primary and Secondary Orbital Lesions

“…In intraconal tumors we used the surgical corredor between middle and inferior rectus muscle ( Figure 1H). Otherwise, if this space was not enlarged, or if middle rectus muscle was infiltrated, a technique of rectus muscle retraction developed by McKinney et al [3] was done, whereby the medial and inferior rectus muscles are isolated with vessel loops as they insert on the globe ( Figure 1I). A 1 cm conjuntival incision was performed in middle point between middle orbital cantus and the pupil.…”

“…However, as in some cases of these reports, when these space are normal or reduced, the microsurgical dissection are limited due the movable and elastic nature of these orbital structures. In these cases we use a middle and inferior muscle retraction as McKinney et al [3] recommended with good results. Nevertheless there are other alternate techniques for controlling the rectus muscles: using a special instrument (double ball instrument), transeptal retraction, transchoanal retraction or detachment [17] of medial rectus muscle opening the medial orbit like a book with medial rectus pedicled on the annulus of Zinn [3].…”

“…McKinney et al 3 recommended do not extend papiracea removal near to the level of ethmoidal arteries in other to avoid damaged to these vessels and reduce the risk of retrobulbar hemorrhage and vision loss. Work between rectus muscles preserve their function and transmuscular approach are not recommended [3].…”

“…However, techniques for more advanced endoscopic intraconal surgery in benign tumors and orbital preservation in malignant nasosinusal tumors are in their nascent stage [2][3][4][5][6][7][8][9][10][11][12].…”