Carrau, Ricardo L.

Gardner, Paul

Germanwala, Anand V.

Kassam, Amin B.

McKinney, Kibwei A.

Prevedello, Daniel M.

Snyderman, Carl H.

Stefko, Susan T.

Wheless, Stephen A.

Zanation, Adam M.

PubMed

Carolina Digital Repository

Seeing the light: Endoscopic endonasal intraconal orbital tumorsurgeryDr. Kibwei A. McKinney, MD, Dr. Carl H. Snyderman, MD, Dr. Ricardo L. Carrau, MD, Dr.Anand V. Germanwala, MD, Daniel M. Prevedello, MD, Dr. Susan T. Stefko, MD, Dr. PaulGardner, MD, Dr. Amin B. Kassam, MD, Mr. Stephen A. Wheless, and Dr. Adam M. Zanation,MDDepartment of Otolaryngology–Head & Neck Surgery (Drs. McKinney and Zanation, and Mr.Wheless), and Department of Neurological Surgery (Dr. Germanwala), University of NorthCarolina–Chapel Hill, Chapel Hill, NC; Department of Otolaryngology–Head and Neck Surgery(Dr. Snyderman), Department of Neurological Surgery (Drs. Snyderman and Gardner), andDepartment of Ophthalmology (Dr. Stefko), University of Pittsburgh Medical Center, Pittsburgh,PA; Department of Otolaryngology–Head and Neck Surgery (Dr. Carrau), and the Department ofNeurological Surgery (Dr. Kassam), Neuroscience Institute & Brain Tumor Center, Santa Monica,CAExternal approaches to the orbit are well established, including the lateral, medial, andinferior orbitotomy. Orbitozygomatic craniotomy can be used for tumors that extend bothintracranially and into the orbit and is used for exposure of the optic nerve and canal.1 Sincethe 1980s, endoscopic measures have been used to enhance visualization in standardexternal approaches.2 Endoscopic endonasal orbital and optic nerve decompressions havebecome accepted treatments for thyroid eye disease and traumatic optic neuropathy that isunresponsive to steroids. A few case reports of endoscopic decompression, biopsy, andresection of tumors that involve the orbit also have been reported.3–5 The expandedendonasal 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 theanatomic principles, indications, technical nuances, and limitations of the medial-inferiorintraconal 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) inthe medial-inferior quadrant of the orbit that do not extend superolaterally. The use of thisCorresponding author: Adam M. Zanation, MD, Department of Otolaryngology–Head and Neck Surgery, University of NorthCarolina–Chapel Hill, 170 Manning Drive, Physicians Office Building, Ground Floor, CB#7070, Chapel Hill, NC 27599-7070.adam_zanation@med.unc.edu.Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.Author ContributionsKibwei A. McKinney, data acquisition, interpretation and analysis, and preparation of the manuscript; Carl H. Snyderman, planningof the neurosurgical aspects of the cases, data acquisition and analysis, and preparation of the manuscript; Ricardo L. Carrau,planning of the neurosurgical aspects of the cases, data acquisition and analysis, and preparation of the manuscript; Anand V.Germanwala, planning of the neurosurgical aspects of the cases, data acquisition and analysis, and preparation of the manuscript;Daniel M. Prevedello, planning of the neurosurgical aspects of the cases, data acquisition and analysis, and preparation of themanuscript; Susan T. Stefko, selection of surgical candidates, planning of the ophthalmologic aspects of the cases, data acquisitionand analysis, and preparation of the final manuscript; Paul Gardner, surgical planning, data acquisition and analysis, and preparationof the manuscript; Amin B. Kassam, surgical planning, data acquisition and analysis, and preparation of the manuscript; Stephen A.Wheless, data acquisition and analysis, and preparation of the manuscript; Adam M. Zanation, surgical planning, data acquisitionand analysis, and preparation of the manuscript.DisclosuresCompeting interests: Ricardo L. Carrau, speakers bureau, payment for travel: Storz Endoscopy.NIH Public AccessAuthor ManuscriptOtolaryngol Head Neck Surg. Author manuscript; available in PMC 2011 February 28.Published in final edited form as:Otolaryngol Head Neck Surg. 2010 November ; 143(5): 699–701. doi:10.1016/j.otohns.2010.07.010.NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author Manuscripttechnique would avoid the technical difficulties in approaching such masses and limit thedissection to the areas bordering the endonasal corridor.Operative TechniqueApproval for this review was obtained from the University of North Carolina InstitutionalReview Board. The key anatomic difference between intraconal and extraconal orbitaltumors is the position relative to the boundaries of the extraocular muscles. For medial/inferior intraconal lesions, the dissection corridor is between the medial and inferior rectusmuscles. The extraconal fat is reduced via bipolar cautery, and the rectus muscles areidentified. The soft-tissue structures of the orbit are all freely mobile and compressible, thusmaking entry into the intraconal space difficult.A technique of rectus muscle retraction was developed whereby the medial and inferiorrectus muscles are isolated with vessel loops as they insert on the globe (Fig 1). It allows fortraction to be placed on the muscles to make them less compressible and easier to dissectbetween. Once the intraconal corridor is developed, the tumor is identified and removedwith limited bipolar cautery and extensive sharp dissection (Fig 2). It is helpful to have onesurgeon retracting the mass inferomedially, while the other surgeon uses a bimanualtechnique to incise the lateral tumor margin. Because the optic nerve should be superior andlateral to the tumor, once the lateral margin is cleared, the nerve is out of the field ofdissection. The remaining soft-tissue tumor attachments are then incised, and the tumor isremoved en-bloc. Postoperative magnetic resonance imaging demonstrated complete tumorresection without evidence of residual disease.In an alternate technique for controlling the rectus muscles, the medial rectus is detachedfrom the globe and tagged with a long silk suture, which is then passed from the orbit intothe nose. This step opens the medial orbit like a book, with the medial rectus pedicled on theannulus of Zinn. A vessel loop is placed endoscopically around the contralateral posteriorseptum and the posterior medial rectus muscle, which allows for medial retraction of themuscle to open the lateral corridor of the intraconal space.Once the tumor is removed, meticulous hemostasis is obtained, and the rectus muscle vesselloops are released so that extraocular movements can be assessed. The rectus muscles areplaced back into their native positions, and the medial rectus muscle is sutured back onto theglobe by an ophthalmologic surgeon. The orbital fat is then pulled over the muscles toprevent scarring. When a septal flap is used, it is placed directly over the defect andbolstered in place with Surgicel (Ethicon, Inc., Somerville, NJ) and fibrin glue. Typically, nopacking is used because of the potential for raising the intraocular pressure in the case of alarge orbital defect.DiscussionThe medial-intraconal EEA was successfully performed on all six patients in our cohort. Ofthese, total resection was achieved in four patients (67%) and a subtotal excision in onepatient (17%). In the remaining patient, the surgery was performed for diagnostic purposes.In all five of the tumor resections, the patients experienced complete resolution of thepresenting symptoms with no evidence of optic nerve injury or worsening of diplopia.Several key anatomic principles must be followed for safe resection of orbital tumors withan endonasal approach. First, it is critical to avoid crossing the optic nerve. Thus, tumorsthat are localized to the superior/lateral orbit are contraindicated for an endonasal approach.Second, entry through the lamina papyracea should occur below the level of the ethmoidalforamina to avoid damage to the ethmoid arteries and reduce the risk of retrobulbarMcKinney et al. Page 2Otolaryngol Head Neck Surg. Author manuscript; available in PMC 2011 February 28.NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author Manuscripthemorrhage and vision loss. Finally, the dissection should occur between muscle groupsrather than through individual muscles for preservation of function.The endonasal corridor has some advantages over external approaches for medial/inferiorlesions. The endonasal approach minimizes external scarring and preserves cosmesis.External approaches to lesions of the medial orbital require significant displacement oforbital structures including the globe. Given the deep, cone-shaped surgical windowprovided by the external approach, it also has the disadvantage of suboptimal visibilityrelative to the endonasal approach. In addition, external approaches to intraconal lesionsmay also require deinsertion of extraocular muscles, with subsequent impact on extraocularmobility. The added illumination and magnificence of the endoscope cannot be understated;however, the loss of three-dimensional perception may be disorienting to the surgeon who isunfamiliar with these endoscopic techniques.AcknowledgmentsSponsorships: Kibwei A. McKinney, National Research Service Award T32 training grant for postdoctoralresearch in otolaryngology (T32DC005360). This funding source had no direct role in the design and conduct ofthis study. It provided salary support for Dr. McKinney during the time when this study was conducted.References1. Mercandetti, M. Tumors, Orbital. eMedicine Chapter. [Accessed March 1, 2010]. Last UpdatedFebruary 5, 2010. Available at: http://www.emedicine.com/oph/topic758.htm2. Norris JL, Cleasby GW. Endoscopic orbital surgery. Am J Ophthalmol 1981;91:249–52. [PubMed:7468741]3. Miller NR, Agrawal N, Sciubba JJ, et al. Image-guided transnasal endoscopic resection of an orbitalsolitary fibrous tumor. Ophthal Plast Reconstr Surg 2008;24:65–7.4. Gerencer RZ, Patel U, Hunter C, et al. The role of endoscopic sinus surgery in the diagnosis andtreatment of metastatic orbital carcinoid tumors. Ear Nose Throat J 2007;86:157–61. [PubMed:17427777]5. Lund VJ, Rose GE. Endoscopic transnasal orbital decompression for visual failure due to sphenoidwing meningioma. Eye 2006;20:1213–9. [PubMed: 17019421]McKinney et al. Page 3Otolaryngol Head Neck Surg. Author manuscript; available in PMC 2011 February 28.NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author ManuscriptFigure 1.External view of the left extraocular muscles identified and vessel looped for control.McKinney et al. Page 4Otolaryngol Head Neck Surg. Author manuscript; available in PMC 2011 February 28.NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author ManuscriptFigure 2.Intraconal identification and dissection of the hemangioma. MR, medial rectus; IF, inferiorrectus.McKinney et al. Page 5Otolaryngol Head Neck Surg. Author manuscript; available in PMC 2011 February 28.NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author Manuscript

Seeing the light: Endoscopic endonasal intraconal orbital tumor surgery

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Seeing the light: Endoscopic endonasal intraconal orbital tumor surgery

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