Endoscopic endonasal surgical resection of tumors of the medial orbital apex and wall

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Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright Author's personal copy Clinical Neurology and Neurosurgery 114 (2012) 93–98 Contents lists available at SciVerse ScienceDirect Clinical Neurology and Neurosurgery journal homepage: www.elsevier.com/locate/clineuro Case series Endoscopic endonasal surgical resection of tumors of the medial orbital apex and wall John Y.K. Lee a,∗ , Vijay R. Ramakrishnan b , Alexander G. Chiu b , James Palmer b , Roberta E. Gausas c a Department of Neurosurgery, University of Pennsylvania School of Medicine, 235 South Eighth Street, Philadelphia, PA 19106, United States Department of Otorhinolaryngology and Head and Neck Surgery, University of Pennsylvania School of Medicine, Philadelphia, PA, United States c Department of Otorhinolaryngology and Head and Neck Surgery Ophthalmology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States b a r t i c l e i n f o Article history: Received 9 September 2010 Received in revised form 28 July 2011 Accepted 11 September 2011 Available online 11 October 2011 Keywords: Orbital apex Skull base Endoscopy Cavernous hemangioma Fibrous dysplasia Schwannoma 1. Background Tumors of the orbital apex can present in a variety of ways based on the complexity of the neurovascular anatomy in this region. The differential diagnosis of lesions in this region range from benign, slow-growing lesions such as cavernous hemangioma, schwannoma, pseudotumor, and fibrous dysplasia to more aggressive, and fast-growing lesions such as lymphoma, sarcoma, and metastasis. Symptoms from optic nerve compression and a lack of clinical diagnosis prompt surgical management. The surgical approach to lesions in the orbital apex includes orbital approaches and intracranial approaches [9,11]. These approaches, however, involve traversing normal ocular tissue or normal brain tissue to reach the orbital apex. In 1990 David Kennedy first described an endoscopic approach to decompression of the orbit for dysthyroid opthalmopathy [8], and this was expanded upon by Sethi and Lau in 1997 who described the natural benefits of endoscopic approaches to biopsying and decompressing tumors of the orbital apex [21]. Since that time there has been increasing interest in the use of the endoscope to target tumors located in orbital apex [1,5,7,17,18,22,23]. Because the use of the endoscope through the nose was pioneered by otolaryngologists and is routinely used for inflammatory sinus conditions, otolaryngologists have the greatest familiarity with the technique. However, neurosurgeons have increasingly worked with otolaryngologists to target tumors of the pituitary gland, anterior skull base, clivus and orbit [3,6,20]. A multidisciplinary surgeon approach to the orbital apex is a natural extension of these efforts. 2. Objective The goal of this study was to describe the benefits and limitations of endoscopic endonasal surgical resection of tumors involving the orbital apex. We chose to focus on operative techniques as opposed to long term tumor outcomes, since the tumors that involve this location tend to be uncommon and heterogeneous. A specific emphasis on multidisciplinary skills and techniques are described in this case series. 3. Materials and methods ∗ Corresponding author. Tel.: +1 215 829 5189; fax: +1 215 829 6645. E-mail address: leejohn@uphs.upenn.edu (J.Y.K. Lee). 0303-8467/$ – see front matter © 2011 Published by Elsevier B.V. doi:10.1016/j.clineuro.2011.09.005 This is a retrospective review of patients from July 2009 to June 2010 who underwent endoscopic resection of tumors involving the medial orbital apex and wall at the University of Pennsylvania. We excluded patients whose tumors did not approach the orbital Author's personal copy 94 J.Y.K. Lee et al. / Clinical Neurology and Neurosurgery 114 (2012) 93–98 Fig. 1. This figure has three columns: preop axial CT, preop coronal CT scan, and postop coronal CT scan slices of orbital apex fibrous dysplasia in patients one (A) and two (B). The bone lesion involves the orbital apex in both cases. There is some residual tumor in the first patient just at the skull base on the left in case #1. In the third column of (B), there is a bony opening into the optic foramen/canal through the fibrous dysplasia allowing for optic nerve decompression. apex, and we excluded patients who only underwent open surgical resection without use of endoscopic endonasal techniques. 4. Results Five patients were identified in this series. Two patients had fibrous dysplasia, one patient had a schwannoma, one patient had a multiply recurrent adenoid cystic carcinoma, and one patient had an intraconal cavernous hemangioma. Their history and surgical procedures are summarized in Table 1. Case 1: A 16 year old female presented with slowly progressive nasal obstruction and left-sided proptosis. Ophthalmic examination was significant for left proptosis and the absence of optic neuropathy. Nasal endoscopy identified a smooth mucosally lined mass in the left middle meatus. CT scan demonstrated a sino-orbital fibroosseous lesion–ossifying fibroma. Endoscopic endonasal removal of this lesion was performed by a single ENT surgeon approach through the left nostril without a posterior septostomy. This allowed for gross removal of the mass with a drill, and removal of the periphery of the mass from the orbit with blunt dissection. The superior attachment was drilled flush with the skull base. No complications were encountered. Postoperatively, her proptosis improved and her vision remained stable. The pathology was consistent with fibrous dysplasia. A gross total resection of the perceived involved bone was accomplished based on the surgeon’s intraoperative impression. The postoperative imaging, at 1 year follow-up demonstrates a small amount of residual tumor in the superior skull base, but otherwise there is evidence of a substantial resection of the great majority of tumor (Fig. 1A). Case 2: A 51 year old male presented with asymptomatic optic nerve swelling and papilledema. He had a history of benign fibrous dysplasia status-post debulking. The first endonasal procedure was performed 25 years ago in a foreign country, and more recently he underwent an endonasal biopsy 13 years ago in the United States. His ophthalmic examination was significant for papilledema with mild disc swelling on the right. The left optic nerve also demonstrated some mild venous congestion and minimal blurring of the disc margins. Visual field testing with Humphrey perimetry was full. His acuity was 20/25 on the right and 20/20 on the left. Nasal endoscopy revealed a firm nasal mass. A CT scan demonstrated extensive fibrous dysplasia involving the ethmoid, medial orbital wall, and sphenoid bone. An endoscopic endonasal debulking of the bony lesion was performed through a single nostril without a septostomy. A two surgeon technique through a single nostril was employed to allow for careful decompression of the right optic canal. In this case, the neurosurgeon worked through the same nostril while the otolaryngologist assisted. The optic nerve and its dura were identified and dissected with the use of a high speed (60,000 rpm) drill and diamond bit with continual irrigation. Once the dura of the optic nerve was identified, gentle efforts to decompress the optic nerve were performed with the use of a Jcurette and drill. A kerrison rongeur was not used to decompress the optic canal. The dura of the optic nerve sheath was intentionally not opened. At last follow-up of 1 year, he remained visually asymptomatic with full visual fields on Humphrey perimeter exam. On fundoscopic exam he still had mild disc swelling with indistinct margins. There was no contralateral left-sided venous congestion. His visual acuity remained stable (Fig. 1B). Case 3: A 79 year old male with a history of adenoid cystic carcinoma of the ethmoid sinus presented with a local recurrence 1 year after primary surgery and postoperative radiotherapy. Ophthalmic examination revealed motility restriction. Neuroimaging revealed recurrent tumor involving the ethmoid and the medial orbit extending posteriorly toward the apex. A combined endoscopic endonasal and medial transconjunctival approach was undertaken, the latter in order to dissect tumor directly from the globe. The medial transconjunctival approach facilitated protection of the orbital soft tissues by the oculoplastic surgeon. Because of the extensive, infiltrative nature of the recurrence, maximal tumor debulking was performed without complete resection. In addition, the patient preferred not to have a complete exenteration of his orbit and preferred serial debulking. At 3 months follow-up, the patient had improved vision and extraocular motor function. Author's personal copy J.Y.K. Lee et al. / Clinical Neurology and Neurosurgery 114 (2012) 93–98 95 Table 1 Demographics, presentation, or procedure for patient series. Id Age Sex Pathology Ophthalmologic sign/symptom Surgical procedure 1 16 F Fibrous dysplasia Proptosis 2 51 M Fibrous dysplasia Papilledema 3 80 M Adenoid cystic (recurrent) Ophthalmoparesis 4 49 F Schwannoma Proptosis 5 25 F Cavernous hemangioma Optic pallor/vision loss Endoscopic endonasal biopsy/decompression Endoscopic endonasal biopsy/decompression Endoscopic endonasal biopsy/decompression Endoscopic endonasal resection Endoscopic endonasal resection Unfortunately, at last follow-up 18 months from surgery his tumor had recurred (Fig. 2A). Case 4: A 49 year old female presented with worsening headaches. Physical examination demonstrated a nasal cavity mass and right-sided proptosis without optic neuropathy. Preoperative CT and MRI imaging revealed a large sinonasal mass encroaching upon the orbit with remodeling of the medial orbital wall. After an initial biopsy which confirmed a diagnosis of a benign schwannoma, the surgical resection began with transnasal endoscopic Additional surgical procedure required for access/resection Multidisciplinary No Yes Medial transconjunctival Medial transconjunctival Posterior septostomy Yes Yes Yes removal of the majority of the tumor, isolating its attachment to the medial orbital wall. A single nostril approach was used without a posterior septostomy. In this area the tumor was fibrotic and adherent to the underlying orbital tissues. A medial transconjunctival approach was performed by an oculoplastic surgeon, facilitating protection of the orbital contents and sharp dissection of the tumor from the periorbita. No adverse postoperative ophthalmologic symptoms were encountered (Fig. 2B). Case 5: A 25 year old female presented with progressive visual loss in the right eye over an 18 month period. Examination of the affected eye was significant for a reduced visual acuity of count fingers only, loss of color vision and a relative afferent pupillary defect. She had a large right central scotoma and pale optic nerve consistent with compressive optic neuropathy. Nasal endoscopy was unremarkable. Neuroimaging revealed a 10 mm × 8 mm orbital mass located intraconally at the apex and inferior to the optic nerve and associated with bony erosion. A completely endoscopic endonasal approach with a septostomy and maxillary antrostomy was performed, thus allowing multidisciplinary, binostril surgery by neurosurgery, oculoplastic surgery and otolaryngology. Dissection of the mass required opening the optic canal. This procedure benefited tremendously with the multidisciplinary approach. The neurosurgeon used bimanual technique and used his suction and cottonoid patty to keep the orbital fat retracted. Occasional bipolar cautery was used to reduce the fat herniation into the field. While the left hand kept the orbital fat and muscles away, a blunt probe dissector was used to dissect gently and to tease apart the relevant anatomy. An initial dissection between the medial and inferior rectus failed to identify the lesion. Hence, a more superior dissection was performed by identifying the optic canal, removing the bone over the optic nerve with a drill and curette to remove the thin bone. Once the optic nerve had been identified, the dura was opened over the optic nerve and connected to the more anterior opening in the periorbita. The round, bluish purple tumor was identified inferior and medial to the optic nerve and superior to the medial rectus muscle. A complete, en bloc resection was performed simply by using a blunt Lusk probe to circumferentially dissect around the lesion. Postoperatively, the patient had stable vision. Serial imaging has demonstrated no evidence of recurrence at 9 months postoperatively. Although her vision remains limited in the right eye, she has been given the option of strabismus surgery for stable exotropia (Fig. 2C). 5. Discussion Fig. 2. (A) Demonstrates axial and coronal contrast-enhanced MRI scan of patient 3 with recurrent adenoid cystic carcinoma. (B) Demonstrates axial and coronal CT scan of patient 4 with schwannoma. (C) Demonstrates axial and coronal CT scan of patient 5 with intraconal cavernous hemangioma. The surgical approach to the orbital apex is challenging, particularly for tumors located medial to the optic nerve. The orbital apex is an area of limited surgical access because of the many critical structures that occupy this space and the risk of morbidity to them. The structures that exist within the orbital apex include the optic Author's personal copy 96 J.Y.K. Lee et al. / Clinical Neurology and Neurosurgery 114 (2012) 93–98 Table 2 Review of literature - endoscopy for orbital apex lesions. Author Year Pathology Intraconal only Surgery type Endonasal only Posterior septostomy Sethi et al. 1997 Rhabdomyosarcoma Adenocarcinoma Lymphoma Undifferentiated carcinoma Squamous cell carcinoma Lymphoid tissue No No No No No No Biopsy/decompression Biopsy/decompression Biopsy/decompression Biopsy/decompression Biopsy/decompression Biopsy/decompression Yes Yes Yes Yes Yes Yes No No No No No No Herman et al. Mir-Salim et al. 1997 1999 Cavernous hemangioma Cavernous hemangioma Yes Yes Resection Resection Yes Yes No No Tsirbas et al. 2005 Cavernous hemangioma Anaplastic high-grade sarcoma Myxoid liposarcoma Yes No No Caldwell–Luc transantral Caldwell–Luc transantral Caldwell–Luc transantral No No No No No No Karaki et al. Miller et al. 2006 2008 Cavernous hemangioma Solitary fibrous tumor Yes No Resection Resection Yes Yes No No Murchison et al. 2008 Chondrosarcoma Squamous cell carcinoma Schwannoma No No No Biopsy/decompression Biopsy/decompression Biopsy/decompression Yes Yes Yes Yes Yes Yes Yoshimura 2010 Cavernous hemangioma Yes Resection Yes No Lee et al. 2011 Fibrous dysplasia Fibrous dysplasia Ethmoid adenoid cystic carcinoma Schwannoma Cavernous hemangioma No No No No Yes Biopsy/decompression Biopsy/decompression Biopsy/decompression Resection Resection Yes Yes Yes Yes Yes No No No No Yes Endonasal refers to ethmoidectomy and sphenoidectomy and through the nose only without Caldwell–Luc. nerve, the ophthalmic artery, the ciliary ganglion, and the origin of the extraocular muscles at the annulus of Zinn, as well as their motor innervation. Any injury to these structures can result in possible loss of vision, mydriasis, or diplopia. Minimizing manipulation of these tissues allows the surgeon to minimize possible complications, therefore minimally invasive surgery is an important goal. However, this goal must also be balanced with the need for adequate exposure to allow for controlled dissection of tumors and maintenance of hemostasis, both equally important to avoid complications as well. Historically, the need to meet these surgical goals has driven the development of several approaches to the orbit. 5.1. Review of conventional surgical approaches to the orbital apex Lesions located in the medial orbit can be reached through the periorbital space via a transconjunctival or transcaruncular incision. Such an approach is reasonable when the tumor is located more anteriorly in the orbit, but these approaches are more difficult when the tumor is located in the medial orbital apex because of the limits of the medial orbital wall and the globe. Hence, McCord initially described combining a lateral orbitotomy with the transconjunctival approach to create room for retraction of the globe, thus providing access to the medial orbital apex [15]. Because of the complexity and morbidity of this approach and because of the limited ability to resect larger tumors, additional surgical approaches have been described. A standard neurosurgical frontotemporal craniotomy can provide excellent access to the orbit from above [9,14]. This approach provides good view of the lateral orbital wall, posterior superior orbital apex, optic canal, as well as the superior orbital fissure. However, access to the medial and inferior orbital apex is limited and necessitates transgression through multiple delicate structures including the optic nerve itself. Hence, Schick et al. described a contralateral pterional approach which provides access to the medial orbital apex, but it requires significant brain retraction [19]. This approach has not been adopted to any significant degree by most neurosurgeons as the degree of brain retraction is most significant. An alternative approach to the medial and inferior orbital apex has been described by Kennerdell and Maroon in 1998 [10]. They described four patients whose tumors were resected via a transmaxillary, transantral Caldwell–Luc approach to the inferior and medial orbit. Tsirbas et al. modified this approach with the addition of an endoscope, taking advantage of the superb illumination it provides [22]. Its disadvantage, however, is a supragingival incision with associated dysesthesias. The endonasal approach with endoscopes appears to avoid the need for this direct approach via a Caldwell–Luc through the maxillary sinus by employing a maxillary antrostomy. In summary, the standard approaches to the medial orbital apex include a medial orbitotomy with or without a lateral orbitotomy [15], a transantral Caldwell–Luc approach [10], or a pterional craniotomy either from ipsilateral or contralateral side [19]. It is in this context that the endoscopic endonasal approach to the orbit has been explored and gained popularity. 5.2. Endoscopic endonasal approach The endoscopic endonasal approach to the orbit was initially described by Kennedy et al. in 1990 for treatment of dysthyroid orbitopathy, or Grave’s orbitopathy [8]. With safe access to the medial and inferior orbit, surgeons have expanded the indications for this approach by first biopsying and decompressing the orbital apex. The previously published approaches are summarized in Table 2. The first reported use of the endoscope to approach tumors of the orbital apex was described by Sethi and Lau in 1997. They described a series of six patients with extraconal tumors that were successfully biopsied and decompressed in 1997 [21]. Subsequent to that, surgeons were able to successfully enter the periorbita and dissect around the extraocular muscles and orbital fat, to perform complete resection of an intraconal orbital apex cavernous hemangioma [5,17]. Tsirbas et al. described a conventional Caldwell–Luc transantral approach to the orbital apex aided by the illumination Author's personal copy J.Y.K. Lee et al. / Clinical Neurology and Neurosurgery 114 (2012) 93–98 of the endoscope [22] but which did not take advantage of natural orifices to perform the resection. In 2006 Karaki et al. described an endoscopic endonasal resection of an intraconal cavernous hemangioma [7], and Miller et al. described resection of an extraconal solitary fibrous tumor in 2008 [16]. Murchison et al. described a series of three extraconal orbital apex tumors that were biopsied and debulked, but not resected, through an endonasal endoscopic technique [18]. In their series they emphasized the added advantage of a posterior septostomy to improve the angle of access and allow for a second surgeon to add up to four hands. In 2010, Yoshimura et al. described another resection of an orbital apex hemangioma through the endoscopic endonasal route [23]. In the world’s published literature, four patients with intraconal cavernous hemangiomas have been completely resected via a transnasal route alone. Herman et al. performed a sphenoidotomy and ethmoidectomy and appear to have resected the tumor through a single nostril approach. Mir-Salim et al. published their work in German language only. Karaki et al. described a technique which appears to be similar to Herman et al. Yoshimura et al. performed an wide sphenoidotomy, ethmoidectomy and maxillary antrostomy to resect the tumor en bloc. Our paper adds a fifth patient to the world’s literature and provides some additional evidence of the reproducibility and generalizability of the surgical technique. Nevertheless, we consider this type of surgical approach to be an advanced technique requiring a multidisciplinary team approach. Otorhinolaryngologists are the surgeons most comfortable with endoscopic techniques, since they employ endoscopes in rhinology on a routine basis in both the outpatient and inpatient setting. The two-dimensional, but panoramic perspective requires time and experience to learn which is gained in all otorhinolaryngologist training programs. In addition, otorhinolaryngologists provide the basic exposure to the orbital apex on the basis of their appreciation of rhinology and its functional sinus anatomy. However, we believe that a single rhinologist is not sufficient to perform these advanced surgical procedures with success. A single rhinologist is limited to one-handed surgery as their other hand is holding the endoscope. The addition of a surgical partner provides immense value with respect to microdissection. By virtue of their experience having operated on intracranial tumors such as craniopharyngiomas and tuberculum sella meningiomas both open with the microscope and minimally invasively with the endoscope, neurosurgeons can aid in the resection of orbital apex and orbital medial wall tumors. Indeed, neurosurgeons are increasingly using endoscopes in the resection of simple pituitary adenomas as well as more complex lesions. Oculoplastic surgeons do not generally employ endoscopes in their surgical arena; however, because most of the intraorbital anatomy and its intimate relationships are less familiar to either the neurosurgeon or otorhinolaryngologist, the oculoplastic surgeon is an indispensable member of the surgical team. Their fine microdissection techniques are gradually translated from the open surgical approaches to the orbit to the endoscopic approaches to the orbital apex. It is clear, however, that the progression of cases should start with extradural extraconal surgery such as the decompression of the optic nerve in fibrous dysplasia or ossifying fibroma to the more complex cases such as intradural intraconal surgery of hemangiomas. In our series of five cases, the endoscopic endonasal technique successfully achieved the desired surgical goal. Instrumentation through the air-filled paranasal sinuses avoids transgression of otherwise critical tissues. It provides excellent illumination, and it avoids the need to retract orbital fat, minimizes bleeding, and provides access to the orbital apex. Although this series is small, there is clearly a learning curve for both the individual surgeons and the team of surgeons. For example, in case #2 and case #4 which was earlier in the experience, a single nostril approach was employed without a posterior septostomy. In case #4 a medial 97 transconjuntival incision was perfomed to retract on the orbital contents by the oculoplastic surgeon. With increasing endoscopic experience, we might approach both of these cases purely endoscopically with a two nostril approach. A posterior septostomy would add little morbidity, but it would greatly increase the ability to work within the orbit especially within the intraconal space [18]. Indeed, this is the approach that provided a minimally invasive approach to the intraconal hemangioma in case #5 thus avoiding any need for a transconjunctival incision. Certainly, the addition of the posterior septostomy facilitates two surgeon, four-handed technique by allowing multiple surgeons to place instruments at the optimal angle to target pathology. 5.3. Alternatives to surgical resection Because of the inherent risks of surgery in the orbital apex, some authors have described a conservative alternative for presumed benign lesions in this location. Kloek et al. describe five patients treated with decompression of the medial orbital wall with followup ranging from 6 months to 5 years [12]. Almond et al. describe a similar procedure with decompression only [2]. Four of the five patients improved, but mean follow-up was only 25.6 months. Although this approach may minimize the morbidity during the initial surgical approach, these patients will require a significant follow-up as their tumors, although benign, are most likely to continue to grow. Similar strategies are sometimes employed in neurosurgical management of complex meningiomas where the risk of complete resection exceeds the oncologic benefits. However, in many of these situations, postoperative radiation therapy in the form of stereotactic radiosurgery is often employed [4,13]. In the case of orbital apex tumors such as cavernous hemangiomas, we remain skeptical that decompression alone will provide adequate management for slow-growing tumors in a confined and complex anatomic space such as the orbital apex. 6. Conclusion Based on the growing adoption of endoscopic techniques by neurosurgeons working in collaboration with otolaryngologists, we believe that this approach is a valuable tool in the armamentarium of surgeons who have already gained comfort with endoscopic resection of pituitary adenomas, anterior cranial fossa meningiomas, and clival chordomas. 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