Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Manage orbital apex lesions via posterior lateral orbitotomy Xiyue WU1*, Shufa ZHENG1, Changzhen JIANG1, Chenyang WANG1, Dezhi KANG1 and Jin FU2* 1 Dept of Neurosurgery, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China; 2Dept of Medical Science, Medical College, Xiamen University, Xiamen, Fujian, 361005, China. * Corresponding author: XYW, Dept of Neurosurgery, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, PRC. Tel: +86-591-87983333, FAX: +86-591-87983334, Email: [email protected] JF, Dept of Medical Science, Medical College, Xiamen University, Xiamen, Fujian 361005. Tel: +86-592-2187210 E-mail: [email protected] Background: Technically it is most challenging to reach orbital lesions located in the apex. We intend to show that posterior lateral orbitotomy is a valid and effective surgical approach to manage orbital apex lesions. Methods: Posterior lateral orbitotomy was performed on 9 patients, including 4 males and 5 females, who were diagnosed with orbital apex tumors located lateral to optic nerves. Results: For the 9 patients diagnosed with orbital apex lesions, the apical tumors were accessed and resected via posterior lateral orbitotomy. En bloc resection of apical lesions was achieved in 7 patients, whereas subtotal resection was done in 2 patients whose tumors were too close to the surrounding vital structures. There is no mortality, postoperative ptosis or lateral rectus disorder. Exophthalmos symptoms disappeared completely after the surgery, and visual acuity or visual field was improved in most patients. Conclusion: Posterior lateral orbitotomy is a valid and reliable alternative for extraorbital approaches in managing the orbital apex lesions as it provides sufficient exposure to the lesions and incurs minimum cosmetic defects and damages to normal tissues. Keywords: orbitotomy, orbital apex, posterior lateral orbitotomy, extraorbital approach, transorbital approach INTRODUCTION Two types of surgical approaches can be used to access orbital lesions, i.e., the transorbital approaches and the extraorbital approaches. There are four primary transorbital approaches, including (i) the anterior orbitotomy; (ii) the lateral orbitotomy; (iii) the medial orbitotomy; and (iv) a combination of the lateral and medial orbitotomy. Extraorbital approaches include the transcranial approach and the inferior orbital approach1. The selection of surgical approach depends on the type, size, and exact location of the lesion as well as the direction it extends. The ideal surgical approach is that can get a good exposure of tumor but is minimally invasive to normal tissues. Technically it is most challenging to reach orbital lesions located in the apex as so many important and vital structures gather in this narrow area and make it a difficult section to approach. Though apical lesions are mostly managed by extraorbital approaches, posterior lateral orbitotomy is a valid and effective alternative with considerable advantages to access certain orbital apex tumors. Posterior lateral orbitotomy, a modified lateral orbitotomy that extends posteriorly by drilling the sphenoid wing to allow access to posterolateral lesions, can offer a direct visual contact with the apical lesion through a small opening created by osteotomy. There are very limited publications evaluating the use of posterior lateral orbitotomy, particularly in managing the apical lesions. It was previously assessed only by Carta F et al2 on 8 patients with apical lesions. Our approach, with slight modifications and improvements, aims to create a small window on bones within the region of sphenoid greater wing near temporal bone and sphenoid lessor wing, in order to directly expose the apical lesion and allow the en bloc removal of the lesion2. This approach preserves the frontal edge of the orbit roof and the lateral orbital rim, and therefore incurs minimum cosmetic defects. As surgical approaches accessing orbital apex carry significant risk and require strong expertise and skills, it is important to have surgeons with related experience to share their know-how and discuss and evaluate the surgical interventions they practiced on a number of patients, so as to minimize surgical damage to normal tissues and benefit patients. We herein retrospectively studied 9 cases of orbital apex lesions that were excised via posterior lateral orbitotomy. METHODS Surgical Procedure The surgery was performed under the operating microscope. The patient was placed in the supine position, with the head turning to the side opposite to the lesion. Starting at the point about 1.0-1.5 cm before tragus and above the zygomatic arch, a 5 cm curvilinear incision was made along the hairline at frontotemporal region, and skin was retracted anteriorly. The temporal muscle attached to the zygomatic process of frontal bone was resected in order to expose the zygomatic process of frontal bone, the frontal process of zygomatic bone, the keyhole, the lateral wall of orbit, the pterion, and the squama temporalis. Osteotomy was carried out to create an approximately 2.5 cm by 3 cm window on the posterior half of the lateral wall (Fig. 1A-B); depending on the location and size of the lesion, it may be necessary to grind down partial superior orbital fissure, the anterior margin of squama temporalis, partial frontal process of zygomatic bone and the posterolateral portion of zygomatic process of frontal bone. The lateral fascia and dura mater were incised under the operating microscope; the tumor was separated from the surrounding tissues, and thence resected. After the tumor was removed and complete hemostasis was achieved, a titanium mesh cranioplasty was applied to fix said bone window created previously, and then the cranial was closed in accordance with the standard protocol. RESULTS Patient clinical data 9 patients, including 4 males and 5 females aged between 16 and 59 years old, were all diagnosed with orbital apex tumors located lateral to optic nerves. Tumor sizes are indicated in Table 1. Most of patients suffered from proptosis and vision loss; only one patient carried no obvious symptoms during physical examination. Cranial MRI contrastenhanced scan and CT were performed on all patients. The lesions, located lateral, superior lateral, or inferior lateral to the optic nerve, had clear boundaries that can be identified from the surrounding tissues. Post-operation image Posterior lateral orbitotomy was performed on 9 patients diagnosed with orbital apex lesions, in 7 of which the tumors were completely removed. Subtotal resection was achieved in 2 patients as the tumors adhered closely to or merged with the surrounding vital structures, e.g., lateral rectus and optic nerve. There was no mortality resulted from or associated with the surgeries. As confirmed by the pathology results, one female patient suffered teratoma and eight patients suffered apical cavernous hemangioma (Table 1). Exophthalmos symptoms disappeared after the surgeries, and the visual acuity or visual field was improved in most cases. All patients were subject to postoperative observation for 6 to12 months. There was no postoperative ptosis or lateral rectus disorder as revealed in Table 1. Figure 1 shows the preoperative MRI results and the postoperative CT result for one patient suffered cavernous hemangioma (Fig. 1C-E). DISCUSSION Two types of surgical approaches are currently available to reach orbital lesions, i.e., the transorbital approaches and the extraorbital approaches1. In general, anterior lesions are treated through transorbital approaches, whereas lesions of the posterior third are best managed by extraorbital approaches. Generally speaking, anterior lesions are treated via anterior approach; lateral lesions are managed by lateral orbitotomy, which can be further extended posteriorly by drilling the sphenoid wing to allow access to posterolateral lesions, though an extraorbital approach may be preferable; small or anteriorly placed medial lesions are best approached by medial approach; large or posteriorly located medial lesions are managed via a combined lateral and medial approach, or alternatively via a fronto-orbital approach. Extraorbital approaches include the transcranial approach and the inferior orbital approach 1. Inferior orbital approach is ideal for apical lesions medial and inferior to the optic nerve. The transcranial approach was first published by Frazier in 1913 and it has since undergone several modifications. The transcranial approach targets intraorbital lesions through the roof and lateral walls of the orbit and therefore it is considered ideally suited for apical lesions and superior orbital fissure lesions1. In fact, some apical lesions can be better managed via an extended lateral approach, such as posterior lateral orbitotomy2. The conventional lateral orbitotomy has difficulty in exposing the tumors that are located in the orbital apex, and is easy to damage the lateral and intraorbital blood vessels and nerves, leading to vision impairment, strabismus, ptosis and other complications. In contrast, per our experience, posterior lateral orbitotomy sometimes appears to be a valid alternative for extraorbital approaches and it is suitable for the removal of orbital apex lesions, particularly those lateral to the optic nerve. In posterior lateral orbitotomy, the skin is incised at the frontotemporal region along the hairline so as to incur minimum cosmetic defect. With this approach we can manage the apical lesions lateral, inferior or inferolateral to the optic nerve with direct visual contact. Despite the encouraging benefits and advantages, posterior lateral orbitotomy, just like other alternatives, has its limitations and disadvantages. A drawback of this approach is that it may incur damage to the frontal branch of facial nerve. New technology and improved equipments may eventually solve this problem. Unlike conventional lateral orbitotomy, posterior lateral orbitotomy requires osteotomy to bore a small hole on the lateral wall. Additionally, posterior lateral orbitotomy is not a practical solution for the lesions medial to the optic nerve, which may be better managed by pterional approach, sphenoethmoidal approach, and transethmoidal route. In addition to the use of operating microscope, several new technologies contribute to the minimally invasive practice and facilitate the surgical management of apical lesions. Neuronavigational systems are effective surgical adjuvants in case of deep apical lesions3. Endoscopic technology has extended its reach and shown the great potential as it evolves3, 4. Our experience further confirms that posterior lateral orbitotomy is a safe and effective surgical approach for apical lesions. It shall be a valid and reliable alternative for extraorbital approaches in managing the troublesome orbital apex lesions as it provides sufficient exposure to the lesions and incurs minimum cosmetic defects and damages to normal tissues. It broadens the options available to surgeons when they develop the surgical strategies to manage the orbital apex lesions. We feel the urge to share and disclose our experience and expertise on apical tumor surgery so as to provide surgeons with more alternatives and feedbacks in managing orbital lesions. Selecting the optimal surgical approach shall minimize invasion and damage to normal tissues and further promote patient benefit. The options available to a surgeon will be expanded as we continuously provide feedbacks and updates on these critical surgeries and surgical strategies. Acknowledgement The authors would like to thank Dr. Yang Chen for generous support and technical consultation. Funding resource: Fujian Health Bureau Funding (Bpb-2100201-1) and Fundamental Research Fund for China Universities (No.2011121059). Conflict of interest The authors have no conflicts of interest. REFERENCES 1. Bejjani GK, KP Cockerham, JS Kennerdel and JC Maroon.A reappraisal of surgery for orbital tumors. Part I: extraorbital approaches.Neurosurg Focus2001;10:E2. 2. Carta F, D Siccardi, M Cossu, C Viola and M Maiello.Removal of tumours of the orbital apex via a postero-lateral orbitotomy.J Neurosurg Sci1998;42:185-8. 3. Sieskiewicz A, T Lyson, Z Mariak and M Rogowski.Endoscopic trans-nasal approach for biopsy of orbital tumours using image-guided neuro-navigation system.Acta Neurochir (Wien)2008;150:441-5; discussion 445. 4. Murchison AP, MR Rosen, JJ Evans and JR Bilyk.Endoscopic approach to the orbital apex and periorbital skull base.Laryngoscope2011;121:463-467. Figure Legends Figure 1. A-B, the diagrams show where a bone window is created by osteotomy during a posterior lateral orbitotomy. C-E, the preoperative MRI result and postoperative CT result for a patient diagnosed with apical cavernous hemangioma. (C) Preoperative T1weighted image; (D) preoperative T2-weighted image; and (E) postoperative CT result. Table 1. The clinical characterization of patients Case Age Gender Pre-operative Symptoms Tumor Size (mm3) Tumor Location Pathology Tumor Resection Post-operative Symptoms 1 43 F Proptosis & Visual field defect 1.1x0.7x0.7 Lateral to optic nerve Cavernous hemangioma Complete removal Proptosis relieved & Visual field improved 2 16 F None 1.0x0.6x1.0 Superior lateral to optic nerve Cavernous hemangioma Complete removal Normal 3 59 M Proptosis & Decreased visual acuity 2.5x0.9x0.6 Inferior lateral to optic nerve Cavernous hemangioma Complete removal Proptosis relieved & Visual acuity improved 4 57 M Proptosis & Visual field defect 1.2x0.8x0.9 Lateral to optic nerve Cavernous hemangioma Complete removal Proptosis relieved & Visual field improved 5 34 F Proptosis & Visual field defect 1.4x1.0x0.8 Lateral to optic nerve Cavernous hemangioma Complete removal Proptosis relieved & Visual field improved 6 46 F Proptosis & Visual field defect 1.3x0.7x0.8 Inferior lateral to optic nerve Teratoma Subtotal resection Proptosis relieved & Visual field improved 7 39 M Proptosis & Decreased visual acuity 1.4x0.9x0.8 Lateral to optic nerve Cavernous hemangioma Complete removal Proptosis relieved & Visual acuity improved 8 51 F Proptosis & Visual field defect 1.0x0.8x0.9 Inferior lateral to optic nerve Cavernous hemangioma Complete removal Proptosis relieved & Visual field improved 9 31 M Proptosis & Decreased visual acuity 1.4x0.8x0.7 Superior lateral to optic nerve Cavernous hemangioma Subtotal resection Proptosis relieved & Visual acuity improved