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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