1. TEACHING ANATOMY
Endoscopic anatomy and approaches of the cavernous sinus:
cadaver study
Bashar Abuzayed • Necmettin Tanriover • Nurperi Gazioglu •
Fatma Ozlen • Gursel Cetin • Ziya Akar
Received: 2 May 2009 / Accepted: 15 October 2009 / Published online: 29 April 2010
Ó Springer-Verlag 2010
Abstract
Objective The objectives of this study were to recognize
the endoscopic anatomy of the cavernous sinus and to
understand the standard, purely endoscopic endonasal
approaches to this anatomic structure. This basic infor-
mation will facilitate our surgical procedures and decrease
the rate of surgical complications.
Materials and methods Seven fresh adult cadavers were
studied bilaterally (n = 14). We used Karl Storz 0 and 30°,
4 mm, 18 cm and 30 cm rod lens rigid endoscope in our
dissections. After cadaver preparation, extended endo-
scopic endonasal approaches were performed to access the
cavernous sinus.
Results In the seven cadavers, the cavernous sinus and
superior orbital fissure, on both sides, were widely exposed
with extended endoscopic endonasal approach. The antero-
inferior portion of the cavernous sinus was exposed by
removing the superior and the middle turbinates and the
posterior ethmoidal cells (extended endoscopic endonasal
transsphenoidal approach); the whole lateral wall of the
cavernous sinus was exposed by removing the anterior and
the posterior ethmoidal cells (endonasal ethmoido-pterygo-
sphenoidal approach: far lateral); and the medial wall of the
cavernous sinus was exposed by introducing the 30° endo-
scope from the contralateral nostril (contralateral endoscopic
endonasal transsphenoidal approach). According to the
neurovascular architecture, the lateral wall of the cavernous
sinus is divided into the superior triangular area, the superior
quadrangular area and the inferior quadrangular area. This
division can facilitate understanding of the anatomic rela-
tions of the cavernous sinus from the endoscopic view.
Conclusion Knowledge of the anatomy of the cavernous
sinus obtained with an endoscopic view of cadaver dis-
sections is an essential step in the learning curve of
endoscopic skull base surgery, and is important for endo-
scopic treatment of various pathologies in this region. In
this anatomic study, we reviewed the approaches to the
cavernous sinus with an endoscopic view and identified the
neurovascular relations. This approach will help in per-
forming safer and minimally invasive surgery.
Keywords Endoscopic endonasal approach Á
Cavernous sinus Á Surgical anatomy
Introduction
The cavernous sinus has a complex anatomy, with impor-
tant related neurovascular structures. Knowledge of this
architecture is essential to perform effective and safe sur-
gery in this region. For this reason, many anatomic studies
were performed to define the surgical anatomy and
approaches to the cavernous sinus [16, 17, 32, 36–38]. With
the introduction of the endoscopic endonasal transsphe-
noidal surgery of the pituitary gland [5, 8, 12–14, 25], many
modifications and approaches were developed to provide a
wider surgical view, including exposure of the cavernous
sinus [6, 7, 9, 11, 20] and, more recently, to remove tumors
located within the cavernous sinus [19, 21, 26].
In the extended endoscopic endonasal transsphenoidal
surgery, the endoscope allows wide exposure of the sellar
B. Abuzayed (&) Á N. Tanriover Á N. Gazioglu Á F. Ozlen Á
Z. Akar
Department of Neurosurgery, Cerrahpasa Medical Faculty,
Istanbul University, Istanbul, Turkey
e-mail: sylvius@live.com
G. Cetin
Morgue Specialization Department, Forensic Medicine Institute,
Ministry of Justice, Istanbul, Turkey
123
Surg Radiol Anat (2010) 32:499–508
DOI 10.1007/s00276-010-0651-3

2. and the parasellar areas, such as the sphenoidal planum, the
clivus, and the optic and carotid protuberances [1–5]. The
aim of this study was to recognize the endoscopic anatomy
of the cavernous sinus and to understand the standard,
purely endoscopic endonasal approaches to this anatomic
structure. This will help us to understand the neurovascular
relations and perform safe and controlled surgery, thus
decreasing the rate of surgical complications.
Materials and methods
Seven fresh adult cadavers were studied and bilateral endo-
scopic endonasal approach to the cavernous sinus was per-
formed (n = 14). Endoscopic dissections were performed at
the Turkish Republic, Ministry of Justice, Forensic Medicine
Institute, Morgue Specialization Department. The selection
criteria were: (1) age of 18 years or older, (2) no history of
head trauma or craniofacial surgery and (3) dissection of
corpses that had already been autopsied or during autopsy
(dissection was not done before the evaluation and permission
of the forensic medicine doctors). Dissection was performed
using Karl Storz 0° and 30°, 4 mm, 18 cm and 30 cm rod lens
rigid endoscope (Karl Storz and Co., Tuttlingen, Germany).
The endoscope was connected to a light source via a fiberoptic
cable andtoa camerafitted withthree-charge-coupleddevices
sensors. The video camera was connected to a 21-inch mon-
itor. As surgical instrumentation, we used the Karl Storz
Kassam-Snydermann endoscopic surgical set. The cadaveric
specimen was placed in a supine position with the head in a
neutral positionand 10–15° adducted toward the leftshoulder.
Dissection technique
The endoscope is introduced into the right nostril. The
choana is identified in the postero-inferior end of the nasal
cavity, at the end of the tail of the inferior turbinte and
medially to the vomer. The endoscope is directed rostrally
along the sphenoethmoidal recess, and the sphenoid ostium
is exposed nearly 15 mm superior to the choana, between
the superior turbinate and the nasal septum [5]. The middle
turbinate is resected to gain wider exposure and a more
comfortable surgical corridor. The mucosa is dissected
laterally and medially by the endoscopic dissector to
expose the sphenoid sinus floor and anterior wall and
medially the rostrum. The posterior part of the nasal sep-
tum is resected from the rostrum, and the septal mucosa of
the left nasal cavity is visualized. The dissector is passed
between the rostrum and the fractured nasal septum to
reach the left nasal mucosa, which is dissected from the left
side of the rostrum and the left sphenoid floor. In this way,
the entire sphenoid sinus floor and the ostia are exposed
(Fig. 1a). A similar procedure is performed from the left
nostril, except that the left middle turbinate is lateralized.
In this way, dissection is continued by the binostril
approach. The rostrum is fractured and with a 2-mm high
speed drill or 2-mm Karrison ronguer, the right ostium is
widened and the inferior and anterior walls of the sphenoid
sinus are resected (anterior sphenoidectomy). During the
resection of the inferior and anterior sphenoid sinus walls
toward lateral direction, care must be taken not to injure the
vidian nerve (the sphenopalatine nerve) and the spheno-
palatine artery. The sphenopalatine artery is located in the
infero-lateral corner to the sphenoid sinus and 1 cm ante-
rior to the rear end of the tail of the middle turbinate in
90% of cases [31]. The septae in the sphenoid sinus and
sinus mucosa are removed by the endoscopic punch
exposing the sellar floor and its anatomic landmarks
(Fig. 1b and c).
At the center of the sellar floor, the sellar fossa is iden-
tified. Rostrally to the sellar fossa, the planum sphenoidale
is identified. Supero-laterally to the sellar fossa and laterally
to the planum sphenoidale, the optic protuberances are
identified on both sides. Laterally to the sellar fossa, the
carotid protuberance is identified with its two parts: supe-
riorly the sellar carotid protuberance and inferiorly the
clival carotid protuberance. Between the optic and carotid
protuberance, the opticocarotid recess, which represents the
base of the anterior clinoid processes, is identified. Lateral
septae generally point to the opticocarotid recess, which is
the reason why these are good anatomic landmarks during
dissection [4, 5] (Fig. 1b). The sellar fossa is fractured by a
sharp dissector and widened by a 2-mm Karrison ronguer to
expose the sellar dura (Fig. 1d).
The inferior portion of cavernous sinus is exposed by
removing the superior and the middle turbinates and the
posterior ethmoidal cells (extended endoscopic endonasal
transsphenoidal approach) (Fig. 2a). To expose the whole
lateral wall of the cavernous sinus, the uncinate process is
resected. After identifying the ethmoid bulla, it is opened
and the anterior and then the posterior ethmoidal cells are
exposed and removed (endonasal ethmoido-pterygo-sphe-
noidal approach) (Fig. 2b). The medial wall of the cav-
ernous sinus is exposed by a 30° endoscope introduced
through the contralateral nostril (contralateral endoscopic
endonasal transsphenoidal approach) (Fig. 2c) [9, 21].
Results
Cadaveric specimens were placed in a supine position with
the head in the neutral position and 10–15° adducted
toward the left shoulder. We found this position to be more
suitable for the surgeon, as it does not disturb the surgical
orientation and avoids lateral bending of the surgeon’s
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3. Fig. 2 Axial paranasal CT
scans demonstrating the
approaches and related areas of
exposure of the cavernous sinus.
a Extended endoscopic
endonasal transsphenoidal
approach; b endonasal
ethmoido-pterygo-sphenoidal
approach (far lateral).
c Contralateral endoscopic
endonasal transsphenoidal
approach
Fig. 1 a Endoscopic view of
the exposed anterior sphenoid
sinus and ostia. b Endoscopic
view after anterior
sphenoidectomy, exposing
the landmarks of the roof of
the sphenoid sinus. Note that the
lateral septae of the cavernous
sinus are located under the
carotid protuberances, and thus
considered as a good landmark.
c A schematic representation of
the anatomical landmarks in the
roof of the sphenoid sinus.
d Endoscopic view of the
pituitary gland exposure after
sellar floor resection. C clivus,
CPc clival part of the carotid
protuberance, CPs sellar part of
the carotid protuberance, ICA-A
anterior bend of the internal
carotid artery, NS nasal septum,
OP optic protuberance,
PG pituitary gland, PS planum
sphenoidale, R rostrum,
SF sellar floor, SICS superior
intercavernous sinus,
SO sphenoid ostium
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4. trunk toward the patient, thus causing less fatigue during
the surgical procedures [1–5].
The antero-inferior part of the cavernous sinus
The sellar floor is resected laterally toward the carotid
protuberance to expose the parasellar portion of the internal
carotid artery (ICA). This resection is continued laterally
until the lateral border of ICA, thus exposing the inferior
part of the cavernous sinus (Fig. 3). Both the anterior and
the posterior bends of the parasellar portion of ICA are
widely exposed.
The lateral part of the cavernous sinus
After exposure of the bone of the inferior part of the cav-
ernous sinus and the middle cranial fossa (Fig. 4a), bone
resection is continued laterally from the lateral border of
the parasellar ICA until the level of the pterygoid apex. In
this way, the whole lateral part of the cavernous sinus,
including the oculomotor nerve (CNIII), ophthalmic nerve
(CNV1), maxillary nerve (CNV2) and mandibular nerve
(CNV3), with the course of the abducens nerve (CNVI), are
exposed (Fig. 4b). The vidian nerve (the sphenopalatine
nerve) exits from the vidian canal, which is located in the
pterygoid base, inferior to the ICA segment between the
vertical paraclival segment and horizontal petrous segment
(lacerum segment) [27]. Thus, the vidian nerve is a good
landmark locating the lacerum segment of ICA at the
turning point between the paraclival and the petrous por-
tions [19–21, 27]. When the opening of the vidian canal is
required to expose the vidian nerve and/or approaching
pathologies in the pterygopalatine fossa, drilling of the
canal is recommended to be started from the inferior and
medial aspect of the canal, as ICA is located along the
superior margin [27]. This will decrease the risk of intra-
operative injury of ICA during drilling of the vidian canal.
After identifying the vidian nerve, a triangular area lateral
to ICA can be identified. The base of this triangle is formed
Fig. 3 Endoscopic view after extended endonasal transsphenoidal
approach to expose the inferior part of the both cavernous sinuses.
C clivus, ICA-A anterior bend of the internal carotid artery, ICA-P
posterior bend of the internal carotid artery, ICA-c paraclival part of
the internal carotid artery, ON optic nerve, PE planum ethmoidale,
PG pituitary gland
Fig. 4 a Endoscopic view of the bone of the inferior part of the right
cavernous sinus and right middle cranial base after the endonasal
ethmoido-pterygo-sphenoidal approach. b The right cavernous sinus
and its neurovascular relations are exposed after bone resection. III
oculomotor nerve, V1 ophthalmic nerve, V2 maxillary nerve, V3
mandibular nerve, VI abducens nerve, C clivus, ICA-Sa anterior bend
of the internal carotid artery–parasellar segment, ICA-Sp posterior
bend of the internal carotid artery–parasellar segment, ICA-C
paraclival segment of the internal carotid artery, ICA-L lacerum
segment of the internal carotid artery, ICA-P petrous segment of the
internal carotid artery, P pterygoid base, PG pituitary gland, VC
vidian canal, VN vidian nerve
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5. by the vidian nerve inferiorly with the apex pointing
superiorly. The lateral arm of the triangle is formed by the
medial pterygoid process, and the medial arm is formed by
the parasellar ICA (Fig. 5). After dissecting the dura cov-
ering the triangular area, the oculomotor (CNIII), abducens
(CNVI) and maxillary (CNV2) nerves are visualized and
together they form an ‘S’ shape (Fig. 6). This is another
useful landmark configuration, which helps to identify the
cranial nerves in the cavernous sinus [9]. The trochlear
nerve (CNIV) is located behind this complex and could be
exposed by retracting the oculomotor nerve (Fig. 7).
The lateral cavernous sinus areas [9] are identified. This
can be facilitated by retracting ICA medially (Fig. 8):
1. Superior triangular area (STA): the base of this area is
formed by the lateral loop of ICA. The superior border
is formed by CNIII and the inferior border by CN VI.
This area contains CNIV.
2. Superior quadrangular area (SQA): this area is bor-
dered superiorly by CNVI, inferiorly by CNV2, medi-
ally by ICA and laterally by the bone of the lateral wall
of the sphenoid sinus, which extends from SOF to the
foramen rotundum. This area contains CNV1.
3. Inferior quadrangular area (IQA): this area is bordered
by CNV2 superiorly, the vidian nerve inferiorly,
interpetrous segment of ICA medially and the
sphenoid bone extending from the foramen rotundum
and pterygoid canal laterally. This area is extensively
external to the cavernous sinus.
By retracting the ICA and CNIV medially away from the
lateral wall of the cavernous sinus, a quadrangular area,
bordered superiorly by the CNVI, inferiorly by the petrous
segment of ICA, medially by the paraclival segment of ICA
and laterally by CNV2, is exposed. This area represents the
anterior part (door) of the Meckel’s cave [27] (Fig. 9).
The medial part of the cavernous sinus
After the exposure of the area between the parasellar ICA
and the pituitary gland, an arachnoid band connecting the
anterolateral surface of the pituitary gland and the anterior
bend of the parasellar ICA is visualized and resected
(Fig. 10). From the contralateral nostril, the 30° endoscope
is introduced. The pituitary gland is retracted medially and
the medial wall of the cavernous sinus and the inferior
Fig. 5 Endoscopic view of the right cavernous sinus and its
neurovascular relations, demonstrating the triangular area formed
by the medial pterygoid process laterally, the parasellar ICA medially
and the vidian nerve inferiorly at the base. III oculomotor nerve, V1
ophthalmic nerve, V2 maxillary nerve, V3 mandibular nerve, VI
abducens nerve, C clivus, ICA-Sa anterior bend of the internal carotid
artery–parasellar segment, ICA-Sp posterior bend of the internal
carotid artery–parasellar segment, ICA-C paraclival segment of the
internal carotid artery, ICA-L lacerum segment of the internal carotid
artery, ICA-P petrous segment of the internal carotid artery, PG
pituitary gland, VC vidian canal, VN vidian nerve
Fig. 6 Endoscopic view of the right cavernous sinus and neurovas-
cular relations, demonstrating the ‘S’ shaped configuration formed by
the oculomotor, the abducens and the vidian nerves. III oculomotor
nerve, V1 ophthalmic nerve, V2 maxillary nerve, V3 mandibular
nerve, VI abducens nerve, C clivus, ICA-Sa anterior bend of the
internal carotid artery–parasellar segment, ICA-Sp posterior bend of
the internal carotid artery–parasellar segment, ICA-C paraclival
segment of the internal carotid artery, ICA-L lacerum segment of
the internal carotid artery, ICA-P petrous segment of the internal
carotid artery, PG pituitary gland, VC vidian canal, VN vidian nerve
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6. hypophyseal artery (IHA) are exposed (Fig. 11a). The
endoscope is advanced inferior to the pituitary gland and
the inferior hypophyseal artery, and the posterior aspect of
the sellar fossa and the posterior clinoid process are
exposed (Fig. 11b).
Discussion
The cavernous sinus is a complicated structure with a
unique architecture. Thus, detailed anatomic knowledge
is necessary for surgical intervention in this region.
Transcranial and/or transfacial approaches are considered
invasive, with unwanted brain retraction and difficulty in
exposing the medial part of the cavernous sinus. To
overcome this problem, different transsphenoidal
[22–24], transmaxillary [10], transmaxillosphenoidal
[35], transethmoidal [11] and transsphenoethmoid [30]
approaches have been described for removal of lesions
located in the anterior portion of the cavernous sinus.
However, these approaches still have their limitations and
drawbacks, such as the narrow straight surgical corridor,
with limited exposure. With the introduction of the
endoscopic endonasal transsphenoidal surgery to the
pituitary gland [5, 8, 12–14, 25], wide endoscopic expo-
sure offered the ability to reach the cavernous sinus by
this route. Recently, anatomic reports have studied the
endoscopic anatomy and approaches of the cavernous
Fig. 7 Endoscopic view (a),
and a drawing (b) of the right
cavernous sinus demonstrating
its neurovascular relations.
c A drawing of the right
cavernous sinus demonstrating
the exposure of the trochlear
nerve after retracting the
oculomotor nerve. III
oculomotor nerve, IV trochlear
nerve, V1 ophthalmic nerve,
VI abducens nerve, ICA internal
carotid artery, OA ophthalmic
artery, OCh optic chiasm, ON
optic nerve, PG pituitary gland
Fig. 8 Endoscopic view of the right cavernous sinus showing its
neurovascular relations and the main anatomic areas. III oculomotor
nerve, V1 ophthalmic nerve, V2 maxillary nerve, V3 mandibular
nerve, VI abducens nerve, C clivus, ICA-Sa anterior bend of the
internal carotid artery–parasellar segment, ICA-Sp posterior bend of
the internal carotid artery–parasellar segment, ICA-C paraclival
segment of the internal carotid artery, ICA-L lacerum segment of
the internal carotid artery, ICA-P petrous segment of the internal
carotid artery, PG pituitary gland, VC vidian canal, VN vidian nerve,
STA superior triangular area, SQA superior quadrangular area, IQA
inferior quadrangular area
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7. sinus [6, 7, 9, 10, 20]. These reports defined surgical
corridors to reach different areas of the cavernous sinus.
The anatomic landmarks of the roof of the sphenoid sinus
and their relations to the cavernous sinus have been
highlighted. The intercavernous segment of ICA has been
classified in relation to the pituitary gland (parasellar
Fig. 9 a Endoscopic view of the right cavernous sinus showing its
neurovascular relations after retracting the internal carotid artery
medially. b Internal carotid artery and the abducens nerve are both
retracted medially to expose the lateral wall of the cavernous sinus
and the anterior part of Meckel’s cave (dotted area). III oculomotor
nerve, V1 ophthalmic nerve, V2 maxillary nerve, V3 mandibular
nerve, VI abducens nerve, C clivus, ICA internal carotid artery,
SF sympathetic fibers, VC vidian canal
Fig. 10 a Endoscopic view of
the left arachnoid band
connecting the anterolateral
surface of the pituitary gland
and the anterior bend of the left
parasellar IC. b Medial wall of
the left cavernous sinus is
exposed after the resection of
the band. B band, C clivus, CSm
medial wall of the cavernous
sinus, ICA-A anterior bend
of the internal carotid artery,
ICA-P posterior bend of the
internal carotid artery,
PG pituitary gland
Fig. 11 a Endoscopic view of
the medial wall of the left
cavernous sinus after retracting
the pituitary gland to the right
side. The left inferior
hypophyseal artery is exposed.
b The endoscope is advanced
inferior to the left inferior
hypophyseal artery and the left
side of the pituitary gland to
expose the anterior surface of
the left posterior clinoid
process. ICA internal carotid
artery, IHA inferior hypophyseal
artery, PC posterior clinoid
process, PG pituitary gland
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8. ICA) and clivus (paraclival ICA), which is found to be
more appropriate for endoscopic approaches [7].
In our study, we highlighted the important structures and
landmarks, from the endoscopic view, which will help us to
understand the neurovascular relations of the cavernous sinus.
Based on the anatomical information provided, appropriate
surgical approach with defined surgical corridors can be
selected for different areas of the cavernous sinus.
To expose the inferior portion of the cavernous sinus,
the superior and the middle turbinates and the posterior
ethmoidal cells are removed (extended endoscopic endo-
nasal transsphenoidal approach). The anatomic landmarks
in the roof of the sphenoid sinus are valuable to determine
the anatomic location of the cavernous sinus. ICA, with its
parasellar and paraclival parts, is delineated by the carotid
protuberance, with the sellar fossa located medially. Also,
when the lateral septae of the sphenoid sinus exist, these
are generally attached to the carotid protuberance and point
to the location of ICA [5]. These important landmarks can
help locate the intercavernous ICA and the cavernous sinus
before bone resection and opening of the dura, which offers
a safer approach [7]. Including the sellar fossa in the bone
resection is preferred, as wide exposure of the related
structures avoid blind manipulation and create a space for
ICA retraction when needed.
The lateral wall of the cavernous sinus is exposed by the
endonasal ethmoido-pterygo-sphenoidal approach [21]. In
this approach, the uncinate process is resected and, after
identifying the ethmoid bulla, the bulla is opened, and the
anterior and then the posterior ethmoidal cells are exposed
and removed. Inside this area, another three areas are
delineated: the superior triangular area, the superior qua-
drangular area, the quadrangular inferior area and a narrow
C-shaped area located medial to ICA [9]. This approach is
suitable especially for lesions involving the area between
ICA and the cranial nerves of the cavernous sinus, as these
lesions are reached directly without the need to pass
through the cranial nerves, in contrast to transcranial
microsurgical approaches.
To expose the medial wall of the cavernous sinus, an
arachnoid band connecting the anterolateral surface of the
pituitary gland and the anterior bend of the parasellar ICA
is resected. From our dissections, we believe that this
band can be a medial extension of the proximal carotid
ring. The medial part of the cavernous sinus is exposed by
the 30° endoscope, introduced through the contralateral
nostril (contralateral endoscopic endonasal transsphenoi-
dal approach). In contrast to microsurgical transcranial
approaches, endoscopic endonasal approaches offer direct
exposure of the medial part of the cavernous sinus,
without the need to pass through the cranial nerves and
ICA. This avoids possible injury to these structures due to
surgical manipulation.
The logic of the infero-medial approaches to the cav-
ernous sinus is based on the following anatomic and sur-
gical observations mentioned by Cavallo et al. [9]:
1. The meningeal wall of the cavernous sinus has three
weak points, through which tumor invasion and
extension is favorable: the venous plexus around the
SOF, the loose texture of the medial wall around the
pituitary body and the dural pockets of the cranial
nerves. The dural wall is extremely thin or absent at
those points [28].
2. The medial wall of the cavernous sinus is formed only
by one continuous thin layer of dura, in contrast to the
lateral and the superior walls, which are formed by two
(meningeal and endosteal) layers [39]. The thin dura in
the medial wall may be incomplete [18] or absent
[15, 29].
3. Venous compartments around the intercavernous
carotid can be differentiated into various sizes and
shapes. From the superior view, the venous space
medial to the ICA is dominant in 48 versus 22% in
which the venous space lateral to the ICA is dominant
[33, 34]. From the lateral view, the venous space
antero-inferior to the ICA is dominant in 60% of cases,
whereas the venous space posterosuperior to the ICA is
dominant in only 16% of the cases [24].
4. The pituitary gland can overlap the intracavernous
carotid artery with a tongue-like projection [34].
These anatomic observations can explain, as recently
reported, the reason why most nonfunctioning pituitary
adenomas extending into the cavernous sinus are neither
aggressive nor invasive [40], but are only growing lesions
through the weak points of the wall of the cavernous sinus.
This growth pattern of the tumors results in enlarging and
widening of the anatomic planes between the cavernous
sinus and the neighboring structures, or between the
intercavernous structures themselves, thus creating a wide
surgical corridor and easier exposure of the pathology.
Recently, Kassam et al. [27] have described the exposure
of the anterior part, door of the Meckel’s cave, by
retracting the ICA and CNIV medially away from the lat-
eral wall of the cavernous sinus. This entrance area to the
Meckel’s cave is bordered superiorly by the CNVI, infe-
riorly by the petrous segment of ICA, medially by the
paraclival segment of ICA and laterally by CNV2. This
approach provides a good access to tumors located or
invading the Meckel’s cave [27].
The main problem in the endoscopic approach is con-
trolling bleeding after incidental injury of ICA. Also,
bleeding from the cavernous sinus, especially after
removing the tumor and decompressing the sinus, can be
problematic. However, sinus bleeding can be controlled
with proper materials for hemostasis. Another potential
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9. complication is the injury to the cranial nerves. However,
the endoscopic approach is more superior in protecting the
cranial nerves, as with the infero-medial the medial part of
the cavernous sinus can be reached directly, without the
need to dissect and pass through the cranial nerves.
Conclusions
Knowledge of the anatomy of the cavernous sinus obtained
with an endoscopic view of cadaver dissections is impor-
tant for endoscopic treatment of various the pathologies of
this region. In this study, we reviewed the endoscopic
anatomy of the cavernous sinus and the related neurovas-
cular structures. Based on these anatomic findings, we
described the appropriate endoscopic surgical approaches
to the different parts of the cavernous sinus. This anatomic
knowledge is important to perform a safer and minimally
invasive surgery.
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