2. Great teachers – All this is their work .
I am just the reader of their books .
Prof. Paolo castelnuovo
Prof. Aldo Stamm Prof. Mario Sanna
Prof. Magnan
3. For Other powerpoint presentatioins
of
“ Skull base 360° ”
I will update continuosly with date tag at the end as I am
getting more & more information
click
www.skullbase360.in
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account for downloading.
5. Bulbar fascia includes
1. Tenon’s capsule 2. Tubular sheat for each orbital muscle 3. medial & lateral
check ligament 4. suspensory ligament of lockwood
10. For detailed understanding of ALSC
see “ SOF 360° ” presentation in
website :
Click
http://www.slideshare.net/muralich
andnallamothu/superior-orbital-
fissure-360
11. The term cavernous sinus addresses only the venous aspect, neglecting the neural and
soft tissue components. A more comprehensive and rational term is lateral sellar
compartment (Parkinson 1990 ) .
• Lateral sellar compartment ( =
Cavernous sinus ) is in
continuation with SOF & Orbit
• SOF devided into
[ SOF = ALSC + Orbital apex]
1. ALSC = Anterior lateral sellar
compartment – Located
anterior to the anterior loop
of the cavernous portion of
the internal carotid artery.
2. Orbital apex
13. Parts of ALSC ( Anterior lateral sellar
compartment )
1. Superior Part – Nervous compartment
a. Lateral Group of nerves - from lateral to medial - LFT[ Liver
functional tests ] Menumonic – Lacrimal N., Frontal N.,TrochlearN.
b. Middle Group of nerves - 3rd , 6th , Nasocilliary N.
2. Inferior part – Venous compartment - Inferior Opthalmic vein – The
inferior venous compartment is given by the confluence of the superior
ophthalmic vein ( SOV ) and inferior ophthalmic vein ( IOV ), which drain
into the cavernous sinus (Froelich et al. 2009 ) .
14. ORBITAL APEX
[ SOF = ALSC +
Orbital apex]
Orbital apex is divided into the
1. intraconal compartment
2. extraconal compartments
- passed by the lacrimal,
trochlear, and frontal
nerves. The frontal and
trochlear nerves ascend
above the Levator muscle &
superior rectus muscle.
Within the intraconal space,
the
1. superomedial
foramen - optic nerve and
the ophthalmic artery pass.
2. superolateral
foramen - oculomotor, nasociliary,
and abducens nerves pass.
15. 1. 3rd nerve supplies to the muscles from medially – so when you are doing principle of
divergence [ to separate the ocular muscles ] to remove the intraconal tumors , don’t stretch
too much , chances of nerve avulsion from the muscle is there sothat muscle palsy
2. SO4 LR6 – all muscles by 3rd nerve , super oblique by 4th nerve , lateral rectus by 6th nerve
3. MG = medial group of nerves – 3rd, 6rth , nasociliary ; LG = lateral group of nerves – LFT [
mneumonic = Lacrimal , frontal , trochlear ]
Orbital
apex
[ SOF = ALSC +
Orbital apex]
17. Parts of Orbital Apex
Orbital apex is divided into the
– intraconal compartment
– extraconal compartments - passed by the lacrimal,
trochlear, and frontal nerves. The frontal and trochlear
nerves ascend above the Levator muscle & superior
rectus muscle.
Within the intraconal space, the
1. superomedial foramen - optic nerve and the
ophthalmic artery pass.
2. superolateral foramen - oculomotor, nasociliary,
and abducens nerves pass.
19. ORBITAL APEX
[ SOF = ALSC +
Orbital apex]
Orbital apex is divided into the
1. intraconal compartment
2. extraconal compartments
- passed by the lacrimal,
trochlear, and frontal
nerves. The frontal and
trochlear nerves ascend
above the Levator muscle &
superior rectus muscle.
Within the intraconal space,
the
1. superomedial
foramen - optic nerve and
the ophthalmic artery pass.
2. superolateral
foramen - oculomotor, nasociliary,
and abducens nerves pass.
20. 1. 3rd nerve supplies to the muscles from medially – so when you are doing principle of
divergence [ to separate the ocular muscles ] to remove the intraconal tumors , don’t stretch
too much , chances of nerve avulsion from the muscle is there sothat muscle palsy
2. SO4 LR6 – all muscles by 3rd nerve , super oblique by 4th nerve , lateral rectus by 6th nerve
3. MG = medial group of nerves – 3rd, 6rth , nasociliary ; LG = lateral group of nerves – LFT [
mneumonic = Lacrimal , frontal , trochlear ]
Orbital
apex
[ SOF = ALSC +
Orbital apex]
22. Zonule of zinn - inserts on the infraoptic tubercle, which is often
found as a canal located beneath the optic strut .
The four rectus muscles insert posteriorly, through the Inferior
common tendon ( ICT ) , on the infraoptic tubercle, a small
depression below the optic strut.
23. More anteriorly, the Inferior common tendon ( ICT ) splits into a superior and inferior
tendon. From the inferior tendon originate the medial, inferior, and lateral rectus
muscles, and from the superior originates the superior rectus muscle.
Inferior common tendon ( ICT ) MG medial group of nerve
(oculomotor, nasociliary, abducens),
black arrow - lateral group of nerves (frontal,
lacrimal, trochlear)
24. Greater wing of sphenoid – at posterior end of orbit – Through orbit if we breach
greater wing of sphenoid we go to the middle cranial fossa
25. Clinoid has three roots of attachment
1. Anteriror root = Anterior Clinoid process attachemnt to planum
2. Posterior root = Optic struct = L-OCR
3. 3rd root = Anterior Clinoid process attachment to Lesser wing of sphenoid
26. Clinoid has three roots of attachment
1. Anteriror root = Anterior Clinoid process attachemnt to planum
2. Posterior root = Optic struct = L-OCR
3. 3rd root = Anterior Clinoid process attachment to Lesser wing of sphenoid
27. Three surgical attachments of the right anterior clinoid process.
(a, sphenoid ridge; b, roof of optic canal; c, optic strut.)
29. 1. SOF present between two structs
2. OS [ optic struct separates optic canal from SOF ]
30. 1. SOF present between two structs
2. OS [ optic struct separates optic canal from SOF ]
31. SOF & IOF are in C-shape when you
see through orbit /maxilla/nose
32. Anterior clinoid process [ ACP ] has 3 roots of attachements :
1. Anterior root – ACP attachment to sphenoid planum medial
to falciform ligament
2. posterior root = OS = L-OCR
3. 3rd root to lesser wing of sphenoid
33. Optic strut [ OS ] =
L-OCR
[ Pneumatisation
of OS ] =
Posterior root of
Anterior clinoid
process [ ACP ]
OS = L-OCR =
posterior root of
ACP
34. 1. Surpa-optic pneumatisation starts from anterior root of ACP & goes to ACP
, infra-optic pneumatization starts in posterior root of ACP [ = OS = L-OCR ] &
may goes into ACP
2. In ACP drilling if there is pneumatization we will directly open into sphenoid
so we have to plug with fat after ACP drilling in neurosurgical skull base
35. Surpa-optic pneumatisation starts from anterior root of ACP & goes to
ACP , infra-optic pneumatization starts in posterior root of ACP [ = OS
= L-OCR ] & may goes into ACP
36. Various types of Optic nerve
• Type I: The most common type, it occurs in 76% of patients.
Here, the nerve courses immediately adjacent to the
sphenoid sinus, without indentation of the wall or contact
with the posterior ethmoid air cell [Figure 11].
• Type II: The nerve courses adjacent to the sphenoid sinus,
causing an indentation of the sinus wall, but without
contact with the posterior ethmoid air cell [Figure 12].
• Type III: The nerve courses through the sphenoid sinus with
at least 50% of the nerve being surrounded by air [Figure
13].
• Type IV: The nerve course lies immediately adjacent to the
sphenoid and posterior ethmoid sinus [Figure
14] and [Figure 15].
37. Figure 11: Coronal CT showing type I optic nerve (arrows) the nerve is seen to course
immediately adjacent to the sphenoid sinus, without contact with the posterior
ethmoid air cell
38. Figure 12: Coronal CT showing type II optic nerve (curved arrows) causing an
indentation of the sinus wall, but without contact with the posterior ethmoid air cell
39. Figure 13: Coronal CT shows type III optic nerve (arrows) where more than 50% of the
nerve is surrounded by air
40. Figure 14: Coronal CT showing type IV optic nerve on the right (arrow) -The nerve
course lies immediately adjacent to the sphenoid and posterior ethmoid sinus. O:
Onodi cell; S: Sphenoid sinus
41. Figure 15: Coronal CT showing type IV optic nerve bilaterally (arrows). O: Onodi cell; S:
Sphenoid sinus
42. Delano, et al., found that 85% of optic nerves associated with a pneumatized anterior
clinoid process were of type II or type III configuration, and of these, 77% showed
dehiscence [Figure 16], indicating the vulnerability of the optic nerve during FESS.
Figure 16: Coronal CT shows pneumatisation of anterior clinoid process (stars) with
type III optic nerve (stars) with bony canal dehiscence bilaterally
43. Pneumatization of anterior clinoid process – in various planes + onodi cell on
both sides of sphenoid [ when transverse septum present in sphenoid it is
onodi cell ] + sphenoid recess on left side between V2 & VN .
44. The same cadaver photo what you are seeing in CT scan above – Note the supraoptic
pneumatisation [ present in anterior clinoid process ] in an onodi cell .
45. The sphenoid sinus septa may be attached to the bony canal of the optic nerve, predisposing the
nerve to injury during surgery .
Figure 17: Coronal CT showing sphenoid septa (arrow) attached to the bony walls of type III optic
nerve bilaterally (stars)
46.
47.
48. The muller’s muscle extends for the whole length of the inferior
orbital fissure, passes above the maxillary strut and enters the
superior orbital fissure.
49. Cadaveric dissection demonstrating the anatomy of the right orbital apex following
removal of the lamina papyracea, periorbita, and orbital fat. (OA, ophthalmic artery; MR, medial
rectus; ON, optic nerve; IR, inferior rectus; MM, Muller muscle; V2, second branch of the
trigeminal nerve.)
50. An important vein travelling the SOF is quite constant. It is immediately under the periorbit,
outside the muscular cone, and reaches the cavernous venous compartment. This vein can be a
limiting factor for drilling the SOF area (Dallan et al. 2013 ).
CS cavernous sinus, IRM inferior rectus muscle, lOCR lateral optico-carotid recess, MM Muller’s
muscle, MRM medial rectus muscle, ON optic nerve, pwMS posterior wall of the maxillary sinus,
VN vidian nerve, V2 second branch of the trigeminal nerve, white asterisk indicates lateral optico-
carotid recess, black asterisks indicate the nasal part of the superior orbital fi ssure, black arrow
indicates the division of the oculomotor nerve, red arrow indicates ophthalmic artery, yellow
arrow indicates maxillary strut
51. By dividing IRM and MRM tendons it is possible to identify the 2 main
branches of the oculomotor nerve, and laterally to it, the first segment of the
ophthalmic artery (Dallan et al. 2013 ).
52. By dividing IRM and MRM tendons it is possible to identify the 2 main
branches of the oculomotor nerve, and laterally to it, the first segment of the
ophthalmic artery (Dallan et al. 2013 ).
54. FN frontal nerve, IRM inferior rectus muscle, LaN lacrimal nerve, LRM lateral rectus muscle,
LWS lesser wing of the sphenoid, MRM medial rectus muscle, NCN nasociliary nerve, ON optic
nerve, SRM superior rectus muscle, SS sphenoid sinus, V2 second branch of the trigeminal
nerve, IIIcn oculomotor nerve, red asterisk trochlear nerve, red arrowhead abducens nerve, red
circle ophthalmic artery
55. Thicker inferior division of 3rd N. & thinner superior division of 3rd N .
2. Nasociliary N passes between divisions of 3rd N.
3. In the annulus, the nasociliary nerve passes medially, and it is located
between the two divisions of the oculomotor nerve; the abducens nerve runs
superiorly and laterally to reach the lateral rectus muscle.
56. Accessing intraconal lesions endonasally requires manipulation of the extraocular
muscles. The nerve branches that supply the oculomotor muscles run in the medial
surface of the muscles. Thus, try to avoid excessive retraction of the extraocular
muscles to avoid inadvertent muscle paresis.
57. The pterygopalatine fossa presents an extension within the superior orbital fissure (
SOF ), inferior to the lateral sellar compartment and Muller’s muscle. It is composed of
fat, small veins, and nerve fibres associated with the pterygopalatine ganglion (PPG)
(Weninger and Prahmas 2000 ) .
58.
59. Cadaveric dissection demonstrating the anatomy of the right orbital apex following
removal of the lamina papyracea, periorbita, and orbital fat. (OA, ophthalmic artery;
MR, medial rectus; ON, optic nerve; IR, inferior rectus; MM, Muller muscle; V2, second
branch of the trigeminal nerve.)
60. a–c Contents of the orbita. (a) Reconstruction of the medial aspect of the orbit. (b) Right orbit, endoscopic view of the
upper part of the anterior medial intraconal space. (c) Right orbit, endoscopic view of the medial intraconal space. AEA,
anterior ethmoidal artery; CAs, ciliary arteries; DNA, dorsal nasal artery; IRM, inferior rectus muscle; IRMb, branch for the
inferior rectus muscle; ITN, infratrochlear nerve; IVcn, trochlear nerve; LCN, long ciliary nerve; MRM, medial rectus muscle;
NCN, nasociliary nerve; OA, ophthalmic artery; ON, optic nerve; PEA, posterior ethmoidal artery; SB, skull base; SOA,
supraorbital artery; SOM, superioroblique muscle; SON, supraorbital nerve; SOV, superior ophthalmic vein; STA,
supratrochlear artery; STN, supratrochlear nerve. Black circles, periorbit.
61. Left orbit, macroscopic vision of the medial intraconal
space. EB, eyeball; IIIcn, oculomotor nerve; IOA, infraorbital artery; IRM, inferior rectus muscle; IRMb, branch
for the inferior rectus muscle; MRM, medial rectus muscle; NCN, nasociliary nerve;
OA, ophthalmic artery; ON, optic nerve; PEA, posterior
ethmoidal artery; SOM, superior oblique muscle; SOV, superior
ophthalmic vein. Stars, long ciliary nerves.
62. The medial and inferior rectus muscles arise from the portion of the anular tendon situated medial to and
below the optic canal. Tributaries of the inferior ophthalmic vein pass downward on the medial side of the
anular tendon and cross below the inferior rectus muscle to join the main trunk of the vein where it exits the
intraconal area by passing between the heads of the lateral and inferior rectus muscles to enter the anterior-
inferior part of the cavernous sinus.
63. 1. Note 3rd nerve on medial surface of medial rectus muscle
2. The medial rectus muscle has been divided near the globe and reflected posteriorly. In this
case, the ophthalmic artery courses below the optic nerve to reach the medial part of the
orbit.
64. Central retinal artery origin from Ophthalmic artery – the only
artery which can’t be mobilized in skull base surgery is
Ophthalmic artery because central retinal artery is torn
65. The ophthalmic artery has been elevated to expose the ciliary ganglion on the lateral aide of
the optic nerve. The motor (parasympathetic) root of the ciliary ganglion arises from the branch
of the inferior division of the oculomotor nerve to the inferior oblique muscle. The sympathetic
root of the ciliary ganglion arises from the carotid sympathetic plexus.
66. “ PEA based Hadad “ flap – useful in where
sphenopalatine artery sacrificed.
68. Branches of V 1
Lateral part- from lateral to medial - LFT[ Liver functional tests ]
Menumonic – Lacrimal N., Frontal N.,Trochlear N.
Immediately after removing the
periorbita
69. 1. Lateral part- LFT [ Liver functional tests ] Menumonic – Lacrimal N., Frontal
N.,TrochlearN. & Superior Opthalmic Vein.
2. The frontal and trochlear nerves ascend above the Levator muscle & superior
rectus muscle.
Frontal N. devides into Sup.Troch.N.
& Supraorb.N. – NOTE Fal.Lig
70. 1. Thicker inferior division of 3rd N. & thinner superior division of 3rd N .
2. Nasociliary N passes between divisions of 3rd N.
3. In the annulus, the nasociliary nerve passes medially, and it is located between the two
divisions of the oculomotor nerve; the abducens nerve runs superiorly and laterally to reach the
lateral rectus muscle.
71. A segment of the orbital portion of the optic
nerve has been removed. This exposes the
branch of the inferior division of the
oculomotor nerve, which passes below the
optic nerve and enters the medial rectus
muscle.
72. When you are approaching endoscopically the upper
most one is Sup.Orb.M superiorly & Medial rectus
inferiorly
76. Anterior limit of Transplanum approach is PEA – when
we are removing a triangular piece of bone in
Transplanum approach , the base of traingle is PEA
79. Orbit from inferiorly
Inferior orbital muscle is complete
muscle , whereas Sup.Obl.M is muscular
& tendinous
Orbit from inferiorly after cutting
the Inferior rectus muscle
83. Optic nerve decompression:
Remove the bone (by drilling) over the
orbital apex and
identify the optic foramen and optic nerve
canal:
a) superior and medial aspect of the orbital
apex
b) 4-6 mm posterior to the posterior
ethmoidal artery
c) at a level that grossly corresponds with
the level of the
rostrum of the sphenoid (coronal axis).
Use the drill to thin the bone of the optic
nerve canal.
Remove the remaining bone using dissecting
instruments
or 1mm Kerrison’s rongeurs.
Most commonly, the optic canal
decompression extends
posteriorly to the level of the lateral optic
carotid recess
(LOCR).
LOCR corresponds to the pneumatization of
the optic strut.
The anterior clinoids are at the superior
aspect of the
optic canal just above the LOCR; therefore, it
is at this level
that the optic nerve enters its canal after it
intradural
course (i.e. it is not surrounded by bone).
85. In 83% the OA passes around the lateral aspect of the optic
nerve (b, left); in the remaining cases the OA stays medial to the
optic nerve, 17% - this point important in optic nerve
decompression
86. One artery in the head which we can’t move – is
OA – Central retinal artery is avulsed
87. Relation of PEA & ON
Anterior limit of Transplanum approach is
PEA – when we are removing a triangular
piece of bone in Transplanum approach ,
the base of traingle is PEA
88. Anterior limit of Transplanum approach is PEA – when
we are removing a triangular piece of bone in
Transplanum approach , the base of traingle is PEA
90. The sphenoid ostium (SO) is first opened inferiorly (black arrow, 1) then laterally (black
arrow, 2). This should afford a
clear view into the sphenoid sinus and the remaining anterior face of the sphenoid can
be removed up toward the optic tubercle (OT) but
usually stopping short of the tubercle to lessen the potential risk to the optic nerve.
91.
92.
93.
94. Opthalmic artery – Retrograde branch of Intracranial carotid
Branches of the cavernous internal
carotid artery ( ICA ), a rare
variation: ophthalmic
artery passing through the superior
orbital fissure
95. classification of the ophthalmic artery types
http://www.springerimages.com/Images/MedicineAndPublicHealth/1-
10.1007_s10143-006-0028-6-1
a = intradural type,
b = extradural supra-optic strut type [ Optic strut = L-OCR ]
c = extradural trans-optic strut type
on optic nerve, pr proximal ring, cdr carotid dural
ring= upper dural ring , ica internal carotid artery
I think this variation is type c
96. In both type a = intradural type,
b = extradural supra-optic strut types Opthalmic
foramen is in Optic canal
97. In Type c = extradural trans-optic strut type , the Opthalmic
foramen in Optic strut
99. Origin and intracranial and
intracanalicular course of
the ophthalmic artery and its
subdivisions, as seen on opening
the optic canal (reproduced from
Hayreh67).
Both from one specimen. (a) The extradural
origin of the right ophthalmic artery, so that
no ophthalmic artery is seen even on
opening theoptic canal; a thinning of the
dural sheath is seen at 'X', indicating the
position of the artery. (b) The ophthalmic
artery is seen after removing the dural
sheath covering it (reproduced from Hayreh
and Dass2).
100. Schematic drawing origin (a medial, b central, c lateral) and exit
(d lateral, emedial) of superior wall of the ophthalmic artery
101. A diagrammatic representation of variations in origin and intraorbital course of ophthalmic artery.
(a) Normal pattern. (b–e) The ophthalmic artery arises from the internal carotid artery as usual,
but the major contribution comes from the middle meningeal artery. (f and g) The only source of
blood supply to the ophthalmic artery is the middle meningeal artery, as the connection with the
internal carotid artery is either absent (f) or obliterated (g) (reproduced from Hayreh and Dass3).
102. Note central retinal artery
- book name “ The Orbit and Sellar Region
Microsurgical Anatomy and Operative Approaches “ – author Rhoton
103. Origin, course, and branches of the ophthalmic artery in two adult specimens. Segment Y
disappeared in (a) and segment Z disappeared in (b), resulting in the ophthalmic artery crossing
under the optic nerve in both. In (b) an anastomosis is seen in lateral wall of the cavernous sinus
between the part of the internal carotid artery lying in proximal part of the cavernous sinus and a
branch from the ophthalmic artery passing through the superior orbital fissure (reproduced from
Hayreh67).
104.
105. Various relations of OA [ Opthalmic artery ] to ON
left figure when it crosses under the optic
nerve (in 17.4%) and right figure when it
crosses over the optic nerve (in 82.6%).
109. Sree Ram Murthy Dr : Dear surgeons it is a endoscopic endonasal
cadaveric ORBITAL TRANSPOSITION technique
The steps follows
1 complete exposure of anterior skull base
2 identification of septal branch of a e a and 1st olfactory fibre
3 removal of lamina papyracea
4 identification of aea and pea
5 cutting of both arteries and release the globe
6 gentle lateralization globe along with periorbita up to mid
pupillary point
7 complete exposure of medial orbital roof and further
according to pathology
110. Murali Chand Nallamothu: What are
indications of orbital transposition.
Sree Ram Murthy Dr Vizak ENT: Now a days it is important
part the indications
1. removal of infections lateral to mid pupillary level
2. lateral osteomas of frontal sinuses
3. trans orbital approaches to middle cranial tumours
4. exposure of cavernous sinus trans orbitally
I think 1 & 2 indications can be done by external
approaches by brow or bicoronal incisions
116. rbital cavernous haemangioma via transconjectival +Lat canthotomy
incision ( Ant Orbitotomy) yesterday. Transconjectival is a nice approach
to infra orbatal rim or to inferior orbit! – Dr.P.K.Banerjee [
+919407983485 ]
134. Two papers – click
Transnasal Approach to the Medial Intraconal
Space: Anatomic Study and Clinical
Considerations – click - http://sci-
hub.cc/10.1055/s-0030-1263106
Compartmental endoscopic surgical anatomy of
the medial intraconal orbital space
http://onlinelibrary.wiley.com.sci-
hub.cc/doi/10.1002/alr.21320/abstract
135. To get any paper of any journal free click
www.sci-hub.bz or www.sci-hub.cc
How to get FREE journal papers in www.sci-hub.bz or www.sci-hub.cc
1. When same paper published in different journals , the same paper has
different DOIs -- so we have to try with different DOIs in www.sci-
hub.bz orwww.sci-hub.cc if one of the DOI is not working.
2. If the paper has no DOI , copy & paste URL of that paper from the main
journal website . If you can't get from one journal URL try with different
journal URL when the author publishes in different journals .
3. Usually all new papers have DOIs . Old papers don't have DOIs . Then
search in www.Google.com . Old papers are usually kept them free in Google
by somebody . Sometimes the Old papers which are re-published will have
DOIs. Then keep this DOI in www.sci-hub.bz or www.sci-hub.cc
4. Add " .pdf " to title of the paper & search in www.Google.com if not found
in www.sci-hub.bz or www.sci-hub.cc
136. For Other powerpoint presentatioins
of
“ Skull base 360° ”
I will update continuosly with date tag at the end as I am
getting more & more information
click
www.skullbase360.in
- you have to login to slideshare.net with Facebook
account for downloading.
