Decision making between anterior skull base & lateral skull base

Decision making between
Anterior skull base & Lateral skull
base [ Neurosurgical skull base +
Trans-temporal skull base ]
7-5-2017
8.40 pm

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.

There is no consensus in below topics . So experts ( Both neurosurgeons &
ENTs ) has to sortout the issues & keep decision making proposals / charts in
skull base society websites .

This “decision making of skull base ” takes years of
experience & It changes from time to time with
advancement of instruments & better understanding of
anatomy & pathology . I am still in the process of acquiring
this decision making of skull base from various experts . So
this PPT is not final . The aim of this PPT is to develop
thought process in the skull base surgeon .
So please share your ideas of this
“ Decision making in skull base ” to my
e-mail : muralichand76@gmail.com , I
will change accordingly to this PPT .

Over the years Neurosurgical skull
base & Lateral Trans-temporal skull
base developed . Recently Anterior
skull base developed . So Decision
making of some of the skull base
tumors changed .

Main 3 pricinples which determines the Decision making of skull
base i.e., Best skull base approach for a tumor depends upon
1. Getting both proximal & distal control over
the carotid in case of carotid rent/rupture
2. Don’t cross the cranial nerves as far as
possible .
3. Without brain retraction – Remove the bone
leave the brain alone .

1. External corridor doesn’t matter except cosmesis , only
internal corridor matters – so in Open approaches of skull
base also use endoscope to get best results – see this video
how the Dr. Dugani Suresh ; Neurosurgeon is using
endoscope in Weber Fergusson incision
https://www.youtube.com/watch?v=Y95Jf3u8S8o&feature=y
outu.be
2. Most of the times “Don’t cross the NERVES”

Anterior skull base decision making
– By Prof. Amin Kassam & Dr. James
K. Liu

Prof. Amin Kassam
CORRIDOR SURGERY
Video – Click
https://www.youtube.com/watch?v=Q
oMCqwJ6Ke0

What is skull base 360° ???
Click
https://www.youtube.com/watch?v=kSeYK_-T9Qk
&
https://www.youtube.com/user/SkullBaseMD/videos
For better understanding -
Must watch above videos signifying importance of
www.skullbase360.in
by Prof. James K. Liu

Lateral Trans-temporal skull base
approaches – Decision making – by
Prof. Mario Sanna

" Decision making in skull base surgery " chapter
well written by prof. Mario sanna in pre-ESBS
surgery era in book [ Trans-temporal skull base ] – I
will update soon further – click
http://books.google.co.in/books?id=4bvs6yV2WTQ
C&printsec=frontcover&dq=atlas+of+microsurgery+
of+lateral+skull+base&hl=en&sa=X&ei=VmkFVInxB
oToggT-
94GoDQ&ved=0CCYQ6AEwAA#v=onepage&q=atlas
%20of%20microsurgery%20of%20lateral%20skull%
20base&f=false
Now this chapter has to be revised. This is the
need of the hour.

Neurosurgical skull base approaches
– Decision making – by Laligam
sekhar

Pterional craniotomy is itself a SKULL BASE
APPROACH – click -
https://www.youtube.com/watch?v=wyO_3pBFbxU
GIANT PITUITARY ADENOMA- MICROSURGERY-
dr suresh dugani/HUBLI/KARNATAK/INDIA
https://www.youtube.com/watch?v=Npwu_CvK
wsM&feature=youtu.be

Prof. Laligam Sekhar says - When the ICA is invaded
or encased by tumor, two controversies continue to
rage.
1. The first is whether one should attempt to
skeletonize the vessel by removing tumor or
whether the vessel should be resected.
2. The second concerns the question of whether all
patients should be revascularized, or only those
whose collateral circulation is demonstrated to
be limited.

Whether or not the ICA should be left intact
depends on the surgeons attitude and the nature of
the tumor. Benign tumors other than meningiomas
(e.g. schwannoma, pituitary adenoma) may usually
be dissected from the ICA. With meningiomas,
however, encasement and narrowing of the ICA
frequently indicates that the vessel wall has been invaded by tumor.
This has been conrmed by histological
study of removed arteries [19]. Therefore,
total resection often requires ICA resection. Of
course, the surgeon may choose to leave tumor
behind and treat it with radiosurgery. Generally,
chordomas and chondrosarcomas can be dissected
from the ICA, but some require replacing the artery
with a bypass graft. With slowly growing malignant
tumors such as adenoid cystic carcinomas, total
tumor removal requires resection of the ICA-CS.
Furthermore, resecting and replacing the artery encased
with tumor allows the surgeon to give the task
of preserving cranial nerves his full attention.

• Should a revascularization procedure be
performed in every patient where tumor
resection creates jeopardy for the ICA, or only
in those who fail preoperative balloon-
occlusion testing? This is a hotly debated
issue, but the occurrence of stroke even when
excellent collateral circulation is present
convinces us that a bypass should be
performed every time tumor resection places
the ICA at risk.

Our patients also undergo cerebral angiography.
Collateral circulation and tolerance to temporary
occlusion is assessed by compressing the
ipsilateral common carotid while injecting
contrast material into the contralateral ICA and
the dominant vertebral artery. We no longer
perform balloon occlusion tests since we
revascularize all patients in whom ICA
resection or injury seems likely.

Combined approaches of skull
base – click
http://www.slideshare.net/muralicha
ndnallamothu/combined-
approaches-of-skull-base-360

Carotid injury – Prevention &
Management

BEST PROTOCOL , I
have ever seen so
far – BY Dr.Paul
Gardner
---- copy &
paste & see in
any picture
software

Regarding anterior skull base when there is
rupture of carotid only 3 options are
1. Covered stents 2. Clamping 3. Coilling .
Covered stents which can be passed into parasellar
carotid told to me by vascular neurosurgeon – This
is a big boon to anterior skull base approach –
Several seniors opinions has to be taken regarding
longterm effects of these stents
http://www.ncbi.nlm.nih.gov/pubmed/25415067

Benign with recurrence esp.of post RT or malignancy with radical resection when Balloon
Occlusion test fails first we must do ECA-ICA anastomosis . This ECA-ICAanastamosis done by
pterional /FTOZ approach & tumor can be removed by same approach or combined with
endoscopic endonasal or trans-temporal skull base approaches . We shouldn't go only by
endoscopic endonasal without ECA-ICA anastomosis because there won't be cross circulation
if ICA ruptures . Leads to catastrophie. Check others at " Carotid injury " PPT & "Decision
making of anterior & lateral skull base " PPT at www.skullbase360.in

first thing we have to check BOT .
• 1. If cross circulation is not there there is no point in going for
surgery . So direct Shunting has to be done . Surgery has to be done
after 6 - 8 weeks .
• 2. If cross circulation good we can proceed for surgery with muscle
patch & interventional radiologist ready . Even then there are
higher chances of death .
• 3. So in revisions & post radiotherapy especially chordomas cases
pre-op carotid coilling which completely occludes the carotid has to
be done . Then you have to remove tumor . Even then in children it
gives false sense of security . In adults we can safely remove tumor .
Even then if the rent is more than 1.5 cm coilling may come out .
But this is absolutely safe procedure
• I will write /update in detail in few days

How far carotid transposition is safe in
anterior skull base ???????
Micro-aneurysms may present in
ICA which have high potential for
rupture - picture from Trans-
temporal skull base

Management of carotid artery
injury in Lateral skull base
- Reference from Prof.Mario Sanna

Prof.Mario Sanna - Management of
great vessels in Lateral skull base –
lecture – click
https://www.youtube.com
/watch?v=7tW3Ev9siCs&fe
ature=youtu.be

Modalities of surgical management of
the ICA include:
1. Skeletonization
2. Displacement
3. Subperiosteal/subadventitial dissection
4. Dissection and resection after permanent
balloon occlusion
5. Subadventitial dissection after reinforcement
with stent

1. Skeletonization
This is done in tumors reaching but not adhering to the
artery. The most common lesions are represented by
petrous bone cholesteatomas and type C1 glomus
tumors. The artery can be exposed in certain approaches
to provide proximal control, e. g. the infratemporal fossa
approach or the modified transcochlear approach type A.
In the middle fossa transpetrous approach the artery is
one of the anatomical boundaries that are skeletonized to
avoid injuring while drilling the petrous apex.
Skeletonization carries little risk in experienced hands. An
exhaustive knowledge anatomy is mandatory; a large
diamond burr parallel to the course of the artery is used
to remove the last shell of bone covering the artery.

2. Displacement
Displacement is used
to gain access, e. g.,
during an
infratemporal fossa
type B approach to
the petrous apex .
Displacement should
be done gently and
complete liberation of
the artery is needed
first.
A case of right clival chordoma. The vertical
internal carotid artery (ICA) is gently displaced to
allow proper control of the petrous apex (PA) lying
medial to the artery.

3.Subperiosteal/Subadventitial Dissection
Subperiosteal/subadventitial dissection is accomplished for
tumors that involve the ICA to a greater extent, such as C2
glomus tumors and meningiomas (Fig. 15.24a, b). In general,
dissection of the tumor from the artery is relatively easier
and safer in the vertical intrapetrous segment, which is
thicker and more accessible than the horizontal intrapetrous
segment.
A plane of cleavage between the tumor and the artery
should be found first. In most cases, the tumor is attached to
the periosteum surrounding the artery. Dissection is better
started at an area immediately free of tumor. Aggressive
tumors may, however, extend even to the adventitia of the
artery and subadventitial dissection may be needed. This
should be done very carefully in order to avoid any tear to the
arterial wall, which can become weakened (Fig. 15.25), with
the risk of subsequent blowout.

A case of left glomus jugulare tumor in our early experience.
Subadventitial dissection has been performed because the artery had
been so weakened after the tumor removal. Although the patient had no
relevant complications postoperatively, such excessive manipulation is
better avoided and permanent balloon occlusion or stenting are preferably
tried preoperatively.

4. Dissection and Resection after
Permanent Balloon Occlusion of the
Internal Carotid ArteryIn patients in whom the tumor is adjacent to the carotid artery, the
preoperative examination to determine whether the carotid artery has to be
resected is a crucial and difficult task that can lead to false-negative and false-
positive results.
Carotid artery invasion is difficult to assess even at operation: often the tumor
obscures a portion of the carotid artery or completely surrounds it; malignant
tumors, by their infiltrative nature, do not allow for their separation from the
ICA; manipulating vascular tumors can increase the difficulty, as bleeding
impairs visualization.
When the carotid artery has been controlled by balloon occlusion these
problems are lessened but not eliminated.
Dissection of the occluded ICA is started the cervical level; after isolation, the
artery is ligated immediately after the proximal balloon; then dissection and
separation from the tumor proceeds fromthe vertical petrosal segment until
the junction between horizontal petrosal and lacerum segments; finally,

thanks to the presence of a balloon in the cavernous segment,
the petrous portion of the artery is resected, possibly with a
portion of tumor adherent to it, and sent for pathological
examination . Indeed only after serial sections of the
suspected arterial segment are made can a determination be
made whether there has been vascular invasion.
Despite the lack of carotid wall infiltration, removal of these
tumors and of the adventitia can significantly weaken the
carotid wall and lead to blowout; therefore, PBO of the ICA
should be strongly considered in skull base tumors with
massive radiological involvement of the ICA.

5. Subadventitial Dissection after
Reinforcement with Stenting
From a surgical point of view, preoperative stent insertion allows the skull base
surgeon to perform subadventitial dissection of the ICA with a significant reduction of
the surgical risk.
In the presence of an intraluminal stent, in fact, the surgeon is usually able to establish
a cleavage plane reaching the external surface of the stent, so removing all the
involved portion of the arterial wall. At the same time, the presence of the metallic
net of the stent represents protection against accidental rupture; this is particularly
true when working at the level of the carotid genu and the horizontal segment of the
petrous ICA. In this area the surgical room and the mobility of the artery are reduced
and direct control of the medial wall is particularly demanding, increasing the
difficulty and the risk of surgery. The thickness of the struts of the stent, which
determines its rigidity and its resistance to crushing, can offer different surgical
sensations: although surgical dissection in the presence of thicker stents has seemed
more comfortable, it has been possible without surgical problems even in the
presence of softer stents.

Medication schedule associated with
stenting into the internal carotid artery

Changes of anatomy of the internal carotid artery after stent
insertion. One month after the stent insertion, the neointimal
layer is developed and subsequent subadventitial dissection can
be safely performed.

Dissection usually starts at the cervical level, away
from the tumor, where it easier to find the correct
cleavage plane and proceed distally; the
anteromedial wall of the artery is considered the
most difficult to manipulate because direct
visualization requires bony decompression and
anterior displacement of the intrapetrous segment
of the ICA. The unsolved surgical problem remains
the medial wall of the ICA at the level of the
anterior foramen lacerum, until now unreachable
with the available surgical approaches.

The plane of dissection between the internal carotid artery and the overlying periosteum is best
developed at the entrance of the artery into its canal.
C basal turn of the cochlea (promontory) , ICA internal carotid artery
P periosteum

a Intraoperative view of the balloon used to permanently
occlude the internal carotid artery. b, c Schematic drawings showing
the permanent balloon occlusion of the internal carotid artery. MCA
middle cerebral artery. BA basilar artery. ACA anterior cerebral artery.
OA ophthalmic artery.

a, b Schematic drawings showing the stent reinforcement of
the internal carotid artery. MCA middle cerebral artery. BA
basilar artery. ACA anterior cerebral artery. OA ophthalmic
artery.

Mario sanna lateral skull base book
Sacrifice of the Internal Carotid Artery (Figs. 8.46−8.49)
The internal carotid artery can be sacrificed in the rare
cases in which the artery is markedly encased by the
tumor with subsequent stenosis or in cases with fragile
wall of the artery due to previous surgery or irradiation. A
preoperative balloon occlusion test is mandatory. If the
test shows that the artery can be safely sacrificed, a
permanent balloon is left to close the artery (Figs.
8.46−8.49). In our early practice, carotid resection was
performed more frequently; with time, we have adopted
a less aggressive attitude for fear of long-term
consequences.

Carotid injury – Management in
both anterior & lateral skull base -
click
http://www.slideshare.net/muralichand
nallamothu/carotid-injury-
management-in-both-anterior-lateral-
skull-base

• In Aldo Stamm book it is mentioned that while
managing the Internal carotid artery - " Suture
repair is possible ,albeit technically difficult
and in most instances impractical . "
http://books.google.co.in/books?id=5dczLBfol
BcC&pg=PP7&dq=aldo+cassol+stamm&hl=en
&sa=X&ei=iM85UoeeNYOtrAehwYHIAQ&ved=
0CDsQ6wEwAg#v=snippet&q=Suture%20repai
r%20is%20possible%20%2C%20albeit%20tech
nically%20difficult&f=false

How far carotid transposition is safe in
anterior skull base ???????
Micro-aneurysms may present in
ICA - picture from Trans-
temporal skull base

Debate
• Lateral Skull Base is Accessible by Endonasal
Surgery – Click for video Lecture :
https://www.youtube.com/watch?v=HroWRSJ
Z_N4
• Lateral Skull Base is Inaccessible by Endonasal
Surgery – Click for video Lecture :
https://www.youtube.com/watch?v=JNt5hPp
b28o&sns=fb

Debate
• Endonasal Surgery is Effective for Malignant
Skull Base Tumors – Click for video Lecture :
https://www.youtube.com/watch?v=Hl2MiuHl
HVQ&sns=fb
• Contraindications for Endonasal Surgery for
Malignant Tumors – Click for video Lecture :
https://www.youtube.com/watch?v=Uk57ME
gkde8&sns=fb

Allready published JNA classifications are anatomical
classifications in literature . We don't need another
anatomical classification .
But Dr. Amit keshri made a remarkable difference to
combat the fear complex & real worry of ICA bleeding in
JNA by including vascular component in anatomical
classification.
So whatever further anatomical classifications in JNA are
useless . It is redundancy .
Only Dr. Amit keshri classification is useful for surgeon .
Please read Dr. Amit keshri paper for better
understanding.

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

JNA classification based on vascular
supply to tumor – by Amit keshri

Midfacial degloving combined with lefort 1 osteotomy or
maxillotomy , it gives very wide approach to the clivus and skull
base . – pg 2428 new scott brown
Transmaxillary Microscopic approach to infratemporal fossa &
cavernous sinus - very simple for beginners - both surgeon &
assistant use both hands & both use binocular view - teaching
becomes simple : see video
http://www.youtube.com/watch?v=Uk57MEgkde8&sns=fb

• Murali Chand Nallamothu : Sir , i found this chapter interesting as i
discussed earlier " Midfacial Degloving - Microsurgical Approach " -
chapter 46 --- in book " Micro-endoscopic Surgery of the Paranasal Sinuses
and the Skull Base " - please read -
https://www.facebook.com/photo.php?fbid=10152305800027126&set=o
a.762203323852615&type=3&theater
• When we are dong extensive angiofibromas which extended to middle
cranial fossa we don't have control on carotid - so when we use
microscope with midfacial approach , i am thinking we can do suture
carotid also . But my experience is not sufficient to comment futher . I am
just thinking . Even in petroclival meningiomas also there is no need of
sacrifice of cochlea in transcochlear approach in this way of using
microscope instead of endoscope in anterior skull base approaches

Microscopic Midface Degloving -----
Under general anesthesia, with the patient in the supine position the procedure begins with a bilateral
incision in the gingival sulcus, as in a conventional Caldwell-Luc procedure. A complete transfixion
incision of the membranous septum extended around the piriform aperture to the space between the
superior and inferior lateral cartilages is made. The soft tissues of the nasal dorsum are then elevated
in a subperichondrial and subperiosteal plane by using an elevator and Metzenbaum scissors. The
remaining connections between the columella and the anterior nasal spine are dissected transnasally,
joining the nasal cavity to the sublabial incision. The periosteum is then elevated, exposing the
anterior maxillary wall, the ascending branch of the maxilla and the piriform fossa. The degloving
approach is then completed by elevating the soft tissue of the upper lip, nasal dorsum, and superior
maxillary region, thus exposing the bony structures of the middle third of the face (up to the
infraorbital foramen leaving the infra orbital nerve intact and the infraorbital rim) (Fig. 29.5). ------- An
ipsilateral wide resection of the anterior wall of the antrum is performed, leaving the
infraorbital opening and its contents in place. The next step is the opening of the posterior wall of the
maxillary sinus. Depending on the size of the tumor, the wall has the consistency of an eggshell, and,
in the other cases, it may not be present.

• The surgical microscope is then brought into the field in order to facilitate the ligation and
section
of the vascular pedicle of the tumor in the pterygomaxillary fossa. It is important to not
touch the
tumor until all the exposure is completed. The entire medial nasal wall is opened through a
posterior
and inferior detachment of the inferior turbinate that can be kept anterior until the end of
the procedure
or totally resected. The middle turbinate is displaced superiorly, increasing the visualization
of the
tumor.
An ethmoidectomy is done and the sphenoid sinus is opened, taking care to expose and
resect the
sphenoid rostrum, to allow visualization of the basisphenoid bone, which is one of the most
important
areas of the tumor’s origin.
After an entire exposure, using forceps, suction tubes, and bipolar electrocautery, the tumor
is
dissected free from the mucosa of the posterior wall of the nasopharynx, the mucosa of the
posterior
third of the nasal septum, the dura mater (if involved), and the basisphenoidal area of origin.
The tumor is removed, and a final look is done in order to avoid leaving some tumor
remnants. It
is important to drill the infiltrated surface of the basisphenoid bone with a diamond burr.
Finally, after hemostasis, the middle and inferior turbinates are sutured to the periosteum of
the
inferior orbital border (Fig. 29.6). The sublabial incision is sutured, and the surgical cavity is
carefully packed. In Figure 29.7, is an example of a stage IVA angiofibroma resected by
microscopic midfacial degloving.

• Prof . Aldo Stamma advocating “ Microscopic
Midfacial degloving “ approach for Stage IV
JNAs ---------- 1. The open surgical treatment
is most frequently reserved for grade IV
angiofibroma. A great number of open
approaches have been described
(transpalatal, lateral rhinotomy, midface
degloving, medial maxillectomy, transantral,
infratemporal fossa, and frontotemporal
craniotomy). I often use the midface
degloving approach under microscopic
visualization since it does not produce
external scars. ------------2. The endoscopic
endonasal approach to excise angiofibromas
(stages I, II, and IIIA, B) has shown good
results. Large angiofibromas can be treated
by this approach but requires an experienced
surgeon. Sometimes, the use of endoscope-
assisted and external approaches with the
microscope can achieve better results for
stage IV tumors

JNA surgery by 4 corridors approach - by Dr.
James K. Liu - I feel this 4 corridor is safest
surgery for intracavernous & intracranial
extension JNAs rather than removing only by
nose. Orbitozygomatic transcavernous gives
proximal & distal control of ICA . Endoscopic
Caldwell-Luc ( Tranasmaxillary ) preserves Nose
anatomy – see video
https://www.youtube.com/watch?v=ekwOfEmH
GWg&feature=youtu.be

Amit keshri JNA case – decision
making
https://www.facebook.com/groups/3
47913135290330/permalink/877060
909042214/

Petroclival meningioma decision
making

Petroclival meningiomas decision
making by Prof.Mario Sanna – Click
https://www.youtube.com/watch?v=
kUa9fQ4_aQY&list=UU3vRSTN8Rx46
MQwq06XRJIA

Pituitary tumors decision making

360-degree skull base surgery for giant pituitary adenoma.
A. Coronal T1 with contrast MRI.
B. Sagittal T1 with contrast MRI.

The patient is a 43-year-old female who presented
with worsening vision changes. An MRI revealed a
giant pituitary tumor with severe suprasellar extension
and clival invasion (Figs 21–6A and 21–6B). Prolactin
levels were normal. Also, multiple flow voids
are noted surrounding the tumor and “pinching”
the tumor margins. These are the anterior (ACAs)
and middle cerebral (MCAs) arteries. This case illustrates
the importance of having a knowledge and
understanding of ALL skull base surgical options.
This tumor should be examined with a 360-degree
approach.
An endonasal approach should be used for the clival and sellar portions and
could likely
even decompress the midportion of the suprasellar
portion for optic chiasm decompression. However
an anterior-lateral (orbito-zygomatic-craniotomy)
approach would be best for clearance of the tumor
away from the ACAs and MCAs and the intraventricular
portion of the tumor. Endoscopic assistance
via the craniotomy could be used in conjunction
with the microscope to get angled views.

https://www.facebook.com/groups/347913135290330/permalink/867688616646110/
Iype Cherian In this case, I can use a modified Dolencs approach, transcavernous dissection and
trans diaphragma approach to take out most of the tumour using endoscopic assistance to see
inside the sella for residue.. I won't have problem with the part attached to the vessels, but
would be worried about the cranial nerve paresis.. Would be ready for a bypass if the consistency
is hard..Just did one in SRMC a couple of months back.. Had to be dissected of the carotid.. Used
the window between 4 and V1...demonstrated the entire anatomy to the boys... But I agree that
a combined approach would be the best...both of us could clean that tumour up... Without any
residue or possible deficits

https://www.facebook.com/groups/34
7913135290330/permalink/86768861
6646110/•
Narayanan Janakiram Parkinsons triangle is a small
triangle.. the incidence of 6 pares is is very high.. is that
corridor enough to approach the cav sinus drIype Cherian
• June 13 at 8:17pm · Like
• Iype Cherian Dear Narayan, V1 can be displaced a
bit...without much fear..but as you said, 6th paresis is
common since 6th is just medial to V1..however if the
tumour is soft, this space is enough.. If it is hard, I might
need the carotid Oculomotor triangle as well...needs to be
careful with the arachnoid of the third nerve.

Accoustic neuroma decision
making

Dr. Sampath Chandra Prasad - in what way trans-labyrinthine approach is better than
retrosigmoid approach in removing accoustic neuroma. How to convince my
neurosurgeon. – click
https://www.facebook.com/groups/383508355070291/permalink/973599532727834/
• This is a short question with a long answer! The TLA does not replace RS approach. The indications
are different. Broadly speaking, the main indication for TLA is excision of large (very large) tumors
with sacrifice of hearing if any. RS is used for smaller (upto 3 cm) tumors with an intention to
preserve hearing. The handicap of a neurosurgeon is his/her unfamiliarity of the intra-temporal
anatomy and hence the reluctance to use the TLA. The Otology based Skull Base Surgeon is
comfortable doing both the approaches. The problem comes when the neurosurgeons, to cover
this handicap, extend the limits of RS approach. This leads to increased incidence of recurrences.
This is being camouflaged by using the term 'partial resection or subtotal/near total' resections,
thereby legitimizing them.
This has also led to the irrational and un-necessary use of Radiosurgery in the skull base. Tumors
which cannot be removed by the RS approach are subjected to radiosurgery and in a way our own
surgical fraternity is to be blamed for the irrational use of radiosurgery for BENIGN tumors.
Finally, the often used arguement that RS is a hearing preservation surgery is also over-
emphasized. Almost 40-50% of the RS approaches do not preserve hearing. Secondly, another
significant population of those with audiologically good post-op hearing actually do not have good
speech discrimination and hence they do not have what we otologists call 'serviceable' hearing. So
most of the RS approaches do not offer the hearing preservation that they claim to.
It is important to adapt the technique to the situation and not vice versa.

Please note the areas of cerebellar ischemia in the images due to
extreme retraction of cerebellum. if you post the MRI you will
find a better evidence of ischemia.

Sampath Chandra Prasad In a 4 cm tumor with hearing loss is it better to do RS or TLA? I'm referring to
cerebellar retraction.
In huge cystic tumors where hearing is lost is RS better than TLA? I'm referring to adherence of the capsule
to the vital structures.
Moreover, in an NF2 where the surgery is on the 2nd side with only hearing, will you be able to do a ABI
with a RS as effectively as with a TLA?
If the FN is sacrificed at the level of IAM, can you do a nerve graft as effectively as in a TLA?
In a case with pre-op hearing loss, if you discover the tumor to have intracochlear extension or if it is a
cochlear tumor can u ensure adequate closure without increasing incidence of CSF leak in a RS?
The indications for RS and TLA are clearly defined. The results of RS CANNOT be compared to TLA or the
other way round. Iv discussed indications of RS in a post earlier in this thread. So your statement that the
results are comparable is factually incorrect.
If you still believe after all the developments in the field of SBS that transtemporal approaches were
developed due to the whims and fancies of an overzealous ENT surgeon, without distinct benefit to the
patient compared to earlier techniques, then you are either ignorant or arrogant. Around the world the
indications of TLA and RS are scientifically defined and followed. If we have not done so in India it's time we
did. To offer benefit to the patient. It's not ENT vs NS or TLA vs RS.
I think it's unfair to keep reiterating the 'I'm an expert in this technique, so I do it'. In view of developments
in SBS, as in all fields, the different techniques have to be adapted to the patient and not the other way
round.

Sampath Chandra Prasad The articles you quote are from the 1990s where a suboccipital approach was the
gold standard. A lot of water has flown under the bridge since then. After that there has been the evolution
into RS and subsequently into transtemporal approaches.
Secondly, you will see that Madgid (and other NS) talks of hearing preservation when he does not follow the
AAO-HNS or the European Consensus document on Hearing. He relies only on a simple audiogram. A good
post op audiogram does not necessarily mean good post op hearing. The speech discrimination has to be
good and ABR has to be intact too. Otherwise you hear a sound without any usable hearing. It is NOT
hearing preservation. In any case the preservation as claimed by even Samii is only 30 to 50%. I would also
like to know the logic behind risking cerebellar retraction in patients with hearing loss which occurs in almost
all grade 2 tumors. The grade 1 or 0 tumors do not need to be operated (wait and scan is the option) any
way as only 30% of them show growth (please read my paper in Journal of Neurosurgery). I can go on and
on. I cannot summarise what is a 1.5 hr plenary session here in Facebook.
These things have been debated ad nauseum in Skull Base Meetings across the world (a few of which I was
an invited faculty by the way) and the matter is sealed. The indications of each of these approaches are
clearly defined and accepted by NS and ENT alike. I suggest that you attend the European Skull Base Surgery
Meeting is in Berlin a couple of months from now to know what real skull base surgery is. Samii, Sanna and
Al Mefty will all be there. I will be on a panel with Samii on partial resections in VS. You will be surprised to
know that it does not begin and end with a RS or a Suboccipital.
Finally, with due regards to 'Goldfinger' Madgid, a successful procedure is that which can be replicated
across the world by any surgeon. That includes you and me. Not that which is done only by an
'accomplished' few with 4000 cases. If it takes a 1000 cases to get the same result as a TLA, then I think the
TLA is a damn good procedure because even a guy with my experience can get exceptional results with it!

Decision making in acoustic neurinoma
surgery
Read chapter 3 “Decision making in acoustic
neurinoma surgery” in Prof. Mario Sanna
Acoustic Neuroma surgery book – Click
https://books.google.co.in/books?id=TkmBDG7s
ooEC&printsec=frontcover&dq=mario+sanna+ac
oustic+neuroma+surgery&hl=en&sa=X&ei=haee
VIKOHYjluQT384LACQ&ved=0CFMQ6AEwCA#v=
onepage&q=Decision%20making%20for%20the
%20management&f=false

Lower cranial nerve neuroma
decision making

Rt lower cranial nerve shwannoma, which approach will be
better ,which approach will be better considering this side is
dominant sinus.

Answer
• Amit Keshri says - eight nerve was normal,so was 7th,removed tumor
completely with retrolab approach and to get space,the sigmoid plate was
decompressed and sinus retracted posteriorly after RMSO [ Retro mastoid
sub-occipital ] craniotomy without opening dura posteriorioly.
• Murali Chand Nallamothu For lower cranial nerve schawnnoma POTS
approach is the best - but here you are saying it is dominent sinus , no
need to sacrifice sigmoid sinus -- so in this case we can use extended
translabyrinthine approach for the AFB area part & at carotid canal area
part of the tumor can be removed by externally which is included in the
lower C - shaped incision
• Murali Chand Nallamothu if the 8 th nerve is good we can try
retrolabyrinthinne & retrosigmoid approach & take the help of endoscope.
• Post-op :

Facebook discussions
• https://www.facebook.com/groups/learningent/permalink/730657780305
432/
• https://www.facebook.com/groups/347913135290330/permalink/531287
173619591/
• https://www.facebook.com/groups/347913135290330/permalink/575333
442548297/
• Sampath Chandra Prasad Dear Murali Chand Nallamothu I have had the
good fortune of working with both mario sanna and paolo castelnuovo. As
you know one is a legend in lat skull base and the other in ant skull base.
In case of any tumor encircling the carotid or any tumor with extensions
lateral to it the policy is to always do a lateral skull base exposure. A
variety of combinations can be used. In this case I would prefer a
transcochlear or itfa type b with subtemporal craniotomy to expose the
mcf. It's very simple to expose the temporal lobe skull base. I will post pics
shortly. Sanna's death stats 3 in 4500 cases. Same percentages for paolo.
Secondly the policy here is that if the surgery is too risky they stop
because it is the patients choice to die now or later not the surgeons.

https://www.facebook.com/groups/347913135290330/permalin
k/575333442548297/
Amit Keshri We have seen the bleeding from
ICA,in one of our angio and it bled like
hell,finnaly we were able to save the patient
with help of our neurosurgeon but it bled 2
litres in 5 minutes,so whenever we do this kind
of cases we put it in neuro-ot and another back
up is of neurovascular radiology for any
unforseen damage .

k/531287173619591/?__mref=message_bubble
Amit Keshri Murali Chand Nallamothu, in anterior skull base lesions,its
going to lateral wall of sphenoid,i.e cavernous sinuses, a pre-op
intervention angiography to see the status of carotid vessel and to test
cross flow and embolize if its angiofibroma,if there is no feeders from
ICA, it can be approached and bleeding from cavernous sinus can be
managed by glue and muscle etc,but if there is feeder from ICA, its
little difficult if it the feeder tear off from the main vessel while pulling
the tumor out,its need a skilled neurosurgeon or skull base surgeon to
control that and save the patient, it happened to me once and my
neurosurgery prof controlled it with some struggle. worst if there is
ruprure of main trunk of ICA, patient need to be shifted to for stenting
immediatly to Radiology,after some control,check angio is must as
pseudoanurysm can happen even if bleeding stop, here the crossflow
help,u can take lower contro and tie the carotids in dire emergency.

Approach does NOT depend on the competency of
the surgeon in endo or lat SBS
Sampath Chandra Prasad Honestly, I feel this argument is quite unwarranted. The
answer to all the arguments that we are having here have already been discovered
in many centers of excellence in many parts of the world years back after decades of
trial and error. It is up to us whether to visit such centers and learn from their
experiences (both fortunate and unfortunate) and apply them in our practice or to
continue in the pursuit 'our own' experience. In other words self learning.
Science is factual and there are no grey areas. There is ABSOLUTELY no doubt in my
mind as to what tumor should be done endoscopically or laterally as I have been
with and seen the very best in the field of both endo and lateral SBS. If you are in
the pursuit of the science of skull base and you stay for long periods in centers
where such complicated surgeries are taught, you will learn the science of skull
base, not just theoritical stuff. For instance, JF tumors and PC meningiomas cannot
be done endoscopically. PERIOD. It does NOT depend on the competency of the
surgeon in endo or lat SBS. For someone who is interested in the science of this
specialty, it is obvious why or why not. If you have seen one single case of JF tumor
excision skin to skin with a total removal and a normal FN status on a 1 yr follow up
without any CSF leak, you have learnt the SCIENCE behind the procedure. You also
have learnt what is BEST for the patient. Otherwise you are just wannabes, not
serious about your specialty, pampering your egos....and more importantly harmful
to your patients.

k/575333442548297/
• Murali Chand Nallamothu Sampath Chandra Prasad - your opinion about "
don't cross the nerves " proposed by prof. Amin kassam as we are crossing
3, 4, 5, 6 nerves as we are approaching by lateral app. to parasellar
siphon carotid . December 18, 2013 at 6:09pm · Like · 1
• Sampath Chandra Prasad This is a difficult question. For the expert sanna
is he is still queasy about entering the contents of the cavernous sinus. 5th
is not a problem with lat skull base. We manipulate it practically
everyday. We see the 6th in the dorello twice a week but try to let it be.
3rd and 4th are encountered in lat skull base only in infrequent cases or
chordomas chondrosarcomas, petrous apex cholesteatomas and
meningiomas. On the other hand castelnuovo is comfortable with the
cavernous and is contents. The part of 5th outside the cp angle is the
clearly the territory of the ant skull base surgeon. Somewhere in this area
the 2 specialties must shake hands!!!
I am writing a chapter on petrous apex management in michael paperellas
new text book. So I'll try to incorporate the essence of this discussion
there and try to answer some of the questions there. Thanks for leading
me into this.

k/867688616646110/
• Prof. Mario sanna says " The unsolved surgical problem
remains the medial wall of the ICA at the level of the
anterior foramen lacerum, until now [ until 2005 ]
unreachable with the available surgical approaches." in
below book – Now this area can be reached very easily
by anterior skull base approaches
http://books.google.co.in/books?id=4bvs6yV2WTQC&
printsec=frontcover&dq=atlas+of+microsurgery+of+lat
eral+skull+base&hl=en&sa=X&ei=VmkFVInxBoToggT-
94GoDQ&ved=0CCYQ6AEwAA#v=onepage&q=atlas%2
0of%20microsurgery%20of%20lateral%20skull%20base
&f=false

Murali Chand Nallamothu : Sarvejeet Singh - petro-clival
window is the only area which we have not accessed in lateral
skull base . Other than this there is no problem in lateral skull
base . JUST for this petro-clival window we can use anterior skull
base approach. We have maximum control over the carotid in
lateral skull base . Then without understanding the ONLY
limitation of lateral skull base why to venture into RISKY [ which
has NO control over the carotid ] anterior skull base . In a pursuit
of discovering something we should not discard TIME TESTED &
SAFE procedures.

k/867688616646110/
• Murali Chand Nallamothu : Iype Cherian sir , is it
possible to suture lateral part of
intracavernous carotid suppose if there is avulsion of
infero-lateral trunk by dolenc approach .
• Iype Cherian I would never do that ... Murali .. If there
are chances for that, I would get neck control... And
instead of suturing a torn artery, will try to clip recon
and then do a bypass as fast as possible..It all depends
on how healthy and accessible is the tear... In the
cavernous sinus, not very straight forward...😛

• Carotid rupture
https://www.facebook.com/groups/347913135290330/search/?qu
ery=carotid%20rupture
• Murali Chand Nallamothu When 360 degree encased carotid that
to in a carcinoma think twice about anterior approach , there are
chances of aneurysms of carotid which are potential for rupture . So
I am thinking of combination of anterior & type B infratemporal
fossa approach to get maximum control over carotid .
If ruptures you can do microvascular repair or reinforcement of
aneurysms April 8, 2014 at 11:08am · Like · 4
• Murali Chand Nallamothu I am thinking of doing type B or C
infratemporal without sacrificing V3 , just by transposing V3 by
drilling pterygoid trigone - recently discussed with Satish Jain sir -I
think this is ideal case

• Murali Chand Nallamothu Sampath Chandra Prasad - Prof. Amin kassam
says " The overarching principle in selecting the approach is to avoid
crossing the plane of a cranial nerve." DO NOT CROSS THE NERVES . How
far this principle is true/safe in selecting approach for petrous/petroclival
& parasellar lesions . September 5, 2014 at 11:52pm · Edited · Like
• Sampath Chandra Prasad Every letter in that sentence is worth its weight
in gold. It came from Kassam because he has mastered ESBS to the extent
that he not only knows what to do but more importantly what NOT to do.
ESBS can never replace LSBS. They are never in comparison. The
exposure achieved by LSBS and the safety of structures is unparalleled.
ESBS is used for smaller lesions in the midline and in the anterior and
middle fossas. Crossing the carotids is usually done because the
endoscopic surgeon is unfamiliar with the lateral approaches. It is one
thing to visualize the acousticofacial bundle in the cadaver through and
endoscope and get an orgasm and another to actually go there and
remove a tumor where there is ZERO control over the neurovasculature in
case of a intra-op complication like opening of even a small arteries like
the pontine branches of the basilar.

• Murali Chand Nallamothu Vinod Felix- here
again in type 2 trigeminal schwannoma where
predominantly posterior fossa tumor & large
tumors which extended to prepontine cistern
you may think that by doing anterior skull
base , you are avoiding transcochlear . But
again here my main worry is you are removing
tumor from basilar artery from anteriorly
which is even more dangerous than removing
tumor from carotid .

• Saleem Abdulrauf ; Neurosurgeon : Dear Dr Murali, you are
indeed correct, it is essentially impossible to get complete
control of the ICA through a standard ant skull base
approach. The Lateral approach, with extra-dural exposure
of the ICA (petrous segment) just below GSPN and just post
to V3 allows ample proximal control. I do not recommend
operating on any tumor that is wrapping the ICA without
proximal and distal control. If there is a hole in the ICA, DO
NOT try to bipolar it, it will make the whole bigger. In this
situation, a proximal and a distal temporary clips to be
placed, and then use a 9-0 prolene to suture. If not
experienced in micro-suturing, then place a sundt clip,
which is a circling clip that covers the hole and leaves the
parent vessel open.

• Murali Chand Nallamothu to Sampath
Chandra Prasad - how far it is safe to do
carorid transposition in anterior skull base by
endoscopy , where Prof. Mario sanna says
subperiosteal dissection of carotid has
potential risk of carotid rupture even when we
are doing under microscopy.

• Sampath Chandra Prasad Well Murali, you have asked a dynamite of a question.
This is a war of the two specialties and I am too small a person to have an opinion
here when legends in the fields are at loggerheads in this matter.
ICA transposition is extremely risky whichever approach. The transposition of the
'siphon' is reasonably 'safe'. However the transposition of the petrous ICA (around
the lacerum) via the endoscope is fraught with danger. The release of the lacerum
itself is a risky process with all the ligaments attached to it and then to drill it up to
the carotid canal and transpose it is surely risky. But why do it when the petrous
ICA can be dealt with so much more easier via the lateral approaches? This is
where the two hands never shake!!
The endoscopic guys want to expand and the lateral guys are not happy.
But I completely agree when Prof. Sanna says 'I dont deny that they can work
around the carotid, but if I puncture the carotid (which has happened to me
more than a couple of times), it can still be managed by the lateral (and more
open) approach (by means of packing with a muscle and then suturing) whereas
endoscopically if that happens the only option is PBO...which means surely a
neurological deficit'.

• Narayan Jayashankar Nice discussion ! To start off, I do the entire
gamut of lateral and endoscopic procedures. Thus, having
experience of both, I would still prefer the lateral skull base
approach. It is safer to transpose the carotid than an endoscopic
approach. In fact, in the lateral approach we can lift off the carotid
from neck till the petrous segment but mobilization is restriced at
the laceral segment. In the endoscopic approach, it is easier to
release the petrous and laceral segment. However, I agree
with Sampath Chandra Prasad observations. In fact, one should not
attempt carotid transposition via endoscopy route till u have
trained more than adequately. Transposing is possible, however,
the important consideration here is in case of carotid injury, is it
safer and easier to handle the same INTRAOPERATIVELY via a
lateral or endoscopy approach ?? Janakiram Narayanan and Satish
Jain are excellent endoscopy surgeons and we look forward to their
observations.

Sampath Chandra Prasad : The adventitia of the petrous ICA merges with
the periosteum in the bony canal of the petrous ICA. Hence it is more
vulnerable to manipulation. It is important to drill out all the bone around
this part of the carotid carefully before manipulating it. Otherwise the danger
is arterial vasospasm, if not a frank blow out. But this becomes difficult if the
tumor is encircling the artery.
In case of a tumor encircling the petrous carotid (C3) it is important to pre-
operatively assess the carotid by Angio and if necessary reinforce it with a
stent. Intra-operatively if the spasm occurs it has to be identified and
immediate application of papavarine must be made. Or else a neurological
deficit is certain.
Even, in the event of a blow out, the artery can be quickly sutured after
application of vascular clamps. Any reverse flow via the rent is encouraging as
this is evidence of cross flow. However in endoscopic surgery this option is
practically absent.
I agree with Narayan Jayashankar. As it stands today, the foramen lacerum is
the 'Line of Control' between endoscopic and lateral skull base surgery!

• Vinod Felix , Prof. Amin Kassam says in book
http://books.google.co.in/books?id=16y4UJEHjr8C...
• " With pituitary surgery, the ICA is most susceptible to injury at the medial
optico-carotid junction where the parasellar ICA courses medially. Other risk
factors for ICA injury include prior surgery or radiation therapy, anatomical
variations, and tumor encasement or displacement of the ICA. If there is an
injury to the ICA, the goals of treatment are to maintain cerebral perfusion,
obtain focal control of the hemorrhage, and transport the patient to
angiography for definitive management of the injury. Contrary to common
practice, the blood pressure should not be lowered to decrease bleeding since
this may result in cerebral hypoperfusion. Neurophysiological monitoring is
invaluable in this situation to reflect cerebral perfusion and establish
thresholds for blood pressure. Immediate treatment options include bipolar
electrocauterization, compressive packing, direct suture repair, clip
reconstruction, and ligation of the vessel. If there is a very small laceration or
avulsion of an arteriole from the wall of the ICA, this can be sealed with careful
use of bipolar electrocautery.

If the injury is substantial, the hemorrhage is directed up the suction to maintain
visualization while focal packing (cottonoid) at the site of the vascular injury provides
temporary
control. If this is effective and neurophysiologic monitoring stable, additional
packing can be placed while the patient is transferred to angiography for definitive
management. If packing does not control the bleeding, it is best to get further control
prior to transfer. While the vessel is compressed with focal packing, additional
bone can be removed to better expose the vessel proximal and distal to the site of
injury. Although direct suture repair is possible, it is technically difficult and may not
be a realistic option. With adequate exposure vessel preservation can be attempted
through aneurysm clip reconstruction (e.g. Sundt- Keys clips). Otherwise, the vessel
can be occluded with additional packing or placement of aneurysm clips. If packing
is used, it needs to be focal so that bleeding is controlled and blood is prevented from
tracking through a craniotomy defect intracranially. The patient is then transported
to radiology for angiographic assessment and treatment. Preservation of blood flow
with a covered stent is technically difficult in the region of the cavernous sinus and
currently not FDA approved; therefore, permanent occlusion with coils is often the
preferred option. Assessment of collateral blood flow is then performed to assess the
risk of ischemic stroke and the potential need for revascularization (bypass).

After drilling the carotid canal what we see is endosteal layer /
periosteum, not directly the ICA
Subperiosteal/Subadventitial Dissection
Subperiosteal/subadventitial dissection is accomplished for tumors that involve the ICA to a greater extent,
such as C2 glomus tumors and meningiomas (Fig. 15.24a, b). In general, dissection of the tumor from the
artery is relatively easier and safer in the vertical intrapetrous segment, which is thicker and more accessible
than the horizontal intrapetrous segment. A plane of cleavage between the tumor and the artery should be
found first. In most cases, the tumor is attached to the periosteumsurrounding the artery. Dissection
is better started at an area immediately free of tumor. Aggressive tumors may, however, extend even to the
adventitia of the artery and subadventitial dissection may be needed. This should be done very carefully in
order to avoid any tear to the arterial wall, which can become weakened (Fig. 15.25), with the risk of
subsequent blowout.

A case of left glomus jugulare tumor in our early experience. ubadventitial dissection has been
performed because the artery had been so weakened after the tumor removal. Although the
patient had no relevant complications postoperatively, such excessive manipulation is better
avoided and permanent balloon occlusion or stenting are preferably tried preoperatively.

JR DISSECTOR : it incorporates both a
ball probe and a knife - can be used as
both. - very useful to cut dura.. fatastic
tool over ica

JR REVERSE KNIFE : used to cut backwards. 1. CUT NATURAL OS
IN MMA 2. ANY STRUCTURE WHERE THE SCISSORS IS DIFICULT
TO ENTER.

My understanding
With the pretext " DON'T CROSS THE NERVES " in endoscopic skull base , anterior skull base surgeons
trying to remove tumor lateral to parasellar carotid . But this don't cross the nerves won't stand in lateral
transtemporal skull base or neurosurgical skull base . Since ages neurosurgeons and lateral skull base
surgeons removing the tumor lateral to parasellar carotid by anterior medial & anterio-lateal & parkinson
traiangle Or they don't hesitate to cut V2 & V3 . Moveover these lateral approaches have GREATEST
control over the carotids . The remaining tumor medial to the parasellar carotid can be removed by
endoscopic aproach [ combined approach – click
http://www.slideshare.net/muralichandnallamothu/combined-approaches-of-skull-base-360 ]
1. If there is any rupture of parasellar carotid you can't even pass the stent also & it may occlude the
opthalmic artery . But recently Covered stents which can be passed into parasellar carotid told to me
by vascular neurosurgeon – This is a big boon to anterior skull base approach –Several seniors opinions
has to be taken regarding longterm effects of these stents
2. One senior surgeon adviced Pre-operative coilling especially in revison , fibrous & post-RT cases &
pre-operative middle meningeal artery & opthalmic artery communication has to be checked ( DSA )to
prevent the catastrophie of occlusion of Opthalmic artery origin by coilling . So if the communication
good we can safely coil parasellar carotid & proceed Endoscopic anterior skull base approach . Even
then in children it gives false sense of security . In adults we can safely remove tumor . Even then if the
rent is more than 1.5 cm coilling may come out .
So to my understanding it is always better to have pterional approach exposure ready & then remove the
parasellar tumor by endoscopic or combined especially in revison , fibrous & post-RT cases . If there is
rupture of cavernous carotid , you can do SHUNT procedure by pterional exposure. But with pre-operative
coilling we can proceed by endoscopic approach . Still so many senior surgeons opinions has to be taken .

For better understanding of Decision
making between anterior & lateral
skull base PPT must read “Carotid
injury PPT ” – click
http://www.slideshare.net/muralichand
nallamothu/carotid-injury-
management-in-both-anterior-lateral-
skull-base

Decision making between
Endoscopic lateral skull base [
transcochlear approach ]
&
translabyrinthine approach in
Accoustic Neuroma

Discussion from facebook post -
https://www.facebook.com/vinod.fel
ix.5/posts/10155183857884294
• Murali Chand Nallamothu Cochlea shouldn't be drilled
in accoustic neuroma. We have to keep Cochlear
implant . So transpromontorial approach should not be
done in accoustic neuroma . Cochlear nerve is
functional in accoustic neuroma
• Sampath Chandra Prasad Endoscopic ear surgery must
restrict itself to the middle ear and Mastoid and
anything beyond is bunkum and doesn't deserve to be
commented upon. The endoscopic approach to the IAC
is full of illogical and dangerously unscientific steps and
should be condemned. At least in its present form

• Niteshore Moirangthem Every attempt should be
made to preserve cochlea and cochlear nerve...
• Amol Deshpande Destructing cochlea just for an
obsession of endoscopic approach is
unscientific......
• Murali Chand Nallamothu Even in unilateral deaf
patients , Keep Cochlear implant in that cochlea .
We shouldn't sacrifice . Binaural hearing is far far
better

• Murali Chand Nallamothu EABR has to be done to
check cochlear nerve function intra-op
• Murali Chand Nallamothu Tomorrow or after 1 year
other ear also develops accoustic neuroma , how much
stress it creates on Cochlear implant surgeon while
inserting Cochlear implant & in EABR if other ear
cochlear nerve is not functional , patient becomes total
deaf in his life . Brain stem implant useless.
• Murali Chand Nallamothu Without cochlear implant
knowledge & experience one shouldn't attempt lateral
skull base . - funda

• Murali Chand Nallamothu Cochlear sacrificing is
only permitted in petroclival meningiomas . In
these also kawase approach & endoscopic
transclival are thouroughly discussed before
sacrificing cochlea . Sampath Chandra
Prasad enlighten more
• Mohnish Grover If possible do not sacrifice the
cochlea.. this organ is able to give surprises
beyond what we can imagine.. it's a
bioengineering marvel .Good point Murali Chand
Nallamothu ji .

• Sampath Chandra Prasad Blunders in the endoscopic approach to IAC.
1. Transmembrane approach; the TM is one of the most important and natural
barriers to CSF. TM is not only taken down but blind sac closure is done in all cases.
Totally unnecessary. In TLA
TM and EAC is preserved.
2. Anterior wall of Tympanic bone is drilled out exposing the condyle to get the
much needed exposure. Totally unnecessary and morbid. In TLA this is untouched.
3. Trajectory of approach involves working around all the intratemporal segments
of the FN. Dangerous and unnecessary. In TLA only the IAC segment comes into
play (but there's also the tumor there). We work away from all other segments.
4. Cochlea is drilled out. This is the most stupid and dangerous of steps. That
means the guys who are practicing this have no idea of SBS. Cochlea is used to do
CI to restore hearing after VS when Cochlear nerve can be preserved. This is more
important, infact crucial in single side deafness (long topic in itself) especially in NF
II. A CI is the only hope for the patient.
5. The shortest distance to the IAC is from the Mastoid. The longest and the most
tortuous and dangerous approach is from the EAC!

• 6. Visualisation of CPA is minimal. Most tumors are in CPA not limited to
IAC. In fact it is hilarious to think of single handed manipulation around
the Mastoid, Tympanic and labyrinthine segments of the FN (after
destroying the TM, EAC, exposing the TMJ).....and deal with tumor
removal with the AICA looped around it!! How will you use the bipolar to
coagulate the tumor? With one hand and in the narrow space between
the facial segments?
FINALLY, the most important thing. The tumors that are indicated to be
removed by the endoscopic approach are small tumors limited to the IAC.
These tumors have good hearing and otologists and neurosurgeons have
spent over half a decade to develop techniques that preserve hearing in
these tumors (retrosigmoid and middle fossa appraches). Now just
because someone desparately wants to remove these tumors
endoscopically, they want to sacrifice hearing turning all tenets of VS
surgery developed over decades upside down?
And before I conclude, imagine a superior petrosal sinus bleed or an AICA
rupture that is supposed to be managed by a one handed endoscopic
surgeon in the narrow approach that he's managed to create to reach the
IAC.
Surgery is about science. Not tumor removal. And bloated egos.

• Amit Keshri Well put Sampath...even the people who described it
said indication is only Internal Acoustic meatus either primary or
residual. ..and in non serviceable hearing loss.
Middle fossa is more elegant with preservation of Cochlear nerve
for Internal Acoustic tumors limited to IAM.
• Sampath Chandra Prasad Why would anyone destroy hearing and
close the EAC (with increased chances of CSF leak and iatrogenic
Cholesteatoma) and destabilise the TMJ in an IAC tumor which
usually has good hearing?
Completely illogical and condemnable approach. This approach dies
not have a scientific or ethical basis.
• Sampath Chandra Prasad All IAC tumors are to be waited and
scanned. No surgery for this set of tumors except in certain
situations which is beyond the scope of discussion here. No MCF
approach also. Just leave the tumor alone.

• Murali Chand Nallamothu just leaving the tumor restricted to IAC with
hearing loss also risky . If other ear also develops hearing loss then golden
period of CI is lost in the initial hearing lost side
• InSeok Moon Very mEETTA is applied in very limited situations.
Even your teacher do not perform CI in every TLA cases.
CI takes long rehabilitation.
And BB and BAHA can makes pseudo
biaural hearing with minimal adaptation effort.
• InSeok Moon My main policy is also wait and scan for intracanalicular
accoustic neuroma .
I know how much Prof. Sanna hate Marchini's method.
• Murali Chand Nallamothu just leaving the tumor restricted to IAC with
hearing loss also risky . If other ear also develops hearing loss then golden
period of CI is lost in the initial hearing lost side

• Sampath Chandra Prasad There are many situations Murali Chand Nallamothu
Bilateral good hearing-wait and scan
Good ipsilateral hearing bad recent onset gradual contralateral HL- wait and scan
with contralateral CI
Good ipsilateral hearing bad long standing contralateral HL (single sided deafness)-
wait and scan and when hearing comes down ipsilaterally, TLA with simultaneous
ipsilateral CI or MCF debulking
Bad long standing ipsilateral HL with good contralateral- wait and scan followed by
TLA +/- sleeper implant
Bad short onset ipsilateral HL with good contralateral- wait and scan followed by
TLA+CI
Bad hearing bilaterally with recent onset on ipsilateral side- TLA +CI
Bilateral bad long standing HL-TLA +CI.
More situations if NF II

• Murali Chand Nallamothu In simple way cardinal principles of
selection of lateral skull base approach for any skull base tumor
( www.skullbase360.in ) .... exception is petroclival meningioma .
1. Hearing preservation approach
2. Cochlea preservation approach
3. Cochlear nerve preservation approach
In petroclival meningioma also kawase & endoscopic transclival
approaches has to be thouroughly discussed/ considered . But Prof.
Mario Sanna recommends sacrifice cochlea .
• Sampath Chandra Prasad Petroclival meningiomas also can be wait-
and-scanned and operated only when there are symptoms. But
Transcochlear approach is the best for such lesions.

• InSeok Moon Now, I just finished today’s work - Korean otology Society meeting.
Sorry for late come back.
If you can, we can discuss now.
If you can’t tomorrow is also okay.
Dr. Prasad and Dr. Nallamothu, Thank you for your opinion.
But every situation is different and most important thing is patients’ need and quality of life. Don’t
stick to cochlear. Please see the patients.
If the tumor is small and is not growing, and there was no vertigo attack or other symptoms, I think
wait and scan is proper way to manage, even his ipsilateral hearing is profound. That patient
doesn’t get binaural hearing. If cochlear is intact, his hearing is unilateral. Is this policy is illogical? It
leaves the patients in monoaural status for several years to permanent. But, wait and scan is some
times most proper way.
Yes, Hearing preservation/ rehabilitation are very important. But CI is not the only way.
Even Prof. Sanna don’t do CI in every patients when he perform the TLA.
Even he didn’t insert the dummy.
According to your opinion, most of his TLAs are also illogical.
Sometimes patients cannot afford the cost of CI, sometimes they don’t want to receive
implantation.

• InSeok Moon World keeps changing, even CI was criticized
as illegal medical affair 30years ago. Opposition protests
were held many places.
Endoscopic surgery, of coarsely, it is not a perfect method,
but not an illogical thing.
• InSeok Moon Endoscopic surgeries for VSs can be applied
only in profound HL patients with small tumor. Tumor
growing or annoying symptoms are accompanied.
If patients want to get CI, TLA + CI is better as your opinion.
If patients don’t want to get CI, EETTA is better option than
TLA.
If patients want to binaural hearing after several years, BCI
can be great alternatives.

• InSeok Moon Of coarsely, MCFA and preserving cochlear
for the future as Dr. Nallamothu’s, It’s alternative and I’ll
consider.
• Sampath Chandra Prasad How many intracanalicular
tumors does one encounter with profound HL? And even if
so why would you destroy the cochlea in an attempt to
remove the tumor? Why not do a MCF approach or a TLA
+CI or even just wait and scan. What if the patient develops
a contralateral tumor with poor hearing? In your case ABI is
the option. In my case, the hearing is restored in the 1st
side with an implant so an ABI can be avoided.
• Alamgir Chowdhury what is the percentage of contralateral
tumor development? I just want to know

• InSeok Moon How many cases do you meet bilateral
tumors except NFII? How long did you follow up the
patient with TLA + CI?
• InSeok Moon Do you think you can do TLA + CI in every
patients?
• InSeok Moon I also do TLA + CI, and I also do MCFA.
• InSeok Moon But I think sometimes EETTA is better
• InSeok Moon That article is just case report of two, but
I perform more than that. I try to TLA + CI and I explain
that to patients, but the final choice is made by
patient, not by me.

• Sampath Chandra Prasad NF II is more common than intracanalicular
tumors with profound HL. Even more common is contralateral hearing loss
due to a variety of other causes that I think I don't need to elaborate here.
In any case, that question of yours doesn't answer my question: why do
you want to knock off the cochlea when there are procedures that can
save it.
As far as annoying symptoms are concerned, the only annoying symptom
associated with VS is vertigo for which, once again TLA is the solution, not
cochlear excenteration.
Finally, we have published our long term results of TLA +CI. I am one of the
authors. Of the about 50 cases, all but one case have done extremely well.
You can also see my paper on wait-and-scan in VS. You will be surprised to
see how many grade 0 and 1 tumors preserve hearing over 5 yrs FU. With
our hearing preservation approaches we have preserved hearing in over
60% of cases. I think that's a good enough argument to preserve the
cochlea.

• InSeok Moon TLA + CI is not an almighty. If there is no endolymph, the
environment of spiral ganglion is rough. So sometimes the function is
gradually down. After several years the CI function is not so good as usual
CI.
• InSeok Moon You want to limit to the point to the cochlear, but please
don’t
• Sampath Chandra
Prasad https://www.ncbi.nlm.nih.gov/pubmed/27816972
Our paper on VS +CI. Reported 1st 15 cases but we now have over 50.
• InSeok Moon stick to cochlear. The more important thing is hearing, not
cochlear. Cochlear is hearing organ. What is the difference between TLA
without CI and cochlear exenteration
• InSeok Moon I performed more than 200 TLA by myself and around 20
MCFA, around 20 RSA+RLA+Transcrusal, 6 EETTA
• Sampath Chandra Prasad So let's talk about the 6 EETLA. What are the
results. What was the pre op hearing?

• Sampath Chandra Prasad What if these 6 patients are a
part of NF II
• Sampath Chandra Prasad What if they develop a
contralateral hearing loss due to presbyacusis, noise indices
HL, trauma, ossification or otosclerosis?
• Sampath Chandra Prasad I want to know the PTA and SDS
of all these patients to know if they could be implanted or
not. Secondly, you did not answer my question on what if
the other side goes deaf?
• Sampath Chandra Prasad Do you agree that IF the results
of TLA +CI are good over long term.....not 6 months....but 3
to 4 years, then TLA+CI is a better option?
• InSeok Moon Sure TLA + CI is good option, but if patients
don't want CI, do you perform CI?
• InSeok Moon Or patient can not pay for CI, do you perform
CI/
• InSeok Moon Why do you stick on CI? If situation is not
available, BCI can be available in next.

• InSeok Moon Do your group perform CI in TLA cases?
• InSeok Moon Or insert dummy in every TLA cases?
• Sampath Chandra Prasad If patients don't want a CI in a
patient with an intracanalicular VS I will wait and scan.
These tumors grow less than 1 mm a year and the
intracanalicular tumors are the slowest growing. The global
recommendation for this subset is wait and scan. I will
operate after 5 or 7 years when the tumor is grade III on
CPA. There is also option of RT (where cochlea is preserved
for a future implant) which personally I don't agree but
many centers do practise it.
• Sampath Chandra Prasad We give the patient the option of
CI. And many opt for it. Placing a dummy is also an option.

• Sampath Chandra Prasad The cochlea does not undergo ossification if the
cochlear artery is preserved. No dummy is not necessary if artery is
preserved
• InSeok Moon Please, I told you my main policy is wait and scan. And I also
recommend CI when I perform TLA, but I don't do CI in every TLA cases.
• Sampath Chandra Prasad So coming back to the point, how does
EETLA....why do you call it TLA....it should be
Transcochlear.....EETCA....score over other options?
• InSeok Moon I know Grippe's policy, and I agree with TLA + CI policy, but
till now many institute think BCI(BAHA, bone bridge) is standard treatment
after TLA.
• InSeok Moon Aim is same . Hearing preservation and more rehabilitation .
TLA? I mean translabyrinthine approach . EETTA means exclusive
endoscopic transcanal transpromontorial to prevent confusion with
transcochlear
• Sampath Chandra Prasad BAHA cross is another topic all together. CI gives
binaural hearing that cross hearing aids don't. All our cases undergo cross
hearing aids or cross baha.
Bonebridge??? How will you follow up these patients with a bonebridge?
The magnet gives artifacts on MRI.

• InSeok Moon Model release 2nd version of VSB and BB which can
be available to MRI . Sure artifact thing is still problem . Anyway
BAHA, Siphono, I mean BCI which can making pseudo-binaural
hearing can be one of option.
• Sampath Chandra Prasad Only upto 1.5 T machines. Not all MRI
machines.
• Sampath Chandra Prasad So you agree that wait and scan and
TLA+CI are better options. Thank you. I rest my case.
• InSeok Moon sure, If patient wan to get CI, it's better option. But if
patient don't want or can't , Some cases endoscope is better than
translab .
• Sampath Chandra Prasad If they can't you must still preserve the
cochlea so that if they develop contralateral hearing loss then there
is the option of CI in the ipsilateral side .

• Sampath Chandra Prasad No one in the world today operates on
intracanalicular tumors. They don't even do MCF. Surgery is not
recommended in this subset.
So endoscopic surgeon is being morbid by operating in the first place
when it is not indicated and by destroying the cochlea!
• InSeok Moon Yes, sure wait and san is best way for IAC tumor. But in
patient with growing tumor or symptoms, we can perform the operation .
• InSeok Moon Please.... I don't do endoscopic approach in every small
tumor patients
• Sampath Chandra Prasad In a growing tumor you don't need to sacrifice
the cochlea. Also in symptoms, vertigo, a labyrinthectomy is indicated
(tla). Not cochlear excenteration
• Sampath Chandra Prasad Bottomline, there are no indications for
Endoscopic approach

• Murali Chand Nallamothu Cochlea has
1. Audiology
2. Cochlea surgery
3. Programming of CI
4. Audio verbal therapy
5. Physics
6. Electricity
7. Bioengineering
8. Endoscopy of cochlea
9. Tissue culture of hair cells
10. Sensory substitution
11. Auditory neuropathy of spectral disorders
12. Mathematics
13. Mysteries / unknowns
14. Etc etc ...so many &
15. Interdisciplinary
To understand each topic one lifetime of humanbeing not sufficient .
So let us SAVE cochlea ...... slogan

• InSeok Moon I perform many study and discuss several times before surgery
• InSeok Moon Gruppo Otologica use their own hearing standard to decide treat
acoustic tumor. Indication of hearing preservation surgery is narrower than other
surgeon’s standard. But no one criticize that because it is from great surgeon’s
opinion and experiences, so many doctor’s accept it. We know that hearing
preservation is difficult and less meaning in group worse than moderate HL
But theoretically it is possible to preserve hearing, so RSA is applied rather than
TLA if there is remnant hearing. From Neurosurgeon’s perspective, TLA is not
proper, even there are great advantages.
If cochlear drilling in deaf patient who don’t want to CI is illogical, TLA without CI in
moderate HL patients is more illogical.
I agree that we try to preserve hearing and try to rehabilitate hearing, but CI is not
an only method.
In SSD by removing the acoustic tumor, BCI is still standard, even I agree to CI.
What is the rate that tumor + SSD patients want to receive simultaneous CI? Even
they can pay for it.
What is the rate of tumor + SSD patients want receive serial CI several years after
TLA?
About TLA, it has also its own problem, additional scar, destruction of plenty bone,
sacrifice hearing......
Don’t stick to just cochlear. Please meet and discuss with patients and then decide.

• InSeok Moon Decision making and treatment strategies are made according to doctor’s
perspective, development of devices, and patients’ need. So that strategies of their own can be
changed. My experience is not so plenty as prof. Sanna’s, so my strategy still has possibility of
changing.
Below is my strategy in this time.
Limit to usual cases. Exceptional cases such as NFII, contralateral hearing loss are totally not in
consideration for endoscopic surgery.
If contralateral hearing is intact, and age is under 60, and they don’t want cochlear implant.
1. Large size tumor – Operation using TLA
2. Medium size tumor
i) Recommend Surgery RSA in serviceable hearing or TLA in unserviceable hearing
ii) If refuse, recommend gamma knife or Wait & Scan
3. Small size tumor
i) Recommend Wait and Scan
ii) If tumor is growing or intractable symptom, surgery or gamma knife were recommended
MCFA or RSA in Serviceable hearing,
TLA or EETTA in profound HL
Gamma knife is another option

• Sampath Chandra Prasad Dear InSeok Moon. We can discuss Sanna classification of hearing,
advantages of RS over TLA and the indication for TLA+CI in a moderate HL (we would never do that),
incidence of SSD, NF II, another day.
Here the argument is 'what is the indication for endoscopic approach for VS which involves cochlear
sacrifice.
The only indication I see in your argument is small size (I assume you are talking about grade 0)
tumor with profound HL. Another is intractable symptom (I assume it is vertigo).
Let's discuss both these scenarios.
1. The number of cases of intracanalicular tumors with 'profound' HL is very rare. There's always
some residual hearing till they grow big. Even so, why would you sacrifice the cochlea? What if the
patient develops contralateral deafness? There are a million reasons for the patient to develop
contralateral deafness from trauma to presbyacusis to NIHL to ossification to otosclerosis to SSNHL
to autoimmune disease to NF II. In this scenario any other option (including not doing anything ie
wait and scan) that preserves the cochlea is a better option than the endoscopic option. The more
cochlea we have the more options at rehabilitation.
2. For vertigo you need to do a labyrinthectomy. Means TLA. Why would you do a cochlectomy?

• Narayan Jayashankar Sampath Chandra Prasad . very good
discussion !! I agree with your viewpoint totally. You will
always have alternate thoughts in everything (not
necessarily correct also), thats how science develops. You
have made your point crystal clear. However, dont argue
any more on social media. Glad to see your basics so strong
and kudos to Prof Sanna for creating so much science. Keep
up your good work always and very glad that you are an
Indian - wish you the best in future too !
• Kapil Sikka I am enjoying it and this discussion is
awesome!! Dr Sampat, pls elaborate on "wait and watch"
for asymptomatic intracanalicular Tumors versus
symptomatic ones (especially ones with deafness)

•
Narayan Jayashankar Kapil Sikka wait and watch is obviously for
intracanalicular tumors that are asymptomatic or even those with
occasional vertigo but good hearing as also excellent speech
discrimination scores. Follow up with serial MRI and audio grams is
mandatory. However, in subjects with only hearing loss as a symptom also
you can wait and watch in a certain group of subjects. This is the group
where you have to decide on individual basis as to whether to operate
especially if the hearing is deteriorating on serial audiograms. In an
intracanalicular Tumor with significant vertigo, early surgery is preferred to
wait and watch.
• Narayan Jayashankar For Class A and B hearing (Sanna hearing
classification)I.e serviceable hearing and good SDS , it is middle cranial
fossa. For Class C,D, E it is translab approach especially so if tumor is at the
Lateral end of IAM. If tumor is not going too far Lateral in the IAM and if
hearing is Class C, then even a retro labyrinthine approach to IAM is used

• Alamgir Chowdhury what is the ultimate result?
• Like
• · Reply · April 3 at 5:48pm
• Narayan Jayashankar Middle cranial fossa - complete tumor removal with preserved hearing
• Like
• · Reply · 1
• · April 3 at 6:07pm
• Narayan Jayashankar Translab approach - complete tumor removal with no hearing
• Like
• · Reply · 1
• Narayan Jayashankar Retrolab approach - limited indications - complete removal with preservation of functional
hearing
• Like
• · Reply · 1
• Alamgir Chowdhury thank you very much. In translab approach will CI work?
• Like
• · Reply · April 3 at 6:10pm
• Murali Chand Nallamothu 100% works Alamgir Chowdhury sir

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