Decision making between Anterior skull base & Lateral skull base [ Neurosurgical skull base +

Trans-temporal skull base ]

7-5-20178.40 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=youtu.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=QoMCqwJ6Ke0

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 – clickhttp://books.google.co.in/books?id=4bvs6yV2WTQC&printsec=frontcover&dq=atlas+of+microsurgery+of+lateral+skull+base&hl=en&sa=X&ei=VmkFVInxBoToggT-94GoDQ&ved=0CCYQ6AEwAA#v=onepage&q=atlas%20of%20microsurgery%20of%20lateral%20skull%20base&f=falseNow 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_CvKwsM&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 tobe limited.

Whether or not the ICA should be left intactdepends on the surgeons attitude and the nature ofthe tumor. Benign tumors other than meningiomas(e.g. schwannoma, pituitary adenoma) may usuallybe dissected from the ICA. With meningiomas,however, encasement and narrowing of the ICAfrequently indicates that the vessel wall has been invaded by tumor. This has been conrmed by histologicalstudy of removed arteries [19]. Therefore,total resection often requires ICA resection. Ofcourse, the surgeon may choose to leave tumorbehind and treat it with radiosurgery. Generally,chordomas and chondrosarcomas can be dissectedfrom the ICA, but some require replacing the arterywith a bypass graft. With slowly growing malignanttumors such as adenoid cystic carcinomas, totaltumor removal requires resection of the ICA-CS.Furthermore, resecting and replacing the artery encasedwith tumor allows the surgeon to give the taskof 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 temporaryocclusion 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 ICAresection or injury seems likely.

Combined approaches of skull base – click

http://www.slideshare.net/muralichandnallamothu/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 http://www.ncbi.nlm.nih.gov/pubmed/25790070 http://www.ncbi.nlm.nih.gov/pubmed/15337877

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&feature=youtu.be

Modalities of surgical management of the ICA include:

1. Skeletonization2. Displacement3. Subperiosteal/subadventitial dissection 4. Dissection and resection after permanent balloon occlusion5. 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. DisplacementDisplacement 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 fortumors that involve the ICA to a greater extent, such as C2glomus tumors and meningiomas (Fig. 15.24a, b). In general,dissection of the tumor from the artery is relatively easierand safer in the vertical intrapetrous segment, which isthicker and more accessible than the horizontal intrapetroussegment.A plane of cleavage between the tumor and the arteryshould be found first. In most cases, the tumor is attached tothe periosteum surrounding the artery. Dissection is betterstarted at an area immediately free of tumor. Aggressivetumors may, however, extend even to the adventitia of theartery and subadventitial dissection may be needed. Thisshould be done very carefully in order to avoid any tear to thearterial wall, which can become weakened (Fig. 15.25), withthe 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 norelevant complications postoperatively, such excessive manipulation is

better avoided and permanent balloon occlusion or stenting are preferablytried 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 afterReinforcement 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 arteryP periosteum

a Intraoperative view of the balloon used to permanentlyocclude the internal carotid artery. b, c Schematic drawings showingthe 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 ofthe 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/muralichandnallamothu/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=5dczLBfolBcC&pg=PP7&dq=aldo+cassol+stamm&hl=en&sa=X&ei=iM85UoeeNYOtrAehwYHIAQ&ved=0CDsQ6wEwAg#v=snippet&q=Suture%20repair%20is%20possible%20%2C%20albeit%20technically%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

Debates

Debate

• Lateral Skull Base is Accessible by Endonasal Surgery – Click for video Lecture : https://www.youtube.com/watch?v=HroWRSJZ_N4

• Lateral Skull Base is Inaccessible by Endonasal Surgery – Click for video Lecture : https://www.youtube.com/watch?v=JNt5hPpb28o&sns=fb

Debate

• Endonasal Surgery is Effective for Malignant Skull Base Tumors – Click for video Lecture : https://www.youtube.com/watch?v=Hl2MiuHlHVQ&sns=fb

• Contraindications for Endonasal Surgery for Malignant Tumors – Click for video Lecture : https://www.youtube.com/watch?v=Uk57MEgkde8&sns=fb

JNA decision making

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. http://www.ncbi.nlm.nih.gov/pubmed/26302935

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=oa.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 bilateralincision in the gingival sulcus, as in a conventional Caldwell-Luc procedure. A complete transfixionincision of the membranous septum extended around the piriform aperture to the space between thesuperior and inferior lateral cartilages is made. The soft tissues of the nasal dorsum are then elevatedin a subperichondrial and subperiosteal plane by using an elevator and Metzenbaum scissors. Theremaining 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 theanterior maxillary wall, the ascending branch of the maxilla and the piriform fossa. The deglovingapproach is then completed by elevating the soft tissue of the upper lip, nasal dorsum, and superiormaxillary region, thus exposing the bony structures of the middle third of the face (up to theinfraorbital 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 theinfraorbital opening and its contents in place. The next step is the opening of the posterior wall of themaxillary 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 sectionof the vascular pedicle of the tumor in the pterygomaxillary fossa. It is important to not touch thetumor until all the exposure is completed. The entire medial nasal wall is opened through a posteriorand inferior detachment of the inferior turbinate that can be kept anterior until the end of the procedureor totally resected. The middle turbinate is displaced superiorly, increasing the visualization of thetumor.An ethmoidectomy is done and the sphenoid sinus is opened, taking care to expose and resect thesphenoid rostrum, to allow visualization of the basisphenoid bone, which is one of the most importantareas of the tumor’s origin.After an entire exposure, using forceps, suction tubes, and bipolar electrocautery, the tumor isdissected free from the mucosa of the posterior wall of the nasopharynx, the mucosa of the posteriorthird 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. Itis 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 theinferior orbital border (Fig. 29.6). The sublabial incision is sutured, and the surgical cavity iscarefully 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=ekwOfEmHGWg&feature=youtu.be

Amit keshri JNA case – decision making

https://www.facebook.com/groups/347913135290330/permalink/877060909042214

/

Petroclival meningioma decision making

Petroclival meningiomas decision making by Prof.Mario Sanna – Click

https://www.youtube.com/watch?v=kUa9fQ4_aQY&list=UU3vRSTN8Rx46MQwq06XRJIA

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 presentedwith worsening vision changes. An MRI revealed a

giant pituitary tumor with severe suprasellar extensionand clival invasion (Figs 21–6A and 21–6B). Prolactin

levels were normal. Also, multiple flow voidsare noted surrounding the tumor and “pinching”the tumor margins. These are the anterior (ACAs)

and middle cerebral (MCAs) arteries. This case illustratesthe 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 likelyeven decompress the midportion of the suprasellarportion for optic chiasm decompression. Howeveran anterior-lateral (orbito-zygomatic-craniotomy)

approach would be best for clearance of the tumoraway from the ACAs and MCAs and the intraventricular

portion of the tumor. Endoscopic assistancevia 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/347913135290330/permalink/867688616646110/• 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.

Neurosurgeon opinion

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=TkmBDG7sooEC&printsec=frontcover&dq=mario+sanna+acoustic+neuroma+surgery&hl=en&sa=X&ei=haeeVIKOHYjluQT384LACQ&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

Facebook discussions• https://www.facebook.com/groups/learningent/permalink/730657780305432/• https

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297/

• 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.

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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 .

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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.

https://www.facebook.com/groups/347913135290330/permalink/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.

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• 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+lateral+skull+base&hl=en&sa=X&ei=VmkFVInxBoToggT-94GoDQ&ved=0CCYQ6AEwAA#v=onepage&q=atlas%20of%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.

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• 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/?query=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 establishthresholds 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 temporarycontrol. If this is effective and neurophysiologic monitoring stable, additionalpacking can be placed while the patient is transferred to angiography for definitivemanagement. If packing does not control the bleeding, it is best to get further controlprior to transfer. While the vessel is compressed with focal packing, additionalbone can be removed to better expose the vessel proximal and distal to the site ofinjury. Although direct suture repair is possible, it is technically difficult and may notbe a realistic option. With adequate exposure vessel preservation can be attemptedthrough aneurysm clip reconstruction (e.g. Sundt- Keys clips). Otherwise, the vesselcan be occluded with additional packing or placement of aneurysm clips. If packingis used, it needs to be focal so that bleeding is controlled and blood is prevented fromtracking through a craniotomy defect intracranially. The patient is then transportedto radiology for angiographic assessment and treatment. Preservation of blood flowwith a covered stent is technically difficult in the region of the cavernous sinus andcurrently not FDA approved; therefore, permanent occlusion with coils is often thepreferred option. Assessment of collateral blood flow is then performed to assess therisk of ischemic stroke and the potential need for revascularization (bypass).

PJ wormald

After drilling the carotid canal what we see is endosteal layer / periosteum , not directly the ICA

Subperiosteal/Subadventitial DissectionSubperiosteal/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. 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 .

http://www.ncbi.nlm.nih.gov/pubmed/25415067 http://www.ncbi.nlm.nih.gov/pubmed/25790070 http://www.ncbi.nlm.nih.gov/pubmed/15337877 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 .

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 http://www.ncbi.nlm.nih.gov/pubmed/25790070 http://www.ncbi.nlm.nih.gov/pubmed/15337877

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

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

For better understanding of Decision making between anterior & lateral skull base PPT must read “Carotid injury PPT ” – click

http://www.slideshare.net/muralichandnallamothu/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.felix.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 pseudobiaural 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 approach2. Cochlea preservation approach3. 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 surgery3. Programming of CI4. Audio verbal therapy5. Physics6. Electricity7. Bioengineering 8. Endoscopy of cochlea9. 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 TLA2. Medium size tumor i) Recommend Surgery RSA in serviceable hearing or TLA in unserviceable hearingii) 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 recommendedMCFA or RSA in Serviceable hearing, TLA or EETTA in profound HLGamma 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• · April 3 at 6:07pm• Narayan Jayashankar Retrolab approach - limited indications - complete removal with preservation of functional

hearing• Like• · Reply · 1• · April 3 at 6:08pm• 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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