Decision making between anterior skull base & lateral skull base

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1. Decision making between Anterior skull base & Lateral skull base [ Neurosurgical skull base + Trans-temporal skull base ] 7-5-2017 8.40 pm 2. For Other powerpoint…
  • 1. Decision making between Anterior skull base & Lateral skull base [ Neurosurgical skull base + Trans-temporal skull base ] 7-5-2017 8.40 pm
  • 2. 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 - you have to login to with Facebook account for downloading.
  • 3. 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 .
  • 4. 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 : , I will change accordingly to this PPT .
  • 5. 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 .
  • 6. 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 .
  • 7. 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 2. Most of the times “Don’t cross the NERVES”
  • 8. Anterior skull base decision making – By Prof. Amin Kassam & Dr. James K. Liu
  • 9. Prof. Amin Kassam CORRIDOR SURGERY Video – Click oMCqwJ6Ke0
  • 10. What is skull base 360° ??? Click & For better understanding - Must watch above videos signifying importance of by Prof. James K. Liu
  • 11. Lateral Trans-temporal skull base approaches – Decision making – by Prof. Mario Sanna
  • 12. " 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 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.
  • 13. Neurosurgical skull base approaches – Decision making – by Laligam sekhar
  • 14. Pterional craniotomy is itself a SKULL BASE APPROACH – click - GIANT PITUITARY ADENOMA- MICROSURGERY- dr suresh dugani/HUBLI/KARNATAK/INDIA wsM&
  • 15. 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.
  • 16. 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.
  • 17. • 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.
  • 18. 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.
  • 19. Combined approaches of skull base – click ndnallamothu/combined- approaches-of-skull-base-360
  • 20. Carotid injury – Prevention & Management
  • 21. BEST PROTOCOL , I have ever seen so far – BY Dr.Paul Gardner ---- copy & paste & see in any picture software
  • 22. 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
  • 23. 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
  • 24. 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
  • 25. 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
  • 26. Management of carotid artery injury in Lateral skull base - Reference from Prof.Mario Sanna
  • 27. Prof.Mario Sanna - Management of great vessels in Lateral skull base – lecture – click /watch?v=7tW3Ev9siCs&fe
  • 28. 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
  • 29. 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.
  • 30. 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.
  • 31. 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.
  • 32. 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.
  • 33. 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,
  • 34. 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.
  • 35. 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.
  • 36. Medication schedule associated with stenting into the internal carotid artery
  • 37. 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.
  • 38. 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.
  • 39. 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
  • 40. 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.
  • 41. 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.
  • 42. 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.
  • 43. Carotid injury – Management in both anterior & lateral skull base - click nallamothu/carotid-injury- management-in-both-anterior-lateral- skull-base
  • 44. • 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 . " 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
  • 45. How far carotid transposition is safe in anterior skull base ??????? Micro-aneurysms may present in ICA - picture from Trans- temporal skull base
  • 46. Debates
  • 47. Debate • Lateral Skull Base is Accessible by Endonasal Surgery – Click for video Lecture : Z_N4 • Lateral Skull Base is Inaccessible by Endonasal Surgery – Click for video Lecture : b28o&sns=fb
  • 48. Debate • Endonasal Surgery is Effective for Malignant Skull Base Tumors – Click for video Lecture : HVQ&sns=fb • Contraindications for Endonasal Surgery for Malignant Tumors – Click for video Lecture : gkde8&sns=fb
  • 49. JNA decision making
  • 50. 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.
  • 51. To get any paper of any journal free click or How to get FREE journal papers in or 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- 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 . 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 or 4. Add " .pdf " to title of the paper & search in if not found in or
  • 52. JNA classification based on vascular supply to tumor – by Amit keshri
  • 53. 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 infrate
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