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Anterior cranial fossa 360°


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Anterior cranial fossa 360°

  1. 1. Anterior cranial fossa 360° 29-9-2016 7.49 pm
  2. 2. Great teachers – All this is their work . I am just the reader of their books . Prof. Paolo castelnuovo Prof. Aldo Stamm Prof. Mario Sanna Prof. Magnan
  3. 3. For Other powerpoint presentatioins of “ Skull base 360° ” I will update continuosly with date tag at the end as I am getting more & more information click - you have to login to with Facebook account for downloading.
  4. 4. Anterior & Posterior perforated substance
  5. 5. Anterior perforated substance & olfactory track relation
  6. 6. Trasnasal endoscopic view FPA = Fronto-polar artery ; FOA = Fronto-orbital artery
  7. 7. Recurrent artery of HUEBNER
  8. 8. Recurrent Rathke's Cleft cyst,previously operated in Russia by external approach.Case done with Dr.V.S.Mehta sir...Showing the beautiful anatomy of suprasellar area. Note the loss of right optic nerve fibers due to compression of the cyst.
  9. 9. Endoscopic subfrontal – Courtesy by Dr. Sukhdeep Jhawar
  10. 10. Trascranial view FPA = Fronto-polar artery ; FOA = Fronto-orbital artery
  11. 11. FPA = Fronto-polar artery ; FOA = Fronto-orbital artery Transnasal endoscopic view Trascranial view
  12. 12. Bifrontal craniotomy view FPA = Fronto-polar artery ; FOA = Fronto-orbital artery
  13. 13. The carotid bends laterally in the nasopharynx before entering the petrous temporal bone. It then swings anteriorly before becoming the paraclival carotid in the floor of the sphenoid and progresses vertically into the cavernous sinus and then enters the anterior cranial fossa giving off the middle cerebral artery (MCA) to become the anterior cerebral artery.
  14. 14. Dry bone specimen following a frontal drillout procedure. This specimen clearly shows the close relationship between the frontal sinuses and the cribriform plate, and hence the advantage of the drillout procedure for anteriorly based lesions. AT of FS, anterior table of frontal sinus; PT of FS, posterior table of frontal sinus; FC, foramen cecum; CP, cribriform plate; CG, crista galli.
  15. 15. Always one cell [ AEC ] present anterior to AEA . Cadaveric dissection image of the left ethmoid cavity revealing the anterior ethmoidal artery (AEA) located one anterior ethmoidal cell (AEC) posterior to the frontal sinus (FS). OF, orbital fat; PO, periorbita.
  16. 16. . • When approaching an olfactory groove meningioma, regardless of approach, both the extra- and intradural arteries associated with the tumor must be controlled. The anterior and posterior ethmoidal arteries provide the major extradural blood supply to the tumor
  17. 17. Anterior ethmoidal artery has to be cauterized on cerebral side , if you do on orbital side it may retract & cause retro-orbital haemorrhage
  18. 18. Cadaveric dissection image demonstrating the left anterior ethmoidal artery (AEA) and nerve (AEN) running across the skull base toward the middle turbinate (MT) attachment. Here it can be seen dividing into several branches including the anterior falcine artery (AFA) to supply the falx cerebri. LP, lamina papyracea. - In Olfactory meningioma surgery the small, falcine arterioles that feed the tumor can be coagulated. Sacrificing these arteries early in the dissection provides further tumor devascularization.
  19. 19. Cadaveric dissection illustrating the anatomy of the anterior skull base following partial resection of both middle turbinates (MT) and nasal septum. The communal frontal sinus (FS) ostium can be seen anteriorly with both fovea ethmoidalis (FE) exposed. The lateral margins are the lamina papyracea (LP) and posteriorly the planum sphenoidale (PS) can be seen. OF, olfactory fossa; AEA, anterior ethmoidal artery; PEA, posterior ethmoidal artery; AEN, anterior ethmoidal nerve; PEN, posterior ethmoidal nerve.
  20. 20. Cadaveric dissection with osteotomies created using a diamond drill.
  21. 21. The anterior attachment of the falx cerebri (FC) to crista galli (CG) is seen. Note the superior sagittal sinus (SSS) running in the superior aspect of the falx cerebri within the inferior sagittal sinus (ISS) in the lower margin of the falx cerebri. The inferior sagittal sinus becomes the straight sinus (SS) after it joins with the great cerebral vein.
  22. 22. Cadaveric dissection demonstrating the skull base scissor cutting the attachment of the falx cerebri (FC) to the crista galli.
  23. 23. The skull base is placed under traction and the remaining posterior falx cerebri still holds the skull base. This needs to be cut before the skull base can be dropped into the nose.
  24. 24. I THINK AFTER SEPERATION OF FRONTAL LOBES WE SEE ANTERIOR CEREBRAL ARTERIES - REFER Cadaveric dissection image: the skull base has been removed affording a view of the inferior aspect of both anterior cerebral lobes. The olfactory bulbs (OB), branches of the anterior cerebral artery (ACa), and cut inferior aspect of the falx cerebri (FC) can be seen. FS, frontal sinus; AEA, anterior ethmoidal artery; LP, lamina papyracea. -
  25. 25. Fronto-polar artery
  26. 26. ACA anterior cerebral artery, APAs anterior perforating arteries, FOA fronto-orbital artery, FOV fronto-orbital vein, FPA fronto-polar artery, ICAi intracranial segment of the internal carotid artery, MCA middle cerebral artery, OlfT olfactory tract, OlfV olfactory vein, ON optic nerve, PS pituitary stalk, TL temporal lobe, black asterisk anterior communicating artery
  27. 27. Dear surgeons cadeveric craniectomy see frontal lobes gyrus recti falx fronto polar arteries draff type3 all in one – Dr. Sree Ram Murthy
  28. 28. F = Frontal , LP = Lamina papyrecea , GR = Gyrus rectus
  29. 29. Two-suction technique for tumor resection. Note that the righthanded suction is providing traction while the other suction is dissecting soft tumor. Microneurosurgical techniques for tumor removal include the internal debulking of the tumors, followed by the mobilization of the tumor capsule to allow early identification and extracapsular dissection of neurovascular structures, and the coagulation and removal of the remaining capsule. This sequence is repeated multiple times until final sharp dissection of the residual capsule is completed. These time-proven techniques are designed to minimize the risk of injury to important structures and are critical elements for the removal of any tumor with any surgical approach. Endoneurosurgical tumor removal adheres to the same dissection principles of open approaches and avoids blind dissection of tumors from vessels and nerves. Under no circumstances are tumors extracted by pulling without seeing the underlying structures. If the technique above cannot be performed the resection mustbe abandoned.
  30. 30. Prof . Amin kassam statements
  31. 31. Suprasellar/transplanum approach: Drill the bone of the planum sphenoidale until paper-thin. It is important to recognize that the planum has a rhomboid geometry, bound by the optic nerve canals laterally and the tuberculum sella strut posteriorly. The bone of the planum is removed in an anterior to posterior direction displacing it inferiorly to gain distal access. The dura is very adherent over this area. Removal of the bone using rongeurs in a posterior to anterior direction universally results in a dural injury (before intradural control of the anatomy). The tuberculum strut needs to be drilled until very thin; then, it can be fractured and removed. This will expose the superior intercavernous sinus that can be then be coagulated and/or clipped and divided & surgiflo applied if it is still bleeding . Open the dura and identify the optic nerves, (RON & LON) chiasm and tracts, the infundibulum, and ICAs.
  32. 32. Anterior and posterior ethmoid arteries control: Identify the anterior (AEA) and posterior ethmoid arteries (PEA) inside the orbital cavity, displacing the periorbita laterally to assist with their visualization. Note the orientation of the arteries. Uncap their bony canal, dissect the neurovascular bundle out of the canal and transect them.
  33. 33. Frontal sinusotomy (Draf III): Enlarge the nasofrontal recess anteriorly and medially (drill or rongeurs) to reach the nasal septum (Draf IIb). Extend the resection of the posterior nasal septum to reach the level of the anterior wall of the frontal sinus. At this point you should be able to see both nasofrontal recesses from either side of the nose. Remove the floor of the frontal sinuses across the midline while remaining anterior to the posterior wall of the frontal sinus and the crista galli. Remove the “frontal beak” and extend the resection of the floor anteriorly until you can visualize the anterior wall of the frontal sinus.
  34. 34. Anterior craniofacial resection (Trans- cribiform Approach): Resect any remnants of the superior attachments of the posterior nasal septum, middle and superior turbinates. Complete a “sequential layered resection” removing the mucoperiosteum and olfactory filaments; then, the bone of the fovea ethmoidalis and cribiform plate; and then, the dura: a) remove the mucosa with through- cutting instruments. b) drill the fovea ethmoidalis medial to its junction with the roof of the orbit and the cribiform plate until they are paper- thin and remove with blunt instruments c) drill out crista galli.
  35. 35. Incise the dura along the lateral edge of the bony defect and join the longitudinal incisions anteriorly with a horizontal incision. Extend the latter medially to reach the falx cerebri bilaterally.
  36. 36. The falx cerebri can be transected in an anterior to posterior fashion, only after the identification of the anterior fossa vasculature ( frontopolar and fronto-orbital vessels).
  37. 37. Sharp dissection [ key principle in transcibriform approach ] is utilized to allow for extracapsular dissection. Note, that the suction provides retraction of the tumor (T) and tension along the band. The fronto-polar artery (FPa) is preserved along the frontal lobe (F) while an olfactory groove meningioma (T) is being removed.
  38. 38. A blunt dissector is being utilized to establish a dissection plane between a left olfactory bulb (OB) invaded by cancer and the gyrus rectus (GR).
  39. 39. What is Danny’s ligament
  40. 40. Recurrent artery of heubner originates near Acom (A) The middle cerebral artery (MCA) gives rise to the lateral lenticulostriate arteries (LLA) at the bifurcation complex. The medial lenticulostriate arteries (MLA) arise from the proximal section of A1. At the juncture of A1-AComm-A2 the recurrent artery of Heubner (RAH) is given off. AComm completes the anterior portion of the circle of Willis and has several perforating vessels ( Acomm Perf) that head posteriorly. In the first 5 mm of A2 the orbitofrontal ( OF) artery is given off with the frontopolar (FP) artery staying more medial. (B) A clinical picture after removal of a tuberculum sella meningioma with a well-defined display of the anterior cerebral arteries.
  41. 41. In the lateral border of the chiasmatic cistern the first part of the ICAi is visible. Dry bone dissection image taken with a 30-degree endoscope demonstrating the fovea ethmoidalis (FE) and cribriform plate (CP) junction with the planum sphenoidale (PS). This is marked approximately by the posterior ethmoidale artery (PEA). ISS, intersinus septum of sphenoid sinus; ON, optic nerve; CCA, anterior genu of the intracavernous carotid artery.
  42. 42. Preoperative CT angiogram showing the close association of the tumor capsule of an olfactory groove meningioma with the anterior cerebral arteries (arrows). – sometimes ACA present in the posteior part of the tumor
  43. 43. In contrast, craniopharyngiomas within the pre-chiasmatic space can be removed via a supraorbital or endonasal route, while tumors with lateral extensions or supra-chiasmatic extensions can be most effectively removed by a supra-orbital or lateral transcranial approach. – from craniopharyngioma book
  44. 44. When the ACAs present in the posterior part of the tumor BIFRONTAL approach is used – by Dr.Lee • Add video clipping
  45. 45. MRI scans show the A1 (solid white arrow) leaving the middle cerebral artery juncture toward the AComm (dashed white arrow) with the A2s (black arrow) progressing superiorly. These vessels are all within the substance of the tumor. The clinical dissection of this tumor is seen in (C) and (D) with tumor encompassing the perforators (Perf) coming off the AComm. Once all tumor had been removed the vascular complex with A1-AComm,-A2 and the important branch of A1, the recurrent artery of Heubner ( RAH), and the A2 branch, orbitofrontal (OF) artery, are clearly visible.
  46. 46. The lateral limit of resection for olfactory groove meningiomas is the midorbital vertical meridian (fig. 5). This limitation is created by, as we believe most limitations are, a nerve, in this case the optic nerve. Removal of the lamina papyracea allows gentle retraction of the periorbita and orbital contents to allow access to the orbital roof out to the midorbit. Coronal post-contrast T1-weighted MRI showing the lateral limit of resection at the midorbital vertical meridian (dotted line). b Postoperative post-contrast T1-weighted MRI showing complete resection out to midorbit via EEA.
  47. 47. Endoscopic endonasal view of the anterior skull base following the sinonasal portion of the approach. Dashed lines represent the osteotomies to be performed for dural access. Endoscopic endonasal view of the right posterior ethmoidal artery for bipolar coagulation and ligation.
  48. 48. • There are often multiple fine falcine arterioles that provide additional blood supply to olfactory groove meningiomas. Following tumor debulking on either side of the falx, these arterioles can be carefully transected and coagulated during the resection of the falx to provide further tumor devascularization. • The tumor should not be detached anteriorly before all of the internal debulking is complete, as frontal lobe descent can obscure visualization.
  49. 49. In coronal MRI scans (A,B) and parasagittal MRI (C) the two consistencies of tumor are visible. The soft tumor is marked with a solid white arrow whereas the calcified tumor is marked with a broken white arrow. In coronal CT scan (D) the calcified part of the tumor is clearly seen (white broken arrow). (A,B) Brain edema is indicated with a solid black arrow. The other important feature seen in (C) is the close approximation of the tumor to the posterior wall of the frontal sinus (broken black arrow). This means that the anterior osteotomy should be through the posterior wall of the frontal sinus.
  50. 50. video of olfactory groove Schwannoma Olfactory groove meningioma – endoscopic approah Olfactory groove meningioma – microsocpic approah &spfreload=10
  51. 51. Transcribriform tumor excision - by Dr.Satish Jain /watch?v=ZRNSAc8B3So
  52. 52. Interhemispheric approach & transcallossal for craniopharyngioma
  53. 53. 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.