2. Relevant Cerebro-Vascular Anatomy for Carotid Intervention Ricardo A Hanel, MD Elad Levy, MD L N Hopkins, MD

3. Cerebrovascular Anatomy Why should I learn it For CAS ? Basic anatomy and collateral circulation is enough Basic anatomy and collateral circulation is enough Always obtain baseline films for comparison Always obtain baseline films for comparison Knowing the anatomy helps avoid complications Knowing the anatomy helps avoid complications

4. 2 ICA’s &VA’s carry 20% of Cardiac OP 2 ICA’s &VA’s carry 20% of Cardiac OP ICA’s fixed from skull base to supraclin ICA ICA’s fixed from skull base to supraclin ICA VA’s fixed in vertebral foramen VA’s fixed in vertebral foramen

5. Carotid artery interventions Clinical applied Anatomy will influence: Clinical applied Anatomy will influence: –The best therapeutic option (CEA x CAS) –The best Access (femoral, brachial, direct) –Device selection –Complication avoidance –Complication management

6. Aortic Arch Develops from the L 4 th embryonic arch Develops from the L 4 th embryonic arch Branches Branches –Brachiocephalic trunk (Inominate A) –L Common carotid A –L Subclavian A Many variations Many variations Disease alters anatomy and risks Disease alters anatomy and risks

7. Aortic Arch Views Arch angio to assess access Arch angio to assess access LAO 30-45 degrees best LAO 30-45 degrees best Multiple views…origin ds Multiple views…origin ds RAO 20.. R subclavian from RCCA RAO 20.. R subclavian from RCCA

8. Positioning for an Ideal Arch Angiogram Straight AP 30-45° LAO

9. Straight and LAO Arch Images

10. Aortic Arch Views Common Variants: Common Variants: –Bovine origin of LCCA off of Brachiocephalic Trunk 7-20% of patients 7-20% of patients –L Vertebral origin off arch 0.5% of patients 0.5% of patients Proximal to L SCA Proximal to L SCA –Aberrant right subclavian 0.4 to 2% of patients 0.4 to 2% of patients R Subclavian originates from the arch distal to the left subclavian R Subclavian originates from the arch distal to the left subclavian

11. Common variants A) Brachiocephalic trunk (BCT) and LCCA share a common origin (25- 30%) B) L CCA arises from BCT (7%) C) L Vert arises directly from the arch (0.5%) Osborn A, 1998 D) R subcl. Origin from L

12. Bovine Arch - 7% ?? Brachial Approach Bovine Arch - 7% ?? Brachial Approach

13. Uncommon L Arch + Aberrant R Subclavian (0.4-2%) L Arch + Aberrant R Subclavian (0.4-2%) R Arch with aberrant L subclavian R Arch with aberrant L subclavian Rt arch with mirror-image branching Rt arch with mirror-image branching Double Aortic Arch Double Aortic Arch

14. What is this??

15. Dextrocardia with mirror-image

16. And This??

17. Multiple Anomalies…What ‘s This??

18. R Subclavian (No R vert)

19. Supra-aortic vessels (R to L) Supra-aortic vessels (R to L) –R CCA R Vert from RCCA R Vert from RCCA –LCCA –L Vert –L Subclavian –R Subclavian Multiple Anomalies R CCA R VA L CCA L VA R&L Subcl

20. R Vert arising from R CCA

21. Weird Anatomy!! Weird Anatomy!!

22. Carotid Artery Variability enormous Variability enormous Bifurcation C1 – T2 Bifurcation C1 – T2 Best working view… lat/obl Best working view… lat/obl Bony landmarks … Bony landmarks … -Unsubtract -Unsubtract Skull Base Petrous Carotid ECA ICA

23. Cervical Carotid Views Obtain AP, Lateral and Oblique projections Obtain AP, Lateral and Oblique projections Clear ICA origin from ECA Clear ICA origin from ECA Evaluate for dissection, thrombus, calcium, kinks Evaluate for dissection, thrombus, calcium, kinks Measurements using NASCET criteria Measurements using NASCET criteria –1 - (Stenosis diameter/Non- tapered segment diameter)

24. Cervical ICA “No Branches” Hi flow…Don’t overdilate! Fixed near skull base Carotid Sinus

25. What is this?? Where to put the filter?

26. Pcomm Otic Primitive trigeminal Hypoglossal Pro atlantal Connections ICA to VA

27. ECA anatomy

28. ECA Branches 1.Key source of collateral 2.Anastomoses to ICA or VA 3.Stent will not occlude ECA

29. When handling the ECA remember… EC-IC anastomosis common EC-IC anastomosis common May not be seen on angiogram May not be seen on angiogram With major vessel occluson these anastomosis may hypertrophy With major vessel occluson these anastomosis may hypertrophy ECA embolus may cause stroke ECA embolus may cause stroke BE AWARE! BE AWARE!

30. Most Common Extra-cranial Intra-cranial anastomosis EXTRACRANIAL ARTERIESINTRACRANIAL ARTERIES Anterior branch of middle meningeal Ophthalmic (ethmoidal) Anterior meningealAnterior cerebral Petrosquamosal branch of middle meningeal Petrous internal carotid (cranial nerve VII) OccipitalVertebral Neuromeningeal branch of ascending pharyngeal Posterior inferior cerebellar/ anterior inferior cerebellar (cranial nerves IX ‑ XI)

31. Post-intervention CineE. Deflate the GuardWire ® protection balloon and evaluate final result The GuardWire® Balloon Protected Procedure Pre-intervention Cine

32. The GuardWire ® Balloon Protected Procedure Carotid stenting sampleSVG with covered stent sample Complication: Visual Loss due to retrograde embolization of retinal arteries via ECA branches

33. ICA Anatomy Base of Skull Petrous ICA Cavernous ICA Ophthalmic a Supraclinoid ICA

34. ICA becomes fixed 2-3mm proximal to skull base ICA becomes fixed 2-3mm proximal to skull base Petrous ICA up to supraclinoid ICA fixed in bone/ligamentous/dural encasement Petrous ICA up to supraclinoid ICA fixed in bone/ligamentous/dural encasement Intracranial vessels more mobile but fragile and easily damaged/ruptured Intracranial vessels more mobile but fragile and easily damaged/ruptured Onward and Upward…

35. Skull Base From Below ICA Entrance Horizontal Petrous ICA ANT Post

36. Skull Base From Above Ant Post Horiz Petrous ICA

37. Petrocavernous ICA Side View - Right Ascending Petrous Cavernous

38. Cavernous – Supraclinoid ICA Anterior Medial Loop Horizontal Cavernous ICA Supraclinoid ICA Perforators Post Communicating

39. Quiz … What is this?? Quiz … What is this?? Although uncommon, carotid-basilar anastomoses, other then PComm, may occur: Although uncommon, carotid-basilar anastomoses, other then PComm, may occur: –Persistent trigeminal artery (0.25%) From Cavernous ICA to basilar From Cavernous ICA to basilar Primitive Trigeminal Ascending Petrous ICA

40. Intracranial Vascular Anatomy After giving origin to the Ophthalmic A, PComm and Ant Choroidal artery the ICA finally bifurcates into the Anterior Cerebral Artery - ACA and Middle Cerebral Artery – MCA After giving origin to the Ophthalmic A, PComm and Ant Choroidal artery the ICA finally bifurcates into the Anterior Cerebral Artery - ACA and Middle Cerebral Artery – MCA

41. Intracranial Vascular Anatomy A Must….pre op AP and Lateral Angio Have them handy!!!!

42. Variations are the Rule Many variations of these vessels Many variations of these vessels Always have pre op films to compare in case of trouble Always have pre op films to compare in case of trouble And always do a baseline Neuro exam pre op And always do a baseline Neuro exam pre op 3 M-2 branches MCA embolus ?????

43. The Circle of Willis Connection between: Connection between: –Carotid-basilar system –Rt/Lt side –Vessels involved: ACAs & AComm ACAs & AComm ICAs & PComms ICAs & PComms PCAs PCAs Basilar Basilar T/F : The Circle is Always Intact ??

44. Acomm Pcomm

45. The Circle of Willis The Circle of Willis is complete in only 30- 40% of the cases The Circle of Willis is complete in only 30- 40% of the cases Many variations Many variations Hypoplasia of one of the A-1 segments of the ACAs… Hypoplasia of one of the A-1 segments of the ACAs… Or ICA stenosis??? Or ICA stenosis??? A-1 What is this?

46. MCA & ACA Anatomy ACA MCA M-1 M-2 ACA A-2 Acomm A-1

47. MCA Where is the ACA ?

48. MCA … Many Variations

49. ACA Anatomy A-1 A-2 PComm

50. Variations, variations, variations … Message ???

51. Vertebral Artery Anatomy Rich Muscular Collateral

53. Department of Radiology

55. Variations, variations, variations … A complete diagnostic angiogram with clinical/anatomical correlation should be performed and available before any major intervention A complete diagnostic angiogram with clinical/anatomical correlation should be performed and available before any major intervention

56. What is this??

57. Interesting Collateral Asx LCCA origin stenosis R CCA & BILAT VA OCCL Interesting Collateral Asx LCCA origin stenosis R CCA & BILAT VA OCCL R VA(thyrocervical trunk) R CCA(inf thyroid a)

58. ICA Occlsion ICA Occlsion

59. R ICA Occl with Collateral …Circle of Willis L Carotid R Vertebral

60. R ICA Occl with Pial Collateral

61. R ICA Occl with Vertebral Collateral to MCA PComm

62. ICA Occlusion with Ophthalmic Collateral L CCA Ophthalmic To ICA

63. R ICA Occl with Ophthalmic and Pial Collateral

64. Vascular Territories

65. Normal Angiogram Capillary Phase

66. Pre Embolus Capillary Phase Post Embolus

67. Complications Interventional procedure going uneventfully until….. Interventional procedure going uneventfully until….. Pt agitated & hemiparetic Pt agitated & hemiparetic What is this? What is this? What should you do? What should you do?

68. Complications Intracerebral Hemorrhage ACA and MCA spread…Barrel Shift

69. Hemorrhage CT Scan CT Scan You DO NOT need to angiographically visualize extravasation to have bleeding. You DO NOT need to angiographically visualize extravasation to have bleeding.

70. What is This ? Proceed with CAS ??

71. And this ?

72. …And This ??

73. Dangerous Anatomy Elderly Patient

74. “Corkscrew” Carotid “Corkscrew” Carotid Stay Away!!

75. Trouble …for sure!

76. Judgement!! Backing out is OK Causing a Stroke is Not Roubin

77. Catheter skills + Anatomic Knowledge = Better results Conclusion…