1. Week 8- Aneurysms, SAH, Dissections and Arteritis

2. Week 8- Aneurysms, SAH, Dissections and Arteritis
Week 8 Objectives-
Define Brain Aneurysm
Define Pseudoaneurysms
Recognize different types of aneurysm radiographically
Be familiar with the angiographic evaluation of patients with cerebral aneurysms
Be familiar with the angiographic evaluation of patients with subarachnoid hemorrhage (SAH)
Identify methods of surgical treatment of aneurysms
Discuss aneurysm coiling
Perform basic set-up for Aneurysm coiling
Discuss the treatment of wide-necked aneurysm
Discuss the balloon remodeling technique

3. What Is An Aneurysm?
A cerebral aneurysm is a bubble like outpouching from an artery which predisposes its carrier to cerebral hemorrhage and stroke
Images © Frank H. Netter, CIBA Collection of Medical Illustrations

5. History 1927 Moniz - angiography
1937 Dandy describes the clipping of intracranial aneurysm
1949 Robertson described post-mortem lesions after aneurysmal SAH.
Brain 72:150, 1949
1951 Ecker & Reimenschneider angiographic spasm

6. Aneurysm Demographics
Aneurysms are found in 2-5% of the population
More likely to occur in adults age 40-60
There are as many as 27,000 aneurysms that could be diagnosed and treated per year in the U.S.
They are more common in women (Sharon Stone had an aneurysm that was treated with coils by an interventional neuroradiologist)
The annual rupture rate is approximately 1.5%
Rupture of an aneurysm results in approximately 50% mortality and 25% stroke incidence

7. Aneurysm Facts Factors believed to contribute to brain aneurysms:
Smoking
Hypertension
Traumatic head injury
Alcohol use
Use of oral contraception
Post menopausal women > Men
Family history of brain aneurysms
Other inherited disorders: Ehler’s syndrome, polycystic kidney disease, and Marfan syndrome

8. Aneurysm Facts Symptoms of ruptured aneurysms:
The worst headache of your life
Localized and intense headache
Nausea and vomiting
Stiff neck or neck pain
Blurred or double vision
Pain above and behind eye
Dilated pupils
Sensitivity to light
Loss of sensation

9. The Configuration of Aneurysms
Aneurysms can be categorized by their configuration. There are three basic distinctions between aneurysms. They are as follows:
Fusiform Aneurysms – Whole vessel circumference involved
Saccular Aneurysms – The lesion is eccentric.
Pseudoaneurysms - Occur when the layers or wall has been perforated and the rupture is contained by an extraluminal hematoma.

10. Terminology Associated With Cerebral Aneurysms
Ectasia is a mild dilatation of a segment of vessel but is not considered to be an aneurysm at this point.
Dissection is occurs when a tear in the lining of the artery occurs and blood flows in between layers of the blood vessel.
Arteritis is inflammation of the cerebral arteries that obstructs and occludes them.
Infundibulum is a funnel-shaped origin of a branch vessel.

11. Classifications of Aneurysms
Aneurysms of the Neurovascular system can also be classified into 4 main groupings.
The groupings are as follows:
Extradural Aneurysms
Pseudoaneurysms
Intradural Aneurysms
Giant Aneurysms

12. Classifications of Aneurysms Extradural Aneurysms
Extradural Aneurysms occur outside of the Dura Mater and are less likely to cause subarachnoid hemorrhage.

13. Classifications of Aneurysms True Vs. Pseudoaneurysms
Other terms you will also hear are True Aneurysms and False (“pseudo”)Aneurysms
True Aneurysms are when the intima, media and advential layers are all intact.
False (Pseudoaneurysms) occur when the layers or wall has been perforated and the rupture is contained by an extraluminal hematoma.
Causes of Pseudoaneurysm may include:
Trauma
Dissection
Surgical or Endovascular Interventional Injury
Biopsy
Adjacent Infection

14. Classifications of Aneurysms Intradural Aneurysms
There are several categories of Intradural Aneurysms. They are as follows:
Fusiform - (Associated with tortuosity, hypertension, atherosclerosis and advancing age)
Mycotic and Inflammatory – (Caused by bacteria)
Oncotic – (Caused by metastasis)
Dissecting – (Caused by a disruption in the vessel walls)
Saccular (Berry) – (Develop over time and resemble a “berry”)
DeNovo – (Caused by carotid occulsion or ligation)

15. Classifications of Aneurysms Giant Aneurysms
Giant aneurysms are defined as aneurysms that are 25 mm or larger in size.

16. Anatomy of an Aneurysm
A cerebral aneurysm (also called an intracranial aneurysm or brain aneurysm) is a bulging, weakened area in the wall of an artery in the brain, resulting in an abnormal widening or ballooning. Because there is a weakened spot in the artery wall, there is a risk for rupture (bursting) of the aneurysm.
A cerebral aneurysm generally occurs in an artery located in the front part of the brain which supplies oxygen-rich blood to the brain tissue. A normal artery wall is made up of three layers. The aneurysm wall is thin and weak because of an abnormal loss or absence of the muscular layer of the artery wall, leaving only two layers.
The base is the “Neck and the top is the “fundus “ or “Dome"

17. Sites of Aneurysm Formation
The most common sites of Cerebral aneurysm are:
The Circle of Willis
Branch Bifurcations .

18. Sites of Aneurysm Formation
Anatomical distribution and relative incidence of Intracranial Aneurysms.

19. Left: Vessels of the circle of Willis showing multiple aneurysms.
Right: Inferior view of brain showing subarachnoid hemorrhage.

20. Hemodynamic Properties of Aneurysms
Aneurysms have the capacity to expand over time.
The risk of rupture is related to the size of the aneurysm
The tensile strength of an aneurysm is assumed to decrease according to Laplace’s formula which is as follows: P = 2 T/r

21. Hunt and Hess Scale (Clinical Grading of SAH)
Grade Description
Hunt and Hess Scale
1 Asymptomatic or minimal headache and slight nuchal rigidity
2 Moderate to severe headache, nuchal rigidity, no neurological deficit other than cranial nerve palsy
3 Drowsiness, confusion, or mild focal deficit
4 Stupor, moderate to severe hemiparesis, possible early decerebrate rigidity and vegetative disturbances
5 Deep coma, decerebrate rigidity, moribund appearance

22. Major Causes of SAH 95% of cases Ruptured arterial aneurysm
Ruptured AVM
Perimesenchymal vein or capillary bleeding
95% of cases

23. Clinical Manifestations of SAH
Ruptured aneurysm
headache
stiff neck
focal deficit
Ribeiro JA., et al, Acta Medica Portuguesa. 11(12): , 1998 Dec.

24. Subarachnoid Hemorrhage: Signs and Symptoms
Decreased alertness, Confusion, or Irritability
Temporary
Persistent
Progressively worse to coma and death
Syncope
Mental Status Exam
Abnormal vital signs
Respiratory variation
Hypertension
Irregular heart rate

25. Warning or “Sentinel” Bleeds
Up to 50% of patients with SAH report a distinct, severe headache in the days or weeks before the index bleed
Milder symptoms
History of Headaches
J Neurosurgery 1987

26. Features of Misdiagnosed Patients
JAMA. 2004;291:866-8

27. Features of Misdiagnosed Patients
JAMA. 2004;291:866-8

28. Features of Misdiagnosed Patients
JAMA. 2004;291:866-8

29. Who Needs Imaging? Occipital location Worsens with Valsalva
Awakens from sleep
Associated with syncope, nausea, or sensory distortion.
Patients with a sudden acute-onset headache
Prospective studies report that 30% of patients complaining of the “worst headache of their life” had positive findings on CT.

30. Computed Tomography Sensitive for blood Sensitivity drops when
day of the bleed 95%
within 12 hours of symptom onset  as high as 98%.
Sensitivity drops when
symptoms are days in duration
amount of bleeding is small  85%
study is difficult to interpret

32. Ruptured Ant CoA aneurysm

33. SAH 20 ruptured right PCA

34. Normal Circle of Willis 3-D CTA

35. Normal Circle of Willis 3-D CTA

36. 3-D CTA
SAH 20 ruptured ACA aneurysm

37. 3-D CTA
SAH 20 ruptured PCoA aneurysm

38. Lumbar puncture and CSF Exam
LP whenever the CT or CTA is negative, equivocal, or technically inadequate
Blood or red blood cells in the first 8 hrs.
Xanthochromia or an inflammatory reaction when CSF exam delayed

39. Lumbar Puncture (LP)

40. SAH Survival Depends On…
Elimination of risk of rebleeding by treating aneurysm (Aneurysm clipping or coiling)
Management of Vasospasm
Management of Intracranial Pressure (ICP)
Management of Hydrocephalus
Manangement of Other Complications
Management of Cardiac Issues

41. SAH Survival Depends On … Management of Vasospasm
Normal Caliber

42. SAH Survival Depends On … Management of Vasospasm
Diagnosis
Hypervolemic-hypertensive therapy
Calcium channel blockers
Cerebral angioplasty
Intracisternal thrombolytic therapy

43. SAH Survival Depends On … Management of Intracranial Pressure
Major Cause of Death
ICP monitoring
Fluid restriction?
Raising head
Hypothermia
Hypocarbia
Barbiturate coma?
Ventriculostomy
Steroids?
Mannitol

44. Increased Intracranial Pressure
The pressure exerted in the cranium by its contents:the brain, blood and cerebrospinal fluid.

45. Components of Cranial Vault (ICP can cause herniation!!!)
Meninges
Dura
Arachnoid
Pia
Brain
Brain tissue 80-88%
Blood
Blood 2-11%
CSF
CSF 9-10%

46. Animated GIF taken from http://www.artie.com
Elevated ICP = Danger
Animated GIF taken from

47. Other Problems Elevated ICP can also affect the perfusion of the brain
Cerebral Perfusion Pressure (CPP) is measured by taking the Mean Arterial Pressure (MAP) and subtracting Intracranial Pressure (ICP)

48. What does this mean?
This shows that if the ICP goes up… and MAP stays constant… then the CPP decreases.
This means the patient is not getting as much blood flow to the brain.

49. Poor Outcomes
Having an elevated ICP is one of the most damaging aspects of neurological trauma, and is directly related to poor prognosis.

50. Normal Values A normal ICP in an adult ranges from 0-15 mmHG
An ICP cannot surpass 40 without causing harm.
Even values between are considered fatal if they are prolonged.

51. Causes of ICP?
An elevated ICP can be caused by many different etiologies.
Traumatic Brain Injuries
Lyme Disease
Hydrocephalus
Brain Tumor
Severe Hypertension
Venous Sinus Thrombosis
Restricting Jugular Venous flow (i.e. C-collars)
Etc.

52. Monitoring of ICP There are 4 main types of devices for monitoring ICP
Intraventricular Catheters
Fiber optic Monitors
Subarachnoid Bolts
Epidural Monitors

53. Stages of ICP Initial compensatory Secondary compensatory
Final compensatory

54. ICP: Initial Compensatory
Displacement of the cerebral spinal fluid into the spinal canal or into venous blood through the arachnoid mater

55. Intercranial Pressure Regulation
When BP increases, cerebral arterioles constrict; when BP falls, cerebral arterioles dilate to increase Cerebral Blood Flow (CBF)
Metabolic regulation: Low O2 and high CO2 cause vasodilation; CSF reabsorption and decreased Cerebrospinal Fluid (CSF) production

56. ICP: Secondary Compensatory
Reduction of blood volume to the brain. This stage alters cerebral metabolism and produces brain tissue hypoxia and necrosis.

57. ICP: Final Compensatory
Displacement of brain tissue which is herniation and often leads to death.

58. Clinical Manifestation of ICP
Alteration in LOC – arousal and awareness
Restlessness
Irritability
Confusion
Dec.Glasgow coma score – scale for evaluating the best motor, verbal and eye opening response (score 3-15)
Changes in speech
Pupillary reaction – dilation of pupil ipsilateral to lesion, sluggish to respond to light

59. Clinical Manifestations of ICP
Bradycardia HA
Vomiting – not preceded by nausea
Double vision, ptosis of eyelid, inability to move eye upward
Vital Sign changes – Inc.systolic pressure- widened pulse pressure
Seizures

60. SAH Survival Depends On … Management of Rebleeding
Leading cause of death or morbidity during the first 2 weeks after SAH
Incidence:
4-10% in 24 hours
15-25% in 2 weeks
2-3% after 1 month for 10 years
Presents with sudden change in neurological status, new headache and coma.

61. SAH Survival Depends On … Management of Rebleeding
Aneurysmal Clipping
Endovascular Coiling
Hematoma Evacuation
Procoagulatants

62. Hematoma Evacuation

63. Hematoma Evacuation

64. Teaching Points SAH is often misdiagnosed
CT is sensitive but not fool-proof
LP for patients with normal or equivocal CT
Early angiography and IR/ Neurosurgery eval to facilitate intervention
Treat to prevent multisystem and neurological complications of SAH.
Attend to the airway and BP
Monitor and Control ICP
Prevent Re-bleeding and Vasospasm

65. Treatments for Cerebral Aneurysms
Endovascular Coiling
Surgical Clipping

66. Aneurysm Therapy
Surgical clipping (approximately 60-65% in the United States)
Endovascular coiling (approximately 30-35% in the United States)
In certain countries such as Finland, Great Britain and France, close to 90% of aneurysms are treated with endovascular coiling
After the release of the ISAT results, the percentage of aneurysm patients treated with coiling in England went from 40% to 90%

67. International Subarachnoid Aneurysm Trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomized trial
The Lancet
Vol 360, October 26, 2002

68. ISAT
A recent large prospective study of patients with ruptured aneurysms who could equally be treated with clipping or coiling had to be prematurely stopped short of planned enrollment of 2500 patients because the coiled patients suffered significantly less death and dependency as compared to clipped patients (6.9% absolute difference, 22.6% relative difference) and it would have been unethical to continue the study

69. ISAT Study Patients with ruptured intracranial aneurysms
Dependency or Death at 1 year
Neurosurgical Clipping 243/793 (30.6%)
Endovascular Coiling 190/801 (23.7%)
Lancet. 2002;360(9342):

70. Aneurysm Clipping
Done under general anesthesia through a craniotomy (hole in the head)
The brain is gently retracted in order to gain visual access to the aneurysm
A clip is placed at the neck of the aneurysm
1 week in the hospital
1 month recovery

71. Aneurysm exposed & PCA and SCA are identified as vessels at risk.
Right Cerebellar Aneurysm Surgical Clipping - Step 1: Identify Vessels at Risk
ACA
Aneurysm exposed & PCA and SCA are identified as vessels at risk.
Optic nerve
ICA
Oculo-
motor
nerve
Aneurysm
MCA

72. Right Cerebellar Aneurysm Surgical Clipping - Step 2: Measure Baseline Flows
Basilar a
Baseline SCA & PCA flows are measured
SCA = 18 cc/min
PCA = 36 cc/min
Flowprobe
SCA
Aneurysm
PCA

74. Right Cerebellar Aneurysm Surgical Clipping - Step 3: Clip and Re-measure
Positioning of Clip
Temporary Clip
Flow Integrity Checked
SCA = 2-4 cc/min
PCA = cc/min

75. Right Cerebellar Aneurysm Surgical Clipping - Step 4: Check Flow Integrity Post-Clip
Clip Repositioned
Clip Repositioned
Flow Integrity Checked
SCA = 16 cc/min
PCA = 33 cc/min

76. Where is the aneurysm?
SAH

77. Where is the aneurysm?

78. Surgical clip

79. Before
After

80. Clips

81. ANEURYSM COILING
A minimally invasive procedure usually performed under general anesthesia by an interventional neuroradiologist
A very small plastic tube (microcatheter) is threaded from the groin to the aneurysm in the brain, and fine platinum threads (coils) are inserted into the aneurysm to fill it from the inside, much like filling a pothole
The catheter is then removed and the small groin incision covered with a Band-Aid
For an unruptured aneurysm, the patient is discharged home within 24 to 48 hours

82. The History of Coiling FDA approval in 1995
: Dr. Guido Guglielmi (University of Rome) visits Dr Viñuela (Interventional Neuroradiologist) at UCLA and research work on coiling concept starts
1989: Dr Guglielmi comes permanently to UCLA
: Bench and animal research
March 6, 1990: First clinical use of Guglielmi Detachable Coil
FDA approval in 1995

83. Imaging of the Aneurysm
Non-invasive imaging (CT) has already been done. The Physician probably has a good idea where the aneurysm is located prior to angiography.
A diagnostic angiogram is performed and the aneurysm is localized.
A 3-D rotational spin can be performed while on the patient is still on the procedure table prior to coiling the aneurysm.

84. Rotational/3D Angiogram

85. Rotational/3D Angiogram
The above image can then be transferred to another computer which will take the acquired images and information and transform it into a 3-D image, as pictured below.

86. Rotational/3D Angiogram
Measurements of the aneurysms can be obtained from these 3-D images.

87. Procedure Set-Up
As you will note, the beginning set-up is the same for all interventional cases.
The following slides will review the following:
Pressure Bag Set-up
Sheath or Guide Catheter positioning

88. Pressure Line Set-Up

89. Don’t Forget To Label Both Ends!

90. Tuohy-Borst Adapter

91. Three-Way Stopcock

92. Before Screwing to Sheath or Guide Catheter…
Carefully Flush
Check for bubbles
Hook to Pressure Bag Line
Check and Re-Check for Bubbles

93. The Flow of things…the Pressure Bag
Most times the pressure bags are even done ahead of time due to the non-invasive studies already done prior to angiography.

94. The Flow of things…Placement of the Catheter, Shuttle Sheath or Guide Catheter
Depending on the Physician and the situation, the Physician may either leave the diagnostic catheter in place or exchange for either the Shuttle Sheath or Guide Cath.
If the diagnostic catheter is left in a microcatheter is selected and placed inside the diagnostic catheter.
If either a Guiding Catheter or Shuttle Sheath is chosen, they are placed in the Common Carotid and the diagnostic/microcatheter combo is reinserted after being properly flushed with saline.

95. The Flow of Things…The Shuttle Sheath
The Shuttle Sheath is a
long (usually 90 cm) sheath
used to engage the Common
Carotid artery.
It provides stiffness and
stability when coiling.
The Pressure Bag line is attached
to the sideport of the Shuttle Sheath

96. MicroCatheters
This is one of several types of microcatheters (there are also microwires used with the microcatheters).
They are ideally positioned directly within the aneurysm sac where the coils will be delivered.

97. Roadmapping and Steering of Coaxial System
Use of Bi-plane fluoroscopy
Use of Roadmapping feature may be helpful
Advance system carefully (Intracranial arteries are thinner than peripheral arteries- less media and adventitia)
Hand injections should be done carefully so as not to rupture any perforators.

98. Roadmap During Coiling

99. The Flow of Things…Aneurysm Coiling
Once the aneurysm is identified and analyzed,the microcatheter is placed within the aneurysm and the coiling process is started.
Follow-up DSA runs are periodically acquired to check the progression of the coiling

100. The Coiling Process

101. The Flow of Things…Aneurysm Coiling
The coiling process will probably last for several hours, so one thing to consider, does the patient have or require a Foley catheter?
Another note about the drugs. During the coiling process, it’s a good idea to have Protamine Sulfate readily available in case of aneurysm perforation and the need to reverse Heparin.

102. GDC Coil Detachment Device

103. Cable Attachment Black and Red Cables are placed in the
corresponding holes of the
detachment mechanism

104. Coil Preparation

105. An Aneurysm Coiling Seen Step-By-Step
The next several slides will demonstrate an Aneurysm Coiling step-by-step.

106. SAH
Rupture of an aneurysm at the tip of the basilar artery

107. Tip of Ventriculostomy

110. before
after

111. Pros and Cons of Coiling
Minimally invasive
Short recovery
Safer than surgery
Cheaper than surgery
CONS
Shorter track record
Possibly less durable
Requirement for follow-up angiography

112. The Future
Increased percentage of patients treated with coiling, in large volume referral centers
Use of adjunctive maneuvers increases the percentage of aneurysms treatable with endovascular techniques
Increased efficacy of coiling therapy (new, bioactive materials, tissue healing strategies)
Development of non-invasive follow-up techniques with CT or MR scanning
Better educated population will actually demand availability and discussion of both endovascular coiling and surgical clipping options

113. What about Aneurysms with Wide Necks?
Aneurysms with wide necks must be treated in a slightly different manner.
The use of a Neuroform stent or some similar
stent must first be placed across the base or neck of the aneurysm. This is done so that the coils will remain within the aneurysm sac.

114. Wide neck mid basilar aneurysm

115. Stent + Coil

116. Wide-Neck Aneurysm Coiling with Stent Assistance

117. Stent + coils

118. Balloon Remodeling
Balloon remodeling is the use of a balloon while placing coils within the aneurysm.
The balloon is inflated while the coil is placed and then deflated once coil is in place.

119. Onyx is another possible choice to treat aneurysms

120. Take Home Points
The ISAT study recently demonstrated a substantially better clinical outcome (22.6% less death and dependency relative difference, 6.9% absolute difference) in patients with ruptured aneurysms treated with endovascular coiling compared to patients treated with surgical clipping

121. Take Home Points
All patients with aneurysms should be informed of the availability of both endovascular coiling and surgical clipping by a neurosurgeon and an interventional neuroradiologist
The death and complication rate for aneurysm therapy is dramatically reduced in high volume centers that offer both surgical clipping and endovascular coiling

122. Information and Links http://www.asitn.org/
American Society of Interventional and
Therapeutic Neuroradiology (ASITN)

123. Homework Assignments
Read Chapter 16 (pp )and Chapter 25 (pp )

124. References Morris, P.P. Practical Neuroradiography, 2nd Edition, 2007
Osborn, A.G. Handbook of Neuroradiology, 2nd Edition, 1999
Bontrager, K.L. TEXTBOOK of Radiographic Positioning and Related Anatomy , 5th Edition, 2001
Snopek, A.M Fundamentals of Special Radiographic Procedures, 5th Edition, 2006
Tortorici, M.R. Fundamentals of Angiography, 1982
Various other Internet sources